said. The cause is reduced impact of Galactic Cosmic Rays (GCRs) on formulation of low clouds over earth in the last 150 years, says a paper by U R Rao, former chairman of Indian Space Research Organisation, released by Environment minister Jairam Ramesh.
The GCRs are the ones that enter solar system from outside, mostly from exploding of stars, and help in forming low-level clouds over the earth. The theory is that the solar magnetic field deflects GCRs, thereby impacting low-level cloud formation.
Analyzing the data between 1960 and 2005, Rao found that lesser GCRs were reaching the earth due to increase in solar magnetic field and thereby leading to increase in global warming.
"Consequently the contribution of increased CO2 emission to be observed global warming of 0.75 degree Celsius would only be 0.42 degree Celsius, considerably less than what predicted by IPCC," the paper said to be published in Indian Journal Current Science had said. This is about 44 % less than what IPCC had said.
Ramesh in 2009 had released a similar scientific paper saying that the IPCC's claim that most Himalayan glaciers will melt by 2035 was wrong. A few months later, after a review the IPCC regretted the error. If Ramesh latest bid gets globally recognition, it can alter the rules of UN run climate negotiations of 200 nations.
Impact of GCRs on global warming had been highly controversial since 1998, when Henrik Svensmark of Danish National Space Center said it was causing global warming. A decade later a joint European study debunked the claim, saying there was no coorelation.
V Ramanathan of US based Scripps Institute of Oceanography at University of California said the Rao's paper strengthens the case for greenhouse a primary driver for global warming. "The observed rapid warming trends during the last 40 years cannot be accounted for the trends in GCRs," he said, in his comments on Rao's paper.
"I just want to expand scientific debate on impact of non-Green House Gases on climate change," Ramesh said, when asked whether he was again challenging the IPCC. "Science is all about raising questions."
International climate science is mainly western driven and collaborates the view of the rich world that gases such as Carbon Dioxide (CO2) are the main contributor for global warming. Any scientific work challenging the view has been debunked as work of a sceptic.
"Climate science is much more complex than attributing everything to CO2," said Subodh Verma, climate change advisor in the Environment ministry.
And, its first impact has come from IPCC chairperson R K Pachauri, who has told the government, that impact of GCRs on global warming will be studied in depth in the fifth assessment report to be published in 2013-14. In its earlier four assessment reports, IPCC had not studied the impact of GCRs in detail.