rapid increase in carbon dioxide emissions observed during the
last 250 years is expected to continue for several decades to
come. Various scenarios have been examined, depending on factors
like fuel use and efficiency. Even the best case scenario predicts
further increases in carbon dioxide emissions until about 2040.
Many of the scenarios indicate that by the middle of the 21st
century emissions of carbon dioxide should ate least start to
level off, though some predict increase in emissions throughout
the different scenarios predict a wide range of trends in carbon
dioxide emissions, the predicted net effect on atmospheric carbon
dioxide concentrations in the future is fairly consistent.
All predict further increase in carbon dioxide concentrations
by the end of the is century, with some of the scenarios predicting
a doubling or even trebling of today's levels of carbon dioxide.
If the predicted increases in greenhouse gas concentrations are
then translated into temperature changes, a global temperature
increase of between 1 and 5.5 degrees centigrade is predicted
average predicted temperature increase over the next 100 years
is around 3 degrees centigrade. This compares to an increase of
about 1 degree centigrade due to previous man-made greenhouse
The large amount of variation between predictions of the different
scenarios underlines the complexity involved in making such predictions
and the large amount of uncertainty inherent in climate change
common feature of global warming stories in the media is sea level
rise. Sea level rise, through the thermal expansion of water and
icemelt around the world, poses a potentially very serious threat
to millions of people.
Like temperature change, predictions vary widely, from a low
of 20 cm to a high of around 60cm.
The impact of such sea level rise is likely to be greatest in
those low lying countries, like Bangladesh, least able to adapt
to the sea level rise by building expensive sea defences.
Figures reproduced with the kind permission
of the Intergovernmental Panel on
Climate Change (IPCC).