The city's declaration of a climate emergency in the same week it begins major repairs to the Gardiner Expressway sends a mixed message about Toronto's commitment to fighting climate change, environmental advocates say.

Starting at midnight on Friday, construction crews will begin demolishing, and will eventually rebuild, the westbound off-ramp to Jarvis and Sherbourne streets.

The intensive work will carry into the spring of 2020. It's part of a more than $3.6-billion construction project to keep the Gardiner operational until the late 21st century.

"It's definitely a contradiction," said Sarah Buchanan, a manager with the advocacy group Environmental Defence.

"This major infrastructure project will lock us into more carbon pollution from cars," she said. "There were cheaper, greener options that were available."

In 2015, Mayor John Tory and city council narrowly approved a plan to repair and rebuild the Gardiner, instead of demolishing the eastern portion in favour of a ground-level boulevard.

A city report released at the time said the boulevard option would have resulted in a 12 per cent reduction in greenhouse gas emissions while also improving local air quality.

The decision was roundly criticized by environmentalists and many downtown councillors at the time, but it has come under a new round of scrutiny after the city formally declared a climate emergency on Wednesday.

<a href="https://twitter.com/hashtag/ClimateEmergency?src=hash&ref_src=twsrc%5Etfw">#ClimateEmergency</a> Action #1 for the City of Toronto: cancel the rebuilding of the eastern portion of the Gardiner and redirect the one billion dollars into sustainable transportation infrastructure. Bike Lanes. Bus Rapid Transit. Safe crosswalks and intersections for pedestrians. —@jen_keesmaat

Toronto to adopt new 'climate lens'

The declaration calls for the city to "deepen" its commitment to fighting climate change while also committing to a target of net zero emissions by 2050.

The declaration also calls for the city to adopt a new "climate lens that evaluates and considers the climate impacts of all major city of Toronto decisions."

Critics say the controversial decision to maintain an elevated roadway that cuts through the heart of Toronto's waterfront would never have been approved under that approach.

Protesters marched through the streets of downtown Toronto during a climate rally in September.

Emmay Mah, executive director of the Toronto Environmental Alliance, said there was a "clear choice" between funding the Gardiner repairs or investing in public transit, and that city councillors ultimately chose the more damaging option.

"The Gardiner Expressway, I think, provides a good case study and I hope there are some lessons learned," she said.

Tory says transit the priority

In response to re-emerging criticism over the Gardiner repairs, Tory has argued that the project will ultimately be beneficial to the fight against climate change.

At a news conference last week, Tory said maintaining the Gardiner will continue to prevent cars from entering downtown Toronto, saving the core from additional pollution.

But more important, he said, is the city's ongoing commitment to fund a variety of transit projects, where true strides against climate change can be made.

"The amount we're spending on rebuilding a small part of the Gardiner Expressway pales in comparison to what we're investing in public transit to get people out of their cars entirely," Tory said.

Toronto Mayor John Tory says the city's commitment to transit projects far outweighs its investment in maintaining the Gardiner. (Linda Ward/CBC)

Toronto's four largest transit projects currently in the works — the Ontario Line, the Scarborough subway extension, a subway extension to Richmond Hill, and the Eglinton West LRT extension — have an estimated cost of $26.7 billion, though much of the funding will come from the federal and provincial governments.

Environmentalists say the city is now under increased pressure to follow through on projects like those, and to make further strides against climate change.

Buchanan pointed to the tens of thousands who turned out for the Toronto climate rally a week ago as proof that public expectations are changing.

"There is a big and growing public appetite for stronger action," she said.

"When [residents] are not feeling like governments are doing enough, they'll get out there and they'll disrupt."