James Hansen....."We must get back below 350 ppm to preserve civilization" [View All]

[RedEarth]

Twenty years ago today, before he became America’s top climate scientist, NASA’s James Hansen was among the first to warn Congress and the nation about the dangers of human-caused global warming. For a new analysis of that testimony, see Grist here.

Hansen just spoke at the National Press Club. He is also giving a briefing to the House Select Committee on Energy Independence & Global Warming. Looks like C-SPAN will skip both. Sad.

You can see look at his presentation and recent postings on his website. Here are some words of wisdom from his speech today:


This is not a time to celebrate. Emissions just keep going up.

You may have seen a lot of ads on TV about clean energy. It’s greenwashing.

Contrary to what you may have read on some blogs — we are not entering a global ice age. The world continues to warm even though we had a cold winter thanks mainly to La Niña.

I preferred to do science then communicate with the public after 1988 until 2004. At that time I realize there was a huge gap between what is understood by scientists vs. what is known by public

Planetary emergency because of tipping points.

>> 99% confidence that the dangerous level of atmospheric carbon dioxide concentrations is 350 ppm.

Yes, we can overshoot 350 ppm, but only on a timescale of decades.

We must get back below 350 ppm to preserve civilization.

We have reached one tipping point. We will lose all summer ice in Arctic over the next 5 to 10 years.

And that endangers Greenland ice sheet, whose mass loss accelerating.

The subtropics have expanded in size — that is desertification

The glaciers are receding. hundreds of millions of people will lose their reservoir of water for summer/fall. We have a few more decades before they’re all gone.

The less oil production the better.

We must phase out coal by 2030 and go to carbon-free energy.We need a low-loss high voltage DC electric grid.

Basic conflict today is between fossil fuel special interests and young people/unborn/nature

The disinformation campaign today borders on crimes against humanity. We do know the consequences of inaction.

Drilling off the Outer Continental shelf is exactly the wrong thing to do. A crazy thing. Extends the addiction (a little).

Geoengineering is a last resort. You wouldn’t want to go down that path.

Nothing about the climate system that says it has to be stable. Sea level stable 7000 years. We have been in the ice “sweet zone”: Stable Ice sheets on Greenland, antarctica, ice covering the artic sea but not the continents.

450 ppm gets us an ice free planet.

http://climateprogress.org/2008/06/23/drilling-off-shore-is-a-crazy-thing-says-hansen-on-20th-anniversary-of-his-famous-testimony/