Current General Studies Magazine (September 2014)
General Studies - III (Environment & Bio-diversity Based
In the atmosphere, gases such as water vapour, carbon
dioxide, ozone, and methane act like the glass roof of a greenhouse by trapping
heat and warming the planet. These gases are called greenhouse gases. The
natural levels of these gases are being supplemented by emissions resulting from
human activities, such as the burning of fossil fuels, farming activities and
land-use changes. As a result, the Earth’s surface and lower atmosphere are
warming, and this rise in temperature is accompanied by many other changes.
Rising levels of greenhouse gases are already changing the
climate. According to the Intergovernmental Panel on Climate Change (IPCC)
Working Group I (WGI) Fourth Assessment Report, from 1850 to 2005, the average
global temperature increased by about 0.76ºC and global mean sea level rose by
12 to 22 cm during the last century. These changes are affecting the entire
world, from low-lying islands in the tropics to the vast polar regions.
Climate change predictions are not encouraging; according to
the IPCC WGI Fourth Assessment Report, a further increase in temperatures of
1.4°C to 5.8°C by 2100 is projected. Predicted impacts associated with such
temperature increase include: a further rise in global mean sea level, changes
in precipitation patterns, and more people at risk from dangerous “vector-borne
diseases” such as malaria.
Vulnerability of biodiversity to the impacts of climate change
The present global biota has been affected by fluctuating
Pleistocene (last 1.8 million years) concentrations of atmospheric carbon
dioxide, temperature, precipitation, and has coped through evolutionary changes,
and the adoption of natural adaptive strategies. Such climate changes, however,
occurred over an extended period of time in a landscape that was not as
fragmented as it is today and with little or no additional pressure from human
activities. Habitat fragmentation has confined many species to relatively small
areas within their previous ranges, resulting in reduced genetic variability.
Warming beyond the ceiling of temperatures reached during the Pleistocene will
stress ecosystems and their biodiversity far beyond the levels imposed by the
global climatic change that occurred in the recent evolutionary past.
Current rates and magnitude of species extinction far exceed
normal background rates. Human activities have already resulted in the loss of
biodiversity and thus may have affected goods and services crucial for human
well-being. The rate and magnitude of climate change induced by increased
greenhouse gases emissions has and will continue to affect biodiversity either
directly or in combination with other drivers of change.
Links between biodiversity and climate change
There is ample evidence that climate change affects
biodiversity. According to the Millennium Ecosystem Assessment, climate change
is likely to become one of the most significant drivers of biodiversity loss by
the end of the century. Climate change is already forcing biodiversity to adapt
either through shifting habitat, changing life cycles, or the development of new
Conserving natural terrestrial, freshwater and marine
ecosystems and restoring degraded ecosystems (including their genetic and
species diversity) is essential for the overall goals of both the Convention on
Biological Diversity and the United Nations Framework Convention on Climate
Change because ecosystems play a key role in the global carbon cycle and in
adapting to climate change, while also providing a wide range of ecosystem
services that are essential for human well-being and the achievement of the
Millennium Development Goals.
Biodiversity can support efforts to reduce the negative
effects of climate change. Conserved or restored habitats can remove carbon
dioxide from the atmosphere, thus helping to address climate change by storing
carbon (for example, reducing emissions from deforestation and forest
degradation). Moreover, conserving in-tact ecosystems, such as mangroves, for
example, can help reduce the disastrous impacts of climate change such as
flooding and storm surges.
Ecosystem-based adaptation, which integrates the use of
biodiversity and ecosystem services into an overall adaptation strategy, can be
cost-effective and generate social, economic and cultural co-benefits and
contribute to the conservation of biodiversity.
Conservation and management strategies that maintain and
restore biodiversity can be expected to reduce some of the negative impacts from
climate change; however, there are rates and magnitude of climate change for
which natural adaptation will become increasingly difficult. Options to increase
the adaptive capacity of species and ecosystems in the face of accelerating
climate change include:
- Reducing non-climatic stresses, such as pollution, over-exploitation,
habitat loss and fragmentation and invasive alien species.
- Wider adoption of conservation and sustainable use practices including
through the strengthening of protected area networks.
- Facilitating adaptive management through strengthening monitoring and
Ecosystem-based adaptation uses biodiversity and ecosystem
services in an overall adaptation strategy. It includes the sustainable
management, conservation and restoration of ecosystems to provide services that
help people adapt to the adverse effects of climate change. Examples of
ecosystem-based adaptation activities include:
- Coastal defence through the maintenance and/or restoration of mangroves
and other coastal wetlands to reduce coastal flooding and coastal erosion.
- Sustainable management of upland wetlands and floodplains for
maintenance of water flow and quality.
- Conservation and restoration of forests to stabilize land slopes and
regulate water flows.
- Establishment of diverse agroforestry systems to cope with increased
risk from changed climatic conditions.
- Conservation of agrobiodiversity to provide specific gene pools for crop
and livestock adaptation to climate change.
1Q. How does climate change affects Biodiversity ? (200 words) 10
(Courtesy- The Convention on Biological Diversity @http://www.cbd.int/)