If you thought it was hard to keep up your New Year's resolution, try keeping an 85-year pledge.

That's exactly what Canada and the other G7 countries are committing themselves to as they try to get control of global greenhouse gases. While Canada failed on its Kyoto agreement and won't meet its 2020 Copenhagen target, that's not stopping Prime Minister Stephen Harper from making even more long-lived environmental pledges.

First, a deep cut in carbon emissions by 2050 and second, an eventual end to fossil fuel use by 2100.

At first glance, it's praiseworthy. The world's leading economies commit to decarbon the world economy. Some environmental groups were quick to call the G7 announcement "groundbreaking," although not everyone is as supportive and approving.

"It's not groundbreaking. It is politically cheap to pledge a non-binding commitment that falls way behind someone's time in office," said David Keith, an engineering professor at Harvard University and former University of Calgary professor who was one of Time magazine's "heroes of the environment" in 2009.

"What we really need is specifics in the next few years or decades."

Vague on execution

The pledges do add weight to the movement to get off of fossil fuels, but how the G7 countries achieve their goals is unclear.

Policy time horizons, in terms of descendants. By 2025: Think of the children. By 2100: Think of the great-great-grandchildren. —@paulisci That shouldn't come as a surprise considering how vague Canada has been in the past about achieving its emissions targets. Just last month, the federal government promised a 30 per cent cut to emissions below 2005 levels by 2030. It gave little indication how it exactly planned to do it. Eliminating all cars for a year would only put a dent in carbon emissions.

The problem with the G7 is the simple fact there are only 7 countries involved. Even if the group dramatically cuts emissions, there will be little impact on climate change if developing countries do not take similar actions.

The G7 admitted as much, noting it will only be able to reach its 2050 target, "recognizing that this challenge can only be met by a global response."

Carbon tax

There are many ways Canada could act to try to control greenhouse gases. First and foremost is a carbon tax or carbon pricing similar to what is already in place in British Columbia. Even some members of Alberta's oil industry are in favour of such a system.

Keith argues it's the most effective step to take.

"We need to put in an economic disincentive against using the atmosphere as a free wasteland," he said.

While Canada has failed to follow environmental promises in the past, it's debatable whether the latest pledges will be kept.

At the G7 meeting, Canada and Japan blocked attempts at a stronger statement on binding greenhouse gas reduction targets, according to sources quoted by The Canadian Press.

"That's shameful," said Keith. "If you want a stable climate, we have to get to net zero emissions. For a government to try and avoid such a statement, is really a shame."

Nuclear

Prime Minister Stephen Harper, right, talks with Japanese Prime Minister Abe Shinzo, left, during dinner at the G7 meeting at Schloss Elmau near Garmisch, Germany on Sunday. While Canada failed on its Kyoto agreement and won't meet its 2020 Copenhagen target, that's not stopping Harper from making even more long-lived environmental pledges. (Adrian Wyld/Canadian Press) Several environmental groups praised the G7 countries for declaring war on carbon, which, they say, will surely lead to a rise in renewable energy. But the G7 never actually said that renewables will be the energy source of the future. They only mentioned the need for carbon-free energy. In effect, the group of countries left the door open to nuclear energy.

Nuclear power has been praised as a climate change fighter because of its reliability and near-zero emissions. Nuclear power already provides 11 per cent of the world's electricity, according to the World Nuclear Association.

Oilsands

The G7 emission targets seem to be a death sentence for Alberta's oilsands. It's no secret the oilsands are a high cost and high carbon operation. Not only is the sector battling low commodity prices right now, any type of carbon reduction strategies, such as a carbon tax, would add extra financial pressure. The industry will have to find a way to remain competitive if the global economy shifts its focus towards low carbon.

"We are all clear, we are still going to need fossil fuels for some time to come. Now we have, at the global level, the latest day for when we need to be off fossil fuels," said Ed Whittingham, with the Pembina Institute, an environmental think tank. "CEOs in Calgary are smart; they will do the planning that needs to be done."

If you like promises about the environment, there are more to come. Countries will be lining up to announce even more pledges later this year at the United Nations climate change conference in Paris in December.