Climate change
• It is very likely that, overall, human
activities since 1750 have had a global
warming effect on the Earth.
• The Earth’s climate is influenced by many
factors, mainly by the amount of energy
coming from the sun, but also by factors
such as the amount of greenhouse gases
and aerosols in the atmosphere, and the
properties of the Earth’s surface, which
determine how much of this solar energy is
retained or reflected back to space.
Sahara – 8 000 years ago
and now
Climate change
• Greenhouse gases such as carbon
dioxide (CO2), methane (CH4) and
nitrous oxide (N2O) have
significantly increased since the
beginning of the industrial
revolution. This is mainly due to
human activities, such as the
burning of fossil fuels, land use
change, and intensive agriculture.
Greenhouses in Alméria (Spain) –
producing of tomatoes, cucumbers
Climate change – Greenhouse effect
Water vapour, carbon-dioxide and
methane form a natural blanket of
air around the Earth. However, the
burning of fossil fuels and
deforestation has led to a massive
increase in the amount of carbondioxide released into the
atmosphere. We are also releasing
larger quantities of other
greenhouse gases, such as methane
and nitrous oxide.
The surface of the earth is
heated by the sun. As it warms
up, it reflects heat back into the
atmosphere.
About 70% of the sun's energy is radiated
back into space. But some of the infrared
radiation is trapped by greenhouse gases,
which warm the atmosphere, and reflect
heat back down to Earth.
As a result of the greenhouse effect, the
Earth is kept warm enough to make life
possible. But some scientists say that
increased emissions of greenhouse gases
are disturbing the balance of this complex
system, causing global warming. In the last
100 years, the average global temperature
has increased by about 0.4 to 0.8° C.
Climate change – Greenhouse Gases Emissions
Expressed in Giga
tonnes of CO2
equivalent per year
which includes
different
greenhouse gases
scaled using global
warming potentials.
(Note: 1 Giga tonne
= 1 000 000 000
tonnes)
Climate change
1. Temperature
2. Sea level
3. Snow cover
From 1850 to 2000
Climate change - problems
• Sea level rising – people are loosing
their homes - migration
• More rain in rain forrests and higher
latitudes – risk of floods
• Less rain in middle latitudes and low
semideserts – lack of water
Climate change - problems
• Continental and mountain
glaciers melting
• Animals are loosing their
habitats – higher extinction
and new habitats colonization
Glacier Rongbuk (near Everest in 1921 and 2008)
Climate change - problems
• More diseases and deaths caused by extreme
hot, floods, droughts, fire....
• Changes in insect habitats and thus occurence
of some diseases (malaria, tropical fevers,...)
Soil
Soil – nonrenewable source
Threats to Soil:
-Erosion
-Desertification
-Pollution – salinization, chemical substances
-Deforestation
•
•
•
•
•
1 Humus
2 Arable soil
3 Subsoil
4 Fragments of
stale rock
5 Bedrock
Loss of soil in large surfaces is nonreturnable (Syria)
Erosion
loss of upper layer of soil caused by deforestation or bad agriculture
habits (trees stabilize this layer) and rain or wind.
Some types of soil are more endangered (loess).
Bad agriculture habits – slope fields, large fields withour ridges, some
crops (corn, potatoes, sunflower, hop)
Loess erosion in slopes, China
Intensive agriculture in extreme
slopes, Virunga, Rwanda
Desertification
• Desertification is the persistent degradation of dryland
ecosystems by variations in climate and human activities.
Desertification is caused by a combination of social,
political, economic, and natural factors which vary from
region to region
• It threatens the livelihoods of some of the poorest and
most vulnerable populations on the planet. Desertification
is largely caused by unsustainable use of scarce resources.
• Some 10 to 20% of drylands are already degraded, and
ongoing desertification threatens the world’s poorest
populations and the prospects of poverty reduction.
Therefore, desertification is one of the greatest
environmental challenges today and a major barrier to
meeting basic human needs in drylands
Present – day drylands and their cathegories
Desertification
Progressive enlarging of desert and lossiong of soil
Steps against desertification
The same place in Burkina Faso in
1986 (in photo)
-Better water using
-Afforestation = soil protection
-Stone lines building
-Barrier building (sand dunes stabilization)
-Increasing the value of soil by nature fertilizer, composting
(humus layer enlarging)
- Soil property assessment
Salinization
Destruction of soil caused by salts (natural, artificial)
Salts are brought to soil by water (evaporates, not enough to take the soils away)
Usually irrigated or arid areas
Overexploiting of water sources
Makes cultivation impossible
global problem
climate change
lack of drinking water
deforestation / desertification
fresh water pollution
public domain bad shape
decreasing biodiversity
increasing population and migration
social values change
waste disposal
air pollution
soil degradation
ecosystems funktion
chemical pollution
urbanization
ozone depletion
energy consumption
new diseases
natural resources decreasing
food uncertainty
%
51
29
28
28
27
23
22
21
20
20
18
17
16
16
15
15
14
11
11
Global problems
by 200 researchers
from 50 countries
Population
• Natality
• Mortality
Limits to Growth
(1972) –
Rome Club
Children/woman –blue = 0-1, violet = 7 and more
Industrial growth
must be stopped
(no natural
sources)
Population
•
•
•
•
Urbanization – 1800 = 3% of population in cities
- 2010 = 51%
Migration to the cities = slumms, lower life standard,
New work places needed = low earning = increase of
poverty
World population
Population
(in
1
2
3
4
5
6
7
8
9
billions)
1804 1927 1960 1974 1987 1999 2012 2027 2046
Year
In …years –– 123 33 14 13 12 13 15 19
Age pyramids: developed countries and less developed countries (young
population)
Slumm in Mexico City
Sustainable development
• Sustainable development is a pattern of resource use that
aims to meet human needs while preserving the natural
environment so that these needs can be met not only in
the present, but in the indefinite future. The term was used
by the Brundtland Commission which coined what has
become the most often-quoted definition of sustainable
development as development that "meets the needs of the
present without compromising the ability of future
generations to meet their own needs.„
• The field of sustainable development can be conceptually
broken into three constituent parts: environmental
sustainability, economic sustainability and sociopolitical
sustainability.
Sustainable development
• Economic Sustainability: Agenda 21 clearly identified
information, integration, and participation as key building
blocks to help countries achieve development that
recognises these interdependent pillars
• Sustainable development is an eclectic concept, as a wide
array of views fall under its umbrella. The concept has
included notions of weak sustainability, strong
sustainability and deep ecology. Different conceptions also
reveal a strong tension between ecocentrism and
anthropocentrism. Thus, the concept remains weakly
defined and contains a large amount of debate as to its
precise definition.
Sustainable development
• Questions about
• Natural sources
• Population growth
• Food problem
• Biodiversity and Ecosystem preservation
• Energy consumption
• Waste production and degradation
• Global social problems
• ...........
Can be development uninterrupted?
• The ecological footprint is a
concept that calculates the area
of land and water needed to
sustain a defined human
poulation, based on the
population’s use of energy, food,
water, building material and other
consumables. In 1961 humanity
was globally using about half of
the Earth’s capacity to renew its
natural resources. Now this
capacity is exceeded, and overuse
is still growing
Ecological
footprint Sustainability
National Footprint
Czech Republic
Greece
www.footprintnetwork.org/atlas
Portugal
Norway