H Pathak, an investigator with the Indian Agricultural Research Institute's Climate Change Challenge Program, said global warming isn't limited to a rise in average temperatures.
"It's a little more complicated than that. There is for example also a rise in carbon dioxide and a change in rainfall patterns, which could affect India very severely because much of our agriculture is still rain-fed," Pathak told The Times of India.
India would be the hardest hit by climate change in terms of food production, said a study, ''The Food Gap -- The Impacts of Climate Change on Food Production: A 2020 Perspective'' released last month by the Universal Ecological Fund. The report predicts that crop yield in India would decrease by as much as 30 percent by the end of the decade.
While some regions of India are getting too much rain, other regions aren't getting enough, affecting crops ranging from coffee and tea to grapes and rice.
In the south, erratic rain patterns are causing the coffee crop to fruit twice and sometimes three times, resulting in inferior beans. The Coffee Board of India has instituted an insurance program to help coffee growers in Karnataka deal with the declining yields.
In the Kuttanad region of Kerala in the southwest, considered the state's Rice Bowl, heavy rains delayed the normal sowing season, which begins in October, until December, which triggered an onslaught of pests.
Changing weather patterns are also affecting the cultivation cycles of the western state of Maharashtra's 444,790 acres of grapes.
Mahendra Sahir, president of the Maharashtra State Grape Growers Association, says rainfall in November for the last three to four years has delayed pruning and thus harvesting, making it increasingly difficult to meet deadlines for supplies of grapes sent to the European Union.
D P Maheshwari, president of the Tea Association of India, said incessant rain, followed by a severe attack of pests, caused a massive crop loss in 2010.
Maheshwari estimated that some tea plantations throughout the country suffered losses up to 20 to 30 percent on the previous year's output.
Of particular concern is the change in the quality of Assam tea, known for its strong brew. The Assam region, in the northeastern part of the country, accounts for 52 percent of India's tea production. Last year the area saw a drop of 33 million pounds of Assam tea, compared to the previous year.