By IANS,
Washington : Even if greenhouse gas emissions are fixed at 2005 levels, irreversible warming will lead to biodiversity loss and substantial glacial melting, warns a new analysis by an Indian-American scientist.
“This paper demonstrates the major challenges society will have to face in dealing with a problem that now seems unavoidable,” said V. Ramanathan, the paper’s co-author and professor at Scripps Institution of Oceanography, San Diego.
“We hope that governments will not be forced to consider trade-offs between air pollution abatement and mitigation of greenhouse gas emissions.” he said.
Ramanathan and co-author Yan Feng, assumed a highly optimistic scenario that greenhouse gas concentrations would remain constant at 2005 levels for the next century.
The earth will warm about 2.4° C above pre-industrial levels even under extremely conservative greenhouse-gas emission scenarios, according to their analysis.
The researchers argued that coping with these circumstances will require “transformational research for guiding the path of future energy consumption,” reports Eurekalert.
For the concentrations to remain at such levels, emissions of carbon dioxide must decrease drastically within the next decade, but which is likely to be undone by economic expansion.
The researchers then analysed expected future warming by assuming that the cooling effect of man-made aerosol pollution will be eliminated during the 21st Century.
Currently, particulate air pollution caused by fossil fuel combustion, forest fires and smoke from cooking and agricultural waste burning serves to mask global warming caused by greenhouse gases. The smog does so chiefly by creating a dimming effect at Earth’s surface.
But mitigation of this type of pollution has been increasingly successful by countries around the world. Because soot and similar particles remain airborne only for a matter of weeks, it is expected that clean-up efforts produce relatively immediate results.
Therefore, the authors based their projections of temperature increase assuming the absence of these pollutants in the atmosphere. Conversely, greenhouse gases can remain in the atmosphere for decades or, in the case of carbon dioxide, more than a century.
These findings appear in the online edition of the Proceedings of the National Academy of Sciences.