07/08/2015 04:01 EDT | Updated 07/08/2016 01:12 EDT

Climate change conference kicks off today in Toronto

TORONTO — A major climate-change conference gets underway in Toronto today with hundreds of invitation-only delegates in attendance.

The two-day Climate Summit of the Americas hosted by Ontario aims to bolster the fight against global warming.

The emphasis is on the role provinces, states and other subnational governments can play in reducing greenhouse-gas emissions.

Speakers include former Mexican President Felipe Calderon and former U.S. vice-president Al Gore.

Ontario's Environment Minister Glen Murray says the provinces have had to step up to the plate because Ottawa has been missing in action.

Various groups are planning to march on the summit in protest.

The United Nations and International Energy Agency have warned of the need to curb greenhouse gas emissions to avoid global warming of as much as four degrees, which would lead to rising sea levels and have drastic climate impacts.

Murray called the need to cut greenhouse gases urgent but said Ottawa needs to do its part.

"The federal government has moved for the last 10 years to the sidelines of this discussion," Murray said.

Federal Environment Minister Leona Aglukkaq is not attending the meeting, but a spokesman says they are the first government in Canadian history to achieve a net-reduction in greenhouse gas emissions and have done so "without implementing carbon taxes or carbon-pricing schemes."

On Tuesday, Ontario's acting environment commissioner warned that the province won't meet its own 2020 emission-reduction targets without aggressive action.

In a progress report, Ellen Schwartzel said car and truck emissions along with energy-hogging buildings present the single biggest problem in the province's fight against climate change.

Schwartzel called for a large boost in the use of electric vehicles.

"Our power supply, our electricity, is very low carbon, so it makes a lot of sense to use that to electrify transportation more and more," Schwartzel said.

The Canadian Press