The GNL Quebec liquefied natural gas megaproject would increase life cycle greenhouse gas emissions by more than 37 million tonnes per year, a group of more than 150 Quebec scientists is warning in an open letter to Prime Minister Justin Trudeau and Premier François Legault.

The project would consist of a 782-kilometre gas pipeline, the Énergie Saguenay LNG plant, and a marine terminal for ships carrying the product through Saguenay Fjord and the St. Lawrence River, the scientists say in the letter, published Monday on National Observer.

“In this era of climate change and biodiversity collapse, we believe that scientists have a duty to take a stand on major projects that would affect the future of our civilization,” they write. “It is in this spirit that we are taking part today in the public debate on the GNL Quebec project.”

The group of professors in the pure, environmental, health, and social sciences take direct aim at proponents’ claim that the project would boost the fight against the climate crisis, since Quebec’s hydropower would be used to liquefy the gas and the end product would be sent to export markets to replace oil and coal. In reality, “it would facilitate the daily extraction, in the Canadian Prairies, of 44 million cubic metres of natural gas, which amounts to 2.6 times the total daily consumption of Quebec,” they write. “Canada, which is already the world’s fifth-largest natural gas exporter, would see its net natural gas exports jump by 27% if this project went forward.”

That would equate to more than 7.8 million tonnes of new greenhouse gas emissions per year, at a time when Canada is falling behind its Harper-era target to reduce those emissions, according to a life cycle assessment commissioned by industry, the scientists say. “This means the total emissions associated with this project within Canada would be comparable to the sum total of GHG emission reductions in Quebec since 1990.”

And the impact would almost inevitably be much worse. “A key uncertainty in these calculations is the amount of fugitive gas emissions (leaks) occurring during its extraction, throughout the whole transport chain and after wells are abandoned,” the scientists write. “Considering that natural gas is mainly methane, a greenhouse gas 84 times more potent than CO2 over a 20-year period, the global warming effect of these leaks is enormous, and there is therefore potential for total GHG emissions associated with this project to be considerably higher than the best available estimate.”

In its calculations, GNL Quebec also “carefully avoids highlighting the large amounts of downstream CO2 emissions resulting from the combustion of the gas,” they add. “According to our calculations, these emissions would add roughly 30 million tonnes of CO2 per year, assuming no fugitive gas emissions. That number spikes dramatically when applying average fugitive emissions under normal operating conditions.”

Project proponents can make no guarantees about the coal or oil their product will replace, the scientists say, and the project also carries serious biodiversity risks, on land and at sea. “By cutting right across the natural environment of Northern Quebec, from Abitibi-Témiscamingue to the Saguenay Fjord, the Gazoduq pipeline would fragment the habitat of 17 vulnerable, threatened, or endangered species,” they write. “It would go through the catchment areas of the Harricana, Nottaway, Moose, Outaouais, Saint-Maurice, and Saguenay rivers. Finally, exporting this liquefied gas would require six to eight mega-tanker transits per week in the fjord. The deafening underwater noise from these giant ships would jeopardize the survival of the St. Lawrence beluga in the only acoustic refuge it still has.”

“Exporting Canadian natural gas in no way guarantees marginal gains when it comes to GHG reductions, and is incompatible with the changes that are essential to the energy transition,” writes Caroline Brouillette, senior climate policy researcher at Équiterre, in a critique of the project for Policy Options. “We must also ask ourselves about the economic impact of investing in such an industry.”

That impact includes the very real risk “that the massive investment required to build a natural gas export infrastructure―pipelines, liquefaction plants, marine terminals―ends up as stranded assets, because the useful life necessary to make these projects cost-effective is not guaranteed,” she explains. “Canada wants to build pipelines and liquefaction plants while knowing full well that to avoid catastrophic climate warming, it will be forced to decommission them before the end of their useful life.”

That’s because “the policies needed to curb climate warming will also dampen the demand for natural gas. In a scenario where global warming is below 2.0°C (the signatories to the Paris Agreement are committed to limiting it to 1.5°C), the International Energy Agency is forecasting that global natural gas demand will peak toward the end of the 2020s before dropping after 2030, and will eventually fall below 2000 levels in 2050.”

Against that reality, “we must recognize that exports of Canadian natural gas are at odds with the evolution toward an energy transition.”