An Indian origin scientist at the US Department of Energy's Oak National Laboratory has developed a new methodology to determine to what extent there is a connection between human activity and climate change.
The model allows climatologists to relate extremes of a space and time variable like a 100-year rainfall at two locations or two time periods as well as extremes of two or more variables such as 100-year precipitation extremes and heat waves.
Traditional climate models, on the other hand, are not especially useful for predicting extremes, particularly, rainfall extremes.
According to Dr. Auroop R Ganguly, who developed the model along with his colleagues, their statistical approach, outlined in the journal Advances in Water Resources, is a big step in the direction of modelling rainfall extremes from observations and climate model simulations.
"If for example, 100-year events at two locations occur simultaneously, and if our measure says they are completely independent, then their simultaneous occurrence becomes a 100 times 100 -- or 10,000-year event -- and therefore can be used to predict change more confidently," said Dr. Ganguly, a B. Tech in Civil and Environmental Engineering from IIT Kharagpur.
"If, however, our method says the events at the two locations are completely dependent, then the simultaneous occurrence remains a 100-year event overall," he said.
"Once we understand the nature of these connections our hope is that we will be able to determine if there is a relation between two extreme weather events - like heat waves and droughts.
"We may then be able to determine whether there will be more intense storms, hurricanes or floods, and this information could perhaps be used as an early warning tool or to help develop policies," he said.
He believes the methodology will have widespread use.
"In addition to water resources, hydrologic sciences, climate and ecology, the applications can include geospatial intelligence and security," he said.