Thousands Protest Keystone Pipeline in Washington March

Thousands of protesters marched to the White House yesterday in opposition to the Keystone XL pipeline, which environmental groups say would worsen the risks of climate change by encouraging development of Alberta’s oil sands.

The rally attracted 35,000 people, according to organizers, who called it the largest climate-change protest in U.S. history. They said it marked the rise of a national movement demanding action on global warming as President Barack Obama weighs whether to approve the $5.3 billion pipeline.