GEOMAR researchers show limitations and side effects of large-scale climate intervention
With global greenhouse gas emissions continuing to increase proposals to limit the effects of climate change through the large-scale manipulation of the Earth system are increasingly being discussed. Researchers at the GEOMAR Helmholtz Centre for Ocean Research Kiel have now studied with computer simulations the long-term global consequences of several “climate engineering” methods.
They show that all the proposed methods would either be unable to significantly reduce global warming if CO2 emissions remain high, or they could not be stopped without causing dangerous climate disruption. The study is published in the international journal “Nature Communications”.
Despite international agreements on climate protection and political declarations of intent, global greenhouse gas emissions have not decreased. On the contrary, they continue to increase. With a growing world population and significant industrialization in emerging markets such as India and China the emission trend reversal necessary to limit global warming seems to be unlikely. Therefore, large-scale methods to artificially slow down global warming are increasingly being discussed. They include proposals to fertilize the oceans, so that stimulated plankton can remove carbon dioxide (CO2) from the atmosphere, or to reduce the Sun’s incoming radiation with atmospheric aerosols or mirrors in space, so as to reduce climate warming.
All of these approaches can be classified as ”climate engineering”. ”However, the long-term consequences and side effects of these methods have not been adequately studied,” says Dr. David Keller from the GEOMAR Helmholtz Centre for Ocean Research Kiel. Together with colleagues the expert in earth system modelling has compared several Climate Engineering methods using a computer model. The results of the study have now been published in the internationally renowned online journal “Nature Communications”.
”The problem with previous research was that in most cases the methods were studied with different models using different assumptions and different sets of earth system components, making it difficult to compare the effects and side effects of different methods,” Dr. Keller says. He adds: “We wanted to simulate different climate engineering methods using the same basic assumptions and Earth system model”. For their study, the researchers chose five well-known climate engineering approaches: The reduction of incoming solar radiation, the afforestation of large desert areas in North Africa and Australia, and three different techniques aimed at increasing ocean carbon uptake. In parallel, the scientists also simulated future changes in the Earth system without climate engineering, based on the high-CO2 emission scenario used by the UN IPCC.
Even under ideal conditions assumed in the simulations, the potential benefits of the various climate engineering methods were limited. Only a continuous reduction of solar radiation could prevent the Earth from warming significantly. The afforestation of the Sahara and the Australian outback, however even caused some additional global warming: “The forests removed carbon dioxide from the atmosphere, but at the same time the earth’s surface became darker and could store more heat,” Dr. Keller explains of this phenomenon. All of the other techniques showed significant side effects, too. For example, the fertilization of the oceans allowed plankton to remove CO2 from the atmosphere, but also changed the size of ocean oxygen minimum zones.
Another important question for the researchers: What happens if climate engineering is stopped after a few decades for technical or political reasons? ”For several methods we saw a rapid change in the simulated climate when climate engineering ended,” says Dr. Keller. For example, if after 50 years the sun’s rays were no longer partially blocked, the Earth warmed by several degrees within a few decades. “This change would be much faster than the current rate of climate change, with potentially even more catastrophic consequences,” says Keller.
The study is the basis for further research in the priority program “Climate Engineering: Risks, Challenges, Opportunities?” of the German Research Foundation (DFG), coordinated by co-author Prof. Dr. Andreas Oschlies from GEOMAR. “In addition to natural science studies, we also want to learn more about the potential social, political, legal and ethical aspects of proposed climate engineering methods. For one thing, this study clearly shows that there would always be many losers in addition to possible winners. Some side effects would even affect future generations. A decision for or against climate engineering thus would have to be considered carefully and be fully legitimized, and must thus be based on a much better understanding of possible effects, uncertainties and risks than we have today,” says Professor Oschlies.
Reference:
Keller, D. P., E. Y. Feng, A. Oschlies (2014): Potential climate engineering effectiveness and side effects during a high CO2-emissions scenario. Nat. Commun. 5: 3304, http://dx.doi.org/10.1038/ncomms4304
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The biggest thing we could do would be to get the Chinese to clean up their power plants so that less soot is deposited on arctic ice.
Murray Leinster invented the concept of climate engineering in a science fiction novella that was one of four in a collection called “The Planet Explorer”, written IIRC back in the 1950’s. In it, sodium was lofted into orbit around a planet and vaporized to form a kind of “permanent comet’s tail” around a planet — in the context of the story to prevent the FREEZING OUT of CO_2 in a marginally inhabitable ice world that would have killed its GHE altogether and caused its temperature at the poles to drop below the dew point of oxygen and nitrogen, at which point the atmosphere would have fallen as a deadly rain and turned the planet into an airless iceball. Basically, the tail formed an additional, permanent, solar heated GHG layer that reradiated in the VISIBLE, brightening the entire sky more than it diminished direct incoming sunlight via a higher albedo.
Whether or not the concept is plausible or could be reworked for the Earth, it is enormously risky. In the book it didn’t matter. The people who tried this had nothing to lose — they were days away from a liquid oxygen bath that would have exterminated all life human or otherwise on the planet permanently. On the Earth, it would be difficult to predict the sign of the effects of such a cloud, presuming we could afford to loft enough ionic material to create one.
We still do not know or understand the ice age that occurred during the Ordovician-Silurian transition, which was actually colder than the present (which is the second coldest planetary age in the last 600 million years, ALMOST as cold as the OS transition). It happened when atmospheric CO_2 was 7000 ppm, and peaked with the CO_2 at 4000 ppm — that would be 10x the current level. There are various “theories” to explain it, but they are (frankly) out there in the advanced science fiction level, since we have absolutely no way to go back in time to validate any of them — the Sun drifted through a huge cloud of interstellar gas that blocked sunlight; the Sun is slowly varying variable in the long term much more than we think possible or can detect now, even with astronomical observation of Sun-like stars; dark energy or dark matter “matters”; complicated orbital resonances — who knows? We don’t know why the Pliestocene (the current ice age) began — how could we know what started the one at the OS transition?
Monkeying with this system is dumb, in both ways! Yes, it is dumb to bump CO_2 concentrations without any real understanding of the consequences, but this is a cliff we’ve already jumped off and it will take us decades to understand the trajectory we are following or the landing point (if any, in an ever-changing climate WITHOUT CO_2 complicating the issue). It is even dumber to take any action that is supposed to “cancel” an effect of the CO_2 when we don’t even know what the effect we are trying to cancel really is.
Yesterday I posted remarks about properties of Lotke-Volterra (predator-prey) and other sets of linear or nonlinear coupled ODEs that produce quasi-cyclic orbital trajectories around one or more strange or normal attractors, as this is the general class of differential systems to which the climate system belongs. In such a system measures one might take — such as increasing the number of foxes relative to rabbits because one perceives that the current trajectory of rabbits is “catastrophic” — can have unintended consequences, such as kicking the existing trajectory into a trajectory that represents an even LARGER orbit around the attractor, one that will actually carry the system eventually even CLOSER to a true catastrophe (extinction of both species).
One day I might make a few remarks about control theory and positive or negative feedback as well — how enormously difficult it is to artificially balance dynamic nonlinear systems that are supposed to be naturally stable once they deteriorate to where they are not naturally stable. This is basically what physicians have to do with very old people — they treat high blood pressure, but the treatment affects something else, and when they treat that it affects something ELSE, and when they threat THAT it screws up their blood pressure — and all the time the patient is at risk of one or another of these subsystems collapsing as a consequence of the overall attempt to keep them all in the comparatively narrow range of values that are normal enough to sustain “life”.
Empirical therapy on the basis of a linear empirical model is all well and good in the short run, but in the longer run it can easily be a cure worse than the disease.
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Actually one major value of a sun-blocking climate engineering test would be as an experiment to test Willis Echenbach’s theory. Wouldn’t it be a shock to the Climate-Forcers to see the earth adjust and let more energy in to compensate for the albedo change as in the case of the recovery and compensation for temporary cooling effect of volcanic aerosols that Willis discovered? What would happen would be clouds would disappear in the Tropical Convergence Zone and allow what sun gets through to do its counter engineering work.
At least some news sources are asking others before publishing the Geo-nightmare stories.
Seen on Drudge about three 1000′ high x 150′ wide x ??? miles long ‘Tornado Blocking Walls’ across ND, OK and TX. (Cheap at $600 Million per mile). http://www.usatoday.com/story/weather/2014/02/25/giant-walls-tornado-alley/5808887/
Can they at least get a few Construction Engineers and Material Handling specialist to review their hair brain ideas before pouting off their idiocy.
There isn’t anything here that needs studying, whether there are side effects or not; the very idea of manipulating the atmosphere is insane. What is this… The Truman Show? Me personally, i would rather be dead.
No thanks, i like my arctic high pressure cold,clear and blue.
Unintended consequences can make things worse.
Stephen says: February 26, 2014 at 12:11 am — Precisely.
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@ur momisugly Gary Pearse — How are you, ol’ WUWT buddy ol’ pal? Long time, no “connect.” LOL.
Sounds GREAT! I’m going to apply for a grant today!
Grant App.: “O Mighty, Omniscient, Science Bishops, May You Live Forever, we come before you today humbly beseeching…… and this will almost certainly stop the very likely warming effect of human CO2 because water is a catalyst and moving it around reduces its flux capacity and so forth. The End.”
What will we build that pipeline out of? LOL, PLASTIC (heh, heh, you see, it is actually a secret plan by the petroleum industry to make money — bwah, ha, ha, ha, haaaaaaa —
— and, so long as there is significant free-market competition, I say, God bless them!).
With a nasty legal bunfight over dumping iron dust (allegations of mis-representation and assault fly back and forth): http://www.vancouversun.com/news/Ocean+fertilization+guru+made+misleading+statements+Haida+counter+suit+claims/9549731/story.html
Wasn’t the Gulf oil spill a living experiment of “ferilizing” the ocean? What happened? The oil was eaten up with organisms naturally… Maybe that’s what caused the pause /sarc.