* Figures show emissions set to increase steadily
* Tar sands development booming, so are greenhouse gases
* Canada says will balance environment with need for jobs
By David Ljunggren
OTTAWA, Aug 8 (Reuters) - Canada must do much more to meet its 2020 target for reducing greenhouse gases, given rising emissions as the energy sector develops the oil-rich tar sands of northern Alberta, government officials said on Wednesday.
Canada, the biggest single supplier of oil and gas to the United States, says it will cut output of greenhouse gases by 17 percent of 2005 levels by 2020, a goal that's far less stringent than the international targets Canada abandoned last year.
New figures released on Wednesday show that Canada is half way to meeting its own target. But emissions will rise steadily from now until 2020 unless more action is taken.
"Much work remains and we need everyone to stay on board so we can close the gap and reach our ultimate goal," Environment Minister Peter Kent told reporters.
"(We) will continue to work with our partners to address the remaining major sources of emissions ... our talks have progressed very quickly with the oil and gas sector -- both conventional and the oil sands."
Canada last year formally abandoned the Kyoto protocol on global warming, arguing that the treaty was unfair because it did not include major emitters like China and India.
Ottawa promised to introduce draft regulations on the oil and gas industries in 2013 and Kent said that target date still stood. He said he was planning discussions with the steel and cement industries.
Talk of big cuts in greenhouse gas output is a challenge for the right-of-center Conservative government, which says it wants to balance environmental protection with its desire to create jobs and turn Canada into an energy superpower.
Critics accused the Conservatives of pandering to the energy industry and said Ottawa needed to take more radical action.
"Canadians need to demand a government that works towards a safe and renewable energy future, not a puppet for polluters," said Christian Holz of the Climate Action Network Canada.
Debate over energy policy in Canada usually revolves around the massive tar sands of Alberta, the world's third largest proven oil reserve. Separating the oil from the sands requires large amounts of steam and water, an extraction method that produces more greenhouse gases than conventional methods.
The government figures showed emissions from the oil sands would rise 226 percent between 2005 and 2020, accounting for more than 17 percent of all projected greenhouse gas output in 2020 assuming Canada meets its target.
Pressed to say how energy firms might cut emissions, Kent said the oil sands sector had "an aspirational goal" of reducing output to the level of the conventional sector.
He cited likely technological advances, but gave no details, and said regulations to reduce emissions from coal-fired power plants would be released in the next few weeks.
The opposition Liberal party said the figures were "a joke" and noted they had been revised to show emissions in 2010 were significantly lower than previously estimated.
"This is nothing more than a shell game. The government has changed the accounting rules in order to declare success," said Kirsty Duncan, the party's spokeswoman on the environment.
In May, Parliament's environmental watchdog said Canada was acting too slowly to combat climate change and had little chance of achieving its 2020 target.