The U.S. Department of State seems likely to approve a huge pipeline, known as Keystone XL to carry tar sands oil (about 830,000 barrels per day) to Texas refineries unless sufficient objections are raised. The scientific community needs to get involved in this fray now. If this project gains approval, it will become exceedingly difficult to control the tar sands monster. The environmental impacts of tar sands development include: irreversible effects on biodiversity and the natural environment, reduced water quality, destruction of fragile pristine Boreal Forest and associated wetlands, aquatic and watershed mismanagement, habitat fragmentation, habitat loss, disruption to life cycles of endemic wildlife particularly bird and Caribou migration, fish deformities and negative impacts on the human health in downstream communities. Although there are multiple objections to tar sands development and the pipeline, including destruction of the environment in Canada, and the likelihood of spills along the pipeline’s pathway, such objections, by themselves, are very unlikely to stop the project.

An overwhelming objection is that exploitation of tar sands would make it implausible to stabilize climate and avoid disastrous global climate impacts. The tar sands are estimated (e.g., see IPCC Fourth Assessment Report) to contain at least 400 GtC (equivalent to about 200 ppm CO₂). Easily available reserves of conventional oil and gas are enough to take atmospheric CO₂ well above 400 ppm, which is unsafe for life on earth. However, if emissions from coal are phased out over the next few decades and if unconventional fossil fuels including tar sands are left in the ground, it is conceivable to stabilize earth’s climate.

Phase out of emissions from coal is itself an enormous challenge. However, if the tar sands are thrown into the mix, it is essentially game over. There is no practical way to capture the CO₂ emitted while burning oil, which is used principally in vehicles.

Governments are acting as if they are oblivious to the fact that there is a limit on how much fossil fuel carbon we can put into the air. Fossil fuel carbon injected into the atmosphere will stay in surface reservoirs for millennia. We can extract a fraction of the excess CO₂ via improved agricultural and forestry practices, but we cannot get back to a safe CO₂ level if all coal is used without carbon capture or if unconventional fossil fuels, like tar sands are exploited.

A document describing the pipeline project is available here. Comments, due by 6 June, can be submitted here, or by e–mail to keystonexl@cardno.com or mail to Keystone XL EIS Project, P.O. Box 96503–98500, Washington, DC 20090–6503 or fax to 202–269–0098.

I am submitting a comment that the analysis is flawed and insufficient, failing to account for important information regarding human–made climate change that is now available. I note that prior government targets for limiting human–made global warming are now known to be inadequate. Specifically, the target to limit global warming to 2^oC, rather than being a safe “guardrail,” is actually a recipe for global climate disasters. I will include drafts of the following papers that I recently co–authored:

        Paleoclimate Implications for Human–Made Climate Change that can be found here,
        Earth’s Energy Imbalance that can be found here, and
        The Case for Young People and Nature that can be found here.

I will also comment that the tar sands pipeline project does not serve the national interest, because it will result in large adverse impacts, on the public and wildlife, by contributing substantially to climate change. These impacts must be evaluated before the project is considered further.

It is my impression and understanding that a large number of objections could have an effect and help achieve a more careful evaluation, possibly averting a huge mistake.

Dr. James Hansen is director of NASA's Goddard Institute for Space Studies and adjunct professor in the department of earth and environmental sciences at Columbia University. He was the first scientist to warn the US Congress of the dangers of climate change and writes here as a private citizen. Hansen is the author of "Storms of My Grandchildren: The Truth About the Coming Climate Catastrophe and Our Last Chance to Save Humanity."

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