Pipes for TransCanada's planned Keystone XL pipeline are stored in Gascoyne, N.D. The U.S. House has voted to approve the proposed project, which would allow crude oil to flow from Canada to the Gulf of Mexico. The Senate plans to vote Tuesday on legislation that would greenlight the project. Andrew Cullen/Reuters/Landov hide caption

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Sherri Erkel and her daughter, Asa, cook dinner in their kitchen in Iowa City, Iowa. The Erkel family is part of an EPA study measuring the amount of food wasted in U.S. homes. Pat Aylward/NET News hide caption

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Lightning strikes near Ben Hill Griffin Stadium at Florida Field in Gainesville, Fla., in August. A new study says a rise in average global temperatures due to climate change will increase the frequency of lightning strikes. Phil Sandlin/AP hide caption

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A jogger goes for a run amid heavy smog in Shanghai on Wednesday. China has for the first time agreed to limit its carbon emissions, but critics are questioning whether the move goes far enough. AFP/Getty Images hide caption

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California sheep rancher Dan Macon had to sell almost half of his herd because the drought left him without enough feed. Kirk Siegler/NPR hide caption

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Sen. Mary Landrieu, D-La., chair of the Senate energy committee, spoke Wednesday about getting congressional approval for the Canada-to-Texas Keystone XL pipeline. With her is Sen. Joe Manchin, D-W.Va., a member of the committee. J. Scott Applewhite/AP hide caption

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Chinese President Xi Jinping and President Obama, seen here during a ceremony at the Great Hall of the People in Beijing, announced pledges to reduce greenhouse gases. HUANG JINGWEN/Xinhua /Landov hide caption

itoggle caption HUANG JINGWEN/Xinhua /Landov

U.S. President Barack Obama, right, smiles after a group of children waved flags and flowers to cheer him during a welcome ceremony Wednesday with Chinese President Xi Jinping at the Great Hall of the People in Beijing. In a surprise agreement late Tuesday, China agreed to a first-ever target for capping its carbon emissions, while the United States pledge to cut faster than previously planned. Andy Wong/AP hide caption

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Fishermen Ed Stewart (left) and Tannis Goodsen mend groundfishing nets on Merrill Wharf, in Portland, Maine, last November. Robert F. Bukaty/AP hide caption

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