UNIVERSITY OF MAURITIUS
FACULTY OF SCIENCE
DEPARTMENT OF BIOSCIENCES AND OCEAN STUDIES
DISCUSS SUSTAINABILITY CHALLENGES &SOLUTIONS AND HOW
ANTROPOGENIC DRIVEN CHANGES& CLIMATE CHANGE AFFECTS OCEAN
BIODIVERSITY IN THE WESTERN INDIAN OCEAN
Name: Isaivanee Poullay Renghen 2114576
Year 1
BSc (Hons) MARINE ENVIRONMENTAL SCIENCES
Principles of Marine and Environmental Sciences MES 1001 Y
Submitted to Dr Roshan Ramessur
Department of chemistry
TABLE OF CONTENTS
INTRODUCTION……………………………………………………………………………....3
ANTHROPOGENIC CHANGES …………………………………………………………….. 4
What is meant by anthropogenic changes……………………………………………………... 5
Origins of anthropogenic changes……………………………………………………………... 6
Examples of anthropogenic changes…………………………………………………………... 7
How anthropogenic changes affects ocean biodiversity……………………………………….. 8
CLIMATE CHANGES………………………………………………………………………… 9
Definition of climate change…………………………………………………………………… 10
Causes of climate change………………………………………………………………………. 11
Differentiate between natural and anthropogenic climate change……………………………... 12
IMPACTS OF ANTHROPOGENIC AND CLIMATE CHANGE ON OCEANS……………. 13
SUSTAINABILITY CHALLENGES…………………………………………………………. 14
Definition of sustainability……………………………………………………………………. 15
Principles of sustainability……………………………………………………………………. 16
Contrast between sustainability and sustainable development……………………………….. 17
The sustainability challenges…………………………………………………………………. 18
The sustainability solutions…………………………………………………………………… 19
INTRODUCTION
According to the United Nations “climate change refers to long-term shifts in temperature
and weather patterns. These shifts may be natural, but since the 1800s, human activities
have been the main driver of climate change.”
Climate change is as alarming as ironical; one of the major causes of this phenomenon is
also one of its greatest hopes. Human beings.
Awareness is being raised everyday concerning the current situation. Environmentalist
and experts are looking for solutions to, at least, slow down the heating rate of the planet.
Both terrestrial and marine ecosystems are at risk.

What is meant by anthropogenic changes?
The planet Earth has undergone various variations in its climate over time. Going
from ice ages to greenhouse period, however, this new period of warming known
as climate change has never been experienced before.
Scientists concurred that one of the major factor causing this changes of climate is
human activities, which highly contribute to an increase in the production of
greenhouse gases, resulting in warming up of the Earth. These human-caused
climate changes are also known as anthropogenic climate changes.

Origins of anthropogenic climate changes
It is back in the ancient Greeks period that people first realized that human actions
could have an impact on the climate. Our ancestors who work with soils proposed
that when humans cultivate lands or cut down trees, this affects the temperatures
and even rainfall.
However, it is in the 1800’s that the relationship between climates changes and
human activities was investigated. The latter arose more curiosity than concern
within the scientific community.
John Fourier, a French physicist compared the atmosphere ability to trap heat to a
glass greenhouse. Energy from the sun penetrates the atmosphere and provides the
Earth with heat and light. Infra-red radiations for instance are absorbed by the
atmosphere. The more greenhouse gases (such as carbon dioxide, nitrogen oxide
and water vapor) produced; the more energy is kept in the atmosphere, causing
the global temperature to rise.
Around the 1860’s another scientist named John Tyndall direct his interest
towards coal gas (composed with carbon dioxide, methane and volatile
hydrocarbons). He noticed that carbon dioxide on its own could absorb several
wavelengths of sunlight.
In 1890’s the idea of a warming planet was even welcomed, it was stated by the
Swedish Chemist, Arrhenius “By the influence of the increasing percentage of
carbonic acid in the atmosphere, we may hope and enjoy ages with more equable
and better climates, especially as regards the colder regions of the planet.” His
calculations suggested that if the CO2 levels in the atmosphere were doubled this
would caused the global temperature to rise by 5°C.
High production of Greenhouses gases is extremely alarming as these gases have
the ability to confine heat and keep the heat within the atmosphere at low
altitudes. However, gases like CFC’s attack higher in the atmosphere preventing
heat to rise to the stratosphere, thus leading to the ozone depletion.
Production of greenhouse gases increased drastically during the industrial
revolution. As society was developing, more land was needed for urbanization
and industrial purpose leading to mass deforestation. The fragile balance of the
environment was disturbed. More carbon dioxide was being produced from
burning of fossil fuels than there were trees to absorb it. Carbon Dioxide in the
atmosphere has increased by 48% since the industrial revolution started.
As population increases, demands for food also increased. In order to meet the
demand, fertilizers were added to the cultivations, resulting in production of
nitrous oxide which is also a dangerous greenhouse gas. CFC’s which used
excessively by factories is also responsible for the degradation of our ozone layer.
Human activities are slowly destroying the planet since the mid 20 century.
CLIMATE CHANGE
As mentioned early, the Earth’s climate has being alter even before humans
starting to cause an impact. Natural climate change is due to various factors which
is our of humans control. The angular rotation of the Earth on its axis causes the
global temperature to fluctuate. This is in fact what causes the ice ages and
warmer temperature between the ice ages to be shorter.
In term of sun intensity, the energy emitted by the sun is also another factor, but
for the last few decades, we could notice that it had little impact on the rise in
temperature. However, the Earth’s ability to reflect sunlight has diminished due to
less white (glaciers, snow) surfaces.
One of the major natural contributors of climate changes is the volcanic activities.
During an eruption, large amount of carbon dioxide is released along with sulfur
dioxides which are projected to the upper atmosphere.
EFFECTS OF CLIMATE CHANGE ON THE WESTERN INDIAN OCEAN
More than 50% of the earth is covered with oceans; this implies that climate
changes (Natural &Anthropogenic) highly affects the properties of the oceans
across the globe.
Some of the impacts of climate change on the western Indian oceans reported are

Increase in sea water temperature
As greenhouse gases emission increases, temperature of oceans also rises. This is
because 90% of the excess of heat is stored in our oceans while only 1% is
reflected to the atmosphere. This phenomenon cause fast coral bleaching as the
vibrant color of corals is due to the microalgae that grow on the corals. Corals
experience stressed due to increase in sea temperature that result in exclusion of
algae. Bleached coral reefs often die causing loss of habitat for many marine
species.

Increase in ocean acidity
Due to the increase in concentration of Carbon Dioxide, the pH of the ocean’s
surface becomes more acidic on a global scale. This diminishes the ability of
plankton and coral to maintain their skeletons, thereby resulting to death of those
calcifying species. As plankton dies, the whole ecosystems face a disbalance, as
planktons are at the base of the food chain of marine ecosystems.

More Stratification
Global warming occurs at greater rate as stratification increases. This is because
the warmer layer of water at the surface absorb smaller amount of CO2. Mixing of
the different layers of the oceans takes places at slower rate which in turn impacts
species that requires colder water. Nutrients and plankton are also spread
unevenly. This also affects the distribution of marine life. As species have to
translocate to unknown environment to seek nutrients.

Rise in sea levels
As the polar ice sheets and glaciers are melting, the volume of global seawater
also rises. This highly affects coastal areas mainly via erosion. Both marine and
human lives are affected by rising of sea level as it destroys habitats both.
Climate change is a real threat for the Earth and its inhabitants. Environmentalists
suggest that sustainability can be a key factor in fighting climate change.
WHAT IS MEANT BY SUSTAINABILITY?
Sustainability is defined by the UNESCO as “a paradigm for thinking about the
future in which environmental, societal and economic considerations are balanced
in the pursuit of an improved quality of life.” Sustainability is to preserve and
control our consumption of the limited resources so that the future generations are
not depriving of them. One should be able to contrast between sustainability and
sustainable development; Sustainability is termed as a long-term achievement
while sustainable development is the more of the steps taken to achieve such
goals.