TORONTO - Ontario's greenhouse gas emissions are now below 1990 levels and almost a third lower since the Liberals took office in 2003, Energy Minister Dwight Duncan boasted Thursday, but critics said the government has simply benefited from good luck and should take no credit for the decrease.

Ontario has engineered a 32 per cent drop in dirty coal-fired power generation over the past three years and is the only North American jurisdiction committed to closing such plants, Duncan said.

"When we came to office, coal accounted for 25 per cent of our energy mix," Duncan said. "Today, it's 16 per cent. That's a reduction of a third, and we're going to keep going in that direction."

But the opposition parties said the government is using good weather and better performance at nuclear plants to take credit for the decrease in emissions.

"This is no great policy triumph for government, this is simply getting lucky," New Democrat Leader Howard Hampton said.

"We had a very mild summer, so you didn't have coal plants like Nanticoke running full blast to provide electricity for air conditioning. And most of the province until about two-and-a-half weeks ago has had a very mild winter, so you don't have people using their electric heat."

Hampton also said the province has lost about 140,000 manufacturing jobs since the Liberals took office, which means there are fewer plants and factories consuming energy and spewing out emissions.

Conservative Leader John Tory said it was disingenuous for the Liberals to take credit for lowering emissions when they simply benefited from good timing.

"It takes a lot of gall for the McGuinty government to take credit for reduced emissions when they've done absolutely nothing proactive on their own to bring about a reduction on emissions," Tory said.

Jack Gibbons of the Ontario Clean Air Alliance said he was hesitant to congratulate the government on the numbers since other benchmarks would give a completely different impression of Ontario's pollution.

For example, he said if coal-based emissions from 2006 are compared to those from 1995, it's an increase of about 50 per cent.

But he also acknowledged that pollution is clearly going down, and that's proof the government can soon close down its coal plants.

Premier Dalton McGuinty originally promised to close the coal plants entirely by 2007, but later changed the date to 2009 and then again to 2014.

"What the progress we've made to date does indicate is that it's still possible for us to phase out all the coal-fired power plants by 2009," Gibbons said.

"We have made significant reductions in terms of coal-fired generation, and more new, clean generation is coming online between now and 2009 -- more water power, more wind power, more high-efficiency natural gas -- so now we have a complete coal outage within our grasp. All we need is strong political leadership from Premier McGuinty."

But Duncan said the decrease in emissions will have no effect on the current target of 2014.

"We think the target dates as laid out by the (Ontario Power Authority) are realistic ones: 2011 for closure, probably to 2014 to keep some of them open as insurance. But the point here is that even though we aren't able to close them right away, we're making steady and measurable and dramatic progress in terms of emission reduction."

In December, Environment Canada released figures indicating coal-fired power stations were among Canada's biggest polluters in 2005.

The agency said Canada's largest polluter was the Nanticoke power station owned by Ontario Power Generation, where emissions rose 20 per cent over 2004 levels to 17.6 million tonnes. Nanticoke is one of the largest coal-fired electricity producers in North America.

OPG spokesman John Earl has said Nanticoke's emissions appeared more substantial because it is a massive 4,000-megawatt plant made up of eight regular-sized power-generating units joined together.

Environmentalist David Suzuki, who spoke in Toronto on Thursday, said the province needs to rethink its focus on power supply and work more on addressing excessive consumption.

"I think the premier is being held hostage to really dinosaur thinking," Suzuki said.

"(Everyone's) concerned with trying to supply energy to keep meeting what you think is going to be a rising demand. How about giving a chance to reducing demand? How about going to the Canadian public and saying, `Look, there are all kinds of ways for you to save money and you can actually do good for the planet and reduce emissions.'"