NEW YORK: Painting a grim picture, a new study shows that even if greenhouse gas emissions are fixed at 2005 levels, irreversible warming will lead to biodiversity loss and substantial glacial melt.

The Earth will warm about 2.4 degrees Celsius above pre-industrial levels even under extremely conservative greenhouse-gas emission scenarios and under the assumption that efforts to clean up particulate pollution continue to be successful, an new analysis by a pair of researchers at Scripps Institution of Oceanography show.

That amount of warming falls within what the world's leading climate change authority recently set as the threshold range of temperature increase that would lead to widespread loss of biodiversity, de-glaciation and other adverse consequences in nature.

Given that a potentially large warming is already in the rear-view mirror, researchers say scientists and engineers must mount a massive effort and develop solutions for adapting to climate change and for mitigating it.

The researchers, writing in the online edition of the Proceedings of the National Academy of Sciences, argue that coping with these circumstances will require transformational research for guiding the path of future energy consumption.

This paper demonstrates the major challenges society will have to face in dealing with a problem that now seems unavoidable, said lead author, Scripps Atmospheric and Climate Sciences, Professor V Ramanathan.

"We hope that governments will not be forced to consider trade-offs between air pollution abatement and mitigation of greenhouse gas emissions," he added.