Thousands of protesters have gathered in Washington to urge U.S. President Barack Obama to take strong measures to combat climate change and global warming.
Demonstrators traveled from across the country for Sunday's "Forward on Climate" rally, which is being billed as the largest climate change rally in the U.S.
Protesters are calling for the president to reject the nearly 3,000 kilometer Keystone XL Pipeline that would carry oil from Canada to the Gulf of Mexico. They also want him to order the (U.S.) Environmental Protection Agency to set carbon standards for power plants.
Protesters plan to form a "human pipeline" (chain of people) stretching between the National Mall and the White House.
Last week, Mr. Obama vowed to take action on climate change during his State of the Union address, warning that if Congress failed to act soon, then he would do so.