NEW DELHI: Human beings may be partially to blame for the increasing intensity of rain and snowstorms, says a new climate study published on Thursday.
This is the first time human-induced rise in greenhouse gases has been directly linked to intensity of extreme rain and snow. The study in Nature journal examined data from across the northern hemisphere, including India, and found that the intensity of extreme rainfall and snow had gone up in recent years.
The authors studied the most extreme episodes of rain and snow from 1951 to 1999 and found their magnitude on the rise towards the end of the century. They then compared the actual observations with predictions in various climate models.
It was found that natural variability alone could not account for the intensity of storms, but when the models factored in greenhouse gases, they showed intensity increases similar to those observed — indicating that global warming effects were kicking in.
''Our results provide the first formal identification of a human contribution to the observed intensification of extreme precipitation,'' the paper by scientists in Canada and Scotland said.
This rise held true at scales no smaller than a continent, said the study. That means it is not possible to link single events — like the severe floods in Pakistan last year or the cloudburst at Leh — to climate change, but the trend shows up over a large geographical area in course of time.
''Our results also show that the global climate models we used may have underestimated the observed trend, which implies that extreme precipitation events may strengthen more quickly in the future than projected and that they may have more severe impact than estimated,'' the study warned. The same issue of Nature carries another study by British researchers on flooding in England in the autumn of 2000. It says global warming had doubled the likelihood of the event occurring.
Source: Times of India, 19 -3-2011
This is the first time human-induced rise in greenhouse gases has been directly linked to intensity of extreme rain and snow. The study in Nature journal examined data from across the northern hemisphere, including India, and found that the intensity of extreme rainfall and snow had gone up in recent years.
The authors studied the most extreme episodes of rain and snow from 1951 to 1999 and found their magnitude on the rise towards the end of the century. They then compared the actual observations with predictions in various climate models.
It was found that natural variability alone could not account for the intensity of storms, but when the models factored in greenhouse gases, they showed intensity increases similar to those observed — indicating that global warming effects were kicking in.
''Our results provide the first formal identification of a human contribution to the observed intensification of extreme precipitation,'' the paper by scientists in Canada and Scotland said.
This rise held true at scales no smaller than a continent, said the study. That means it is not possible to link single events — like the severe floods in Pakistan last year or the cloudburst at Leh — to climate change, but the trend shows up over a large geographical area in course of time.
''Our results also show that the global climate models we used may have underestimated the observed trend, which implies that extreme precipitation events may strengthen more quickly in the future than projected and that they may have more severe impact than estimated,'' the study warned. The same issue of Nature carries another study by British researchers on flooding in England in the autumn of 2000. It says global warming had doubled the likelihood of the event occurring.
Source: Times of India, 19 -3-2011
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