Josh Haner/The New York Times. A leaked draft report from the Intergovernmental Panel on Climate Change warns that climate change could have wide-ranging negative effects on global agriculture.
by Justin Gillis, The New York Times, November 1, 2013
An international scientific panel has found that climate change will pose sharp risks to the world’s food supply in coming decades, potentially reducing output and sending prices higher in a period when global food demand is expected to soar.
That finding is by far the starkest warning that the United Nations-appointed group, the Intergovernmental Panel on Climate Change, has ever issued regarding the food supply. Its last report, in 2007, was more sanguine, essentially finding that climatic warming and the rising level of carbon dioxide in the air would boost agricultural production across large areas, though that report did cite some risks.
The warning is contained in a draft report that leaked on Friday. The document is not final and not scheduled for release until after an editing session in Yokohama, Japan, in March.
The draft report warns that sweeping impacts from climate change are already being seen across the planet, and that these are likely to intensify as human emissions of greenhouse gases continue to rise.
Echoing past findings, the draft report points out that land ice is melting worldwide, leading to a rise of the sea that is putting coastal communities at increased risk of flooding. It describes a natural world in turmoil as plants and animals attempt to migrate to escape rising temperatures, and warns that many could go extinct. Saving a significant fraction of the world’s biological diversity may require far more aggressive human management of natural systems, the report declares.
Efforts to adapt to climate change have already begun in many countries, the report found; President Obama on Friday signed an executive order to step up such efforts in the United States. But these efforts remain inadequate compared with the risks, the report says, and far more intensive — and expensive — adaptation plans are likely to be required in the future.
The report found that it is not too late for cuts in emissions to have a strong impact on the future risks of climate change, though the costs would be incurred in the next few decades and the main benefits would likely be seen in the late 21st century and beyond.
The Intergovernmental Panel on Climate Change is the principal scientific body charged with reviewing and assessing climate science, then issuing reports about the risks to the world’s governments. Its main reports come out every five to six years. The group won the Nobel Peace Prize, along with Al Gore, in 2007, for its efforts to alert the world to the risks.
Hundreds of billions of dollars are being spent every year to reduce emissions, in direct response to past findings from the group, though many analysts have said these efforts are so far inadequate to head off drastic climatic changes later in the century.
On the food supply, the new report finds that benefits from global warming may be seen in some areas, such as northern lands that are now marginal for food production. But it added that over all, climate change could reduce agricultural output by as much as 2% per decade for the rest of this century, compared with what output would be without climate change.
During that period, demand is expected to rise as much as 14 percent each decade, the report found, as billions of people in developing countries acquire the money to eat richer diets. Rising food prices would likely hit the world’s poor hardest, as has already occurred from sharp price increases of recent years — spikes caused to a large extent by certain types of weather extremes, like severe heat waves, that have been linked to climate change.
The agricultural risks “are greatest for tropical countries, given projected impacts that exceed adaptive capacity and higher poverty rates compared with temperate regions,” the draft report finds.
If the report proves to be correct, global food demand might have to be met – if it can be met – by putting new land into production. That could entail chopping down large areas of forest, an action that would only accelerate climate change by sending substantial amounts of carbon dioxide into the air from the destruction of trees.
The leak of the new draft occurred on a blog hostile to the scientific panel.
“It’s a work in progress,” said Jonathan Lynn, a spokesman for the intergovernmental panel. “We don’t have anything to say about the contents. It’s likely to change.”
But in a brief interview, Mr. Lynn did not dispute the authenticity of the document. In the Internet era, the group’s efforts to keep its drafts secret are proving to be a failure, and some of the scientists involved have called for a drafting process open to the public.
A report about the physical science of climate change leaked in August, then underwent only modest changes before its final release in Stockholm in late September. The new report covers the impacts of climate change, efforts to adapt to it, and the vulnerability of human and natural systems.
A third report, analyzing potential ways to limit the rise of greenhouse gases, is due for release in Berlin in April.
http://www.nytimes.com/2013/11/02/science/earth/science-panel-warns-of-risks-to-food-supply-from-climate-change.html
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