Gregor Robertson, Vancouver mayor, talks to Pope about climate change

VancouverMayorGregorRobertson joined dozens of other mayors from around the world at the Vatican Tuesday to meet with Pope Francis and discuss the rolecities can play in addressing climate change, sustainability, and poverty.

Robertson was the only Canadian representative in the delegation ofmunicipal leaders.In an interview with CBC News Tuesday, Robertson was critical of Canada's environmental track record.

"It's certainlya big concern for mayors globally when the Canadiangovernment is such alaggard,and is fightingagainstthe tideof commitments to fighting climate change," Robertson said.

"It's really a tipping point about climate change and itimpacts on the mostvulnerablepeople globally."

Urgedbold steps

Themunicipalleaders urged their nationalleaders take bold steps at the Paris climate talks later this year, saying that may be the last chance to keep the warming of the Earth at levels safe for humanity.

• Vancouver Mayor Gregor Robertson to meet Pope

• Mayors meeting at Vatican seek 'bold climate agreement'

• Pope Francis urges climate change action

Robertson and other delegates wereinvited because they back the Pope's environmental message.

Francis last month released an environmental encyclical that denounced what he calls a fossil fuel-based world economy that exploits the poor and destroys the Earth.

Experts have long said that cities are key to reducing global warming since urban areas account for nearly three-quarters of human emissions.

In a written statement,Robertson's office said the meeting was the most significant mayoral gathering ever held at the Vatican.

Robertson is a panelist at the conference, where he is speaking about the importance of sustainable economic development in cities and highlighting Vancouver's leadership in supporting green and low-carbon technology, the statement said.

Other mayors attending hailfrom Boston, Oslo, Norway, San Francisco and Boulder, Colo.

In addition to the climate declaration, mayors will be asked to sign a statement against human trafficking that was first penned by religious leaders at the Vatican last year.