The two-day Climate Summit of the Americas, which opens Wednesday, aims to bolster the fight against climate change by fostering partnerships among jurisdictions and showcasing measures already taken.
Emphasis will be on the role provinces, states and other subnational governments can play in reducing greenhouse-gas emissions and curbing global warming.
In an interview Monday, Ontario's Environment Minister Glen Murray said the provinces have had to step up to the plate because the federal government under Conservative Prime Minister Stephen Harper has been missing in action on the file.
"The federal government has moved for the last 10 years to the sidelines of this discussion," Murray said.
"Prime Minister Harper would not allow the words 'climate change' to be used or discussed for the better part of the last 10 years at the federal-provincial tables."
It was only a few weeks ago that Ottawa finally agreed to a formal discussion on the subject with the provinces, Murray said.
Dan Woynillowicz, policy director for Clean Energy Canada, said the Harper government had shown a "real reluctance" to do much on the issue.
"There is an important role for the federal government to play and they haven't been playing that role," Woynillowicz said from Nelson, B.C.
"That's where we really have seen the provinces step up by virtue of the fact their citizens are demanding that action."
Federal Environment Minister Leona Aglukkaq, who is not attending the meeting, had no immediate comment.
The summit is the latest in a series of meetings among "infranational" — or subnational — governments aimed at developing a strategy to fight climate change.
Last week, Canada's big city mayors passed a resolution calling for binding emission targets for greenhouse gas emissions and co-ordinated leadership on the issue ahead of a major UN conference on climate in Paris in December.
In a statement, Vancouver Mayor Gregor Robertson said cities in Canada and around the world have shown it is possible to reduce air pollution while growing their economies.
"We must have a climate agreement signed in Paris that respects the needs of our cities, our planet and the generations to come," Robertson said.
About three-dozen speakers are expected to discuss various aspects of climate change over the two days.
Various groups are planning to march on the summit in protest, saying some of those in attendance are responsible for environmental degradation and can't be trusted to come up with solutions.
The United Nations and International Energy Agency have warned of the need to curb greenhouse gas emissions to avoid global warning of as much as four degrees, which would lead to rising sea levels and have drastic climate impacts.
Ontario, which says record insurance payouts for extreme weather events are evidence of climate change, closed the last of its coal-fired electricity plants in 2014, calling it North America's single biggest initiative to cut greenhouse-gas emissions.
Last year, Ontario, Quebec, British Columbia and California agreed that a warming planet and the resulting economic impact were critical problems in need of urgent solutions.
"Virtually all scientific research has concluded that climate change is occurring, faster than anticipated a decade ago, and that immediate steps are needed to adapt to this change," the four jurisdictions said in a joint statement.
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