TORONTO - An environmental group is calling on Toronto's frugal new mayor to follow through with a plan for light-rail transit to the suburbs, saying it's not only greener but cheaper than the alternatives.

A study released Tuesday by the Toronto Environmental Alliance appeals to the city's new councillors and Mayor-elect Rob Ford, who ran on a campaign to "stop the gravy train" at city hall.

These trains, the study suggests, will save money.

"From the perspective of reducing greenhouse gas emissions, the most effective way of doing it, per dollar spent, is through light-rapid transit," said the group's executive director, Franz Hartmann.

"It's the best from an environmental perspective and it's the best from a financial perspective."

During the mayoral campaign Ford said streetcars were not the answer to Toronto's transit needs, and said he also wanted to halt a provincially funded plan to build light-rail lines. The right-leaning mayor said he preferred to add buses and extend the subway system in time for the 2015 Pan Am Games.

The Toronto Transit Commission ordered 204 streetcars in 2009 from Bombardier for more than $1.2 billion in what was billed as the largest single order for light-rail vehicles in the world.

Ontario's provincial transit agency, Metrolinx, exercised an option last June with for more than 180 light-rail vehicles to be delivered between 2013 and 2029 from Bombardier at a value of $770 million.

Following the election, Ford back away from his plan to phase out streetcars, saying he would not cancel an order that would "cost the taxpayers an arm and a leg."

Ford has not made a similar retreat from his musings about killing the light-rail plan.

"Mayor-elect Ford said, essentially, 'I want to build subways,' " Hartmann said.

"In an ideal world, if we had a lot of money, if we had a lot of time, if global warming wasn't a pressing issue, sure, subway expansion might be the way to go."

It's unrealistic to think Toronto can accomplish the subway plan, however, because there are limited tax dollars to work with and there are people living in the suburbs who have poor transit service, Hartmann added.

The city will not have compromise cost for a cleaner environment, the report noted.

The group wants the city to continue with implementing the 2007 Transit City plan, unless another solution can demonstrate a greater reduction of greenhouse gas emissions.

"We have to get as many people out of their cars as possible and onto transit, and light-rail transit allows that to happen," said Hartmann.

The report said the plan would reduce greenhouse gas emissions by 213,000 tonnes, the equivalent of 53 million annual car trips.

While subways only produce 29 tonnes of emissions per one million kilometres travelled -- compared to light rail vehicles which produce 39 tonnes -- subways are more expensive to build, said Hartmann, who added it's not an "apples to apples" comparison.

Because subways cost three to five times more, take longer and tend to reach less people they are more costly not just to taxpayers but to the environment, he said.

The report also urged the city to develop an analysis of smog emissions from current practices, and to develop a methodology to assess smog emissions.

Last month, Bombardier said production would soon begin in Thunder Bay, Ont., on the new streetcars that are expected to be delivered starting late in 2012.