Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.


Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup


All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Donate

Twitter Facebook YouTube Pinterest

RSS Posts RSS Comments Email Subscribe

Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...

Keep me logged in
New? Register here
Forgot your password?

Latest Posts


Climate Hustle

Three new studies illustrate significant risks and complications with geoengineering climate

Posted on 5 August 2010 by angliss

Guest post by Brian Angliss

In 1992, the National Academy of Sciences defined "geoengineering" as the "large-scale engineering of our environment in order to combat or counteract the effects of changes in atmospheric chemistry." The most significant changes in atmospheric chemistry today are the emissions of greenhouse gases into the atmosphere by human activities, especially but not limited to carbon dioxide (CO2). In recent years, climate scientists have begun to investigate whether or not geoengineering is practical as a means to give humanity the time it needs to adapt to climate disruption or, as some would prefer, a means to controlling the environment such that no changes in energy consumption patterns are even necessary.

The results of three different geoengineering studies were recently published, and all three found that geoengineering would be fraught with unintended and unexpected consequences.

The first two studies looked into the effects of pumping gigatonnes of sulfur dioxide (SO2) into the stratosphere. This method of geoengineering works by decreasing the amount of energy that reaches the Earth’s surface by increasing how much light reflects off the upper atmosphere. Scientists know that this would work because the Earth cooled for a few years after the eruption of Mt. Pinatubo blew large amounts of SO2 into the stratosphere in 1991. But what scientists don’t know is what the side effects of using SO2 in a long-term geoengineering project would be.

The first study was performed using two different climate models to project what would happen as a result of pumping 5 Tg per year (5 Mt per year) of SO2 into the stratosphere. The scientists ran the models over several decades and compared the results to a baseline CO2 emissions scenario (A1B) assuming rapid economic growth and spread of new energy technologies, a maximum global population of about 9 billion people, and reduced disparities between wealthy and poor nations.

The simulations showed several things. First, continuous pumping of SO2 into the stratosphere cooled the average global surface temperature in less than a decade to approximately pre-industrial temperatures. Second, injecting the simulated amount of SO2 delayed the increase in global mean temperature approximately 30 years. Third, when the temperature returned to approximately the same level as the simulation starting point, the injected SO2 had significantly altered the global temperature pattern from the 1990-1999 means. For example, the Amazon basin was about 1 K hotter, the Arctic still showed polar amplification due to losing very reflective sea ice, while Australia was actually cooler and sub-Saharan Africa were generally cooler. As the authors pointed out, this means that

increases in GHG concentrations can still have a profound impact on regional climate even if geoengineering is successful in counteracting any change in global-mean temperature.

Fourth, along with changes in average global surface temperature, there are also changes predicted in global precipitation. For example, the simulation projected that much of the US Midwest would dry out along with the Texas and Mexican Gulf coasts and the northern area of South America. On the other hand, inland areas of sub-Saharan Africa would get wetter along with northeastern Australia and the Siberian coast.

Figure 1

The dashed lines in Fig. 1 (Fig 3 from the paper, at right) illustrate the fifth result of the simulations, specifically the response of the average global surface temperature if the SO2 pumping was ever turned off. The dashed line in Fig 1a (HadGEM2 model) shows that the temperature rise after turning of the SO2 is projected to be more than double the highest rate of temperature increase from the A1B scenario itself. While the simulation shown in Fig 1b (ModelE model) behaves somewhat differently, both show a rapid increase in temperature starting immediately after the SO2 pumping is turned off. Given there is concern about whether ecosystems and nations could adapt to the rate of global temperature increase defined in the baseline scenario, doubling that rate should be cause for greater concern.

The authors of the study also called for other climate modelers to attempt to duplicate this investigation’s results using other climate models and, ideally, using a standardized set of test conditions in order to make direct comparisons easier.

While the first study found that average global surface temperatures could be delayed by about 30 years by pumping 5 Tg per year of SO2 into the atmosphere, the second study used a different simulation to determine what would happen if the amount of SO2 was increased continually to keep the average global surface temperature stable.

Like the first study, the second study started from the A1B emissions scenario, but then ran 54 different simulations where differing amounts of SO2 were pumped into the stratosphere in order to counteract and then stabilize the average global surface temperature at various points. In addition, the researcher divided up the world’s land area into different regions in order to estimate what the overall effects of geoengineering would be on each region.

Figure 2 (click for larger version)
What the researchers found was that there appeared to be a fundamental trade-off involved in using SO2 to stabilize the average global surface temperature. Specifically, the results appeared to show that more stability in global temperature meant less stability in regional precipitation. In addition, the researchers determined an "optimal" climate where the changes in both temperature and precipitation were held as low as possible, and then they mapped those climates into Figure 2 (Fig. 4 from the paper, at left). Fig 2a & b show the optimal climate in the 2020s vs. the 2070s respectively, following 15 or 65 years of non-stop SO2 injection into the stratosphere. The red and orange regions represent those areas where "optimal" is achieved using less SO2 pumping while the blue and dark green regions are those areas where more SO2 pumping is "optimal."


What Figure 2 shows us is that there’s a number of clear differences between those areas where more SO2 pumping would be preferred vs. those areas where less SO2 is better. For example, the northern hemisphere generally wants more SO2 than the southern hemisphere. But perhaps the most significant is that the developing world, especially western Africa, India, and the island nations of south-east Asia are all going to want less SO2 pumping, while the developed world (the US, Europe, China, Russia, Japan) will all want more SO2 pumping.

This split between north and south, developed vs. developing is very likely to cause conflicts between regions and nations that will complicate any SO2-based geoengineering system. As the researchers point out, these results

suggest that as our understanding improves, serious issues of regionally diverse impacts and inter-regional equity may further complicate what is already a very challenging problem in risk management and governance.

While it’s theoretically possible that more advanced geoengineering technologies than simple SO2 pumping could be tuned to get the regional responses to be closer to "optimal," no technology current exists or has even been proposed that could, for example, bring the optimal precipitation and temperature response of India more in line with that of China. Furthermore, this research focused only on two climate metrics - temperature and precipitation - while the paper says there are any number of other metrics that could be optimized for, such as not shutting down a monsoon or retaining sea ice. And the regional effects are also not the only issue, as conflicts between nations/regions and industries (like maritime shipping) could also develop over such things as the importance of retaining summer sea in the Arctic.

The results of the two SO2 studies agree broadly with each other - pumping SO2 into the stratosphere will cause unintended changes in precipitation globally but with some regions faring better than others. The second study, however, only ran their simulations until 2070. In reality, unless some method of accelerated CO2 removal was implemented, the geoengineering of the stratosphere with SO2 would have to go on for centuries.

The third study investigated the effects of an ideal system that was able to remove CO2 from the atmosphere to project what effect it would have on average global surface temperature.

The researchers ran three different simulations. The first, baseline simulation followed a high CO2 emissions scenario until 2049 and then, in 2050, dropped the emissions instantly to 0 but did not otherwise reduce the CO2 in the atmosphere. In the second simulation, the emissions not only dropped to 0 but all the excess CO2 already in the atmosphere was also instantly removed, but any extra CO2 later released into the atmosphere by the ocean or the biosphere were not removed. The third simulation also removed any extra CO2 added to the atmosphere by the oceans and biosphere as it was added, simulating continued CO2 removal by some geoengineering technology.

Figure 3

Figure 3 (Figure 1 from the paper, at right) shows the CO2 concentration and the global mean surface temperature as they change over the course of the simulations. The first simulation described above ("zero CO2 emissions") is the dashed black line, the second simulation (one-time CO2 removal) is the gold line, and the third ("maintenance of pre-industrial CO2") is the red line.

There are a number of key features of these two graphs. The first key feature is that CO2 concentration doesn’t fall rapidly even after CO2 emissions have been reduced to 0 (top graph, black dashed line). This is because the lifetime of CO2 emitted into the environment is thousands of years, so the CO2 concentrations fall about 100 ppm over the course of 450 years unless the CO2 is actively removed from the atmosphere. The second key feature is that temperature continues to increase even after all CO2 emissions are stopped (bottom graph, dashed black line). This is because the ocean stores massive amounts of energy and it responds relatively slowly. As a result, the global mean surface temperature in 2500 is simulated to be about the same as in 2050.

The third key feature is that even after all the anthropogenic CO2 is removed from the atmosphere in 2050, the CO2 concentration rebounds within a decade or so to around 360 ppm, restoring almost half of the CO2 back into the atmosphere (top graph, gold line). As a result, the effect of the one-time CO2 removal on global mean surface temperature is to only cut the temperature by about half instead of fully back to the pre-industrial level (bottom graph, gold line). The reason this happens is that much anthropogenic CO2 is absorbed by the ocean and the biosphere, and when the atmospheric CO2 concentration drops, the oceanic CO2 comes out of solution and the excess CO2 held in the biosphere gradually re-enters the atmosphere as the fertilization effects of excess CO2 fall.

The fourth key feature is how fast the temperatures respond to CO2 removal. If it were physically possible to remove all the anthropogenic CO2 from the atmosphere, then the global temperature would fall by about a degree Celsius within less than a decade (bottom graph, gold line). And if the excess CO2 being emitted by the oceans and biosphere back into the atmosphere were also removed via some technology as they were released, then the temperature would fall to nearly pre-industrial levels within 70 years (bottom graph, red line).

Beyond the fact that there exists no technology that can instantly remove and sequester hundreds of Gt of CO2 from the free atmosphere, this study points out a number of problems. First, merely transitioning to zero CO2 emissions by capturing CO2 from power plants and switching to renewable energy sources won’t enough. Second, in order to return the global mean surface temperature to about pre-industrial levels, the total amount of CO2 that would need to be sequestered is almost equivalent to the total amount of CO2 that was emitted in the first place. That’s a LOT of CO2, and so CO2 removal will be a long-term and difficult process.

Combined, these three studies paint a bleak picture of geoengineering that runs counter to some proponents' claims. Pumping SO2 into the stratosphere can generally delay or counteract the increase in average global surface temperature, but at the cost potentially serious changes in precipitation and the accompanying changes in various regions’ ability to sustain ecosystems and civilization. There will be other unintended and unexpected consequences from using SO2 to geoengineer the climate, and given the inability of international bodies to presently manage conflicts over climate disruption, it’s unlikely that those same bodies will be able to manage the regional problems that will occur as a result of geoengineering. While more research into better models, the effects of SO2 pumping on sea ice and monsoons, and more effort on standardization of models and tests are all warranted, there are some issues that no amount of geoengineering with SO2 can impact, such as the fact that only reducing CO2 concentrations can do anything for ocean acidification. And while removing CO2 out of the atmosphere directly may well become a viable means to geoengineer the Earth’s climate and slow or reverse the increase in global mean surface temperature, the total amount of CO2 that needs to be removed is more than the entire amount of CO2 present in the atmosphere in any one year. And no CO2 removal technology will be effective unless humanity also stops emitting CO2 by burning fossil fuels.

Climate disruption is a hole, and before we consider how best to use geoengineering to build us a ladder out of the hole, we have to stop digging ourselves even deeper.

You can read Brian's original post here.

0 0

Bookmark and Share Printable Version  |  Link to this page


Comments 1 to 50:

  1. The first and 2nd study have conclusions that should surprise no one. The idea of geoengineering by dumping huge amounts of SO2 into the air has always been a bad one. This should have been obvious.

    It is the third study that interests me most. For it shows that even the best case scenario of geoengineering is nowhere near as good as emission reduction.

    That, of course, is the conclusion we need to get people to realize must be accepted: we must reduce emissions ASAP, we really should have done it two or more decades ago. There can be no excuse for continuing at current levels, far less for increasing it more.

    Yet we still have lemmings bent on pushing us all over the cliff by digging up fossil fuels even more furiously, fighting over oil reserves around the North Pole!
    0 0
  2. There will come a time to panic. We should study geoengineering now so when that time comes we might avoid the worst side effects of whatever geoengineering systems we use. Maybe a little bit of this and a little bit of that will not be as bad as a lot of one.

    The climates where you live and I live are hot, white roofs make so much sense. If all new houses in Australia had a white roof that alone would make a significant difference. Yet I am told again and again that black looks good. We are getting so close to brownouts how cool will the black be with no air conditioning when it is century plus in the water bottle.

    What hope is there when we will not even use the no cost options?
    0 0
  3. Where would one find giga tonnes p.a. of sulphur dioxide to pump into the atmosphere anyway?
    0 0
  4. I'm not all that enamoured of the bright blinding white roof, but what's wrong with the softer creams and greys? Who decided that black and chocolate brown are a good look on a roof! - they're a neat accent on doors and window frames, but more is just plain depressing.

    I think a lot of people have yet to learn the "less is more" principle in exterior decoration.
    0 0
  5. Wouldn't pumping SO2, while not reducing CO2, continue ocean acidification?
    0 0
  6. Ocean acidification, yes. That was my first reaction too.

    It wouldn't much matter if the temperatures were livable if the food supply is crashing around us. (I'm ignoring the intrinsic value of maintaining a rich biosphere here.)
    0 0
  7. There's a whole parallel debate about deep sea carbon sequestration including sequestration in deep ocean sediments which might be worth a post one day.
    0 0
  8. Worth highlighting the need to continue pumping S02 into the air for centuries.

    If a science fiction author wrote a story about a civilization that had doomed itself to pumping S02 into its planetary atmosphere for hundreds of years, we might say, "That's not plausible; if they could do that, they wouldn't have gotten themselves into such a jam in the first place." Truth is stranger than fiction?
    0 0
  9. Another interesting thing about all of these schemes is the impact they'll have on energy requirements. It's darkly amusing to note, the same ideas that would allow us to continue using coal would also require burning yet more of the stuff. "Laughing all the way to the bank" is the phrase that comes to mind.
    0 0
  10. I forgot to say "thank you" for a very helpful article.
    0 0
  11. Great post. A lot of talk like this reminds me of the RAMA series by Clark and Lee, where there was a human population had an enclosure which had an alien super-computer running the weather algorithms. They were told not to use wood fires (they didn't really need them, as the weather was quite pleasant anyway) but decided to cut the trees down anyway and even when a big screen in the sky lit up to tell them to stop, they didn't.
    In the end they broke out, hacked into the super-computer (and could barely control the weather still) and took over another enclosure.
    It seems Clark had picked the current events as well..
    I liked how you summed it up, it's a bit like a line from the Simpsons, "Dig UP stupid!"
    0 0
  12. John Chapman - The SO2 is readily available from the exhaust of coal power plans.

    doug bostrom - Scientific American had an article on a free-atmosphere CO2 removal system that's being developed that is the size of a shipping container. IIRC, initial testing indicates that it's reasonably energy efficient, but I don't recall the details.

    Tony O - I'm all for these studies, as well as limited real world experiments, as they prove concepts and help discover those "unintended and unexpected consequences." For example, there was a test of iron fertilizing in the Southern Ocean which discovered that the unintended consequence of an algal bloom was a population spike in algae-eating shrimp that ate the algae before it could die and sink to the bottom. I'd love to read the report on the tests to see if they think the test still sequestered any carbon.
    0 0
  13. angliss: your comment prompted a quick google search, and I came up with this article, which (along with the referenced comment) suggests that CO2 removal will cost 933kWh per ton of CO2 extracted with that method. There may be others, but that's a whole lotta energy (granted, the bulk is thermal energy that may be provided readily by solar concentrator systems).
    0 0
  14. I'm trying to think of a way to get C02 out of air with a reasonably small energy input and nothing's coming to mind. There are some hills to ascend even if scrubbers are very efficient.

    More on atmospheric scrubbing tech here: Pulling CO2 from the Air:
    Promising Idea, Big Price Tag

    Also some helpful background at RealClimate which mentions off-grid thermal air capture, something promising-sounding.

    It's all probably worth another post!
    0 0
    Response: Someone tweeted me this new solar powered carbon scrubbing technology which makes some pretty big calls re it's potential. Still, interesting technology...
  15. doug_bostrom #14
    Interesting article. In commenting about these "options", it includes the following...

    "launching mirrors into space to deflect the sun’s energy away from Earth — could have far more unpredictable and potentially destabilizing effects."

    Funny how the opposite, the proliferation of "black asphalt highways" arent considered "destabilizing".

    Just think how much white paint would be needed to neutralize the extra heat coming off our roads.
    0 0
  16. Something which is often forgotten is that we are already unintentionally using geo-engineering through industrial SO2 emissions and through CO2 sequestering and albedo changes through forestry.

    Even if we reduce industrial emissions to pre-industrial levels these may have unforeseen consequences on the climate since the level of greenhouse gases is now higher and polar ice area reduced, so we simply create more new climate scenarios.

    So geoengineering is here to stay, its just whether we choose to try and manage it or not. This poses an interesting legal situation as well. Will a nation be held more culpable if they intentionally rather than unintentionally geoengineer change, and if something goes horribly wrong?

    Sorry for opening a can of worms!
    0 0
  17. RSVP, even the Sherwin Williams approach might not be enough when it comes to white paint. Actually, I suppose it might be but we'd all be glued down like hapless insects once the paint dried.

    The benefit of white roofing is a lot about reducing cooling loads though apparently more broadly applied lighter colored pavement etc. can also help reduce the dreaded UHI effect thus leading to further cooling load reductions. The net global albedo effect is insignificant.

    Leading to the inevitable discussion of what latitude suggests going to a darker roof but that's even farther off-topic.
    0 0
  18. One other consideration: We have 2 options, basically.
    - try to create a self-sustaining climate, a system that in the long run won’t need any human ‘help’ (rather cynical that) to maintain equilibrium.Removing the superfluous CO2 from the atmosphere as a one-time action and switching to renewable energy falls into that category.

    - try to control the climate, starting from now, and ending … never. Geo-engineering firmly falls into this second category. If we choose for this option, we will have to keep monitoring and steering to stabilize our climate. But this also presupposes that our current technological civilization will never break down. Which is not realistic. Every human civilization in history – the egyptian, the roman, the aztec – has collapsed at some point in time. We must take into account a possible future human society that may not have the technical means or knowledge to continue this work.
    0 0
  19. Nicely put, Ann.

    "Don't it always seem to go
    That you don't know what you've got
    Till it's gone
    They paved paradise
    And put up a parking lot."

    --Joni Mitchell
    0 0
  20. Isn't the simplest and most sustainable way of CO2 sequestration increased production rate and decreased decomposition rate of organic material?

    Re rooftops: Solar cells or even better, combination of solar and thermal collectors seem to me a better alternative than white paint. Whenever there is a significant cooling need because of the sun, much of that can be covered by absorption type cooling, driven by excess heat from solar collectors. The most important thing with such measures is that they can directly replace fossil energy use.
    0 0
  21. Ann, while human cultures have collapsed there have been few instances of technological back-treading... not even the religiously enforced ignorance of the 'Dark Ages' stopped technological progress. It caused some 'heathen' advances to be lost to PART of the world for a few centuries, but history shows that once technological breakthroughs are made they are seldom lost.

    Of course, while the internet is becoming a vast repository of human knowledge it is slowly trending towards being the ONLY such repository... suggesting that some future cataclysm which wiped out our computer networks could set humanity back in a way not previously experienced. Hopefully no such cataclysm will occur... or we'll have developed multiple localized backups of vast amounts of information by then.

    On geo-engineering... we're going to have to go there (even more than we already have) eventually. Yes, we can deal with AGW more effectively by reducing emissions. Yet somewhere several thousand years down the road we're looking at another ice age unless we change things. Sooner or later we're going to have to find a way to reverse the ongoing collapse of life in the oceans. Go way out and the Sun is going to become a problem as it gets hotter. Et cetera.

    The fact is humanity is going to need geo-engineering. Hopefully we'll be smart and buy ourselves enough time to understand the complexities rather than jumping in blindly... but we may not have a choice if we continue mucking things up the way we have been for another couple of decades.
    0 0
  22. I think the potential political fallout of these kinds of geoengineering are grossly underestimated. (To say nothing of the eventual political fallout of AGW, in general.) What happens if China decides to start pumping SO2 into the stratosphere and it dries out the US midwest? Or if the US starts doing it, and it causes massive flooding in China or India? There are a large number of destabilizing scenarios, and political leaders are always happy to blame someone else for the problems in their country. If the situation deteriorates, you get military strikes on the suspect facilities, and it escalates from there. Sure, a nuclear war would result in global cooling, and reduced carbon emissions from industry, but I don't think it would be in civilization's best interest.
    0 0
  23. CBW: I think you've hit the nail on the head there. Who will oversee the geo-engineering... if we can't get global agreement on reducing emissions, how are we going to get agreement on an organisation to change the weather?

    And if we do create an organisation to carry out geo-engineering how do we stop it getting sued?

    Where I see a huge problem is in deciding what geo-engineering to carry out, because it will inevitably involve models. Given that the deniers are so anti-models, how can they support geo-engineering?
    0 0
  24. All of these potential 'solutions' seem to require copious amounts of energy to implement -- something that will become more and more in short supply for the foreseeable future. Humans really need to learn to enjoy life without consuming energy. Until we've cracked fusion (or something similar) anything else is disastrous.
    0 0
  25. Why can't C02 be removed from the atmosphere in a manner something like the Haber process?

    The Haber process removes nitrogen from the air for use as fertiliser. It wasn't an easy process to perfect, and won Haber the noble prize.

    If huge amounts of energy are required, well, there is- for example in Australia's outback-we have some of the largest uranium deposits in the world, one of the most politically and geologically stable areas, and hardly anyone lives there. Nuclear reactors could be used to drive the removal of c02 from the air.

    0 0
  26. Thingadonta, what's interesting (to me) about thermal processes of the sort you refer to is their neat fit with sometimes fickle sunshine. It would not really matter exactly when C02 was extracted from the air, just that the average amount over time fit the requirements. If a solar thermal extractor were idle for a week because of inclement weather nobody would be inconvenienced.
    0 0
  27. Ann #18
    Well put.
    0 0
  28. The proper Fig 3 is this one.
    0 0
  29. It's a real pity that there's so little recognition of the actual complexities of the jeopardy we face, as it means that widespread mal-assumptions obstruct appropriate strategy. This greatly reduces the chance of avoiding catastrophic outcomes.

    For example, how many people posting here factor in the 30 to 40-year timelag on emissions' warming potential coming into effect ? This timelag not only means that present warming is from around 330ppmv in the mid '70s, and that we'll see what 350ppmv does in about 12 years time, and that we'll see the effects of 390ppmv in about 2045. It also means that a radical cut of global GHG outputs - say 98% by 2040, would be similarly timelagged in effect, which is anyway merely to stop adding to the problem. Entirely necessary, but grossly insufficient.

    Meanwhile, the interactive feedbacks of forest combustion, permafrost melt, cryosphere decline, etc, are now evidently already accelerating at very damaging rates.

    Addressing the actual problem of excess airborne stocks of GHGs is a very different matter to merely ending additions to them. Those who urge that we leave it to nature are patently unaware of the practicalities. Nature, in the form of carbon sinks, has been removing around 1.0ppmv/yr of CO2, but with ocean acidification and warming even this small service is forecast to decline. Meaning that even with a rapid end to anthro emissions, airborne GHG stocks would not decline significantly for many decades. That period would be greatly extended by marine stocks of anthro-CO2 being returned to the atmosphere, with the timelag then still further delaying the effect of those changes.

    Meanwhile, the feedbacks would have had well over a century of acceleration and of potentially massive release of additional GHGs, and the oceans would be dead.
    In short, the problem of excess airborne anthro GHGs is way beyond nature's capacity to handle in a manner we can survive.

    We dropped the spanner in the works – we have to get it out.

    Unwelcome as it may be to received wisdom, under the NAS definition, this means applying geo-engineering techniques [Geo-E]. It has nothing whatever to do with the genocidal corruption that seeks Geo-E as a means to maintain its emissions and thus shareholder profits.

    The primary form of Geo-E is carbon recovery, which attracts little opposition in principle. If it is done via sustainable forestry optimised for biochar, fuels and biodiversity (using around a gigahectare of non-farm land) together with biomass wastes, it is estimated that over 4ppmv/yr of CO2 could be recovered. In addition, it would not only greatly raise farm yields (as is already becoming critically necessary) and provide liquid & gas fuels in rural areas, but also provide vast additional habitat for hard-pressed biodiversity.

    There are also various proposed techno options for carbon recovery, but none as yet are self-funding, nor socially or ecologically constructive, nor demonstrably practical on the required scale of handling gigatonnes of carbon per year.

    The limitation of carbon recovery is that it cannot be done fast enough to keep ahead of the feedbacks’ acceleration. It would certainly take over half a century to recover sufficient airborne stocks, which would then be replenished with the marine stocks seeking equilibrium, and thus needing further decades for their recovery.

    In short, to avoid the feedbacks swamping the atmosphere with their emissions while carbon recovery is under way, they must be decelerated back to an insignificant level of output. That imperative demands the use of Geo-E in the form of albido restoration for the period of carbon recovery needed to restore 280ppmv of airborne CO2. Nothing else, so far as I can see, will prevent the feedbacks from imposing utterly catastrophic change.

    As to which of the many albido restoration techniques should be applied, there is great and urgent need of both discussion and research. Personally I see little prospect of sulphur aerosols being viable due to their dubious net benefits affecting negotiations. My own (far fetched) favourite would be large orbiting facilities robotically producing and releasing massive tonnages of cloned sterile thistledown into the stratosphere. (Max albido for minimal impact).

    The most promising option appears to be the Jetspray vessels that Professor Salter has been working on for some years. In being wind-powered and in putting up spray to generate additional bright clouds where and when appropriate it avoids both the pollution and control problems of sulphates. But given that is has yet to reach protototype stage, its eventual function is far from proven.

    However, until there is public recognition of the need for appropriate Geo-E, we are still just wasting more precious time. For this reason it seems a real shame that all three of the studies posted above should fail to seek the most viable formats for a practical program to meet the indisputable need of Geo-E.


    0 0
  30. Thank you for catching that, Jenikhollan. I'll update the post to the right figure when I get home tonight.
    0 0
  31. Why would anyone sane like to suggest to pump something we been working very hard to get rid off for very well known reasons into the atmosphere?
    0 0
  32. Because they're desperate, batsvensson. The exact nature of their desperation varies from case to case. One person might want to continue a lifestyle, another an income stream, yet another may be concerned about other problems and failing to think it all the way through. Or a mixture of all three.
    0 0
  33. batsvensson - there's also the factor of first presentation.

    When Creutzen proposed using sulphates as a replication of volcanoes' emissions with their proven cooling effects, there were only bizarre space-mirrors, etc, and ocean fertilization under discussion, so his seemed like a great idea and, (with the aid of coal-burners who foresaw a cost saving) it gained a lot of traction.

    In reality, regardless of popular assumptions, sulphates are not the automatic choice as distinctly preferable options have since come into view.

    Yet this is not to criticize Creutzen, who knows full well the potential catastrophe of the runaway feedbacks - against which even serious global sulphate pollution would be relatively small beer.


    0 0
  34. Figure 3 has been corrected.
    0 0
  35. LewisC,

    I come from a country that is known to have the cleanest fresh lakes, soil and air in Europe. Despite this forests was dieing and lakes life was wiped out due to acid rains.

    Since the 70ties chalk has been dumped in lakes and forest has been spray from the air with chalk powder to combat acid rains and prevent forest and lakes from dying. All this in the cleanest country of Europe – imagine the rest... This and this is what happen. Historical architecture was literally falling apart in front of our very eyes due to acid air pollutions. However, the air in Europe has now been cleaned up to such extent that cupper plated roofs now turn black instead of green, I think I can live with out the greenish cupper plated roofs.

    We do not need to know more about acid rains than the already known effects to dismiss such an idea as futile.
    0 0
  36. doug_bostrom,

    It goes beyond my understanding why computer time is wasted on ideas like this. This is no science of public interest, at its best mockery with the subject at worst disconnected from reality.
    0 0
  37. batsvensson -

    you deny that this is a science of public interest, and describe the Swedish acidification impacts and exemplary remediation efforts, but have not explained how ending GHG emissions would be remotely sufficient for controlling the now accelerating interactive positive feedbacks.

    With society having missed the chance in the '70s to end global warming by ending GHG outputs, are you now advocating a similar 30-yr delay to waste the final opportunity to avoid catastrophic climate destabilisation by the additional means of carbon recovery and temporary albido enhancement ?


    0 0
  38. Thought-provoking scientific freshness:

    Many geoengineering projects have been proposed to address climate change, including both solar radiation management and carbon removal techniques. Some of these methods would introduce additional compounds into the atmosphere or the ocean. This poses a difficult conundrum: Is it permissible to remediate one pollutant by introducing a second pollutant into a system that has already been damaged, threatened, or altered? We frame this conundrum as the “Problem of Permissible Pollution.” In this paper, we explore this problem by taking up ocean fertilization and advancing an argument that rests on three moral claims. We first observe that pollution is, in many respects, a context-dependent matter. This observation leads us to argue for a “justifiability criterion.” Second, we suggest that remediating actions must take into account the antecedent conditions that have given rise to their consideration. We call this second observation the “antecedent conditions criterion.” Finally, we observe that ocean fertilization, and other related geoengineering technologies, propose not strictly to clean up carbon emissions, but actually to move the universe to some future, unknown state. Given the introduced criteria, we impose a “future-state constraint”.” We conclude that ocean fertilization is not an acceptable solution for mitigating climate change. In attempting to shift the universe to a future state (a) geoengineering sidelines consideration of the antecedent conditions that have given rise to it --conditions, we note, that in many cases involve unjustified carbon emissions --and (b) it must appeal to an impossibly large set of affected parties.

    Geoengineering, Ocean Fertilization, and the Problem of Permissible Pollution

    0 0
  39. Doug -
    thanks for the synopsis above - sadly the text is "currently unavailable" so I'm hoping you can clarify some points.

    As one who'd still be opposing Geo-E if there were any credible argument that excess airborne GHG stocks could be removed by natural sinks before the feedbacks gain enough momentum to run amok, my interest is in effective sustainable Geo-E techniques.

    The meaning of "antecedent criterion" is unclear - does it refer to "a return to conditions prior to the problem" ? Or perhaps to "problem being insoluble without intervention" ?

    The "future state constraint" appears to generalize an assumption that all Geo-E options generate permanent change from the original condition. True in the sense that you can't step in the same river twice; untrue in that a gigahectare of forest carbon sink would both retore pre-industrial planetary tree cover and would help cleanse the atmosphere. Also untrue for albido restoration via 'cloud brightening,' where miniscule sea-salt particles, lofted in minute seawater droplets, would reliably be rained out within a few days, and would be generated to do so over the oceans.
    So is the paper generalizing unjustifyably, or is it just that the synopsis not able to express a more nuanced argument ?

    If the latter is the case, could you describe it ?


    0 0
  40. Lewis, I can't reliably answer your questions but am inclined to believe the authors are speaking of reactive, interventionist techniques, possibly leading to failure to effectively deal with what spawns the intervention. One of the authors (Morris Judd) has a blog post mentioning the publication of the paper, Geoengineering Article, and seems responsive to folks stopping by with comments.

    For my part, if we can't avoid putting things in the atmosphere it seems to me most conservative to focus on directly removing what we've added, not exactly geoengineering in my book so much as tidying up as we go along. Which of course begs the question, how may we avoid adding what we must remove? If it's cheaper not to add at all that's better than going full circle.
    0 0
  41. If the following is true it will force us into action! Once we pass a peak in oil, gas, and now even coal, surely the economics of these resources change and will encourage a desperate rush to cheap GenIV nuclear reactors that eat nuclear waste? Check it out: yet another study that indicates we are closer to peak coal than anyone would imagine.

    Green Car Congress: Study Concludes Peak Coal Will Occur Close to 2011.
    0 0
  42. Unfortunately Eclipse I suspect a lot of folks are going to look at that coal resource assessment and conclude there's no problem, someday in the vague and hazy future the coal will be gone, so what?.

    It's easy to worry neither about the climate nor about what we're going to do when the fossil fuel party is over. Both problems suffer from being abstract and not immediately visible in front of our noses, as well as being worrisome and messy and thus better pushed under our mental rug. A perfect storm in the risk perception world.
    0 0
  43. Doug,
    Indeed, the authors conclusion is that the IPCC is being alarmist in their projections of CO2 release.

    "The real problem 40 years from 2009 will be an insufficient supply of fossil energy, not its overabundance, as the IPCC economists would have it."

    They do not discuss the need to access alternate energy supplies, which is required if fossil fuels run out. The primary author also told Bloomburg that the gulf oil gusher was probably only 20,000 barrels per day so no worries. That is now known to be 60,000 bpd. My impression is this is a new angle for skeptics: the coal is running out anyway so we might as well continue BAU. I have seen estimates all over the map on when peak coal will happen. scientific american blog on coal for example. The skeptics realize they are losing the "climate is not changing" argument with the temperatures this year and are looking for a new argument to support BAU.
    0 0
  44. This is the link to the scientific american blog:

    Here they say coal will last 200 years.
    0 0
  45. @LewisC at 22:39 PM on 8 August, 2010

    Well Lewis, we will all look forward to see you and your familly be the first to move in to these spot where they plans to put these SO2 exhaust plants. Good luck with your new home.
    0 0
  46. #45 batsvensson at 04:20 AM on 14 August, 2010
    Well Lewis, we will all look forward to see you and your familly be the first to move in to these spot where they plans to put these SO2 exhaust plants

    Don't worry. China takes care of the SO2 exhaust plant program just fine. Her altruism borders self-sacrifice.

    0 0
  47. If the prospect of influencing climate by geoengineering CO2 out of the atmosphere is bleak, so must be the strategy of just reducing our industrial emissions. This seems to me to be a vindication of the need for geoengineering to reduce the damage which is already in the pipeline.

    No strategy is perfect, however the seeding of stratocumulus or cirrus in conjunction with GHG reductions might provide a reversible, solution if anything went badly wrong, unlike pumping SO2 into the stratosphere. Seeding clouds in conjunction with improved climate models might provide some spatial control as well.

    I am surprised no-one has looked into the possibility of removing methane and tropospheric ozone by geoengineering as well, since reducing these gases might help to achieve the reduced forcings necessary.
    0 0
  48. Batsvensson - your sarcasm is misplaced - particularly in a forum dedicated to rational discussion - if you were to read my posts you'd find no support for the use of sulphate aerosols.

    What you would find are some of the argumants why Geo-E is now essential to avoid otherwise inevitable catastrophic climate destabilization.

    You'd do better to address those arguments that to attack a position I don't hold.


    0 0
  49. Fearing unfavorable public reaction, it is unlikely that the United States government will do anything significant to mitigate CO2 emissions in the foreseeable future. But they may spend hundreds of billions on star-wars type geoengineering ideas.

    Here is Representative Bart Gordon's Plan B for the Climate.

    Rep. Gordon said, "Within the next month, I will release a report titled Geoengineering the Climate: Research Needs and Strategies for International Coordination."

    Watch for that report for more details.
    0 0
  50. Continuing a discussion that started here.

    Eric. There are multiple issues here:

    1/ Progress might be inevitable, but you cannot expect progress that violates physical laws and you cannot assume that just because something can be done then it is economic to do so. Just looking at the hurricane or El Nino data and you see that minimum energy costs are huge. Why would you assume that it is economic to spend this energy rather reduce emissions?
    2/ A chaotic system obeys physical laws. Not all states are possible. Air that is cold with respect to surrounding will settle creating the high just as warm air rises. You might move the cyclone belt around (with enormous energy inputs) within some bounds but its general position is determined by the radiative heating profile of the planet.
    3/ The increasing southward trend is warming Antarctica's fringes, bringing rain to melt the ice and increasing the issues of sealevel rise, not decreasing it. Look at the GRACE map of mass loss/accumulation and ice loss trend.
    0 0

You need to be logged in to post a comment. Login via the left margin or if you're new, register here.

The Consensus Project Website


(free to republish)

© Copyright 2019 John Cook
Home | Links | Translations | About Us | Privacy | Contact Us