We are to blame for global shifts in rain

GREENHOUSE GAS emissions from human activity are causing global shifts in rainfall patterns and contributing to wetter weather over the UK, climate scientists said on Tuesday .
Their study is the first to find a "human fingerprint" in the rainfall changes which have been detected in a belt of the northern hemisphere stretching from the Mediterranean to the UK to Norway .

It also found a link between global warming and drier conditions in the northern tropics and subtropics.

"The paper is saying there is a significant human influence on global rainfall patterns," said Dr Peter Stott at the Met Office's Hadley Centre, who was part of a team led by researchers at the Climate Research Division of the Canadian government's environment department.

The results, based on a global comparison of weather records going back to 1925, suggest that levels of rainfall across the UK have increased steadily by an average of 6.2 millimeters every decade. At least half the extra rainfall and possibly up to 85 per cent is caused by the impact of greenhouse gas emissions, the scientists concluded. The research, carried out by the Hadley Centre of the UK Met Office in conjunction with several national climate research institutes, does not prove that any single episode of extreme wet weather can be directly linked to climate change, but it supports the idea of a long-term rise in rainfall linked to emissions.

The study compared records from weather stations around the world going back to 1925 with predictions from 10 computer models of global climate. Some models included the effects of human-induced climate change while others took into account only natural changes or more exotic factors such as volcanoes and the Sun's activity Only mod . els factoring in human-induced climate change could adequately explain the observed changes in rainfall, the scientists found.

Apart from the increase in rain in northern high latitudes - the belt between 40 and 70 degrees north which includes the UK - the analysis found that climate change brought wetter conditions in the southern tropics and subtropics. Chris Huntingford a climate modeller at the Centre for Ecology and Hydrology in Wallingford, said: "It has now been confirmed that the burning of fossil fuels has altered rainfall patterns at the global scale. Next we need to understand how these observed large-scale adjustments translate to local changes in extreme rainfall events."

* Source: Times of India, dated - Wednesday, July 25, 2007*