Three environmental groups have filed a lawsuit against the U.S. government for missing the deadline to list the polar bear as a threatened animal under the Endangered Species Act. The Natural Resources Defence Council, Greenpeace and the Center for Biological Diversity presented their complaint to a court in San Francisco, saying they hoped the move could prompt an early listing of the animal in the Endangered Species Act by the government. According to the three groups, the U.S. government was originally supposed to issue a final decision on the polar bear case on January 9, but it requested a delay and this past Sunday was the deadline for a decision. It is the first time that the U.S. government has ever considered listing a species as threatened due to global warming. The U.S. Geological Survey magazine said in a report that if the trend of global warming continues, the number of polar bears could drop to one-third of the current level by 2050, without any left in Alaska by then