I sent this in to email@example.com. as a comment on the State Department SEIS (supplemental environmental impact statement).
I am a research technician in coastal oceanography. I am not specifically a climate scientist, but I work regularly with numerical model, and my research group works on forecasting the effects on climate change on estuaries. I also read research on this subject. For example:http://climatechange.worldbank.org/sites/default/files/Turn_Down_the_heat_Why_a_4_degree_centrigrade_warmer_world_must_be_avoided.pdf
We are currently at the fulcrum point of the next thousand years of human history. In the next decade, we will determine whether our grand children's great grandchildren live in a world 10 degrees F hotter than our own, or whether it will only be 4 degrees F hotter than our own (we have dithered too long to leave them anything other than a substantially hotter and worse world). A thousand years from now, Obama and George Bush may well be remembered in the same thought as the worst figures of the 20th and 21st century, as destroyers of civilizations and desolaters of much of the world.
In the next decade, we need to shift rapidly away from fossil fuels if we are to avoid the 10 degrees F hotter world (people talk about 2-6 C, but no American thinks in Celcius, not even practicing scientists like myself). We can not do this and aid Canada in fully exploiting the tar sands (some the most carbon intensive, least efficient fossil fuels in existence) at the same time. Deciding whether to authorizing the X-L pipeline is equivalent to deciding which world our grand children will live in. Rejecting the X-L pipeline is not enough by a long shot, but if you authorize it, you will have given up on limiting warming to 4 degrees F, and damned a thousand years of humans to greater suffering.
In President Obama's inaugural address, 2012 campaign, and 2008 victory speech, he promised to lead on climate. In his first major speech as Secretary of State, John Kerry echoed that promise, as did his predecessor, Secretary Clinton. If our government is going to keep those promises, it must start by rejecting tar sands pipelines, especially Keystone XL.
It's impossible to fight climate change while simultaneously investing in the dirtiest, most carbon-intensive fossil fuels on the planet. The administration's bold advances in clean energy and vehicle efficiency have been critical, but much of that progress -- and the credit that comes with it -- will be erased if we also develop the tar sands.
The SEIS (which I haven't read) is here: http://keystonepipeline-xl.state.gov/draftseis/index.htm