Study Suggests Atmospheric CO2 Already in “Dangerous Zone”; Calls for Urgent Reduction Below Today’s Levels With 350 ppm as Initial Target
09 November 2008
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| Top: Fossil-fuel CO2 emissions with coal phase-out by 2030. Bottom: Resulting atmospheric CO2. Click to enlarge. Source: Hansen 2008 |
In an analysis using paleoclimate data to show how the Earth has responded to past changes of CO2, a group of ten scientists from the United States, the UK and France, conclude that the present global mean atmospheric concentration of CO2 (385 ppm and increasing about 2 ppm per year) is already in the “dangerous zone” in terms of long-term climate change.
Averting climate disasters, they argue in an open-access paper published in the journal Open Atmospheric Science Journal, requires the reduction of CO2 this century to less than the current amount via prompt policy changes. The authors argue that such reductions are feasible, but requires a moratorium on any new coal use that does not capture CO2 as the phase out of existing coal emissions by 2030. Dr. James Hansen is the lead author of the study.
The authors advocate an initial target concentration of 350 ppm, noting that it might have to be lower once more studies and analysis are done. Most other current studies have settled on a concentration of 450 ppm as being capable of preventing the worst effects of climate change.
Our current analysis suggests that humanity must aim for an even lower level of GHGs. Paleoclimate data and ongoing global changes indicate that ‘slow’ climate feedback processes not included in most climate models, such as ice sheet disintegration, vegetation migration, and GHG release from soils, tundra or ocean sediments, may begin to come into play on time scales as short as centuries or less. Rapid on-going climate changes and realization that Earth is out of energy balance, implying that more warming is ‘in the pipeline’, add urgency to investigation of the dangerous level of GHGs.
...Our estimated history of CO2 through the Cenozoic Era provides a sobering perspective for assessing an appropriate target for future CO2 levels. A CO2 amount of order 450 ppm or larger, if long maintained, would push Earth toward the ice-free state. Although ocean and ice sheet inertia limit the rate of climate change, such a CO2 level likely would cause the passing of climate tipping points and initiate dynamic responses that could be out of humanity’s control.
—Hansen et al. (2008)
Because a large fraction of fossil-fuel generated CO2 emissions stays in the atmosphere a long time (25% of it remaining airborne for several centuries), a moderate delay of fossil fuel use will not appreciably reduce long-term human-made climate change, according to the authors.
Preservation of a climate resembling that to which humanity is accustomed, the climate of the Holocene, requires that most remaining fossil fuel carbon is never emitted to the atmosphere.
—Hansen et al. (2008)
The only realistic way to sharply curtail CO2 emissions is to phase out coal use except where it is captured and sequestered, they argue. Even with that, however, CO2 would remain above 350 ppm for more than two centuries.
A practical global strategy almost surely requires a rising global price on CO2 emissions and phase-out of coal use except for cases where the CO2 is captured and sequestered. The carbon price should eliminate use of unconventional fossil fuels, unless, as is unlikely, the CO2 can be captured. A reward system for improved agricultural and forestry practices that sequester carbon could remove the current CO2 overshoot. With simultaneous policies to reduce non-CO2 greenhouse gases, it appears still feasible to avert catastrophic climate change.
Present policies, with continued construction of coalfired power plants without CO2 capture, suggest that decision-makers do not appreciate the gravity of the situation. We must begin to move now toward the era beyond fossil fuels. Continued growth of greenhouse gas emissions, for just another decade, practically eliminates the possibility of near-term return of atmospheric composition beneath the tipping level for catastrophic effects.
The most difficult task, phase-out over the next 20-25 years of coal use that does not capture CO2, is Herculean, yet feasible when compared with the efforts that went into World War II. The stakes, for all life on the planet, surpass those of any previous crisis. The greatest danger is continued ignorance and denial, which could make tragic consequences unavoidable.
—Hansen et al. (2008)
Resources
James Hansen, Makiko Sato, Pushker Kharecha, David Beerling, Robert Berner, Valerie Masson-Delmotte, Mark Pagani, Maureen Raymo, Dana L. Royer, James C. Zachos (2008) Target Atmospheric CO2: Where Should Humanity Aim? The Open Atmospheric Science Journal Vol. 2 doi: 10.2174/1874282300802010217
This is not a denial, but with a CO2 growth rate of about 2 ppm per year, it would take (with business as usual) another 32.5 years (up to 2040+) to go from 385 ppm to 450 ppm.
However, business will not be as usual and CO2 growth rate will fall because:
1) Cheap oil will run out.
2) Cheap coal run also run out.
3) CO2 from coal power plants will be captured.
4) more and more electrical power will be from non-CO2 creating sources.
5) transportation + other vehicles and HVAC will be progressively electrified.
6) the current world economic recession will last a few years and reduce oil and coal consumption growth.
7) advanced biofuel production will produce less CO2.
8) we may find ways to absorb and/or use CO2 to produce energy.
I very much doubt that we will continue to create GHG at the rate of almost 25 tonnes per capita for many more years. There are not good reasons why Americans and Canadians cannot reduce their GHG emissions to 10 to 12 tonnes per capita. Many European countries have done it, why not us.
Yes we can!
Posted by: HarveyD | 09 November 2008 at 10:18 AM
Oil and coal don't have to be cheap to be used and the not-cheap oil and coal are often the dirtiest. Case in point: Increasingly America has turned to Canada for its oil and that means more oil sands production (the dirtiest oil you can get and still make a profit).
True there may be no GOOD reason Canadians cannot reduce our GHG emissions but we just returned Harper to the PM office (sorry but that's what happens when you have 3 parties on the left splitting the vote) and as an Albertian he has no good reason to slow down the oil sands, and even if America does not want to buy oil from us the Chinese will. Over all, Harper has no reason to be green in any way, he doesn't believe in AGW or maybe he sees it as a good thing for Canada. Anything he's says to the contrary is just lip-service. Bet on it.
As for Obama, well he may be greener than Bush but he's still beholding to the coal states and the auto unions so if CCS doesn't work what can he do? Even if CCS works it's not 100% effective, from what I'm told it will still let 30-34% of the CO2 go into the atmosphere. And there's still the question of how long the CO2 that does go into the ground will stay in the ground.
In my mind the better hope comes from Biden; he doesn't drive to work, he takes the train.
Posted by: ai_vin | 09 November 2008 at 12:17 PM
Do I get a year's supply of purple koolaid if I jump on the AGW bandwagon? There are plenty of pollutants, (particulates, mercury, sulfur dioxide, etc), that we should be giving a higher priority to than CO2. If these doomer demagogues actually believed their own BS, they'd be advocating things like nuclear power and agrichar. Well people, when you're shivering during a brownout in the dead of winter, remember to put the blame squarely on idiots like Hansen.
Posted by: M stands for Morlock | 09 November 2008 at 12:23 PM
ai_vin:
Post Oil & Coal economies will move in and progressively reduce GHG.
Just watch what China will do to effectively promote PHEVs and BEVs and mass produce affordable battery packs instead of importing (very dirty) Oil from Canada.
Cleaner ICE will be produced but will have to make way for e-motors in all vehicle sizes within a few years.
The transition will happen.
Posted by: HarveyD | 09 November 2008 at 01:04 PM
Harvey,
You may have some reason to think that human emissions will average out to that 2ppm per year. And that this implies a 450 target. There is no reason to believe that natural emissions wont continue the dramatic rise that is shown to be occurring. Measurements are clear but the scientists prefer to see data over consecutive years before committing. Methane releases in the northern tundras, rivers. Whereas similar CO2 emissions from farmlands are well documented over longer time frames.
China IE is committed to 8% expansion of the economy with trillion dollar stimulus package. Other countries are also determined.
I don't know how we can say that determined econmic "recovery" can be expected to see reduction of big emiting activity. Often infrastructure that is intended to increase economic outcomes. In this economic climate ecological outcomes are not a priority.
Australian Olympic Dam uranium mine is opening to comment early next year a project of changing to pen cut Removing 1 1/2 trillion tons of overburden. That will
increase SA electricity use by 50%. This requires more currently coal powered generation.
Posted by: arnold | 09 November 2008 at 01:23 PM
arnold:
I agree with you that we will unfortunately burn all the remaining Oil and Coal reserves before we fully transition to other energy sources.
At the current rate, that will only take a few more decades.
Progressive transistion to post-oil and post-coal economies could make the fossil fuel reserves last a bit longer but not much past 2100.
In the longer term, we have to (and we will) switch to cleaner energy sources. Made made GHG emissions will go down and so will CO2 concentration a few decades latter unless we reach the (unknown) tiping point where natural sources could escalade and run out of control.
The majority don't care that much about the long term and will continue to use the cheapest energies. Elected authories cannot mandate the necessary changes in atitude because they will be quickly voted out. The situation will have to get a lot worse before the majority accepts to do something about it.
Posted by: HarveyD | 09 November 2008 at 02:36 PM
People you do now that the production of steel is finite. The world will run out of steel. Help, what will we do...
Posted by: plop | 09 November 2008 at 02:57 PM
@Morlock
As a Green I do advocate things like nuclear power and agrichar (also known as biochar). As others here will attest; I have stated a perference for biogas over ethanol, and the process that turns biomass into biogas also leaves behind biochar.
However nuclear power does have some risks to it and you have to do it the RIGHT way, so there are some countries (with a poor track record) I wouldn't like to see using it. The telling point is often whether or not they have a real plan for the spent fuel and decommissioned reactors. One way around this might be Micro Nuclear Power- http://www.nextenergynews.com/news08/next-energy-news8.13.08c.html -just truck in the reactor, plug it into the grid for 5-7 years, then truck out the whole thing to the dump site at the end. [Or, if you've buried it deep enough during its operation, leave it in place.]
Posted by: ai_vin | 09 November 2008 at 03:20 PM
@plop
Reduce, reuse and recycle. Or use something else.
Posted by: ai_vin | 09 November 2008 at 03:24 PM
The future is cloudy, as any number of scenarios could unfold, from long term economic doldrums with low GHG, to medium economic prosperity based on coal (with some nuclear, etc). I no longer see an economic situation like we've had for the last two centuries.
Posted by: Will S | 09 November 2008 at 03:52 PM
@ plop.
Your satire is well received. But I fear it went over the head of many green loons. Beware, they may actually believe such satirical nonsense, like a planet substantially composed of Iron, is in danger of "running out" of Iron, is truth.
@Harvey D,
It is welcome to recive realsitic projections such as yours, rather than Chicken-Littlism from the ilk such as poliitcal appointee, James Hansen even as he destroys the integrity of one of the four historical time-series weather data bases,. with his incomprehensible "adjustments".
James Hansen is a well-paid hired apostle of AGW, who holds no climatological or IT degrees. He has personally made millions being the agitprop mouthpiece for the cynical political loons who need an excuse to tax the polity, some more.
Historical scientific measurements from the 18th and 19th centuries measuring atmospheric CO2 levels chemically, some done by Nobel prize winners, have been purposely suppressed by AGW proponents like Calandar et al, and have now been now exposed by Dr. Georg Beck. They show that CO2 levels were naturally as high as 450 ppm at times in the climate cycle, averaging about 340 pppm, and not the supposed 280 ppm postulated for "natural" Pre-technological Man.
The joining of the Siple ice core records to Moana Loa data discarding 83 years of data, to force fit it, is a scientific scandal. The disregard of clathrate formation and such natural reductions of CO2 in the ice cores and the failure to properly account for that, is yet another scientific scandal as revealed by by former IPCC contributor Dr. Z. Jaworowski.
Posted by: stas peterson | 09 November 2008 at 04:09 PM
Quoth M stands for Morlock:
I advocate both nuclear power and agrichar. But I'm not a doomer; anyone who thinks the system is likely to collapse may oppose nuclear power because it is unlikely to be shut down cleanly.Posted by: Engineer-Poet | 09 November 2008 at 04:42 PM
Quoth the Stas-troll:
Ernst-Georg Beck's "work", if you can call it that, implies that many billions of tons of CO2 just vanished from the atmosphere without a trace. He also doesn't account for:- Large error bars in historical measurement methods.
- Systematic sources of error, such as measuring CO2 indoors in a space heated by a coal stove and lit by gas or oil lamps.
Beck's degree is in biology, not climatology. It shows. To quote a debunker:Posted by: Engineer-Poet | 09 November 2008 at 04:56 PM
People are emitting WAY too much CO2. Please correct this problem... now! AGW believers, since this is an emergency, lead the way!
Posted by: MrEnvironment | 09 November 2008 at 08:10 PM
CO2 Sequestration is just plain the wrong thing to do. Plant a tree, make seltzer water, make artificial diamonds, stop popping open soda cans, but CO2 is not a pollutant. It is essential for life on this planet. Plants die if they don't get their daily dose of vitamin CO2.
The earth has a large enough system to do self-correction as it has done many, many times - without help from mankind. Let nature takes its course!
http://peswiki.com/index.php/Directory:CO2_Sequestration
CO2 is an effect, not a cause - http://peswiki.com/index.php/Directory:Global_Cooling
http://www.maccompanion.com/macc/archives/November2008/Greenware/GlobalCooling.htm
Soon we will have to start burning more charcoal briquets (sequestered CO2) to stay warm!
Posted by: Robert Pritchett | 09 November 2008 at 08:52 PM
ROTFLMAF
Really Rob, I do hope I'm laughing with you and not at you because if by some chance you actually believed that it would just be sad.
Posted by: ai_vin | 09 November 2008 at 10:37 PM
@Engineer-Poet,
All that CO2 didn't just disappear, it returned to the planet as non atmospheric Carbon, as it naturally does.
In order for the doomers to have any prospect of convincing anyone that added trace amounts of CO2 was a bad thing, they had to dream up some way to have it persist in the Atmosphere beyond the well established laws that govern gas liquid solubility mixtures. The Science for that is well known, and codified into Henry's Law.
They managed to hypothesize and convince everyone that CO2 was special, and did so for a while, pending proof. It was officially incorporated into IPCC reports, augmenting and hyping the CO2 danger until the 2007 IPCC report.
Did you notice that the doomers can't tell you how long CO2 stays in the atmosphere? They posit it just does for 10, 20, 50, 100, 200, or 300 or more hundreds of years, depending on whatever answer that they need, at any moment.
Well the IPCC officially said in the 2007 report that they were tired of that drivel. In the next IPCC report, they intended to revert to the Laws of Solubility as constantly confirmed by numerous scientific studies, and discard the drivel that has constantly been proven to be unsupportable by experiment. They gave the doomers one more window to develop an experiment that confirms their extended CO2 persistence in spite of the hundreds of such failing experiments to date.
The Ocean does NOT have one-way trap door functions for CO2, unlike all other gases as the doomers postulate.
A CO2 water mixture dissolves and emits CO2 in a equally balanced way and achieves a normal Henry's Law equilibrium. That destroys all the doomer's hypotheses of constantly increasing and long persisting atmospheric CO2.
The actual time that Henry's Law which is used for all other gas solubility mixtures, predicts for CO2 atmospheric existence is all of 5.7 years. Period. Not any extended period of time at all. Naturally, this knocks the legs from under the doomers. When Mankind uses less CO2 producing fuels, the supposedly dangerous CO2 will disappear rapidly, in as short as a half decade. Too bad too; the Earth's biota will not be as lush as it is now, fertilized by greater amounts of needed CO2.
As to your question to where 18th and 19th century CO2 went, it went back into the soils and oceans just like Henry's Law says it does... in 5.7 years.
It did not persist for hundreds of years in the atmosphere or it would be evidence of extended persistence. Yet another experiment proving the doomers theses is pure eyewash.
Posted by: stas peterson | 10 November 2008 at 08:53 AM
ai_vin,
thanks for the link ot Hyperion's 'hype'. As a rabid anti-nuker, i found it very interesting. This resolves many objections to nukes. It's almost too good to be true.
i love the idea of eliminating the construction of those multi-billion dollar hulks that always go way over budget/schedule (passed onto the customers).
if they can also serve as 'permanent' storage facilites that would be huge.
Posted by: danm | 10 November 2008 at 10:07 AM
ai_vin,
thanks for the link ot Hyperion's 'hype'. As a rabid anti-nuker, i found it very interesting. This resolves many objections to nukes. It's almost too good to be true.
i love the idea of eliminating the construction of those multi-billion dollar hulks that always go way over budget/schedule (passed onto the customers).
if they can also serve as 'permanent' storage facilites that would be huge.
Posted by: danm | 10 November 2008 at 10:07 AM
If stas thinks CO2-emissions are no problem, why does he constantly promote nuclear power? After all, coal is cheaper and coal doesn't need to be imported.
Posted by: | 10 November 2008 at 12:25 PM
If stas thinks CO2-emissions are no problem, why does he constantly promote nuclear power? After all, coal is cheaper and coal doesn't need to be imported.
Posted by: | 10 November 2008 at 12:28 PM
Yawn This matters, why? Oh, I know Al has a $700,000,000 venture fund for cleantech!
Now I understand.
If I cared maybe -- nah I really don't.
Posted by: jv | 10 November 2008 at 02:21 PM
Stas is a one-man comedic act;
"A CO2 water mixture dissolves and emits CO2 in a equally balanced way and achieves a normal Henry's Law equilibrium. That destroys all the doomer's hypotheses of constantly increasing and long persisting atmospheric CO2."
====================================================
British Scientists Say Carbon Dioxide Is Turning the Oceans Acidic
Whether or not it contributes to global warming, carbon dioxide is turning the oceans acidic, Britain's leading scientific organization warned yesterday.
In a report by a panel of scientists, the organization, the Royal Society, said the growing acidity would be very likely to harm coral reefs and other marine life by the end of the century.
"I think there are very serious issues to be addressed," the panel's chairman, Dr. John Raven of the University of Dundee in Scotland, said in an interview. "It will affect all organisms that have skeletons, shells, hard bits that are made of calcium carbonate."
Posted by: Will S | 10 November 2008 at 04:56 PM
All that CO2 didn't just disappear, it returned to the planet as non atmospheric Carbon, as it naturally does.
Ah, I see. Man increases the rate of emission of CO2 into the atmosphere by a large factor, and nature magically increases the rate of CO2 removal from the atmosphere to exactly compensate.
Drugs are bad, mkay?
Posted by: Paul F. Dietz | 11 November 2008 at 04:41 AM
If all studies were combined, what would be the CO2 pre-industrial era average level?
Could it be close to the current level of about 385 ppm?
It seems that it could be as high as 300 ppm with +/- 125 ppm variations or cycles.
If pre-industrial era CO2 levels varied from 175 ppm to 425 ppm, is the current 385 ppm still within past changes or swings?
If the current trend continues, we may very break the all time high level by 2030. What would be the effects of an extra 50 or 100 ppm by 2130?
Does anybody have the answers?
Posted by: HarveyD | 11 November 2008 at 09:11 AM