The Canadian press is full of speculation that the Canadian government will push for special treatment and protections from global warming regulation of its fastest growing source of greenhouse gas emissions: the tar sands oil development in Alberta, where much of Canada's oil is derived. Such protection would be disastrous for life on our planet.

The tar sands of Canada constitute one of our planet's greatest threats. They are a double-barrelled threat. First, producing oil from tar sands emits two-to-three times the global warming pollution of conventional oil. But the process also diminishes one of the best carbon-reduction tools on the planet: Canada's Boreal Forest.

This forest plays a key role in the global carbon equation by serving as a major storehouse for terrestrial carbon – indeed, it is believed to store more carbon per hectare than any other ecosystem on Earth. When this pristine forest is strip mined for tar sands development, much of its stored carbon is lost. Canada's Boreal Forest is also the reservoir for a large fraction of North America's clean, fresh water, home to some five billion migratory birds, and some of largest remaining populations of caribou, moose, bear and wolves on the planet.

As a climate scientist, I am focused on what levels of atmospheric carbon dioxide can be considered safe. In the past few years, based on increasingly detailed information about the history of the Earth and observations of ongoing climate change, a startling conclusion has become apparent. The safe level of atmospheric carbon dioxide is no more than 350 parts per million (ppm), if we wish the diversity of other species on the planet to survive – as well as "amenities" that humans require, such as fresh water supplies, stable coastlines and a normal degree of extreme weather events.

Unfortunately, because of our fossil fuel use, our planet is already at 385 ppm. It is still practical, with improved agricultural and forestry practices to get future carbon dioxide levels below 350 ppm, provided we phase out emissions from the largest source, coal, in coming decades. It is a tough challenge to develop the needed renewable energies of the future, but it is doable. Together with improved energy efficiency we can move to the clean world of the future, beyond fossil fuels.

So an underlying fact has become crystal clear. The horrendously carbon-intensive unconventional fossil fuels, tar shale in the US and tar sands in Canada, cannot be developed. The carbon emissions from tar shale and tar sands would initiate a continual unfolding of climate disasters over the course of this century. We would be miserable stewards of creation. We would rob our own children and grandchildren.

And this is what the Europeans are rushing to invest in?  Surely this fit the definition of "a criminal enterprise", investment in which makes one an accessory to the crime?

The difference between theory and practise in practise ...