Global warming is taking a heavy toll on cereal crops. A new study on the impact of global warming on global food production by researchers of a US university says that in 20 years since 1981, there had been an annual loss of about $5 billion for the major cereal crops in the world.
The report has caused ripples among researchers and scientists across the globe. The Indian Council for Agricultural Research is already acting on this by undertaking long-term climate change impact studies.
The Chennai-based MS Swaminathan Research Foundation (MSSRF) is implementing a project on vulnerability assessment and enhancing adaptive capacity to climate change (V&A Programme) in semi-arid India.
According to the first study on the impact of climate change on global food production from 1981 to 2002, fields of wheat, corn and barley throughout the world have produced a combined 40 million tonne less a year because of the increase in temperatures caused by human activities.
Annual global temperatures increased by about 0.7 degrees Fahrenheit between 1980 and 2002, with even larger changes observed in several regions.
David Lobell, from Lawrence Livermore National Laboratory, California, the lead author of the study on climate change impact, said, "There is clearly a negative response of global yields to increased temperatures".
"Though the impacts are relatively small compared
to the technological yield gains over the same period, the results demonstrate that the negative impacts of climate trends on crop yields at the global scale are already occurring."
Lawrence Livermore National Laboratory is managed by the University of California for the US department of energy's national nuclear security administration.
"Most people tend to think of climate change as something that will impact the future, but this study shows that warming over the past two decades has already had real effects on the global food supply," said Christopher Field, co-author of the study and director of Carnegie Institution's department of global ecology.
The importance of this study, the authors say, was that it demonstrated a clear and simple relationship at the global scale, with yields dropping by approximately 3 per cent to 5 per cent for a one-degree Fahrenheit increase.
"A key to moving forward is how well cropping systems can adapt to a warmer world," Lobell said.
The stagnation in Indian cereal production is not entirely attributed to climate change. However, deputy chairman of Planning Commission Montek Singh Ahluwalia said in Chennai recently that a one degree rise in temperature in northern India would reduce wheat production by 10 per cent.
He said that climate change would be a major challenge Indian agriculture has to face in the coming decades.