woensdag 2 april 2014

Climate Change 35


Climate panel issues grim predictions for food's future in a warming world

REUTERS/Adrees Latif
Ask yourself: Of all the human endeavors essential to our survival on this warming planet, which is more critical to get right than food production?
As I looked over coverage of Monday's report from the Intergovernmental Panel on Climate Change, its findings about probable impacts on food and food security seemed especially compelling, for at least three reasons:
  • The predictions of serious problems in world food production seemed more detailed and more confident than those of the IPCC's 2007 report, and considerably more dire.
  • The supposedly offsetting advantages of climate change — better growing seasons in some places, more carbon dioxide everywhere — seemed to have shrunk in significance among the panel's conservative, consensus conclusions.
  • As policy conversations necessarily shift toward adaptation strategies — given our global unwillingness to invest sufficiently in prevention — the vulnerability of agricultural sectors seems a primary concern, at least to me.
Ask yourself: Of all the human endeavors essential to our survival on this warming planet, which is more critical to get right than food production? What other holds comparable potential for sudden and sweeping upheaval as the famines, food riots and other misery that could follow if we get it wrong?

Here’s a selection of what I found, with links for further reading:


So I read widely yesterday in search of the most insightful, analytical and thought-provoking coverage I could find of the IPCC's current thinking on food and food security, as rendered by journalists and publications in the U.S. and abroad who pay special attention to the topic.
At Britain's The Independent, science editor Steve Connor read the report to say that “the much-touted benefits of climate change — such as the ability to grow some crops such as vineyards at higher northerly latitudes — dwindle into insignificance compared to the enormous challenges produced by the much bigger downsides of a warmer and more stressed world.”
He quotes Christopher Field, the Carnegie Institution ecologist who co-chaired the report's author group, as cautioning that the observed impacts of climate change are already widespread and “we’re not talking about hypothetical events.”
“It is true that we can't find many benefits of climate change and I believe it's because there aren't many benefits, even though we tried really hard to find them. There are a few places where there are a few benefits of warming but there are many other places where there are widespread negative impacts.”
Sam Brasch, writing for the U.S. magazine Modern Farmer, was among the few writers who found at least the tone of this year's report to be less bleak than the last.
All together, the panel dropped many of the super-specific predictions that earned rebukes in the past like the claim that yields in some parts of Africa could drop as much as 50 percent by 2020. Instead, they struck a tone of well-founded risk assessment.
This is a report for a savvy poker player — or maybe farm investor. It is not a piece of Biblical plague literature. Still, the challenge feeding a growing population in a warming world only appears more daunting compared to the last report in 2007.
On the subject of adaptation by farmers, Brasch notes the report's finding that incremental changes in farming practices may well work for a while, but will lose their efficacy as warming and its impacts intensify. And the opportunities to adapt will not be distributed evenly:
If you are a 21st century farmer, here’s where you want to be: Somewhere cool with some cush crop insurance and government that is willing and able to help out. Having a wheat-based system would be best. Avoid the tropics, where even aggressive adaptation efforts might not do much good in combating higher temperatures, extreme weather volatility, droughts or rising sea levels if you are farming in a low-lying area.
Emma Bryce, New York-based writer of the "World on a Plate" feature at Britain's The Guardian, found this year's report less optimistic than its 2007 predecessor, which was “by no means cheery.” The tropics seemed headed for trouble back then, “but in some temperate regions, warming would make conditions more favourable for crops in a way that would offset losses in other parts of the globe.”
And if this year's report is less optimistic than the last, other research is even less so. Writing of a recent analysis at the University of Leeds, she says:
“On average, we are looking at yield decreases. By the 2030s most of the changes in crop yields are negative,” says Andy Challinor, University of Leeds climate researcher, author on the paper, and on the new IPCC report, too. “The second half of the century is when the negative impact in yields becomes more common.”
The researchers found this by comparing results from almost 100 independent studies—more than double the number used in the IPCC's [new] assessment—that measured the impact of higher temperatures on three of the globe's primary staple crops: maize, wheat, and rice.
 It's currently the largest dataset we have that demonstrates how crops will respond to changing climates, and it suggests that decreases in yields will grow larger, affect both temperate regions and the tropics, and become increasingly erratic as the weather turns more unpredictable too.
Once mid-century hits, crop losses of up to 25% will become more commonplace, as well—a number that does account for basic mitigation efforts in farming regimes.
Bryce's Guardian colleague, Suzanne Goldenberg, felt that this year's report departed from predecessors in “drawing a clear line connecting climate change to food scarcity and conflict,” including “for instance, the riots in Asia and Africa after food price shocks in 2008.”
The report said climate change had already cut into the global food supply. Global crop yields were beginning to decline – especially for wheat – raising doubts as to whether production could keep up with population growth.
“It has now become evident in some parts of the world that the green revolution has reached a plateau,” [IPCC chairman Rajendra] Pachauri said.
The future looks even more grim. Under some scenarios, climate change could lead to dramatic drops in global wheat production as well as reductions in maize.
“Climate change is acting as a brake. We need yields to grow to meet growing demand, but already climate change is slowing those yields,” said Michael Oppenheimer, a Princeton professor and an author of the report.
Other food sources are also under threat. Fish catches in some areas of the tropics are projected to fall by between 40% and 60%, according to the report.
Over at phys.org, editors spotlighted an analysis by the AP's Seth Borenstein which said, in part, that changing climate “doesn't mean in 50 years there will be less food grown.”
Thanks to the 'green revolution' of improved agricultural techniques, crop production is growing about 10 percent per decade and climate change is likely to reduce yields by 1 percent a decade, so crop production will still go up, but not as fast, said David Lobell of Stanford University, one of the authors of the report's chapter on food problems.
Still, it is as if an anchor is weighing down the improvements to agriculture, Pachauri and Field said. Some places have seen crop yield increases drop from 2 percent a year to 1 percent or even plateau. And places like India, where 800 million people rely on rainfall not irrigation, the green revolution never improved crops much, Pachauri said....
Food prices are likely to go up somewhere in a wide range of 3 percent to 84 percent by 2050 just because of climate change, the report said. "In a world where a billion people are already going hungry, this makes it harder for more people to feed their families," said Tim Gore of Oxfam International, who wasn't part of this study.
Pitta Clark, writing for the Financial Times of London, was among the writers who chose to look more closely at likely impacts of climate change on particular crops and the regions in which they are grown, and to find some mixed results:
The effects of climate change on two other crucial foods, rice and soybeans, have been smaller in the most important producing countries, the IPCC says, and there may be some positive effects on crops in cooler climates in future.
However, the outlook for wheat, rice and maize production in tropical and temperate regions is expected to be more negative than positive.
Only a few writers looked beyond changing climate's impact on food quantity to consider changes in quality as well. Modern Farmer's Brash noted that studies connected to the new report “have shown that cereal crops grown in elevated CO2 end up having less protein. That’s because both biotic and abiotic stresses on the plants could make it harder for them to process air, water and minerals, making foods less nutritious for humans and their livestock.”
And the Independent's Connor, who I'm guessing may not be totally vegan, noted that “meat and cheese may have to be off the menu if there is to be any hope of hitting climate change targets,”  because “cutting greenhouse gas emissions from energy use and transport will not be enough on its own to hold down the global temperature rise.
The research indicates it will also be necessary to slash emissions from agriculture - meaning curbing meat and dairy consumption. Without such action, nitrous oxide emissions from fields and methane from livestock may double by 2070. . . Dr Fredrik Hedenus of Chalmers University of Technology in Sweden, said:
“We have shown that reducing meat and dairy consumption is key to bringing agricultural climate pollution down to safe levels." 
* * *
The IPCC's “summary for policymakers” can be read here, and online video of the press conference held to announce its release can be viewed here.

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Peter Flik en Chuck Berry-Promised Land

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