The Global Heat Is on over Extreme Weather

Article excerpt

LONDON: Scientists are to end their 20-year reluctance to link climate change with extreme weather - the heavy storms, floods and droughts which often fill news bulletins - as part of a radical departure from a previous equivocal position that many now see as increasingly untenable.

Climate researchers from Britain, the US and other parts of the world have formed a new international alliance that aims to investigate exceptional weather events to see whether they can be attributable to global warming caused by greenhouse gas emissions.

They believe it is no longer plausible merely to claim that extreme weather is "consistent" with climate change. Instead, they intend to assess each unusual event in terms of the probability that it has been exacerbated or even caused by the global temperature increase over the past century.

The move is likely to be highly controversial because the science of "climate attribution" is still in the early stages of development and so is likely to be pounced on by climate "sceptics" who question any link between industrial emissions of carbon dioxide and rises in global average temperatures.

In the past, scientists have been extremely reluctant to link a single extreme weather event with climate change, arguing that the natural variability of the weather makes it virtually impossible to establish any definitive association other than a possible general consistency with what is expected from studies based on computer models.

However, a growing number of climate scientists are now prepared to adopt a far more aggressive posture, arguing that the climate has already changed enough for it to be affecting the probability of an extreme weather event, whether it is an intense hurricane, a major flood or a devastating drought. …