Carbon dioxide already in danger zone, warns study

A group of 10 prominent scientists says that the level of globe-warming carbon dioxide in the air has probably already reached a point where world climate will change disastrously unless the level can be reduced in coming decades. The study is a departure from recent estimates that truly dangerous levels would be reached only later in this century. The paper appears in the current edition of the Open Atmospheric Science Journal.

"There is a bright side to this conclusion," says lead author James E. Hansen, director of the Goddard Institute for Space Studies, part of Columbia University's Earth Institute. ""By following a path that leads to lower CO2, we can alleviate a number of problems that had begun to seem inevitable." Hansen said these include expanding desertification, reduced food harvests, increased storm intensities, loss of coral reefs, and the disappearance of mountain glaciers that supply water to hundreds of millions of people.

The scientists say now that CO2 needs to be reduced to the level under which human civilization developed until the industrial age—about 350 parts per million (ppm)—to keep current warming trends from moving rapidly upward in coming years. The level is currently at 385 ppm, and rising about 2 ppm each year, mainly due to the burning of fossil fuels and incineration of forests. As a result, global temperatures have been creeping upward. The authors say that improved data on past climate changes, and the pace at which earth is changing now, especially in the polar regions, contributed to their conclusion. Among other things, ongoing observations of fast-melting ice masses that previously helped reflect solar radiation, and the release of stored-up "greenhouse" gases from warming soils and ocean waters, show that feedback processes previously thought to move slowly can occur within decades, not millennia, and thus warm the world further. Once CO2 gas is released, a large fraction of it stays in the air for hundreds of years.

The scientists, from the United States, United Kingdom and France, are optimistic that current atmospheric CO2 could be reduced if emissions from coal, the largest contributor, are largely phased out by 2030. Use of unconventional fossil-fuel sources such as tar sands also would have to be minimized, they say. They predict that oil use will probably decline anyway as reserves shrink. So-called "geoengineering" solutions that would remove CO2 from the air have been proposed by others, but the group is skeptical; they estimate that artificially removing 50ppm of CO2 from the atmosphere would cost at least $20 trillion, or twice the current U.S. national debt. They suggest that reforestation of degraded land and use of more natural fertilizers could draw down CO2 by a similar amount.

"Humanity today, collectively, must face the uncomfortable fact that industrial civilization itself has become the principal driver of global climate," says the paper. "The greatest danger is continued ignorance and denial, which would make tragic consequences unavoidable."

The paper, "Target Atmospheric CO2: Where Should Humanity Aim?" is at:, pages 217-231 .

Source: The Earth Institute at Columbia University

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Nov 19, 2008
Hallowed are the Ori! Or should it be Gori.(ref.Stargate SG1) I think that I have invented a name for the New Religion.
"Humanity today,collectively,must face the uncomfortable fact that industrial civilization itself has become the principal driver of global climate"
"reduced to a level under which human civilization developed"
So now green fundalmentalists admit they want to destroy civilisation and go back to the dark ages,literaly.Close the power stations and all industry,hospitals,finance,etc,fails.
James, we are getting very tired of the same, obviously exagerated, CRAP.If you would concentrate on your day job then perhaps GISS would get it's monthly global temperatures right. Or even close to what your manipulations say they should be.

Nov 19, 2008
industrial civilization itself has become the principal driver of global climate

Without the sun our global climate would be very static and very cold. How about jet streams and ocean currents?

I'm not saying it's impossible for humans to have some effect on climate but regardless of the validity of AGW this statement is outright false. It is either an insult to the intelligence of Mr.Hansen's audience or evidence that he has lost touch with reality in his quest to prevent AGW.

Nov 19, 2008
Maybe some one can confirm this, but I heard that the optimal CO2 levels for plants is around 3 times what it is now.

Nov 20, 2008
I see something cheesy whenever I see GISS and Dr. Hansen. After getting caught this last time using bogus data to predict the future climate you'd think they'd learn about lying in the name of 'science'.

Nov 20, 2008
Maybe some one can confirm this, but I heard that the optimal CO2 levels for plants is around 3 times what it is now.

It's in chapter 23, verse 9 of the Scrolls of Exxon:

"And verily I say unto you, that thou shalt burn fossil fuels to aid thy plant growth, to a level at least thrice normal. By this I command."

The Scrolls of Exxon are the word of our lord and savior, big oil, and are therefore true.

Nov 21, 2008
Is Noein short for "no einstein"? Not a putdown, I am really just wondering.

Mar 06, 2009
Maybe some one can confirm this, but I heard that the optimal CO2 levels for plants is around 3 times what it is now.

That actually is true. In various studies, plants do much better with increased CO2 levels ppm. Plants actually can do well with as much as 0.9% of atmospheric CO2. Our current CO2 levels are at between 0.03% and 0.04%.

By increasing CO2 levels in greenhouses in studies with various kinds of plants to just 550 ppm there were increases of crop yields as high as ~40%. Current CO2 levels average about 385 ppm or thereabouts. Valleys often have higher average levels of CO2 than on the open plains but still not as high as the levels used in various experiments.

Jun 09, 2009
Let's face it, a warmer, wetter, and CO2 rich world will create an abundance of plant growth when we need it most. Receeding polar regions will open up new arable lands. Just the thing we need to support the 12-14 billion people our world will stabilize at by 2060 or so.

Stop chanting doom with the green fundies and love humanity. Nothing would make me happier then seeing the green movement being shoved to the violent fringes with PETA and Al-Qaeida. It really belongs there if you analyze how it wants to treat the rest of us.

Jun 12, 2009
I recently read a couple articles concerning Greenland farmers beginning again to be able to grow crops that would not grow there for hundreds of years but which were grown by their ancestors. Those interviewed for the articles were pretty happy that they were becoming able to grow their own foods as temps are warming in Greenland.

Jun 12, 2009
If the AGW debate was a poker game, it'd be time to "call." I want to hear the greens' description of the type of government they posthulate as necessary to achieve their aims. I also want them to describe the system of control they have in mind for the rest of us.

No more upping the bets on their claims, I want to hear their "solutions".

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