WASHINGTON Global wheat markets reeling from Russian droughts, thousands of cattle killed by heat in Kansas, and countless crop acres wiped out by floods in Pakistan are glimpses of what can be expected as the world struggles to battle climate change.
But as concerns mount over extreme weather hitting global food systems this year, governments are no closer to forging a pact to fight climate change.
When temperatures rise as a result of smokestack and tailpipe emissions, droughts, heat waves, and floods become more frequent and more intense. The temperatures create "more and more hot extremes and worse unprecedented extremes and that's what we're seeing," said Neville Nicholls, a climate scientist at Monash University in Melbourne, Australia.
As the number of extreme weather events mount, they will likely create havoc in agricultural markets and could lead to food riots in poor countries like those in 2007 and 2008 when prices hit records on rabid market speculation.
Yet global talks to battle emissions are grinding to a near halt after the U.S. Senate failed to pass a climate bill and the administration of President Barack Obama also failed to push for one.
As the United States, the top major emitter per capita, fails to forge a plan, the divide grows between rich and poor countries on sharing the burden of acting on climate change.
U.N. Secretary-General Ban Ki-moon said this week "we may not be able to have that comprehensive binding agreement in Cancun," referring to global talks set for November in Mexico.
Climate change skepticism rose after last year's U.N. talks in Copenhagen fell short. It was also stoked by a dispute over e-mails at a British University climate center in which leading scientists were accused, and later cleared, of exaggerating the effects of global warming, and doubts about a U.N. climate science panel report after it had included an exaggerated prediction of Himalayan glacier melts.
Meanwhile world temperatures continue to rise unchecked. The U.S. National Climatic Data Center said last month the first half of this year was the hottest on record globally.
Until the risks are understood by U.S. farmers, who have mostly lobbied hard against climate legislation because of fuel price concerns, an important base of voters will push American senators to oppose legislation for years to come.
Wheat prices have risen by nearly 70 percent since June after Russia was hit with its worst drought in 130 years. It pushed Russia's Prime Minister Vladimir Putin to ban exports of the grain, setting off alarm bells in Egypt, the world's biggest wheat importer, and other hungry nations.
Agriculture is projected to be just one victim of extreme weather events related to climate change. But the fact that the world's billions depend on reliable, affordable access to agricultural products increases the chances that extreme weather could rapidly become a source of strife.
Already the Russian wheat crisis risks stirring unrest in the Middle East, North Africa and Europe.
"Over the whole globe all of these changes in climate ... are going to cause some real ripples in our capabilities of producing food," Jerry Hatfield, a laboratory director at the U.S. Department of Agriculture's Agriculture Research Service. He said the heat and humidity in the Midwest, where more than 2,000 cattle died in Kansas this month, may hurt yields in corn and other crops.
Nick Robins, an analyst at London-based HSBC, said in a note this week that climate change could reduce grain production in the G20 countries by up to 8.7 percent by 2020 if no significant action is taken to adapt to extreme weather and high temperatures.
When combined with population growth, per capita grain production in the G20 could fall between 11.9 and 16.1 percent by 2020, he wrote.
ALL BETS ARE OFF
In India and other countries that rely more on rice there's concern high temperatures will lead to yield losses. "That could start showing up in the next decade or so, because we're getting these heating peaks already," said Peter Timmer, nonresident fellow at the Center for Global Development, a nonprofit research group based in Washington.
In the near term, droughts and heat waves induced by climate change require farmers to improve management practices.
"In the longer term, all bets are off which crops can and can't grow," said Jay Gulledge, the senior scientist at the Pew Center for Global Climate Change in Washington.
The effects of extreme weather on crops are only beginning to be understood. Many scientists had projected that climate change's rising global temperatures would help countries in the North produce more food.
For decades scientists studied the effect of global warming on crops by simply raising temperatures and carbon dioxide levels in greenhouses. They did not take into account the effects of floods and droughts, or reduced yields that result from higher temperatures.
"There's been a severe failing of the scientific community. on that," said Gulledge. "Climate science proceeded amazingly over that period, but this topic was handled poorly."