Canada’s government is defending its environmental record as thousands attended a climate change rally in Washington, D.C., with hopes of pressuring U.S. President Barack Obama to reject the Keystone XL pipeline.

Environmentalists are staunchly opposed to the planned pipeline, which would carry Alberta oilsands bitumen to refineries along the Texas coast.

They call crude from Alberta's oilsands "dirty oil" and say it contributes to global warming.

Protesters in Washington carried a mock pipeline reading: 'Just say no to Keystone.' ('Richard Clement/Reuters)

Obama, and U.S. Secretary of State John Kerry – have said a decision is coming soon, but have been noncommittal in meetings with a Canadian government keen to go ahead with the project.

Amidst the protests, Canadian Foreign Affairs Minister John Baird, speaking to the Canadian Press by telephone from Lima, Peru, said the U.S. should be following Canada's lead when it comes to climate change issues.

"We're the only country in the world that's committed to getting out of the dirty coal electricity generation business," Baird said.

"These are real meaningful steps that will either meet or even exceed the work that's been done thus far in the United States."

Baird was aware that environmentalists were descending Sunday on Washington for a major protest, and that following a similar protest last year, Obama postponed the keystone decision until after the presidential election.

The Harper government has for years said it would remain in lockstep with the U.S. on climate change, but Baird said Canada has gone even further on coal.

Baird's defence of Canada's environmental record appears to be part of a renewed initiative by the Harper government to burnish Canada's climate credentials as Keystone's future once again hangs in the balance.

The coal lobby was one of the many interests to which Obama was beholden as he fought for re-election last year. Coal is a major industry in the key swing states in the U.S. Midwest, which Obama counted on to win back the White House.

But the coal lobby now fears that Obama will take a harder line on their industry, now that he is secure in a second term. It points to the omission of coal in his State of the Union address as he touted the possibilities of wind and solar energy alternatives.

Baird touts economic benefits of pipeline

Baird reiterated Sunday that the pipeline is good for job creation in the both countries, as well as for weaning the U.S. off of less secure sources of oil in the Arab world and Venezuela, which he visits this coming week.

"They (the U.S.) are our best trading partner, and if you want to create jobs, and you want to have energy security for North America, obviously the pipeline is a central part of that," said Baird.

Environment Minister Peter Kent also said last week that it won't take much work to boost Canada's credibility in the U.S. on climate change.

"We're doing a lot. Our American friends know that."

But the Harper government is clearly bristling at the messaging coming out of Washington since Obama's re-election, and following last week's State of the Union, on the need to combat climate change.

Protest organized by U.S. environmental groups

The Washington rally — supported by the Sierra Club and 350.org — began at noon local time on the Mall. Participants plan to walk in front of the Capitol buildings to within sight of the White House.

Organizers said 50,000 protesters were expected to turn out, but a police officer unofficially pegged the number of demonstrators at around 10,000.

Native author Louise Erdrich has said she will be among the demonstrators. Other prominent Native leaders there include Chief Jacqueline Thomas, Saik'uz First Nation, an outspoken opponent of the Northern Gateway pipeline from the oil sands through British Columbia, and environmental activist Crystal Lameman.

The U.S. president, however, won't see it — he's vacationing in Florida this weekend.

The fate of the $7-billion mega-project is up to Secretary of State John Kerry.

Kerry promises to give Keystone a "fair and transparent" hearing, and hopefully announce his decision "in the near term."

It is the second high-profile protest in a week. Last Wednesday, 48 people, including Michael Brune, the executive director of the Sierra Club; James E. Hansen, a prominent climate scientist; Bill McKibben, a vocal anti-Keystone XL activist; Robert F. Kennedy Jr., environmental lawyer; and actress Daryl Hannah, were arrested at a demonstration.