Warming may trigger agricultural collapse

IPS: India could lose up to 40 percent of its agricultural output because of global warming even as it becomes the world's most populous country, warns a new study. Global farm productivity faces "serious damage" this century, and poor countries will bear the worst of it, unless emissions of greenhouse gases blamed for climate change are held in check, says veteran climate economist William Cline.

He further contradicts analysts who have said that global warming could boost yields. "My work shows that while productivity may increase in a minority of mostly northern countries, the global impact of climate change on agriculture will be negative by the second half of this century," said Cline, who has studied the economic aspects of climate change since the early 1990s.

"There might be some initial overall benefit to warming for a decade or two but, because future warming depends on greenhouse gas emissions today, if we delay action it would put global agriculture on an inexorable trajectory to serious damage," he added.

Cline sees global agricultural productivity falling by 3-16 percent by the 2080s, with worse damage in the following century because of even greater warming.

…Could his expectations turn out to be unduly dismal? Some researchers have said that advances in farm science -- from seeds bio-engineered to resist drought to better management systems -- will boost harvests sufficiently to offset any losses from global warming.

Cline counters that the so-called green revolution is losing steam, with annual growth in global yields slowing from 2.8 percent a year in the 1960s and 1970s to 1.6 percent since around 1980. "With additional investments in technology and adaptation, the effect of climate change on actual agricultural production could be reduced but, because these inputs raise the cost of production, prices would also rise," he said…