Geoscience Reference
In-Depth Information
these gasses is being raised up leading to an increase in the
temperature of the Earth's surface and lower atmosphere. The
changes in climate have a deleterious impact on biodiversity
either directly or indirectly including a shift in the distribution
of the biotic community, timing of biological behaviour, that
is, phenology, assemblage composition, ecological interactions
and community dynamics.
Fossil-age
context of
biodiversity and
climate change
If we look into history, it has been seen that from paleo age
itself, Earth is facing the problem of climate change. In those
historic ages, Earth was cool, warm, dry, wet and CO
2
levels
were both high and low. Constant shifting in vegetation resulted
in such climate changes during those days. Here, we can take
the example of forest communities dominating most areas in
interglacial periods and herbaceous communities dominating
most areas during the glacial period. There was evidence that
climate change influenced the process of speciation and extinc-
tion during that time. For example, the collapse of carbonifer-
ous rain forest which occurred 350 million years ago resulted
in destruction of amphibian population while encouraging the
evolution of reptiles.
present-day
context
There is a growing consensus in the scientific community that
climate change is occurring. According to the millennium eco-
system assessment, a comprehensive assessment of the links
between ecosystem health and human well-being, climate change
is likely to become the dominant direct driver of biodiversity
loss by the end of this century. Projected changes in climate,
combined with land use change and the spread of exotic and
alien species, are likely to limit the capability of some species
to migrate and, therefore, will accelerate species loss. It is well
accepted that the global average surface temperature is increas-
ing day by day and that the snow and ice ranges in the Northern
Hemisphere are decreasing. According to IPCC (2001), the
global surface temperature has increased nearly 1° over the past
century and it is projected that there would be 1.4-5.8° rise in
the next century. Many organisations such as IPCC, UNEP/IES
and scientists working worldwide have shown a growing inter-
est in the impact of climate change on biodiversity and are try-
ing to make people aware of their dangerous outcomes.
Climate
Change and Biodiversity
(by Lovejoy and Hannah, 2005) is a
famous topic overviewing the past and potential future effects
of climate change on biodiversity. In an effort to draw attention
to the mounting threats and opportunities, the Convention of
Biological Diversity (CBD) had called on nations of the world to
