Thursday, May 10, 2012

Hansen on Climate

NYT op-ed yesterday:
Canada’s tar sands, deposits of sand saturated with bitumen, contain twice the amount of carbon dioxide emitted by global oil use in our entire history. If we were to fully exploit this new oil source, and continue to burn our conventional oil, gas and coal supplies, concentrations of carbon dioxide in the atmosphere eventually would reach levels higher than in the Pliocene era, more than 2.5 million years ago, when sea level was at least 50 feet higher than it is now. That level of heat-trapping gases would assure that the disintegration of the ice sheets would accelerate out of control. Sea levels would rise and destroy coastal cities. Global temperatures would become intolerable. Twenty to 50 percent of the planet’s species would be driven to extinction. Civilization would be at risk.

That is the long-term outlook. But near-term, things will be bad enough. Over the next several decades, the Western United States and the semi-arid region from North Dakota to Texas will develop semi-permanent drought, with rain, when it does come, occurring in extreme events with heavy flooding. Economic losses would be incalculable. More and more of the Midwest would be a dust bowl. California’s Central Valley could no longer be irrigated. Food prices would rise to unprecedented levels.

If this sounds apocalyptic, it is. This is why we need to reduce emissions dramatically. President Obama has the power not only to deny tar sands oil additional access to Gulf Coast refining, which Canada desires in part for export markets, but also to encourage economic incentives to leave tar sands and other dirty fuels in the ground.
The near-term picture will not be influenced very much by particular choices on the tar-sands (though the long-term certainly will). Still, Hansen is a first rate scientist and not to be ignored lightly. Those are indeed pretty apocalyptic predictions.

Update (5/11/12): Andy Revkin solicited some dissenting views from other scientists here.


Alexander Ac said...


not as easy to ignore as James Lovelock (on climate),


Alexander Ac said...

Add to that that U.S. experiences warmest 12-month period on record and check out the graphs!


ColdNorth said...

Anthropomorphic global warming - yes. Bitumen as the key threat - no.

Coal has higher GHG intensity than bitumen (per unit fuel) and is expected to see substantially increased production.

"In May 2007, the EIA forecast that global CO2 emissions will increase 59% between 2004 and 2030, with 43% of the 42.88 billion tonnes coming from coal." (

Bitumen might help continue the peak in oils, growing to perhaps 6% of the overall oil supply.

This begs the question of why Hansen focuses on (foreign) bitumen and not (American) coal.

Nick G said...

US coal consumption is falling fast: from about 51% 5 years ago to about 39% lately.

China is by far the biggest consumer of coal, and they're frantically developing natural gas, wind, hydro, etc., to replace coal ASAP.

There is some hope on coal.

Gingerbaker said...

Hoerling and Revkin(as usual) leave a lot to be desired: