Marina owner Mitzi Richards carries her granddaughter in September as they walk on their boat dock at the dried up lake bed of Huntington Lake in California, which was at only 30 percent capacity as a severe drought continued. The state was in the grip of its third year of severe drought, the worst in decades. Mark Ralston/AFP/Getty Images hide caption

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Country representatives listen to opening remarks at the start of the United Nations' Conference of the Parties on Climate Change in Lima, Peru. Cris Bouroncle/AFP/Getty Images 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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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

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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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Oil, carried here by the Trans-Alaska Pipeline, is fundamental to the state's economy. But Alaskans also face the effects of climate change in their daily lives. Al Grillo/AP hide caption

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Manuel Pulgar-Vidal, Peru's Minister of Environment, U.N. Secretary-General Ban Ki-moon, Intergovernmental Panel on Climate Change (IPCC) Chairman Rajendra Pachauri and Renate Christ, Secretary of the IPCC present the Synthesis Report during a news conference in Copenhagen on Sunday. Scanpix Denmark/Reuters/Landov hide caption

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A Haitian woman holds cherries from a coffee tree. Haiti's coffee trade was once a flourishing industry, but it has been crippled by decades of deforestation, political chaos and now, climate change. Patrick Farrell /MCT /Landov hide caption

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Cindy Minnix waits for a bus in a flooded street on Oct. 18, 2012, in Miami Beach. A changing climate is making floods related to high tides more frequent, scientists say. Joe Raedle/Getty Images hide caption

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Artists' renderings of New Meadowland show how the wetland would be designed for human recreational use as well as flood control. The berm shown would be a path through the park when water was low (left). When storms came in, the wetlands would flood, and the berm would protect local development. Courtesy of New Meadowlands hide caption

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President Obama speaks at the U.N. Climate Summit on Tuesday. Discussing America's past, Obama told the group, "We recognize our role in creating this problem." Andrew Burton/Getty Images hide caption

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Demonstrators gather near Columbus Circle before the start of the People's Climate March in New York Sunday. Organizers are hoping 100,000 people worldwide might participate in the rally. Craig Ruttle/AP hide caption

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