Tens of thousands of protesters gathered in Washington yesterday to urge President Barack Obama to take concrete measures to fight global warming.

Waving banners and signs with slogans like “What will be your climate legacy?,” the protesters called on Obama to reject the Keystone XL pipeline that would bring oil from Canada to Texas, and order the Environmental Protection Agency (EPA) to set carbon standards for power plants.

“It’s time for the country to wake up, the US has been dragging its feet too long,” said Mimi Body, one of the protesters.

The event was organised by local and national environmental groups, including the Sierra Club, under an umbrella group named Forward on Climate. The Sierra Club said that 30,000 demonstrators were at the event.

“It’s a big deal because the world is watching us,” said Canadian-born actress Evangeline Lilly, star of TV’s “Lost.”

“We want to challenge president Obama to be a main actor as opposed to being a puppet of the big oil companies,” Lilly said. “It’s about telling him his speech did not fall in deaf ears.”

Organisers claim the event will be the largest climate rally in US history, and includes protesters who have arrived aboard buses from 28 states.

The crowd rallied at the National Mall, and was then set to march to the White House.

The president mentioned climate change during his inauguration speech in January, and in Tuesday’s State of the Union he vowed to take action “for the sake of our children and our future” if Congress fails to do so.

“I will direct my cabinet to come up with executive actions we can take, now and in the future, to reduce pollution, prepare our communities for the consequences of climate change, and speed the transition to more sustainable sources of energy,” Obama said in his speech.