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 was 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 Environmental Protection Agency to set carbon standards for power plants.
Some protesters formed a "human pipeline" - chain of people - stretching between the National Mall and the White House.
Last week during his State of the Union address, Mr. Obama vowed to take action on climate change, warning that if Congress failed to act soon, then he would do so.
Proponents of the pipeline say it would create many badly needed jobs and increase energy production in the U.S.