When the federal government announced its plan to cut its greenhouse gas emissions by 30 per cent below 2005 levels by 2030, it gave little indication how it planned to do it, exactly.

Canada produced 749 megatonnes of greenhouse gas emissions in 2005, according to Environment Canada data. By cutting 30 per cent, the Conservative government is hoping to eliminate more than 200 MT a year.

So, just how doable is that?

Well, to put that amount into more relatable terms, cars, trucks and motorcycles were responsible for 88 MT of GHG emissions for 2013. Include bus, train and domestic flights in to the tally, and that's another 10.

So, if the Conservative government was to take all the cars, buses, motorcycles and trains off the road for a year, they wouldn't even meet half their goal.

How about Alberta's oilsands? A lot of attention has been focussed there, but completely shutting it down would only scrap 62 MT at current levels — and that's for an industry that is projected to grow. In fact, the government could freeze the whole oil and gas industry for a year and it would still come up short — eliminating only 179 MT.

Environment Minister Leona Aglukkaq has admitted that the 2030 goal of reducing greenhouse gases is "ambitious." (Sean Kilpatrick/Canadian Press)

Environment Minister Leona Aglukkaq has admitted that the 30 per cent goal is ambitious (so ambitious, in fact, that she repeated the word four times in a recent interview on CBC Radio's The House with Evan Solomon.)

She has said repeatedly that Canada will take a "sector-by-sector" approach to meet its target. That includes bringing in regulations to reduce methane leaks from the oil and gas sector, and limiting emissions from the chemical and fertilizer industry and natural-gas fired electricity.

These new measures are in addition to phasing out traditional coal-fired power plants, stricter controls on cars and light trucks and counting on the provinces to help.

She wouldn't rule out purchasing international credits — invest in green projects in other countries to balance out rising emissions in Canada — even though former environment minister John Baird once dismissed the idea as "hot air credits."

Two choices: prices or rules

Cabinet documents marked "secret" and obtained by CBC News reveal proposals for Canada's target to cut its greenhouse emissions.

While that particular document was aiming for original cuts of around 24 to 26 per cent of 2005 levels, it still gives an indication of where the government may be looking to make cuts.

For example, according to the document:

Lower oil prices and slower economic growth could eliminate 30 MT a year by discouraging production.

Unidentified reductions from the oilsands could cut 51 MT, while buying international emissions credits would also make up for about 33 MT.

Energy efficiency, clean transportation and clean electricity could eliminate 89 MT.

But environmental economist Marc Jaccard said it basically comes down two options.

"If the government wants to do something it has to either change prices [implementing a carbon tax or a cap-and-trade system] or regulate technologies. There's nothing else."

A nation of these would be a relatively small step to reaching Canada's emissions reductions targets. (Jenna Reid/CBC)

The Conservatives, so far, have ruled out any kind of pricing mechanism, arguing that it's a job killer, although Ontario recently signed a cap-and-trade agreement with Quebec, which already had a deal in place with California.

And while most economists support a carbon tax or cap-and-trade system as the best way to achieve GHG reductions, California has achieved the bulk of its decrease through regulation, Jaccard said.

Those regulations include:

The low-carbon fuel standard, which requires people selling fuels to mix in more bio fuels to lower the carbon content.

Vehicle emission standards that require a growth in the percentage of sales in low-emission vehicles (electric, plug in electric and hybrid vehicles).

Renewable portfolio standards that require a growing share of renewables in electricity generation.

"We know that regulations, not to be too costly, have to be implemented immediately and that they only affect the incremental actions," Jaccard said.

"They don't make you get rid of your car. It's when you're buying a new car ... then they influence that decision.

"But if you try to force people to get rid of their car when it's not very old — or their furnace, or whatever — that will be costly to your economy."