Environment

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Massachusetts Emergency Management Agency Director Kurt Schwartz speaks with the media following a news conference in preparation for the Boston Marathon, Wednesday, April 16, 2014, in Boston. (AP Photo/Charles Krupa)

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Boston Police Commissioner William Evans speaks during a news conference in preparation for the Boston Marathon as Massachusetts Emergency Management Agency Director Kurt Schwartz, right, listens, Wednesday, April 16, 2014, in Boston. (AP Photo/Charles Krupa)

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FILE - In this July 16, 2012 file photo a dry field of corn is seen near Fremont, Neb. Despite varying degrees of drought conditions in the Plains region, predictions of a cool, wet spring in 2014 bring hope of drought relief. Brian Fuchs, a climatologist with the National Drought Mitigation Center in Lincoln, Neb., also expects extra precipitation through April in the central and northern plains. But while the season is looking at some relief, representatives from the agriculture industry and municipal water supply are still wary. Nathan Fields with National Corn Growers association said that after the 2012 drought he learned how quickly it can set in and affect crop production. (AP Photo/Nati Harnik, File)

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FILE - This Nov. 20, 2012 file photo shows a dried pond, the outcome of drought, in Waterloo, Neb. There are varying degrees of drought conditions in the Plains region, but a National Weather Service hydrologist says predicted above-normal rain for spring 2014 might ease some of the problem. Some people in the agriculture industry and with municipal water supplies are still wary. Nathan Fields with the National Corn Growers Association says that during the 2012 drought, he learned how quickly it can set in and affect crop production. (AP Photo/Nati Harnik, File)

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FILE- In this April 3, 2014 file photo, palm trees surround the Hyatt Place hotel near the Pensacola International Airport in Pensacola, Fla. Dead palm fronds litter yards and streets throughout the region where the non-native, tropical trees were hit hard by this winter's abnormally cold weather. (AP Photo/Pensacola News Journal, Tony Giberson, File)

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In this April 11, 2014, a person walks by dying palms in Pensacola, Fla. Dead palm fronds litter yards and streets throughout this region where the non-native, tropical trees were hit hard by this winter's abnormally cold weather. (AP Photo/Melissa Nelson-Gabriel)

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Carolina Hurricanes coach Kirk Muller, center, talks to his team during a timeout in the third period of an NHL hockey game against the Detroit Red Wings in Detroit, Friday, April 11, 2014. The Hurricanes won 2-1. (AP Photo/Carlos Osorio)

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North Dakota Gov. Jack Dalrymple addresses representatives from about two dozen states at the Energy-Producing States Summit in Bismarck, N.D, Wednesday, April 16, 2014. The two-day summit began Wednesday and was hosted by the state Health Department and Bismarck-based Basin Electric Power Cooperative. (AP Photo/The Bismarck Tribune, Tom Stromme)