Even as disaster managers fight hard to tackle the massive human tragedy at flood-ravaged Uttarakhand, researchers are predicting that Indian monsoon could become even more unpredictable.
Daily variability of the monsoon might increase, according to computer simulations run by Potsdam Institute for Climate Impact Research in Germany.
Indian monsoon is a complex system which is likely to change under future global warming, scientists at the institute said.
FLOOD RISK
While it is in the very nature of weather to vary, the question is how much and whether we can deal with it. Extreme rainfall, for example, bears the risk of flooding, and crop failure.
About 80 percent of annual rainfall in India occurs during the monsoon season from June through September.
Focusing on the average is not always useful. If rainfall comes in a spell and is followed by a drought, this can be devastating even if the average is normal.
RAINFALL TRENDS
This requires the right kind of adaptation measures that account for this variability – such as intelligent insurance schemes, authors of a study at Potsdam said.
Factors that could influence rainfall trends include the higher holding capacity of moisture of warm air. But cooling in the higher atmosphere, which changes current pressure, also could change the pattern.
“Increased variability translates into potentially severe impacts on people who cannot afford additional loss,” says Anders Levermann, co-chair of research domain on sustainable solutions at Potsdam.
GLOBAL WARMING
Even if seasonal mean precipitation would remain unchanged, impacts could be substantial, he added.
“Limiting global warming is key, adaptation cannot replace but rather complement it.”
The strongest change of 13 to 50 per cent is found in a scenario in which greenhouse gases continue to be emitted unabated.
Even if global warming would be limited to the internationally acknowledged threshold of two degrees Celsius, this would bear the risk of additional day-to-day variability between 8 and 24 percent above pre-industrial level, the study said.