Hansen, NASA's leading climate scientist, laid out the scenario for global warming before Congress thirty years ago. Big Oil and other major polluters pressured Congress and successive Administrations of both Parties into sidelining Hansen as well as other prescient scientists.
Hansen spoke out on the proposed Canada-US pipeline for oil derived from Canadian tar sands. =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
Silence is Deadly
03 June 2011The U.S. Department of State seems likely to approve a huge pipeline 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. Although there are multiple objections to tar sands development and the pipeline, including destruction of the environment in Canada1
******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 AR4 WG3 report) to contain at least 400 GtC (equivalent to about 200 ppm CO2).and the likelihood of spills along thepipeline's pathway, such objections, by themselves, are very unlikely to stop the project.
Easily available reserves of conventional oil and gas are enough to take atmospheric CO2 well above 400 ppm. However, if emissions from coal are phased out over the next few decades and if unconventional fossil fuels are left in the ground, it is conceivable to stabilize climate2,3 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 are exploited.A document describing the pipeline project is available at
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=B0C, rather than being a safe "guardrail", is actually a recipe for global climate disasters. I will include drafts of the "Paleoclimate Information"4, "Earth's Energy Imbalance"5
1 Asserted impacts include: irreversible effects on biodiversity, 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.and "The Case for Young People and Nature"3 papers, which are so far only published in arXiv; we will submit revised versions of all of these papers for publication this summer.
2 Target atmospheric CO2: Where should humanity aim? Open Atmos. Sci. J., 2, 217-231, doi:10.2174/1874282300802010217.3
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. Brief pointed comments may be just as well as longer statements.
Jim Hansen