The annual climate summit opened in Cancun, Mexico this week. A few days earlier, while releasing a new report, Indian Minister of Environment and Forests Jairam Ramesh emphasized: “It is imperative” that India has “sound, evidence-based assessments on the impacts of climate change.”
Not surprisingly, the report, “Climate Change and India: A sectoral and regional analysis for the 2030s,” claims India will soon be able to forecast the timing and intensity of future monsoons that are so critical to its agricultural base.
Could 250 of India’s top scientists be wrong when they say their computers will soon be able to predict summer monsoon rainfall during the 2030s, based on projected carbon dioxide trends? Do “scenarios” generated by climate models really constitute “sound, evidence-based assessments”? Are attempts to predict monsoons and other climate events any more valid for ten or twenty years in the future, than for a century away?
We do not believe it is yet possible to forecast future monsoons, despite more than two centuries of scientific research, or the claims and efforts of these excellent scientists. The Indian summer monsoonal rainfall remains notoriously unpredictable, because it is determined by the interaction of numerous changing and competing factors, including: ocean currents and temperatures, sea surface temperature and wind conditions in the vast Indian and Western Pacific Ocean, phases of the El Nino Southern Oscillation in the equatorial Pacific, the Eurasian and Himalayan winter snow covers, solar energy output, and even wind direction and speed in the equatorial stratosphere some 30-50 kilometers (19-31 miles) aloft.
Relying on computer climate models has one well-known side effect: Garbage in, gospel out. Current gospel certainly says CO2 rules the climate, but any role played by carbon dioxide in monsoon activity is almost certainly dwarfed by these other, major influences. Computer climate models have simply failed to confirm current climate observations, or project future climatic changes and impacts.
Both Indian and global monsoons have declined in strength and intensity over the last 50 years – and this measurement-based reality largely contradicts climate model “forecasts” and “scenarios” that say monsoonal rainfalls will increase. It is equally well known that climate models have been unable to replicate the decadal to multi-decadal variations of monsoonal rainfalls.