James Hansen on climate change threats

TED lecture by James Hansen, explaining why he must speak out about climate change:

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New paper from Hansen and co-authors predicts extreme weather events will increase with warming, and will have serious consequences. Summary includes:

Practical effects of the increasingly loaded climate dice are likely to occur via amplification of extremes of the water cycle. Higher temperatures exacerbate hot dry conditions, but higher temperatures also increase the amount of water vapor that the atmosphere can hold. Increased water vapor leads to heavier rainfall and floods as well as the potential for stronger storms driven by latent heat including thunderstorms, tornadoes and tropical storms.

There's abstract, and link to download pdf of the paper, at:

Public Perception of Climate Change and the New Climate Dice

At RealClimate, there's a post about a 1981 prediction of global temperature rise by Hansen et al, and how it is close to reality: though actual temperature rise has been rather faster than they predicted.

Evaluating a 1981 temperature projection

Here's chart from the post, with actual temperature curve, and predicted trends:

temperature rising

After reading item on Time website, at http://ecocentric.blogs.time.com/2012/05/10/global-warming-an-exclusive-...

also saw James Hansen in NY Times; sobering reading

- To me, further prove that climate change is not something for solving gently, with feelgood events like turning off lights for an hour once a year

Game Over for the Climate

GLOBAL warming isn’t a prediction. It is happening. That is why I was so troubled to read a recent interview with President Obama in Rolling Stone in which he said that Canada would exploit the oil in its vast tar sands reserves “regardless of what we do.”

If Canada proceeds, and we do nothing, it will be game over for the climate.

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. ... 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 global warming signal is now louder than the noise of random weather, as I predicted would happen by now in the journal Science in 1981. Extremely hot summers have increased noticeably. We can say with high confidence that the recent heat waves in Texas and Russia, and the one in Europe in 2003, which killed tens of thousands, were not natural events — they were caused by human-induced climate change.
We need to start reducing emissions significantly, not create new ways to increase them. We should impose a gradually rising carbon fee, collected from fossil fuel companies, then distribute 100 percent of the collections to all Americans on a per-capita basis every month. The government would not get a penny. This market-based approach would stimulate innovation, jobs and economic growth, avoid enlarging government or having it pick winners or losers. ...

But instead of placing a rising fee on carbon emissions to make fossil fuels pay their true costs, leveling the energy playing field, the  world’s governments are forcing the public to subsidize fossil fuels with hundreds of billions of dollars per year. This encourages a frantic stampede to extract every fossil fuel through mountaintop removal, longwall mining, hydraulic fracturing, tar sands and tar shale extraction, and deep ocean and Arctic drilling.

... we can’t wait any longer to avoid the worst and be judged immoral by coming generations.

James Hansen directs the NASA Goddard Institute for Space Studies and is the author of “Storms of My Grandchildren.”