IEMA Foundation Certificate
in Environmental Management
Element 1
Core environmental principles
Element 1: Table of contents
1.0 Learning outcomes and assessment criteria
4
1.1 Introduction
5
1.2 The main natural cycles and ecological systems
6
Introduction..................................................................................................... 6
Carbon cycle................................................................................................... 8
Nitrogen cycle................................................................................................13
Hydrological (water) cycle..............................................................................18
Phosphorous cycle.........................................................................................20
1.3 Ecosystem services
22
Introduction....................................................................................................22
Types of ecosystem services..........................................................................22
Why Consider ecosystem services?................................................................25
1.4 Biodiversity and ecological stability
26
Introduction....................................................................................................26
Ecological systems.........................................................................................28
1.5 The impact of human intervention on natural cycles and ecological
systems
33
Carbon cycle..................................................................................................33
Nitrogen cycle................................................................................................35
Water cycle.....................................................................................................37
Phosphorus cycle...........................................................................................38
Ecological systems.........................................................................................39
1.6 Pollution sources, pathways and receptors
40
Introduction....................................................................................................40
Main pollution types........................................................................................42
Water pollution...............................................................................................46
Air pollution....................................................................................................49
Stratospheric ozone depletion........................................................................53
Contaminated land.........................................................................................55
2
Element 1
Core environmental principles
1.7 Climate change
56
Introduction....................................................................................................56
The effects of climate change.........................................................................60
Global action..................................................................................................61
3
Element 1
Core environmental principles
1.0 Learning outcomes and assessment criteria
On completion of this element, candidates should be able to demonstrate an understanding
of core environmental principles. They should, through the application of knowledge to
familiar and unfamiliar situations, be able to:
z Explain the importance of:
•
Natural cycles and ecological systems;
•
Ecosystem services;
•
Biodiversity and ecological stability;
z Describe how human interventions impact upon natural cycles and ecological systems;
z Describe the main pollution sources, pathways and receptors;
z Explain the causes and effects of climate change.
4
Element 1
Core environmental principles
1.1 Introduction
There is only one Earth; it is currently the only conceivable home for the species which live
on it, including humans.
There is also no doubt that some human activities have caused and continue to cause harm
to the land, air and water which form the biosphere and to the species which live within it.
As described in Element 2 (Sustainability and Mega-trends), human activities, especially
since the Industrial Revolution, have not been sustainable.
This first element of the IEMA Foundation Certificate Course is designed to introduce core
environmental concepts and to explain how these underpin our knowledge and understanding
of sustainability.
Key vocabulary
Biosphere: The part of the Earth in which living things exist. It includes land, water
and the lower atmosphere.
5
Element 1
Core environmental principles
1.2 The main natural cycles and ecological systems
Introduction
Chemicals such as carbon, nitrogen, water
and phosphorus are continually recycled
between living organisms and the non-living
parts of ecosystems.
Key vocabulary
Ecosystem: Refers to a biological
community of interacting organisms
and their physical environment. It
includes the biotic elements (i.e.
other living animals, plants and
microorganisms) and abiotic (i.e.
non-living) elements such as water
and rocks.
These natural cycles:
z Form an integral part of ecosystems;
z Are fundamental to the Earth’s
sustainable operation;
z Involve the transfer of energy and
material between biotic (i.e. living)
and abiotic (i.e. non-living) elements;
z Are continuous and waste free.
Two fundamental natural rules underpin the action of natural cycles and thereby the
sustainability (i.e. capacity for indefinite continuance) of ecological systems. These rules are
the laws of thermodynamics and the principle of matter conservation.
The Laws of Thermodynamics and the Principles of Matter Conservation
• Principle of matter conservation: Matter cannot be created or destroyed.
• First law of thermodynamics: Energy cannot be created or destroyed.
• Second law of thermodynamics: Matter and energy tend to disperse spontaneously.
The principle of matter conservation states simply that ‘matter cannot be created or
destroyed’. Matter does not just appear or disappear; it has to come from somewhere and
go somewhere. Atoms are not lost or created in chemical reactions but simply combine to
form new molecules. Landfilled waste and waste emitted to the environment according to
the ‘dilute and disperse’ principle does not disappear!
The first law of thermodynamics echoes the principle of matter conservation, i.e. ‘energy
cannot be created or destroyed’; again it comes from somewhere and goes somewhere,
albeit perhaps in a different form.
6
Element 1
Core environmental principles
The first law of thermodynamics and principle of matter conservation are collectively
known as the ‘conservation laws’ and underpin all of the natural cycles and principles of
sustainability. It is only in nuclear reactions and solar processes that matter (i.e. mass) and
energy are interchangeable according to Einstein’s famous E = mc2 equation.
The second law of thermodynamics states that ’matter and energy tend to disperse
spontaneously’. Energy flows from ‘high’ to ‘low’ states encouraging particles to move.
Hence, for example, gases diffuse and intermingle, and nutrients become dispersed in rivers.
7
Element 1
Core environmental principles
Carbon cycle
The Carbon Cycle (Figure 1.1) is arguably the most important of the natural cycles. Carbon
captured by solar energy in photosynthesis ultimately forms the molecules used to create
both the building blocks of life, such as proteins, and the fuels driving the majority of
natural cycles.
Key vocabulary
Photosynthesis: Plants, algae and cyanobacteria all make glucose during the day
using photosynthesis. This diurnal (i.e. daytime) process needs sunlight. The word
photosynthesis comes from two Greek words – [phōs] which means ‘light’; and
[synthesis] means ‘putting together’.
Auto and factory emissions
CO2 cycle
Sunlight
Plant respiration
Photosynthesis
Organic carbon
Animal respiration
Root respiration
Decay organisms
Dead organisms and waste products
Ocean uptake
Fossils and fossil fuels
Figure 1.1: The carbon cycle
Specialised parts of the plant (chloroplasts) use a green pigment (chlorophyll) to convert
carbon dioxide (CO2) and water (H2O) into glucose (C6H12O6) and a waste product, oxygen
(O2), using sunlight (Figure 1.3). The glucose may then be used in either respiration to
provide energy, stored as starch, or used to make new cell parts.
8
Element 1
Core environmental principles
Chlorophyll
6C02
6H20
+
Carbon dioxide
62H1206
Water
602
+
Glucose
Oxygene
Sunlight
Figure 1.2: The chemical formula for photosynthesis
A very small number of recently discovered marine bacteria are chemoautotrophs (i.e. they
make their own food from the chemicals in seawater).These organisms live in the darkest
depths of the oceans and produce sugars or amino acids from carbon dioxide and / or
methane using substances such as hydrogen sulphide (H2S) as an energy source which
leaves sulphur (S) as the waste product (Figure 1.4). Some live within giant tube worms but
most form colonies around thermal vents and deep chasms and crevasses.
12H2S
Hydrogen
sulphide
+
6C02
Carbon dioxide
62H1206
Glucose
+
6H20
Water
+
12S
Sulphur
Figure 1.3: Example of a chemosynthetic reaction
The carbon compounds produced in photosynthesis and chemosynthesis then pass through
food chains (Figure 1.4), transferring both energy and materials.
Key vocabulary
Photoautotrophs: Photosynthetic organisms are photoautotrophs (i.e. ‘selffeeding’; Greek: [autos] means ‘self’ and [trophe] means ‘nourishing’). Herbivores
obtain carbon by eating plants, carnivores by eating herbivores and omnivores by
eating both plants and animals. Decomposers eat waste products including dead
plants and animals.
Chemoautotrophs: These deep ocean dwelling organisms make their own food
from the chemicals around them. They do not use sunlight.
9
Element 1
Core environmental principles
Quaternary
consumers
Carnivore
Carnivore
Tertiary
consumers
Carnivore
Carnivore
Secondary
consumers
Carnivore
Carnivore
Primary
consumers
Herbivore
Zooplankton
Primary
producers
Plant
Phytoplankten
Figure 1.4: Food chain
All cells, regardless of type continuously respire, i.e. ‘burn’ the glucose produced in
photosynthesis together with other complex organic compounds in the presence of oxygen
to release carbon dioxide and water (Figure 1.5); respiration is thus the direct opposite of
photosynthesis.
62H1206
Glucose
+
602
6C02
Carbon dioxide
Oxygene
+
6H20
Water
Figure 1.5: The chemical formula for respiration
When plants or animals produce urine and faeces or die, organic matter is consumed by
decomposer organisms which return carbon to the soil, or to the atmosphere as respiratory
10
Element 1
Core environmental principles
carbon dioxide. If marine life dies and decomposes, a significant amount of organic carbon
builds up in underwater sediments. Respiration by sea life releases some carbon dioxide
directly into seawater.
Billions of tonnes of sedimentary carbon have been deposited, over geological timescales, as:
z Hydrocarbons creating fossil deposits of coal, gas and oil; or
z Calcium carbonate from shells and other skeletal material forming limestone or chalk.
The eventual combustion or dissolution of these long-term carbonaceous materials ultimately
returns the sequested carbon to the atmosphere or water, mainly as carbon dioxide.
Key vocabulary
Respiration: Respiration is happens in the cells of all living organisms. Glucose
and other carbon containing chemicals react with oxygen to produce water and
carbon dioxide. Animals with lungs breathe out this carbon dioxide in the same way
as they breathe in oxygen. Unlike photosynthesis, respiration happens at all times
of the day and night.
Combustion: Refers to the process of burning substances. Significantly this needs
oxygen; the formula for the combustion of glucose is identical to that for respiration.
Sequestration: Refers to the process of storing something. Sequestered carbon is
carbon which has been stored for example as coal or oil.
Deforestation and other habitat loss can also return carbon stored either in living tissue or
soils to the atmosphere. Burning timber releases carbon dioxide to the atmosphere.
Carbon can also be stored, for example as methane. Methane is a gas which is produced
when bacteria decompose organic (i.e. carbon containing material) in the absence of oxygen
or where there is very little oxygen. The degradation or exploitation of carbon rich soils such
as peat can lead to the unintentional release of both methane gas and carbon dioxide.
Peatlands are a major source of carbon storage worldwide. The majority of the carbon stored
in peatlands is found in saturated (i.e. waterlogged) peat soils and has been sequestered
over millions of years.
Stored carbon is released from peat soils when they are drained for agriculture, forestry and
peat extraction. When carbon compounds which are normally underwater or in waterlogged
11
Element 1
Core environmental principles
soils are exposed to air, they decompose and emit gases such as carbon dioxide.
Trapped methane may also be released when large plant roots disturb the soil and cause
‘soil shrinkage’ as they extract water faster than it can be replaced. This phenomenon has
been recorded, for example, in some of the large palm tree plantations needed for the large
scale commercial production of palm oil.
Key Point: Although it is a single cycle, the carbon cycle can be thought of as containing two
distinct elements, i.e. the:
z Fast Loop: The transfer of carbon dioxide into living tissue via photosynthesis and its
release back to atmosphere via respiration and decomposition;
z Slow Loop: Carbon is sequestered and then slowly released by natural processes such
as weathering and fires over millions of years.
Our modern dependency on carbon fuels means that more sequestered carbon is being
burnt and thereby released as carbon dioxide.
12
Element 1
Core environmental principles
Nitrogen cycle
The nitrogen cycle (Figure1.6) works together with the carbon cycle to maintain ecosystem
stability. It is essential to soil fertility and food production. It is the cycle of death and decay.
Precipitation
Gaseous Losses
Organic Residues
Dentrification
Organic Matter
Plant consumption
Nitrates
Ammonium
Nitrification
through bacteria
Leaching
Nitrites
Clay Minerals
Figure1.6: The nitrogen cycle
Like carbon, nitrogen is a key component of amino acids (i.e. the building blocks of proteins).
Plants also use nitrogen to produce chlorophyll, the green pigment required to trap carbon
dioxide for photosynthesis.
Nitrogen forms 78% of the Earth’s atmosphere, making it the largest single component.
However, gaseous nitrogen cannot be used directly by plants.
Plants must secure their nitrogen in a ‘fixed form’, i.e. incorporated into compounds such as:
z Nitrate ions - NO3-;
z Ammonium ions - NH4+;
z Urea - (NH2)2CO.
Animals obtain their nitrogen via food chains, i.e. by eating plants or other animals.
13
Element 1
Core environmental principles
The nitrogen cycle on land
Four distinct processes are involved in the cycling of nitrogen through the biosphere.
These are:
z
z
z
z
Nitrogen fixation;
Decay;
Nitrification;
Denitrification.
Microorganisms are essential to all of these processes.
Nitrogen fixation
As plants and animals cannot use gaseous nitrogen directly, it must first undergo nitrogen
fixation (i.e. conversion) to a more usable form. However, the nitrogen molecule (N2) is quite
inert. Substantial amounts of energy are required to break the atoms apart so they can
combine with other elements.
Nitrogen fixation can be achieved naturally by either:
z Lightning fixation: Nitrogen (N2) and oxygen (O2) are converted to nitrogen oxides (NOx)
which dissolve in rain forming nitrates that are carried to earth; or much more commonly;
or
z Biological fixation: Bacteria combine N2 with hydrogen gas (H2) to make usable nitrogen
in the form of ammonium ions (NH4+).
The majority of nitrogen fixing bacteria are free living in soil and water. However, a few are
symbiotic and live in root nodules on leguminous plants (i.e. peas, beans, lentils, peanuts,
clover, soybeans and alfalfa). The bacteria receive carbohydrates in return for providing the
plant with useable nitrogen.
The first stable product of this process is ammonia (NH3) which can be incorporated into
proteins and other organic nitrogen compounds. It can also be converted into nitrates which
are a much more valuable nutrient source for plants. The conversion process, nitrification,
is discussed below.
Decay
The proteins made by plants enter and pass through food chains just as carbohydrates
do. Ammonium (NH4+) and ammonia (NH3) are made in soil by decomposers such as fungi
which break down waste materials and dead organisms into their component parts. This
process is called ammonification.
14
Element 1
Core environmental principles
Key vocabulary
Nitrogen fixation: The process of converting gaseous nitrogen in the air to a form
which is useable by plants.
Inert: Refers to chemicals which have little or no ability to react with other chemicals;
i.e. are chemically inactive. See also notes on the landfill tax in Section 3.4.
Symbiotic: A symbiotic relationship is a one in which two different types of living things
live together for their mutual benefit. This offers from a parasitic relationship of which
one species (the parasite) gains more from the relationship than the host species on
which it lives but does not normally kill the host – think mistletoe on apple treesl.
Nitrification
Ammonia (NH3) and ammonium ions (NH4+) are poisonous to fish and other animals.
Nitrification is the change of ammonia and ammonium to nitrite (NO2-) and then to nitrate
(NO3-) again by bacteria.
Plants need nitrates to survive. They are a vital nutrient. However, some plants, notably
those on acidic peat soils thrive in a comparatively low nitrate environment. Carnivorous
plants such as sundew and pitcher plants which are only naturally found in these types of
soils obtain additional nitrogen from the bodies of the animals which fall into them.
Many legumes, in addition to fixing atmospheric nitrogen, also perform nitrification —
converting some of their organic nitrogen to nitrites and nitrates. These reach the soil when
they shed their leaves.
Unlike ammonia ions, nitrites and nitrates do not bind readily to clay or humus and therefore
wash out of the soil during heavy rain and irrigation. This can result in significant water
pollution due to a process called eutrophication which is discussed in Section 1.6.
Denitrification
The three processes above remove nitrogen from the atmosphere and pass it through
ecosystems.
Denitrification reduces nitrates and nitrites to nitrogen gas, thus replenishing the atmosphere.
The bacteria responsible for this process live deep in soil and in aquatic sediments where
conditions are anaerobic. They use nitrates as an alternative to oxygen in respiration.
15
Element 1
Core environmental principles
Key vocabulary
Nitrification: The process of making nitrates – think adding nitrogen.
Eutrophication: In surface waters an excessive concentration of nitrates and
phosphates are considered pollutants. These substances stimulate the growth
of green plants and especially green algae and cyanobacteria which reduce the
quantity of dissolved oxygen as discussed in Section 1.6.
Denitrification: The process of removing nitrogen from nitrates
Anaerobic: Without oxygen. The opposite of this is aerobic (as in exercise!). Anaerobic
conditions exist for example in waterlogged soils. Bacteria which live in anaerobic
conditions often cannot survive in aerobic conditions and vice versa. Some bacteria,
known as facultative anaerobes can survive in both. Composting and water treatment
rely on aerobic conditions to keep everything sweet smelling. on apple treesl.
The marine nitrogen cycle
Nitrogen enters the marine ecosystems through precipitation, runoff, or as N2 from the
atmosphere. Nitrogen cannot be utilised directly by phytoplankton; Cyanobacteria are
responsible for almost all nitrogen fixation. Ammonia and urea are released into the water
by excretion from plankton. This must sink together with waste materials in order for bacteria
to be able to convert ammonia to nitrite and nitrate, as the bacteria concerned are inhibited
by light.
Nitrate can be returned to the surface by vertical mixing and upwelling where it can be taken
up by phytoplankton to continue the cycle. N2 can be returned to the atmosphere through
denitrification.
The nutrients in the ocean are not uniformly distributed. Areas of upwelling provide supplies
of nitrogen from below the photic zone (i.e. the zone where enough light penetrates for
photosynthesis to occur; approximately 200m below the surface). Coastal zones provide
nitrogen from runoff and upwelling occurs readily along the coast. However, the rate at
which nitrogen can be taken up by phytoplankton is decreased in nutrient poor waters and
also in temperate water in the summer resulting in lower primary production.
16
Element 1
Core environmental principles
Key vocabulary
Phytoplankton: Microscopic waterborne plants and microorganisms which
photosynthesise to make food..
Cyanobacteria: A specific group of organisms which are also called blue-green algae
due to their colour and structure – there is debate as to whether they are bacteria
or algae! Cyanobacteria are photosynthetic, nitrogen fixing organisms that survive in
wide variety of habitats, soils, and water. They are essential to maintaining the fertility
of semi-aquatic environments like rice paddies. However, they can cause significant
problems in any aquatic environment if eutrophication occurs – see Section 1.6.
17
Element 1
Core environmental principles
Hydrological (water) cycle
The water cycle, driven by the sun’s energy, is responsible for the continuous movement of
water on, above and below the Earth’s surface (Figure 1.7).
Although the mass water on Earth remains fairly constant over time. Over 96% of the planet’s
water is saline. The majority of the remaining circa 4% of freshwater is ‘locked away’, i.e.:
z Over 68% is contained in ice and glaciers;
z 30% is contained in ground water.
Condensation
Precipitation
Snow and ice
Transpiration
(evaporation from plants)
Run off
Infiltration
(water entering soil)
Evaporation
Ground water and soil moisture
Figure 1.8: The water cycle
The relative proportion contained in major reservoirs (i.e. ice, freshwater, saline water and
atmospheric water) at any one time varies depending on a wide range of climatic variables.
The water cycle involves the exchange of energy, leading to temperature changes which
influence the climate. When water evaporates as water vapour into the air, it removes energy
from its surroundings and cools the environment. 86% of the global evaporation occurs from
the oceans, reducing their temperature. When water condenses, it releases energy and
warms the environment. The water cycle is powered by solar energy.
Ice and snow can sublimate, i.e. change directly from a solid into water vapour, a gas. Water
18
Element 1
Core environmental principles
can also be evaporated from the soil and water surface and removed from plant leaves
via transpiration. Rising air currents take the vapour up into the atmosphere where cooler
temperatures cause it to condense into clouds. As clouds move, particles collide, grow, and
subsequently fall out of the upper atmospheric layers as precipitation.
Some precipitation falls as snow hail, or sleet, and can accumulate as ice caps and glaciers,
which can store frozen water for thousands of years. Most water falls back into the oceans
or onto land as rain; surface runoff forms rivers and ultimately returns to the ocean.
Runoff is responsible for almost all of the transport of eroded sediment and phosphorus from
land to rivers and oceans. Ocean salinity is derived from erosion and transport of dissolved
salts from the land. Runoff also plays a part in the carbon cycle, again through the transport
of eroded rock and soil.
Key vocabulary
Precipitation: Refers to rain, snow, hail, sleet etc. Precipitation is responsible
for the transfer of pollutants including transfrontier pollutants such as carbon
dioxide and acid rain. Excessive rain can lead to significant environmental / human
issues such as flooding, the removal of nitrates and phosphates from soil and the
eutrophication of rivers
Water stored in the soil remains there very briefly, because it is spread thinly across the
Earth, and is readily lost by evaporation, transpiration, stream flow, or groundwater recharge.
Some water infiltrates deep into the ground and replenishes the groundwater stored in
aquifers which can again store freshwater for long periods of time. Some infiltration stays
close to the land surface and can seep back into surface-water bodies (and the ocean) as
groundwater discharge. Some groundwater finds openings in the land surface and comes
out as freshwater springs.
Groundwater can spend 10,000 years or more beneath the Earth’s surface; particularly
old groundwater is sometimes called fossil water. The major ice sheets in Greenland and
Antarctica store ice for very long periods; ice from Antarctica has been reliably dated up to
800,000 years before present, though the average residence time is shorter.
19
Element 1
Core environmental principles
Phosphorous cycle
Animal tissues
and feces
Urine
Decomposition by
fungi and bacteria
Plant tissues
Assimilation by
plant cells
Phosphates
in soil
Phosphates
in solution
Weathering
of rock
Loss in
drainage
Incorporation into sedimentary
rock - geologic uplift moves this
rock into terrestrial environments.
Figure 1.8: The phosphorus cycle
Phosphorus is an important element for all forms of life. As phosphate (PO43-), it makes up
part of DNA. Phosphates are also critical to the release of cellular energy necessary for
processes such as building proteins and muscular contraction. Like calcium, phosphorus is
particularly important for important to vertebrates; in the human body, 80% of phosphorous
is found in teeth and bones.
The phosphorus cycle (Figure 1.8) is
characterised by being the slowest cycle.
As phosphorus and phosphorus-based
compounds (i.e. phosphates) are usually
solids within the typical temperature and
pressure ranges found in the lithosphere,
the atmosphere is not significantly
involved in the movement of phosphorus.
Phosphates however, move quickly through
living organisms.
Key vocabulary
Lithosphere: The hard, outer shell
of a rocky planet, i.e. the Earth’s
crust and upper mantle; Ancient
Greek: [lithos] means ‘rocky’.
20
Element 1
Core environmental principles
The largest reservoir of phosphorus is in sedimentary rock where the phosphorus cycle
begins. When it rains, phosphates are removed from the rocks (i.e. via weathering) and are
distributed throughout both soils and water. Plants take up the phosphate ions from the soil.
These move from plants to animals via food chains. Phosphates absorbed by animal tissue
through consumption eventually return to the soil via the decomposition of urine and faeces
and dead tissue. This process is also repeated in aquatic ecosystems.
Phosphates are important plant nutrients. Phosphorus is not highly soluble. In soil,
phosphate is absorbed on iron oxides, aluminium hydroxides, clay surfaces, and organic
matter particles, and becomes incorporated (i.e. immobilised or fixed). It therefore generally
reaches freshwater and oceans by travelling with runoff soil particles.
Phosphates also enter waterways through fertiliser runoff, sewage seepage, natural
mineral deposits, and wastes from other industrial processes, where they tend to settle on
ocean floors and lake bottoms. As sediments are stirred up, phosphates may re-enter the
phosphorus cycle, but they are more commonly made available to aquatic organisms by
being exposed through erosion. Water plants take up the waterborne phosphate which then
travels up through successive stages of the aquatic food chain.
Historically phosphate based detergents have been an important cause of eutrophication.
However, modern detergents have been developed specifically to minimise this problem.
Key vocabulary
Eutrophication: The process by which a body of water acquires a high concentration
of nutrients, especially phosphates and nitrates. These typically promote excessive
growth of algae. As the algae die and decompose, high levels of organic matter
and the decomposing organisms deplete the water of available oxygen, causing
the death of other organisms, such as fish. Eutrophication is a natural, slow-aging
process for a water body, but human activity greatly speeds up the process.
21
Element 1
Core environmental principles
1.3 Ecosystem services
Introduction
All ecosystems consist of dynamically interacting parts including living organisms (i.e. plants,
animals and microorganisms), the communities they make up and the non-living (i.e. abiotic)
elements of their environment.
Ecosystem processes, such as photosynthesis, pedogenesis (i.e. soil creation) and nutrient
recycling regulate the flow of energy and matter through an ecosystem. As indicated in
Section 1.2, these processes are driven by inter-related natural cycles. Without these
ecological systems, there would be no life, including human life, on Earth.
The benefits people get from nature are called ecosystem services.
Key vocabulary
Ecosystem: A biological community of interacting organisms and their physical
environment. It includes the biotic elements (i.e. other living animals, plants and
microorganisms) and abiotic (i.e. non-living) elements such as water and rocks.
Ecosystem Services: Defined as “the benefits that people obtain from ecosystems”
[Source: Millennium Ecosystem Assessment].
Types of ecosystem services
A variety of different approaches can be used to classify / describe ecosystem services. The
widely recognised system was developed by scientists working for the United Nations as
part of the Millennium Ecosystem Assessment.
The United Nations classifies ecosystem services as:
z Provisioning services;
z Regulating services;
z Cultural services;
z Supporting services.
22
Element 1
Core environmental principles
Provisioning services
These are the things that are provided by ecosystems. They include:
z Food – from plants, animals and microbes;
z Freshwater – for drinking, washing and cleaning and also for a range of industrial
processes, including providing a source of energy;
z Fibre – such as wood, jute, cotton, hemp, silk and wool;
z Fuel – such as wood, dung, coal, oil and gas all other serve as sources of energy;
z Genetic resources – genes and genetic information are used for animal and plant
breeding and biotechnology;
z Ornamental resources – animal and plant products such as skins, shells, flowers;
z Medicines and other pharmaceutical products.
Regulating services
These are the benefits obtained from the control, or regulation, of ecosystem processes.
They include:
z Air quality – removal of harmful chemicals, such as excess CO2, from the atmosphere;
z Water – the timing and magnitude of run-off, flooding and aquifer recharge can be
strongly influenced by changes in land cover, such as the conversion of wetlands into
urban areas or the replacement of forests with agricultural land or urban areas;
z Climate – as discussed in Section 3.7, local changes in land cover can affect temperature
and precipitation; globally ecosystems can sequester (i.e. store) or emit greenhouse
gases (GHGs);
z Disease – controlling the abundance of human pathogens (i.e. disease causing
organisms) such as cholera, and disease vectors (i.e. carriers) such as mosquitoes; and
pest regulation to reduce crop and livestock pests and diseases;
z Regulation of natural hazards – coastal ecosystems such as mangroves and coral reefs
reduce the damage caused by storms; and erosion protection – vegetative cover helps
retain soil and prevents landslides and flooding;
z Pollination – the distribution, abundance and effectiveness of pollinators, such as bees
and other insects;
z Water purification and treatment – ecosystems are a source of impurity, but also filter out
and decompose organic wastes and can assimilate and detoxify compounds through soil
processes.
23
Element 1
Core environmental principles
Cultural services
These are the non-material benefits provided by ecosystems. They include:
z Recreation – such as walking, climbing, cycling, running, kayaking and surfing;
z Ecotourism – i.e. tourism which does not exploit the natural environment or local
communities but seeks to benefit them;
z Educational benefits, cognitive development and scientific discovery – based on the
natural world and on associated knowledge systems developed by different cultures;
z Aesthetic and social experiences – such as parks, housing locations, scenic drives,
community cultures, time spent in the countryside etc.;
z Spiritual enrichment – many religions attach spiritual and religious values to ecosystems
and / or to their components;
z Inspiration – for example for art, music, folklore, architecture and advertising etc.
Supporting services
These are essential to support the other three services. They differ from other services
in that their impacts on people are often indirect or occur over a very long time, whereas
changes in the other categories have relatively direct and short-term impacts on people.
Supporting services include:
z Soil formation – many provisioning services depend on soil fertility which in turn influences
provisioning, regulating and cultural services;
z Photosynthesis – producing the oxygen necessary for most living organisms. This process
also removes CO2 from the atmosphere; excess atmospheric CO2 is major factor in the
development of climate change;
z Nutrient cycling – approximately 20 nutrients essential for life, including nitrogen and
phosphorus, cycle through ecosystems and are maintained at different concentrations in
different parts of ecosystems;
z Water cycling – water cycles through ecosystems and is essential for living organisms.
24
Element 1
Core environmental principles
Why Consider ecosystem services?
Human activity has consequences for the natural environment. Some of these effects are
readily identifiable and can be taken into account in decision-making processes; others
are less tangible and therefore more likely to be omitted from these processes. In the latter
situation, the true environmental cost of a product / service is not accounted and cumulatively
these effects add up and consequently degrade the environment.
Ecosystem services are a way of ensuring that all the effects on the environment and human
well-being are taken into account when, for example:
z Developing a new product;
z Planning a new residential development;
z Considering the entire operation of a business.
Impacts on organisations
The potential impacts on organisations as a result of human interference with ecological
systems and services are wide-ranging. According to research by IEMA, these include:
z Resource depletion resulting in higher costs;
z Reduced resource security and potentially an overreliance on resources from conflict
areas;
z Direct and indirect impacts from climate change as a result of more severe weather
events such as:
•
Flooding from rising river and sea levels;
•
Increased insurance costs;
•
Changes to land use;
z Rising air temperatures with an associated increase in conditions such as heat stress
and the prevalence of some diseases;
z Risk to agriculture from decreased pollination etc.;
z Increased expectation from the public to demonstrate sustainable practices especially in
highly competitive markets and / or those which are widely seen to be ‘less ethical’;
z Increased regulatory responsibilities as governments seek to reduce environmental
impacts, as highlighted in Element 3 (Key Environmental Legislation).
25
Element 1
Core environmental principles
1.4 Biodiversity and ecological stability
Introduction
The term ‘biodiversity’ is a contraction of ‘biological diversity’ and describes the variety of
life and its processes. It includes species diversity, genetic diversity and ecosystem diversity
Key vocabulary
Biodiversity: Refers to the variety of:
• Habitats; and
• Species of plants, animals and microorganisms.
Habitat: The place where a particular animal, plant or microorganism normally lives.
Biodiversity plays an important role in all four categories of ecosystem services i.e.:
z Provisioning services;
z Regulating services;
z Cultural services;
z Supporting services.
It is therefore directly linked to those processes which maintain and improve human quality
of life.
The number of described species is now around 1.7 million. The estimated total number of
species in existence ranges in order of magnitude from around 10 million to 100 million.
Unfortunately, lack of scientific knowledge is limiting our ability to accurately predict the
effect of long term changes (such as climate change) on biodiversity.
According to the International Union for Conservation of Nature (IUCNs) Red List of
Threatened species, accurate data on the vulnerability of species to extinction only exists
for less than 5% of known species.
New species are still being discovered, such as the nocturnal raccoon sized olinguito, found
in the mountainous forests of Ecuador and Colombia at night during 2013. Others, such as
the primitive coelacanth caught in 1938 off the coast of South Africa, are rediscovered after
being thought to be extinct for millions of years.
26
Element 1
Core environmental principles
Quantitative data does however, confirm that the rate at which species are becoming
extinct exceeds that which would be anticipated based on previous trends. In 2006, an
IUCN assessment revealed that 56% of the 252 endemic freshwater Mediterranean fish
were threatened with extinction; the highest so far recorded for any regional freshwater fish
assessment.
2030 of the 6260 known global amphibian species were confirmed by the IUCN as threatened
or endangered in 2009. Current, ongoing, research indicates that the situation has decline
further, due to factors such as fungal disease, habitat loss and climate change.
Since 2007 one of our closest genetic relatives, the Western gorilla (Gorilla gorilla), has
moved from endangered to critically endangered due the bush meat trade, habitat loss and
contact with human population infected by the Ebola virus. Illegal logging and forest clearance
for palm oil plantations have significantly reduced orangutan populations in Borneo.
Chimp species in West and Central Africa are also threatened by bush meat and habitat loss
predominantly associated with illegal mining activities. 97% of bonobos, the ape species
most closely related to humans, has disappeared in less than a human generation. Some
populations are now so small that their genetic diversity and thereby long term survival is
further threatened.
As highlighted in Element 3, a key priority for the UK government is the control of invasive
non-natural species (INNS) or invasive alien species (IAS) such as:
z American mink (Mustela vison);
z Signal crayfish (Pacifastacus leniusculus);
z Grey squirrel (Sciurus carolinensis);
z Floating pennywort (Hydrocotyle ranunculoides);
z Asian hornet (Vespa velutina);
z Killer shrimp (Dikerogammarus villosus);
z Monk parakeet (Myiopsitta monachus).
Further information on these and other INNS may be found on the GB Non-Native Species
Secretariat website, http://www.nonnativespecies.org/home/index.cfm.
The UK government estimated in August 2015 that the control of INNS cost approximately
£1.7 billion per annum with the costs being primarily borne by the agricultural and horticultural
sectors and then passed onto consumers.
27
Element 1
Core environmental principles
Ecological systems
Organisms interact with each other and with the environment around them. Ecology is the
study of biological communities. Ecologists study how species interact together with the
processes which enable them to do this (Figure 1.9).
Communities should not be simply considered as the sum of all the organisms present;
there is also a need to consider how these individuals interact.
The Main Types of Ecological Interaction are:
z Competition – two, or more, species want the same limited resource e.g. food or shelter;
they may harm one another trying to get this resource;
z Predation – one animal species hunts, kills and eats all or part of a second animal species;
z Parasitism – two species live in an obligatory association in which the parasite depends
on the host. The parasite (e.g. mistletoe) doesn’t normally kill the host (e.g. an apple
tree) but it may weaken it;
z Mutualism – two species live in close association, to the benefit of both species e.g.
cleaner fish and sharks or salmon;
z Commensalism – two species live in close association, one gains without affecting the
other e.g. clown fish (Nemo!) and sea anemones.
Individual
organism
Animal, plant or microorganism
Population
A group of the same species living in the same place
(i.e. habitat) at the same time
Community
A collection of populations of all the organisms that occur
together in a given place (habitat) and time
Ecosystem
Includes all interacting physical (abiotic) and biological (biotic)
components of an area, which may consist of one or more
communities together with their abiotic surroundings
Figure 1.9: Levels of organisation
28
Element 1
Core environmental principles
Food webs and food chains
Both the carbon and nitrogen cycles illustrate the intimate relationships which exist between
species based on the transfer of material and energy, i.e. on nutrition. At the simplest level,
these interrelationships are illustrated by food chains (Figure 1.14).
Barn owl
3rd trophic level
Carnivore
Secondary consumer
Wood mouse
2nd trophic level
Decomposer
1st trophic level
Herbivore
Primary consumer
Grass
Producer
Figure 1.10: Food chain
In practice, food chains do not exist in isolation but combine to form food webs (Figure 1.11).
Squirrel
Barn owl
(Carnivore)
Oak tree
Caterpillar
Grass
(producer)
Fox
Leaf litter
Shrew
Leaf fall
Funghi
Wood mouse
(Herbivore/Omnivore)
Earthworm
Figure 1.11: Food web
29
Element 1
Core environmental principles
A single oak tree (Quercus robur) can support more than 250 different species of insects
and the associated food chains which encompass these. In this context, the removal (either
temporary or by extinction) of one species may cause no more than a temporary imbalance
in the system.
However, in other situations this may be more critical, for example the Eurasian Otter (Lutra
lutra) almost became extinct in the UK by the mid-1990s due to water pollution, declining fish
stocks, increased road traffic and active hunting. American mink (Mustela vison) released
from fur farms were then able to colonise river banks and play a significant part in the decline
of the water vole (Arvicola amphibius).
Recent significant increases in otter numbers, together with targeted initiatives to reduce
mink populations, are now having a positive impact on some water vole populations.
The deliberate and unintentional introduction of alien species into habitats is now recognised
as one of the greatest threats to ecological stability. The threat may not always be from the
introduced species itself but from an associated parasite as in the case of the squirrel pox
virus and the varroa mite which respectively harm red squirrels and bumblebees.
The impact is greater in the case of bumblebees (Bombus sp.) given their coevolution with
flowering plants and economic importance as an agricultural / horticultural pollinator.
Chemicals may also result in critical imbalances in food chains; for example DDT
(dichlorodiphenyltrichloroethane), a powerful insecticide used extensively in the 1940s and
1950s, bioaccumulated in birds of prey resulting in fatal thinning of egg shells.
Within human populations, DDT and its more stable metabolite (i.e. breakdown product)
DDE (Dichlorodiphenyldichloroethylene) are fat soluble. They are stored in adipose (i.e.
fatty) tissue. These substances break down very slowly and have been found in urine and
breast milk samples taken from Inuit women in Canada who are believed to have been
exposed via contaminated seal and whale meat. The World Health Organisation is currently
investigating anecdotal concerns with regard to fertility.
More recently, increasing veterinary use of the nonsteroidal anti-inflammatory drug
(NSAID) diclofenac in the Indian Subcontinent has led to sharp declines (circa 95% per
annum) in vulture (Gyps sp.) populations due to presumed renal failure, a known side
effect of the drug.
Reduction in vulture numbers has resulted in increases in feral dog populations with an
associated rabies risk and occasional sightings of leopards attempting to prey on wild dogs.
The loss of vultures has had a social impact on the Indian Zoroastrian Parsi community, who
30
Element 1
Core environmental principles
traditionally use vultures to dispose of human corpses in Towers of Silence and now have to
seek alternative methods of disposal.
In 2009 the Government of India started to actively encourage the replacement of diclofenac
with alternatives such as meloxicam, a slightly more expensive NSAID without the associated
side effects.
Keystone species
Certain species have a disproportionately large impact in comparison to their numbers and
are critical for the long term survival of a community or ecosystem. These species are known
as keystone species; they hold the ecosystem together, just like the keystone in the middle
of an arch.
A keystone species is a plant or animal that plays a unique and crucial role in the way
an ecosystem functions. Without keystone species, the ecosystem would be dramatically
different or cease to exist altogether. Good examples include bees, sea otters, lions and
jaguars and beavers.
Ecological stability
The concept of ecological stability is used to describe ecosystem performance. The more
stable an ecosystem, the less likely the populations within it are to become extinct. Stable
ecosystems still experience flux and change.
Hence another term for stability is sustainability. A sustainable ecosystem is one which
maintains, over time, features like levels of productivity, processes of nutrient cycling, levels
of soil fertility, and its characteristic level of biodiversity. Stability, in theory at least, can be
measured by monitoring these kinds of processes.
Stability actually refers to two concepts; resistance and resilience.
Key vocabulary
• Resistance: Refers to how well species and ecosystems can resist changes, for
example in the availability of food and / or pollution levels; and
• Resilience: Refers to species and ecosystems recovery from damage such as
over predation / hunting, pollution or natural disaster.
31
Element 1
Core environmental principles
Resistance (or inertia) measures how much a living system resists change. A system which
remains the same in spite of disturbance or changes in, for example, nutrient input or changes
in pollution level, has a high resistance. Ecosystems which are inhabited by a broad range of
species with few, if any, niche habitats are more likely to have global stability, i.e. to be highly
resistant to change in species composition and / or food web dynamics over the longer term.
They are said to have a high level of constancy.
Resilience measures how quickly a system recovers from disturbance (i.e. external
pressures) and returns to a steady state.
The extent of resistance and resilience therefore depends on both the nature of the ecosystem,
and the type of disturbance. More fragile ecosystems, such as the thermal vents inhabited
by chemoautotrophic bacteria and giant tube worms, have extremely low biodiversity and
narrow nutrient pool.
They are therefore less resistant to change. These systems are likely to have local stability,
i.e. to be stable over small short-lived disturbances, such the influx of light from visiting deep
sea craft. They are however, unlikely to be resilient to repeated changes in the longer term.
32
Element 1
Core environmental principles
1.5 The impact of human intervention on natural cycles
and ecological systems
As highlighted in Section 1.3, natural cycles and ecological systems provide the ‘ground
rules’ which ensure the Earth’s sustainable operation. Current levels of human intervention
(i.e. interference) are unsustainable. Human activities have caused, and continue to
cause, reduced ecosystem stability and harm to ecosystem services, as highlighted by
the notes below.
The notes below provide an overview of the key ways in which human activities interfere
with natural cycles and ecological systems.
Carbon cycle
The most significant and wide-ranging effects of human intervention are in relation to
the carbon cycle. Burning huge quantities of fossil fuel notably for energy generation
and transport has, within generations, returned geological carbon to the atmosphere (as
carbon dioxide) from deposits that were created over millions of years. This process drives
climate change.
Deforestation is also a significant contributor to climate change. It may occur for
example when:
z Trees are cut down to be used or sold as timber, to produce charcoal or directly as a fuel;
z Land is cleared for livestock pasture, plantations of commodities or human settlements.
According to the United Nations Framework Convention on Climate Change (UNFCCC)
secretariat, the primary cause of deforestation is agriculture (80%) logging is responsible for
14% and fuel wood removal / charcoal production for 5%. Urbanisation is only responsible
for about 1%.
Deforestation has adverse impacts on the biosequestration of atmospheric carbon dioxide.
The removal of trees without sufficient / appropriate reforestation also results in habitat loss
and damage to biodiversity and may lead to increased aridity. Soil erosion is a common
problem and areas frequently develop into wasteland. In arid areas this process may lead to
flash flooding and landslides and ultimately to desertification.
Deforestation may also have an effect on biodiversity. Research undertaken in 2015 in the
rainforests of the Island of Borneo revealed that logging makes rainforests more attractive to
33
Element 1
Core environmental principles
rats. The fallen wood contains more insects which they like to eat. Black rats usually avoid
mature forests as they have less available food. Leafy forest floors are also noisy for rats to
run through; this attracts predators.
The acidic, anaerobic conditions associated with peat soils mean that they are sinks for
another significant greenhouse gas, methane (CH4). Deforestation of these areas or cutting
peat for fuel or horticultural purposes can release trapped gas.
Recent studies indicate that the world’s largest peat bog, located in Western Siberia and
the size of France and Germany combined, is thawing for the first time in 11,000 years as a
consequence of climate change. As the permafrost melts, it could release billions of tonnes
of methane into the atmosphere. The formation of peat is also often the first step in the
geological formation of other fossil fuels such as coal and especially low grade coals such
as lignite.
Methane is also a significant component (circa 75%) of the landfill gas released from the
anaerobic breakdown of putrescible waste.
The oceans provide a carbon sink thereby reducing the levels of atmospheric carbon dioxide.
UN scientists anticipate that ocean acidity has more than double in the next 100 years as a
consequence of rising carbon dioxide (CO2) levels. Once dissolved in water, CO2 dissolves
to form carbonic acid. The consequential decreased pH levels depress:
z Metabolic rates in large predators such as Humboldt Squid;
z The immune responses of shell fish such as mussels making them more vulnerable to disease.
Other associated chemical reactions decrease the amount of carbonate ions available,
making it more difficult for shellfish, pertinent plankton feeders and coral to form biogenic
calcium carbonate (CaCO3) leading to shell deformation and coral bleaching. Ecosystems
will also change as species with low resistance to change will either move away or remain
and fail to thrive with ‘knock on’ repercussions for food webs and human food supplies.
Cement manufacturing releases CO2 in the atmosphere both directly when mined calcium
carbonate is heated producing lime and CO2 and also indirectly through the use of energy
if its production involves the emission of carbon dioxide. The UN estimates that the cement
industry produces about 5% of global man-made CO2 emissions, of which 50% is from the
chemical process, and 40% from burning fuel.
Burning of fossil fuels remains by far the greatest anthropogenic (i.e. man-made) contributor
to climate change. Mineral fuels such as petroleum, natural gas and coal constitute major
energy sources for industries, transport and heating in our homes.
34
Element 1
Core environmental principles
It is estimated that burning of fuels (worldwide) produces around 21.3 billion tonnes (21.3
gigatonnes) of CO2 every year. Part of the CO2 released from fossil fuels is absorbed naturally
but the remainder gets caught up in the atmosphere and contributes to global greenhouse
gas warming.
Nitrogen cycle
Nitrous oxide (N2O - also known as nitrogen dioxide or laughing gas) is one of the six most
significant greenhouse gases, the others being water vapour, carbon dioxide, methane,
ozone and CFCs.
Nitrous oxide is emitted by bacteria in soils and oceans, and is thus a part of Earth’s
atmosphere. Human activity is thought to account for 30% of total production with tropical
soils and oceanic release account for 70%.
The primary anthropogenic source is agriculture. Soil cultivation, especially tilling, the use
of supplementary nitrogen fertilisers, and animal waste handling can all stimulate naturally
occurring bacteria to produce more nitrous oxide.
Intensive livestock rearing, primarily cows, chickens, and pigs, produces 65% of humanrelated nitrous oxide. Industrial sources make up only about 20% of all anthropogenic
sources, and include the production of nylon and the burning of fossil fuel in internal
combustion engines.
Intensive agricultural practices seek to maximise yields while minimising associated labour
requirements. The use of supplementary nitrate and phosphate based synthetic fertilisers’
increases the risk of eutrophication (Greek: [eutrophia] meaning healthy, adequate nutrition).
35
Element 1
Core environmental principles
Eutrophication
While obviously beneficial for many biological processes, in surface waters, an
excessive concentration of nitrates and phosphates are considered pollutants.
These substances stimulate the growth of green plants and especially green algae
and cyanobacteria which reduces the quantity of dissolved oxygen. This process is
exacerbated in warm/hot weather and slow moving or stagnant water.
Excess growth of these organisms’ results in the creation of dense vegetative
mats which further reduces oxygen levels, potentially suffocating fish and animals,
while also blocking available sunlight to bottom dwelling species. This cultural
eutrophication supplements the natural autumnal eutrophication process which
provides a supply of long term nutrients to other wintering water systems.
Using untreated human sewage as a fertiliser may also lead to eutrophication and
to the spread of disease when pathogenic microorganisms are released to the
wider environment; depending on the waste’s constituents, fugitive releases of
leachate from poorly controlled landfilled sites may have the same effect
Undertaking intensive agricultural practices without access to sufficient fertilisers will
eventually lead to poor yields. In some poorer parts of the world valuable animal dung
is dried and used as fuel instead of as a fertiliser. This process also deprives soil of the
carbon needed to form humus, an important source of plant nutrients, including carbon and
nitrogen. Humus also acts as an important binder for soil particles. Low humus soils can
readily dry out in low rainfall and / or high winds.
Unprotected, dry soil surfaces blow away with the wind or are washed away by flash
floods, leaving infertile lower soil layers that bake in the sun and become an unproductive
hardpan as exemplified by the Dust Bowls which struck Canada and the United States in
the 1930s and the Horn of Africa in the late 1990s. When combined with excessive tillage,
overgrazing and deforestation this process can rapidly lead to desertification, especially
in already arid areas.
36
Element 1
Core environmental principles
Water cycle
The harnessing of water flows for irrigation and food production, transport, defence
and power has underpinned the development of human civilisation. However, the world
population has tripled in the last 100 years. Water use has been growing at more than
twice the rate of population increase during this period due to increased:
z Access to personal bathing and toilet facilities;
z Availability of washing machines and dishwashers;
z Intensive agriculture;
z Industrialisation;
z Water-based leisure activities.
Although there is no global water scarcity as such, an increasing number of regions are
chronically short of water and especially clean drinking water. Increased urbanisation will
focus on the demand for water among a more concentrated population. Asian cities alone
are expected to grow by 1 billion people in the next 20 years.
Climate change will modify precipitation patterns leaving some areas wetter and others
drier than before. More extreme weather patterns are anticipated including those associated
with flooding and drought. Climate change has already resulted in increased acidity of the
oceans and glacial decline.
Deforestation reduces the content of water in the soil and groundwater as well as
atmospheric moisture from transpiration. Desertification constricts the cycle further.
Simplification of the landscape and destruction of riparian (i.e. riverbank) forests, wetlands,
and estuaries further reduces biodiversity and also encourages the flow of nutrients between
terrestrial and aquatic ecosystems exacerbating the risk of eutrophication and flooding.
Urbanisation increases run off to water courses; concrete and tarmac have a much lower
water retention capacity than soil.
The construction of dams inevitably changes the flow of water in river systems. It may involve
the destruction of human habitats and communities as in the flooding of the Tryweryn and
Derwent Valleys in the UK. It may also in extremis cause less resilient non-human species
to become extinct, as is suspected to be the case with the Baiji, or Yangtze River Dolphin
following construction of the Three Gorges Dam in China.
Excessive water abstraction from rivers changes habitats and artificially moves water
between different parts of the cycle. It may also result in decreased dissolved oxygen levels
37
Element 1
Core environmental principles
in freshwater, especially during the summer. The drawdown of ‘fossil water’ robs future
generations of their water supply and is therefore unsustainable as it puts water from long
term storage back into circulation. As water vapour is a potent greenhouse gas this process
contributes to climate change. It may also lead to rises in sea-levels.
Humans may negatively interfere with the water cycle and associated habitats through
the disposal / release of eco-hazardous chemicals and also from run off from roads,
farms and industry.
Phosphorus cycle
Humans interfere with the phosphorus cycle by mining it, converting it to fertiliser, and
then shipping final products around the globe. As indicated previously, the excessive or
inappropriate use of phosphorus based fertilisers is implicated in cultural (i.e. anthropogenic)
eutrophication.
Surface and subsurface runoff and erosion from high-phosphorus soils may also cause fresh
water eutrophication for example during deforestation. As the forest is cut and / or burned
during deforestation, nutrients originally stored in plants and rocks are quickly washed away
by heavy rains, causing the land to become unproductive.
Historically, the use of laundry and personal care detergents contributed to significant
concentrations of phosphates in rivers, lakes, and streams, but most detergents no longer
include phosphorus as an ingredient. In Europe EU Regulation 648 / 2004 on Detergents
forbids the sale of products which do not meet strict biodegradability criteria.
Organophosphorus materials may still be found in the environment in the form of flame
retardants, plasticisers, pesticides and water treatment chemicals.
38
Element 1
Core environmental principles
Ecological systems
Over the past century, humans have changed ecosystems more rapidly and extensively
than in any comparable period of human history.. The demand for provisioning services,
such as food, fresh water, timber, fibre and fuel has grown substantially.
The changes that have been made to ecosystems have contributed to substantial net gains
in human well-being and economic development, but these gains have been achieved at
growing costs from the degradation of many ecosystem services and the exacerbation of
poverty for some groups of people.
Invasive alien species are the second largest cause of biodiversity loss in the world habitat
loss associated with increasing human populations. Over hunting, whether for food or sport,
has historically been important. However, increasingly this is being replaced by the removal
of live species for the exotic pet trade and plants for horticultural use. Habitats are also
damaged by pollution and also human conflict.
The changing global climate threatens individual species and ecosystems. The distribution
of species (i.e. biogeography) is largely determined by climate, as is the distribution of
ecosystems and plant vegetation zones (i.e. biomes).
Climate change may simply shift these distributions but less resilient plants and animals may
not be able to adjust. The pace of climate change almost certainly will be more rapid than
most plants are able to migrate. The presence of roads, cities, and other barriers associated
with human presence may inhibit distributional shifts for many species.
Examples of the Impacts of Human Activities on Natural Ecological Systems, Habitats,
Species and Individuals
z Resource depletion – such as fossil fuels and rare earth metals;
z Change in land use – such as deforestation and intensive agriculture;
z Reduced biodiversity at the ecosystem, species and genetic levels;
z Species extinction;
z Reduced access to critical resources – such as medicines and clean drinking water;
z Reduced enjoyment of the land because of damage to ecosystems and declining
biodiversity;
z Reduced ecological stability affecting resistance, regeneration and eco-succession;
z Increased poverty, reduced access to clean water, reduced air quality due to direct and
indirect emissions as discussed in Section 1.6.
39
Element 1
Core environmental principles
1.6 Pollution sources, pathways and receptors
Introduction
Pollution is defined simply as the deliberate or accidental introduction of contaminants
(i.e. pollutants) into the environment which causes adverse changes. Pollutants may be
substances or energy.
Pollution can be natural, such as lava flow from an active volcano or overflow from a
flooding river.
Regulation 2 of the Environmental Permitting (England and Wales) Regulations 2010 (as
amended) offers a more precise definition with reference to specific environmental media.
Pollution definition - Environmental permitting (England and Wales)
regulations 2010
… “pollution”, in relation to a water discharge activity or groundwater activity, means
the direct or indirect introduction, as a result of human activity, of substances or heat
into the air, water or land which may:
a. Be harmful to human health or the quality of aquatic ecosystems or terrestrial
ecosystems directly depending on aquatic ecosystems;
b. Result in damage to material property; or
c. Impair or interfere with amenities or other legitimate uses of the environment.
“pollution”, other than in relation to a water discharge activity or groundwater
activity, means any emission as a result of human activity which may:
a. Be harmful to human health or the quality of the environment;
b. Cause offence to a human sense;
c. Result in damage to material property; or
d. Impair or interfere with amenities or other legitimate uses of the environment.
40
Element 1
Core environmental principles
Key vocabulary
Diffuse (or non-point) source: A broad, non-descript source of pollution such as a
flooding river or fertiliser runoff from a field. Once released the pollution from multiple
point sources may become a diffuse source as in the case of traffic emissions:
Mobile source: Mobile sources can be moved from one location to another such as
cars, airplanes and trains.
Point source: A single, clearly identifiable source (think: ‘hand over cup’) such as a
discharge pipe to natural waters or the combustion stack from an industrial process.
Pollution conversion: The reaction of primary pollutants to produce secondary
pollutants.
Primary pollutant: These pollutants are directly produced from a process, such as
ash from a volcanic eruption, carbon dioxide from a car exhaust or furnace stack,
or sulphur dioxide from a coal fired power station.
Secondary pollutant: Secondary pollutants are not emitted directly but from
chemical reactions between primary pollutants. An important example of a secondary
pollutant is ground level ozone.
Note: Some pollutants may be both primary and secondary, i.e. they are both emitted
directly and formed from other primary pollutants, such as ground level ozone (Figure
1.20).
The reaction of primary pollutants to produce secondary pollutants is called pollution
conversion. The difference between primary and secondary pollutants is summarised in
Figure 1.12.
Primary
pollutants
Secondary
pollutants
Produced directly from a process. Examples
include ash from a volcanic eruption or CO2,
NOX, SOX and VOCs from a car exhaust
These are not emitted directly from a pollution
source but are produced by a chemical reaction
between primary pollutants. Examples include
ground level ozone (produced from the reaction
of NOX and VOCs) and acid rain
Figure 1.12: Primary and secondary pollutants
41
Element 1
Core environmental principles
It is important to remember that in practice most pollutants may be both primary and
secondary pollutants, depending how and when they are produced.
Main pollution types
There are many different types of pollutants and also different ways of classifying them.
Three of the most common terms you may hear are:
z Inorganic compounds: These materials do not contain carbon. They include, for example
heavy metals such as cadmium, lead, mercury and arsenic;
z Organic compounds: These materials contain carbon. They include DDT (a powerful now
largely banned insecticide) and polychlorinated biphenyls (PCBs) which were historically
widely used as insulating oils; and
z Organometallic compounds: These are forms when metals react with organic molecules.
For example, when combined with organic molecules, elemental mercury forms
methylmercury (pollution conversion). Methylmercury is neurotoxin that affects the
central nervous system. Methylmercury also can bioaccumulate in the food chain. Tin
is an example of a non-toxic metal (used as a lining in food containers) which becomes
toxic when it bonds with organic molecules to form Tributyltin (TBT). TBT is widely used
as the biocide in antifouling marine paints to discourage the growth of organisms such as
barnacles. However, it is extremely toxic to crustaceans such as lobsters. TBT exposure
can lead to the development of male characteristics in female snail and bivalve species.
The major forms of pollution are summarised in Table 1.1
Pollution type
The release of …
Air
Chemicals, including particulates and aerosols, into the atmosphere
Land
Chemicals onto or into soil, for example via spills or underground
leakage
Light
Excess light including light trespass, over illumination and astronomical
interference
Noise
Excess / unpleasant sound; typical sources include roadways, aircraft,
industry and high intensity sonar
42
Element 1
Core environmental principles
Pollution type
The release of …
Radioactive
(or
radiological)
contamination
Radioactive substances on surfaces or within solids, liquids or gases
(including the human body), where their presence is unintended or
undesirable
Thermal
Chemicals into water (usually aqueous solutions) which are warmer or
colder than the receiving water
Visual
Nothing; visual pollution is an aesthetic issue and therefore highly
subjective. Typical examples include overhead power lines, roadside
billboards, fly tipping and scarred former industrial landscapes
Water
Chemicals into bodies of water
Table 1.1: Forms of pollution
Pollution linkages
Pollutants, whether chemicals such as CO2 or energy such as noise, do not cause pollution
unless they reach a receptor (i.e. target) which can be harmed in some way. In order to
achieve this, the pollutant must travel to the receptor via a pathway; without this linkage,
there can be no pollution. This model is often described as the source-pathway-receptor
model (Figure 1.13).
Source
Example: a spill
on the ground
from oil drums
or tanks
Pathway
Example: drains
through soil to
ground water, over
hard surfaces
Receptor
Example: river
stream, lake,
ground water
Figure 1.13: Example of a pollution linkage [source: Pollution Prevention Guideline PPG1]
Why are pollutant linkages important?
Understanding and be able to predict pollution linkage is a critical component of environmental
risk assessments and the associated management of risk, as discussed in Section 4.3.
They are also used in the investigation of environmental incidents and accidents, notably by
regulators to ‘work backwards’ to determine the cause of a pollution event.
43
Element 1
Core environmental principles
Key vocabulary
Source: Origin of the pollutant. Examples include leaks and spills from an oil
storage tank, road water runoff, by-products of combustion, emissions from an
industrial stack, effluent discharges and dumped or poorly managed waste.
Receptor: Something which can be adversely affected by a pollutant, such as
people, an ecological system property or a body of water. Some scientists may call
this a target especially when highlighting human harm or property damage.
Pathway: A route or means by which a receptor can be exposed to, or affected
by, a pollutant. The most common pathways are: the atmosphere; water (e.g.
rivers lakes aquifers, coasts and seas); land (including surface and underground
contamination; and groundwater. However animals and plants can also act as
pathways, particularly for those pollutants that bio accumulate.
Note: when discussing pollution linkage in the context of contaminated land, the
term contaminant is often used in preference to pollutant
The effects of a pollutant depend on a number of factors as highlighted in Figure 1.14.
Chemical
and/or biological
properties,
including
reactivity
Concentration
in the
environment
Environmental
persistance &
ability to
bioaccumulate
Form, i.e. solid,
liquid, gas or
energy
Effects of
a pollutant
Figure 1.14: Examples of factors which influence the effect of a pollutant
44
Element 1
Core environmental principles
The ‘quality’ of the receptor is also crucial, i.e. the stability of an ecosystem, health of an
individual, materials of construction for property etc.
The concept of pollution linkage can be used to identify both direct and indirect impacts.
For example when considering the potential effects of a leak from an underground oil tank
or subsurface pipework (Figure 1.23).
Source
Pathway
Receptor
Leak from
underground oil
tank or from
subsurface pipework
Leaching to
groundwater supply
Groundwater supply
and drinking water
supply
Figure 1.15: Example of a pollution lnkage in relation to groundwater supply
One of the specific hazards in this scenario is the presence of residual benzene (a known
carcinogen); this would be of particular concern in relation to the drinking water supply.
Simple tables such as the one in Table 1.2 are used to identify specific hazards and their
relationship to pollution linkages.
Hazard
Source
Pathway
Receptor
S-P-R linkage
Benzene
Underground
oil storage tank
Leaching
Groundwater
supply
Yes
Groundwater
supply
Public
supply
Yes
water
Table 1.2: Example of a table representing pollution linkages
45
Element 1
Core environmental principles
Water pollution
Water is essential for life; it provides a diverse range of habitats and is also a vital resource
for manufacturing industries. However, it is not just the water itself that is important but also
the dissolved oxygen contained between its modules.
Under normal atmospheric pressure and ambient temperatures, water should contain over
10 mg / l of oxygen to be saturated. The concentration will vary with pressure and temperature
but if it falls by 50% to 5 mg / l, fish will become distressed and start to die.
Invertebrates are also sensitive and the species present and their relative numbers are a
good indicator of water quality. The most significant water pollutants are those which reduce
oxygen levels as discussed below.
Organic Matter
Organic matter is naturally present in surface water from decaying vegetation and runoff
from fields. If levels rise significantly oxygen is rapidly consumed due to the action of aerobic
bacteria. Common pollutants include sewage, farm slurry, industrial discharges or from spills
of organic substances such as milk from farms or tankers.
Under normal circumstances, the consumed oxygen is replaced by exchange with the
atmosphere at the surface. However, in the presence of a high organic load, the rate of
exchange is too low. High water temperatures and low flows decrease oxygen levels further.
Photosynthesis replenishes oxygen levels during the day as an inherent part of the Carbon
Cycle. However, this stops at night. As aquatic plants and other organisms continue to
respire at night, this is when water sources are most vulnerable to deoxygenation.
The BOD (biological oxygen demand) test is used to determine the level of organic pollutants
in water. A water sample is seeded microorganisms and stored for 5 days in the dark room at
20°C to prevent DO production via photosynthesis. Most pristine rivers will have a BOD level
below 1 mg / l. Moderately polluted rivers have values in the range of 2 to 8 mg / l.
Due to the length of time required for a BOD test, the chemical oxygen demand (COD) test
is commonly used to provide an indirect measure. The test uses a specific indicator reagent.
The is less specific as is also measures inorganic compounds which can be chemically
oxidised, rather than just levels of biologically active organic materials.
46
Element 1
Core environmental principles
Key vocabulary
BOD: Biological oxygen demand is a measure of the amount of dissolved oxygen
(DO) needed by aerobic biological organisms in a body of water to break down
organic material present in a given water sample at certain temperature over a
specific time period.
COD: Chemical oxygen demand is an indirect measurement of the amount of
pollution (that cannot be oxidised biologically) in a sample of water.
Ammonia
Ammonia (NH3) from sewage, farm slurry, landfill leachate and contaminated land is directly
toxic to aquatic organisms. Oxygen in water oxidises it to nitrite (NO2-) and then to nitrate
(NO3-) as part of the Nitrogen Cycle.
Nitrates and phosphates
Nitrates and phosphates are normally introduced into water from a diffuse source, i.e.
fertiliser runoff; excess nitrates may also be produced following ammonia ingress. The
resultant excessive growth of water plants, notably algae, restricts oxygen exchange. As
algae bacterial decay further reduces oxygen levels as eutrophication progresses.
Oil
Oil forms a layer on the water surface restricting or even preventing oxygen exchange. It
may also coat aquatic plant leaves inhibiting photosynthesis.
Pesticides
Pesticides used in agriculture and horticulture may reach water courses through run off or
drift, both diffuse sources. They remain active in water causing damage to food webs; both
target and non-target species may be killed.
Acids and alkalis
The normal pH for fish and aquatic animals to survive is around 7 to 8. Even moderate
changes of pH can cause habitat changes, the creation of secondary pollutants and in
extremis the death of animals and plants. Niche species are especially vulnerable.
47
Element 1
Core environmental principles
Suspended solids
Suspended solids, for example from construction activities or wind-blown dust, increase
turbidity. Even moderate levels can restrict fish gills, inhibit hunting behaviour and settle on
plants reducing photosynthesis. Once on the river bed, it can bury bottom dwelling organisms
leading to a lack of food supply for fish and other aquatic life.
The deposition of sediments can also lead to changes to the substratum by creating a blanket
of sludge. If organic matter is buried, subsequent anaerobic decomposition may result in the
localised production of toxic methane and hydrogen gases. Fish breeding grounds can be
destroyed by the deposit of particulate materials filling in gravel beds and natural pools.
Flow rate
This input of material, even clean water, from a point source with high flow rate may
cause scarification of banks and river beds, releasing buried pollutants and disturbing
suspended solids.
Thermal pollution
Water is used as a coolant in power stations and many industrial processes. If this is returned
to water courses without re-cooling, it may lead to localised increases in water temperature
and decreased oxygen levels; if prolonged, it may promote the growth of bacteria and
algae exacerbating the problem. Input of hot or cold water from point sources may provide
an ‘invisible barrier’ for fish restricting their movements, changing breeding patterns and
modifying food webs. Extreme changes in temperature may result in thermal shock killing
fish and invertebrates.
48
Element 1
Core environmental principles
Air pollution
The most significant air pollutants fall into four distinct categories:
z Sulphur compounds;
z Nitrogen compounds;
z Carbon compounds;
z Particulate matter.
Sulphur compounds
The two oxides of sulphur - sulphur dioxide (SO2) and sulphur trioxide (SO3) are commonly
known as SOX or SOX (pronounced ‘socks’).
SO2 is the more common of the two pollutants. It is produced when sulphur containing
compounds are heated in the presence of oxygen (O2) and is a significant component of
volcanic eruptions. The main anthropogenic sources are the refining metal ores containing
sulphides and the combustion of fossil fuels which contain sulphur compounds as impurities.
SO2 is directly toxic and can cause death in high concentrations. Long term exposure can
cause lung damage and damage to plants. SO2 dissolves in water vapour and also the water
in cell tissue to form sulphurous and sulphuric acids. Short term exposure causes lung and
eye irritation.
When dissolved in water vapour in air, SOX forms a gaseous acid solution with oxides of
nitrogen (NOX) compounds which falls as acid rain (Figure 1.24). The consequences of this
secondary pollutant include:
z Dissolution of metals from soils, especially iron and aluminium leading to soil and water
pollution; aluminium reduces fish fertility, gill thickness and mucus production;
z Acidification of rivers and seas leading to localised habitat damage due to decreased pH;
z Death of coniferous trees;
z Damage to steel structures and buildings made of rocks, such as limestone and marble
which contain large amounts of calcium carbonate. Acids in the rain react with the calcium
compounds in the stones to create gypsum, which then flakes off.
Dry deposition occurs in the absence of precipitation, i.e. particles and gases stick to the
ground, plants or other surfaces.
49
Element 1
Core environmental principles
Gases carried
by the wind
Gases disolve in
rain water and
form acid rain
Acid gasses
(sulphur dioxide and nitrogen
oxides released into atmosphere)
Acid rain kills plantlife, pollutes
rivers and streams, and
erodes stonework
Figure 1.16: Acid rain
Nitrogen compounds
There are three oxides of nitrogen: nitrous oxide (N2O), nitric oxide (NO) and nitrogen dioxide
(NO2); collectively they are known as NOX or NOX (pronounced ‘nocks’). As highlighted in
the discussion on the Nitrogen Cycle, N2O is predominantly form by microbial activity in the
soil and is not normally a significant pollutant.
NO and NO2 are formed during combustion processes, notably the combustion of coal and
in vehicle exhausts. These are the other primary pollutants, which together with SOX, are
implicated in acid rain (Figure 1.16).
NOX are also involved in the formation of ground level smog. N2O is an ozone depleting
compound.
Smog
The word smog is a contraction of smoke and fog. It is caused by the physical mixture and
chemical reaction of a range of primary pollutants including particulate matter, NOX, SOX and
various organic compounds including Volatile Organic Compounds (VOC).
50
Element 1
Core environmental principles
The extent of pollution conversion and the resultant secondary pollutants present in the mist
will depend on the pollutants involved and the associated environmental conditions. The
resultant mist typically causes respiratory irritation and exacerbates asthmatic symptoms.
Long term exposure is associated with an increased rate of mortality.
The reaction is promoted by the presence of a temperature inversion (Figure 1.17) as in
the famous London Smog of 1952 which was attributed primarily to the domestic burning
of fossil fuels.
A variant of smog, photochemical smog was first described in the 1950s. Sunlight acts as
a catalyst for the chemical reaction between NOX and VOCs together with other primary
pollutants. The resultant mixture of secondary pollutants typically includes aldehydes, NO2,
peroxyacyl nitrate, tropospheric (i.e. ground-level ozone) and VOCs. Due to the need for
solar radiation, photochemical smog exhibits a distinct diurnal rhythm.
All of these harsh chemicals are usually highly reactive and oxidising. Photochemical
smog is considered to be a problem of modern industrialisation. It is present in all modern
cities, but it is more common in cities with sunny, warm, dry climates and a large number
of motor vehicles.
The winter sun, low in the sky,
supplies less warmth to the
Earth’s surface.
Warmer air aloft acts as a lid and
holds cold air near the ground.
Pollution from wood fires and
cars are trapped by the inversion.
Mountains can increase
the strength of valley inversions
Figure 1.17: Temperature inversion
51
Element 1
Core environmental principles
Carbon compounds
The two oxides of carbon are carbon monoxide (CO) and carbon dioxide (CO2). The principle
source of both is the combustion of fossil fuels. CO is an asphyxiant and is a regular cause
of accidental death in enclosed spaces. It is also a highly reactive primary pollutant which is
also implicated in ground level smog formation.
The role of CO2 in global warming and climate change is discussed separately in Section 1.8.
Methane (CH4) is also a greenhouse gas. It is the main constituent of natural gas and occurs
with crude oil and in coal mines, where it has been implicated in a number of fires and
explosions. It is also produced during anaerobic digestion.
Volatile organic compound (VOC) is the term used to describe a range of unrelated solvents
which are liquids at normal temperatures and pressures but which release vapour into the
atmosphere by evaporation. The most commonly used are petrol and diesel.
Common examples used in industrial processes include:
z Alcohols such as methanol and ethanol;
z Organic acids such as acetic acid;
z Acetaldehyde;
z Acetone;
z Glycols;
z Isocyanates.
These compounds are used in the manufacture of a wide range of products including plastics,
cosmetics, pharmaceuticals, paints, varnishes, adhesives and antifreeze. Bioethanol is also
increasingly used as a fuel in vehicle engines.
VOCs are highly active primary pollutants which are involved in the production of smog.
Particulate matter
The term particulate matter refers to a wide range of substances including dust, grit, fibres,
aerosols, mists, vapours and fumes.
The damage caused by these particles is dependent on their size, physical properties
and composition. Some, particularly if they are heavy metals such as lead, cadmium and
mercury, are toxic. Fibres such as asbestos and cotton can cause disabling lung conditions
after a long latency period.
52
Element 1
Core environmental principles
The effects of inhaling particulate matter that have been widely studied in humans and
animals now include asthma, lung cancer, cardiovascular issues, respiratory diseases, birth
defects, and premature death.
Particles with a notional diameter of less than ten microns (10µm) (known as PM10’s) can
penetrate the deepest part of the lungs, i.e. the bronchioles or alveoli. Particles smaller than
2.5 µm, (PM2.5) are able to penetrate into the gas exchange regions of the lung, and very
small particles (< 100 nm) may pass through the lungs to affect other organs.
Photosynthesis can be restricted by the presence of sticky soot on leaves and suspended
solids, for example from wind-blown dust, are a significant water pollutant. Particulate
material is also responsible for dry deposition in acid rain.
Stratospheric ozone depletion
The ozone layer is the area of the upper atmosphere which contains the highest concentration
of ozone (O3). It is produced by the interaction of the UV range of the sun’s rays which cause
oxygen (O2) molecules to split and recombine to form O3. This layer absorbs further UV,
preventing it from reaching the Earth’s surface.
Excessive ground-level UV light:
z Increases the risk of sunburn and cancer, especially skin cancer. Sunburn has been
noted in non-human species including the great whales;
z Increases ground-level ozone;
z Reduces photosynthesis in plants;
z Cyanobacteria, such of those in associated with rice are particularly sensitive to
UV radiation.
Levels of ozone in the stratosphere vary from year to year due to fluctuations in meteorological
conditions; seasonal ‘holes’ form over the Antarctic during the polar winter. The reduction in
stratospheric ozone is caused by the (historical) emission of synthetic compounds, i.e.:
z CFCs;
z HCFCs;
z Methyl chloroform;
z Methyl bromide;
z Halon.
53
Element 1
Core environmental principles
These compounds break down in the atmosphere to form halogen atoms such as chlorine
and bromine which in turn break down ozone (Figure 1.18). Following the Montreal Protocol
1987 and subsequent amendments, the manufacture and use of these substances is
increasingly restricted / forbidden worldwide.
N2O is a naturally occurring ozone depleting substance and is more difficult to control. It is
also a greenhouse gas.
Scientists currently anticipate that the ‘holes’ in the ozone will close within 50 years based
on current knowledge of both the persistence of synthetic ozone depleting substances in the
atmosphere and the ongoing seasonal rate of closure.
Figure 1.18: Ozone depletion
54
Element 1
Core environmental principles
Contaminated land
Contaminated land may occur as a consequence of phenomena such as acid rain and also
due to natural and man-made disasters. However, most of the contaminated land in the UK
is associated with the country’s long industrial heritage, i.e. with:
z Mining and extractive industries;
z Iron and steel works;
z Metal treatment and finishing;
z Oil refining, processing and storage;
z Chemical and pharmaceutical processing, manufacturing and storage;
z Railways an associated sidings and depots;
z Iron and steel works;
z Sewage treatment and the disposal of treated sewage sludge;
z Waste disposal.
The common causes of pollution associated with these industries include:
z Accidents and spillage, for example when filling, emptying or transporting containers;
z Leaks from tanks and pipework, especially where these are underground;
z Stack emissions;
z Movement of ground or surface water;
z Migration of toxic or explosive gases, especially underground;
z Demolition of buildings, especially where these contain hazardous building materials
such as lead or asbestos.
55
Element 1
Core environmental principles
1.7 Climate change
Introduction
The word climate is derived from the Greek klima, meaning ‘area’ and is usually used to
describe a region’s long term weather patterns. A range of factures are used to measure
this, notably average precipitation, maximum and minimum temperatures throughout the
seasons, hours of sunshine and the frequency of extreme events.
The concept of climate change can be used to refer to local and regional differences in
weather patterns, but is more often used specifically to mean global climate change.
Key vocabulary
The Greenhouse Effect is the heating of the surface of the Earth due to the
presence of an atmosphere containing greenhouse gases (GHGs) which absorb
and emit long-wave (heat) radiation. Without this effect, the Earth’s average
temperature would be −19oC, rather than 15oC. The Greenhouse Effect is a natural
effect. However, human activity is exacerbating the effect, causing global warming
by increasing the amount of GHGs in the atmosphere.
Global warming is the process by which the average surface temperature on the
Earth increases. This is caused primarily by an increase in the amount of GHGs in our
atmosphere. Global temperatures increased by 0.85 degrees between 1880 and 2010.
[Source: Intergovernmental Panel on Climate Change (IPCC)].
The term climate change describes changes in the long-term distribution and severity
of weather patterns caused primarily by changes in global temperature.
Local climate
Local weather patterns are influenced by the following factors:
z Altitude: Temperature decreases with height above sea level; as the air becomes less
dense, it is able to hold less heat;
z The prevailing wind: Incoming cold air decreases temperature and vice versa;
z Distance from the sea: Coastal areas experience fewer temperature fluctuations as land
heats and cools faster than the sea;
56
Element 1
Core environmental principles
z Ocean currents: Warm ocean currents, especially in the North Atlantic moderate the land
temperatures of cold areas;
z Topography: If moist air is forced to rise and cools, it encourages precipitation;
z Vegetation: The type of ground cover affects sunlight absorption and low-level air flow;
z Urban development: The presence of dense human populations with associated
buildings, transport and industry means that the local climate is normally warmer, less
windy and more polluted than rural areas. As discussed previously, smog is associated
with polluted urban areas.
Regional climate
The regional climate depends on a number of factors, of which the most critical is latitude,
i.e. distance from the Equator. Globally, the decreasing solar energy absorbed at higher
altitudes combined with the rotation of the Earth creates large ‘circulation cells’.
The global climate
The global climate depends on how much solar energy is retained in the land, air and sea. This
in turn is governed by a complex set of interacting cycles, i.e. the atmosphere, hydrosphere
(liquid and vaporised water), cryosphere (frozen water), land surface and the biosphere.
What is (global) climate change?
The term (global) climate change refers to patterns of changes in the Earth’s climate which
have happened in the post Industrial Revolution Era. Some of these changes are a result
of natural causes but there is now significant quantitative and qualitative evidence which
confirms that human activities are underpinning the most significant changes.
What are the gauses of climate change?
The predominant factors underpinning climate change are:
z Increased levels of greenhouse gases;
z Human activities;
z Solar and orbital variations;
z Oceanic circulation;
z Volcanic eruptions.
57
Element 1
Core environmental principles
Increased levels of greenhouse gases
Atmospheric greenhouse gases (GHGs) (Figure 1.27) act as an insular blanket by retaining
heat from the sun which keeps the earth warm. Without these gases, the earth would be
much colder than it is (Figure 1.28). Excessive, i.e. ‘non-natural’, levels of global warming
lead to climate change.
The principle GHGs are sometimes called the ‘Kyoto Six’ in reference to the Kyoto Protocol
where they were highlighted as the principle gases of concern. They are:
z Carbon dioxide (CO2)
z Methane (CH4)
z Nitrous oxide (N2O)
z Hydrofluorocarbons (HFCs)
z Perfluorocarbons (PFCs)
z Sulphur hexafluoride (SF6)
recently added to the original Kayto 6 is NF3 (Nitrogen trifluoride) , HFCs, PFCs, SF6 and
NF3 are collectively known as the ‘F-gases’.
Incoming solar
radiation
Absorbed in atmosphere
by greenhouse
gases
Radiated out
to space
Infrared
radiation from
surface
Figure 1.19: Global warming
As highlighted throughout this Element, modern industrial practices have increased the
atmospheric proportions of all greenhouse gases The key driver however is the burning huge
quantities of fossil fuel notably for energy generation and transport has returned geological
carbon to the atmosphere (as carbon dioxide) from deposits that were created over millions
of years.
58
Element 1
Core environmental principles
Key Human Activities
The key human activities that contribute to climate change are:
Burning of fossil fuels
Mineral fuels such as petroleum, natural gas and coal constitute major, but practically
speaking non-renewable energy sources for industries, transport and heating in our homes.
It is estimated that burning of fuels (worldwide) produces around 21.3 billion tons (21.3
gigatonnes) of carbon dioxide every year. Part of the carbon dioxide released from fossil
fuels is absorbed naturally but the remainder is trapped in the atmosphere.
Land use
Deforestation and other habitat loss can also return carbon stored either in living tissue
or soils to the atmosphere. Burning timber releases carbon dioxide, whereas degradation
or exploitation of carbon rich soils such as peat can lead to the unintentional release of
methane gas.
Waste disposal
Landfill disposal of waste is a key source of man-made methane emissions in the atmosphere.
Poorly managed incineration, i.e. combustion of waste leads to the increased releases of
greenhouse gases, notably carbon dioxide (CO2) and nitrous oxide (N2O).
Cooling units
Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) previously used as
coolants in fridges, freezers and air conditioners are a major source of ozone layer depletion.
They have now been replaced by hydrofluorcarbons (HFCs), i.e. the so-called F-gases, some
of which have a greater global warming potential than CO2. The use of F-gases is controlled
via the EU F-gas regulations which aim to reduce emissions of fluorinated substances with
the highest global warming potential (GWP).
Key non-human activities
Solar and orbital variations
Changes in solar energy can affect global temperature. The Royal Society, the National
Academy of Science in the UK and the Commonwealth confirms that solar activity contributed
to changes in global temperature in the early 20th century. However, satellite measurements
show that there has been little change to solar activity in the last 30 years.
59
Element 1
Core environmental principles
Oceanic circulation
Seas and oceans are key elements in the world’s climate system. They have the capacity to
carry a large amount of heat that can radically affect global climatic conditions. Increases in
greenhouse gases, especially carbon dioxide, also have an impact on seas and oceans by
increasing marine acidity.
Volcanic eruptions
Volcanic activity may last a couple of days, but its effect may affect the climate for a longer
period of time. This is due to the large amount of gas (mainly sulphur dioxide) and ash that
are released when a volcanic eruption occurs. These emissions can linger in the atmosphere
for several years and affect the amount of solar energy reaching the Earth.
The effects of climate change
The principle effects of climate change are the ecological and social changes caused by
the rise in global temperatures. There is a broad, but not universal consensus within the
scientific community that:
z Climate change is occurring;
z Human activities are the primary driver for this.
Evidence of climate change includes the instrumental temperature record, rising sea level,
and decreased snow cover in the Northern Hemisphere According to the Intergovernmental
Panel on Climate Change’s (IPCC) 2013 Report, there is a high level of certainty that most
of the observed increase in global average temperatures since the mid-20th Century are due
to pollution generated by human activities.
Projections of future climate change indicate that there will further global warming, sea level
rises and an increase in both the frequency and severity of some extreme weather events.
The extent of these changes is not expected to be uniform as they will be influenced by
underpinning natural climatic factors. However they are expected to precipitate:
z Associated habitat and ecosystem changes;
z Increased water and food scarcity exacerbating existing problems in water stressed
areas, especially in Africa and Asia;
z Increased health problems, notably those associated with heat stress, respiratory distress
and water borne infectious diseases spread by flooding.
60
Element 1
Core environmental principles
Global action
The intergovernmental panel on climate change
Global action to tackle the effects of climate change began in the late 1980s. The
Intergovernmental Panel on Climate Change (IPCC) was created in 1988. It was set up by the
World Meteorological Organization (WMO) and the United Nations Environment Programme
(UNEP) to prepare, based on available scientific information, assessments on all aspects of
climate change and its impacts, with a view to formulating realistic response strategies.
The UNFCCC and the Kyoto Protocol
The link between fossil fuels, energy production and climate change underpins international,
EU and UK energy policy.
The two key policies at international level are the:
z The United Nations Framework Convention on Climate Change (UNFCCC);
z Protocol to the UNFCCC 1997 (i.e. the Kyoto Protocol).
The UNFCCC is an international environmental treaty. It was negotiated at the United
Nations Conference on Environment and Development (i.e. the ‘Earth Summit’) held in Rio
de Janeiro in June 1992. The treaty came into force in March 1994. The objective of the
treaty is to:
“… stabilise greenhouse gas concentrations in the
atmosphere at a level that would prevent dangerous
anthropogenic interference with the climate system”.
The treaty sets no binding limits on greenhouse gas emissions for individual countries and
contains no enforcement mechanisms and is considered legally non-binding. Instead, the
treaty provides a framework for negotiating specific international treaties (i.e. protocols) that
may set binding limits on greenhouse gases.
The Kyoto Protocol is a complex agreement reflecting the diverse political pressures and
economic realities underpinning carbon reduction targets.
The Protocol’s major feature is that it places mandatory targets on greenhouse-gas
emissions for the world’s leading economies which have accepted it. Commitments are not
placed on developing countries reflecting the greater historical role played by developed
countries in the current high levels of atmospheric greenhouse gases (GHG).
61
Element 1
Core environmental principles
Commitments under the Protocol vary from nation to nation. During the first commitment
period (2008 to 2012), 37 industrialised countries and the European Community committed
to reduce GHG emissions to an average of five percent against 1990 levels. Individual
targets ranged from - 8 per cent to +10, all of which were significant reductions in then
projected emissions.
As these targets were ‘binding’, the agreement offered flexibility in how countries could meet
their targets. Partial credit could be gained, for example by:
z Carbon trading via the so called ‘green market’;
z Engaging in a Clean Development Mechanism (CDM) project such as a rural electrification
project using solar panels or the installation of more energy-efficient boilers; or
z Undertake a Joint Implementation project in another country which either provides
reduction in emissions at source, or an enhancement of removals by sinks (i.e. forests,
which remove carbon dioxide from the atmosphere).
The Doha Amendment to the Kyoto Protocol was adopted in Doha, Qatar on 8 December
2012. The amendment includes:
z New commitments from developed countries who are Parties to the Kyoto Protocol for
second commitment period from 1st January 2013 to 31 December 2020;
z A revised list of greenhouse gases (GHG) to be reported on by Parties in the second
commitment period;
z Amendments to several articles of the Kyoto Protocol which specifically referenced
issues pertaining to the first commitment period and which needed to be updated for the
second commitment period.
Critically, the Doha Conference also called for more international pressure to develop a
universal climate change agreement covering all countries from 2020.
The Paris Agreement
The most recent United Nations Climate Change Conference, COP 21 or CMP 11 was
held in Paris from 30 November to 12 December 2015. It was the 21st yearly session of the
Conference of the Parties (COP) to the 1992 United Nations Framework Convention on
Climate Change (UNFCCC) and the 11th session of the Meeting of the Parties to the 1997
Kyoto Protocol.
The conference negotiated the Paris Agreement, a global agreement on the reduction of
climate change. The final text represented a consensus of the representatives of the 196
parties attending the conference.
62
Element 1
Core environmental principles
The aim of the agreement is to:
z Hold the increase in the global average temperature to well below 2°C above preindustrial levels and to pursue efforts to limit the temperature increase to 1.5°C above
pre-industrial levels;
z Increase the ability to adapt to the adverse impacts of climate change and foster climate
resilience and low greenhouse gas emissions development;
z Make finance flows consistent with a pathway towards low greenhouse gas emissions
and climate-resilient development.”
Signatories are also required to commit to “global peaking of greenhouse gas emissions as
soon as possible” using ambitious and progressive targets.
The agreement will become legally binding if at least 55 countries which together represent
at least 55% of global greenhouse emissions:
z Sign the agreement at the UN Headquarters in New York between 22nd April 2016 (Earth
Day) and 21st April 2017;
z Adopt it within their legal systems (through ratification, acceptance, approval, or accession).
175 Parties (174 states and the European Union) signed the treaty on the first day it was
open for signature (i.e. Earth Day). Significantly, two of the Parties, the United States and
China, jointly represent almost 40% of global emissions. Signing the accord is, of course,
only one step in the process. The leaders must also ratify and approve the agreement within
their home nations, which could take months or years.
On June 1st, 2017, United States President Donald Trump announced that the USA would
cease all participation in the 2015 Paris Agreement on climate change mitigation. During his
presidential campaign, he had pledged to withdraw from the pact, saying a withdrawal would
help American businesses and workers.
In accordance with Article 28 of the Paris Agreement, the earliest possible effective withdrawal
date by the USA cannot be before November 4, 2020. This date is four years after the
Agreement came into effect in the USA and also after the 2020 presidential election. The
White House has since clarified that the USA will abide by the four-year exit process and
maintain its commitments under the Agreement, including reporting its emissions to the
United Nations.
63
Element 1
Core environmental principles
Methods to tackle climate change
The consensus among the world’s pre-eminent scientists is that we should be taking
appropriate steps to mitigate the effects of climate change by reducing emissions of
greenhouse gases. Mitigation means, for example, using cleaner energy sources, such as
renewable sources and reducing reliance on fossil fuels.
It is also necessary to adapt to the current and anticipated effects of climate change, for
example by raising the level of flood defences and using water resources more effectively.
Other techniques include:
z Giving land back to mangroves and everglades, so they can act to break tidal surges
during storms;
z Opening wildlife migration corridors, so that species can move as the climate changes;
z Developing sustainable forms of agriculture that can function on an industrial scale, even
as weather patterns vary wildly.
Mitigate the effects
Adapt how we live
Do
nothing
Figure 1.20: Priority order for managing the effects of climate change
Carbon markets
Carbon markets put a commodity value on GHG emissions. Schemes such as emissions
trading, carbon taxes and voluntary offset have become increasingly common worldwide in
an effort to reduce carbon emissions.
64
Element 1
Core environmental principles
The EU Emissions Trading Scheme (EU ETS), for example, is a mandatory multi-sector,
multi-country cap and trade scheme that is the EU’s primary instrument for regulating
carbon emissions from large energy and industrial installations. Large emitters of carbon are
given a specific ‘allowance’; if they exceed that allowance, they need to buy carbon credits
from those who may have not used their allowance. The nature of the scheme incentivises
companies financially to reduce their emissions, and assist member countries in meeting
their emission reduction targets.
Similarly, the UK’s CRC Energy Efficiency Scheme is designed to encourage large public
and private sector organisations to reduce their CO2 emissions and improve their energy
efficiency. Some public bodies must participate in CRC no matter how much electricity they
consume. Other organisations must meet specific qualifying criteria, notably that:
z They had at least one settled half hourly electricity meter;
z More than 6000 megawatt hours (MWh) of qualifying electricity supplied on the settled
half hourly market.
As well as mandatory schemes, carbon may be traded voluntarily. Under this type of scheme,
credits are allocated to projects that are carbon ‘positive’, thus allowing businesses, countries
and individuals to purchase carbon credits and offset their emissions.
SECR 2019
Streamlined Energy and Carbon Reporting (SECR) 2019 is the greenhouse gas reporting
scheme which has replaced the Carbon Reduction Commitment (CRC) from April 2019
The UK has made it mandatory for large businesses, including charitable organisations,
to report their energy and carbon emissions on a yearly basis, as well as any efficiency
measures taken throughout their financial year.
Who does it apply to ?
If your company has two of the following:
z more than 250 employees
z more than £36m turnover
z more than £18m balance sheet total
There is an exemption for businesses who use 40 MWh or less over the reporting period, but
you’ll need to include a statement confirming your energy use.
65
Element 1
Core environmental principles
© Astutis Ltd.
All rights reserved.
No part of this study material may be stored in a retrieval system,
reproduced or transmitted in any form, or by any electronic, photographic
or other means without the express written permission of Astutis Ltd.
Applications for written permission to reproduce any part of this study
material should be sent to Astutis Ltd., 6 Charnwood Court, Parc
Nantgarw, Cardiff, CF15 7QZ.
Information sourced from the Health and Safety Executive and
Government Departments has been reproduced and / or adapted under
the terms of the open government license for public sector information
version 3.0, as presented by the National Archives at:
www.nationalarchives.gov.uk/doc/open-government-licence/version/3/
Information obtained from other
acknowledged and referenced.
sources
has
been
properly
Whilst every effort has been made to ensure the currency and accuracy
of the information contained within Astutis Ltd. bears no liability for any
omissions or errors; or any concepts and interpretations advanced by
the authors.
Version 1.0 2020