The Potsdam Institute for Climate Impact Research in Germany is the most rabid disseminator of global warming alarm especially about sea-level rise. Stefan Rahmstorf is the Grand Mufti of this religion and most of its”science” is little more than conjecture based on speculation. They have also been forecasting increased variability and catastrophic effects on the Indian monsoon by computer simulations from 20 different climate models (none of which has succeeded in predicting the current temperature hiatus).
A new study now shows that previous Potsdam Institute monsoon forecasts were badly flawed and omitted “a dominant term in the equations of motion” no less. The equations of motion are about as basic as one can get. The new study goes on to show “that both a corrected theory and an ensemble of global climate model simulations exhibit no abrupt shift in monsoon strength in response to large changes in various forcings”. The authors don’t expect any drastic failure of the monsoon for the “next century or two”.
William R. Boos, and Trude Storelvmo, Near-linear response of mean monsoon strength to a broad range of radiative forcings, PNAS January 25, 2016, doi:10.1073/pnas.1517143113
Previous studies have argued that monsoons, which are continental-scale atmospheric circulations that deliver water to billions of people, will abruptly shut down when aerosol emissions, land use change, or greenhouse gas concentrations reach a critical threshold. Here it is shown that the theory used to predict such “tipping points” omits a dominant term in the equations of motion, and that both a corrected theory and an ensemble of global climate model simulations exhibit no abrupt shift in monsoon strength in response to large changes in various forcings. Therefore, although monsoons are expected to change in response to anthropogenic forcings, there is no reason to expect an abrupt shift into a dry regime in the next century or two.
The Calcutta Telegraph reports:
India’s monsoon is in no danger of catastrophic collapse in response to global warming and air pollution, two atmospheric scientists said today, refuting earlier predictions that the monsoon could shut down within 100 years.
The scientists at Yale University in the US who used computers to model the Earth’s atmosphere, land and oceans have found that the expected changes in the monsoon will not abruptly alter their strength or their water volume.
Their results contradict earlier forecasts by scientists at the Potsdam Institute for Climate Impact Research in Germany portending frequent and severe failures and even a breakdown of the monsoon, which is critical to India’s food, water resources and economy.
“Our models show that monsoon rainfall will change smoothly in response to rising greenhouse gas concentrations, air pollution, and changes in land use,” William Boos, an associate professor at Yale University told The Telegraph. “We should expect changes in the monsoon rainfall in response to changes in the global mean temperature in the coming decades, but there is no reason to expect those changes to be abrupt,” Boos said.
The earlier modelling exercises had predicted that the monsoon, under the influence of global warming and air pollution, would experience a “tipping point” that would lead to a sharp drop in rainfall over India.
Boos and his colleague Trude Storelvmo have now shown that the theory and models that were used to predict such “tipping points” had omitted a key term in climate behaviour, ignoring the fact that air cools as it rises in the atmosphere. ……
….. A decade ago, a study by Potsdam Institute researchers suggested that increasing air pollution and forest loss could lead to a sharp reduction in rainfall within a span of decades. And three years ago, another study from the Potsdam Institute predicted a 40 to 70 per cent reduction in rainfall.
The Potsdam Institute is just one of the many so-called institutes which ensure funding by generating alarmist theories which cannot be tested.