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Sore Throat
Joined: 01 Sep 2000
Posts: 1798
Location: x |
No Quick Or Easy Technological Fix For Climate Change
 Thu Jan 01, 2009 9:26 pm
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http://www.sciencedaily.com/releases/2008/12/081217190429.htm
No Quick Or Easy Technological Fix For Climate Change, Researchers Say
ScienceDaily (Dec. 27, 2008) — Global warming, some have argued, can be reversed with a large-scale "geoengineering" fix, such as having a giant blimp spray liquefied sulfur dioxide in the stratosphere or building tens of millions of chemical filter systems in the atmosphere to filter out carbon dioxide.
But Richard Turco, a professor in the UCLA Department of Atmospheric and Oceanic Sciences and a member and founding director of UCLA's Institute of the Environment, sees no evidence that such technological alterations of the climate system would be as quick or easy as their proponents claim and says many of them wouldn't work at all.
Turco will present his new research on geoengineering — conducted with colleague Fangqun Yu, a research professor at the State University of New York–Albany's atmospheric sciences research center — today and Thursday at the American Geophysical Union's annual meeting in San Francisco.
"We're talking about tinkering with the climate system that affects everybody on Earth," said Turco, an atmospheric chemist with expertise in the microphysics of fine particles suspended in the atmosphere. "Some of the ideas are extreme. There would certainly be winners and losers, but no one would know who until it's too late.
"If people are going to pursue geoengineering, they have to realize that it won't be quick, cheap or easy; indeed, suggestions that it might be are utter nonsense, and possibly irresponsible. Many of these ideas would require massive infrastructure and manpower commitments. For example, one concept to deliver reflective particles to the upper atmosphere on aircraft would require numerous airports, fleets of planes and a weather forecasting network dedicated only to this project. Its operation might be comparable to the world's entire commercial flight industry. And even after that massive investment, the climatic response would be highly uncertain."
Given the difficulties of reducing greenhouse gas emissions, the idea of a simple large-scale technological solution to climate change can seem very appealing.
"Global warming due to carbon dioxide emissions appears to be happening even faster than we expected," Turco said. "Carbon dioxide emissions are continuing to grow despite all of the warnings about climate change, despite all of the data showing such change is occurring and despite all of the efforts to control carbon emissions. The emissions are rising, in part, because China and India are using increasingly more energy and because fossil fuels still represent the cheapest source of energy.
"If we continue down this path, the climate is likely to change dramatically — major ice sheets could melt, sea levels could rise, it may evolve into a climate catastrophe. So it is tempting to seek an alternative response to climate change in case we can't get emissions under control. The result is that more and more geoengineering proposals are surfacing. Some of the people developing such proposals know what they're talking about; many don't."
Turco and Yu have been studying a particular geoengineering approach that involves the injection of nanoparticles, or their precursor gases — such as sulfur dioxide or hydrogen sulfide — into the stratosphere from aircraft or large balloons.
While our climate system normally involves a balance between incoming sunlight and outgoing heat radiation, excess atmospheric greenhouse gases trap additional heat and cause the Earth's temperature to rise, Turco noted. "One way to control the potential warming is to reduce the emissions of greenhouse gases," he said. "We haven't been able to get a handle on that. Another idea, instead of reducing emissions, is to somehow compensate for them."
The idea of injecting sulfur dioxide or other toxic gases into the stratosphere in gaseous or liquefied form would mean that planes or balloons would have to fly as high as 13 miles — higher than any commercial aircraft can reach. And the amounts involved range to many millions of tons.
"Some of these proposals are preposterous, mind-boggling," Turco said. "What happens, for example, when you spray liquefied sulfur dioxide into the stratosphere? Nobody knows."
In a study published earlier this year, Turco analyzed what happens when a stream of very small particles is injected into the atmosphere. He showed that when the particles are first emitted, they are highly concentrated, collide frequently and coagulate to much larger sizes than expected.
"To create the desired climate outcomes, you would need to insert roughly 10 million tons of optimally-sized particles into the stratosphere," he said. "You would have to disperse these particles very quickly over the entire stratosphere or they would coagulate into much larger sizes. At such enhanced sizes, the particles do not have the same effect; they're much less effective in forcing climate compensation. In the end, you would have to fly thousands of high-altitude jets every day to get enough particles into the atmosphere to achieve your goal. And this activity would have to be sustained for hundreds of years."
The basic idea behind stratospheric particle injections is that the Earth's temperature depends on the reflectivity of the atmosphere. About one-third of the energy from the sun hitting the Earth is reflected back into space. That fraction is called the "albedo." If the albedo increases, the average global temperature decreases because less energy is available to warm the planet. So if we can increase the albedo sufficiently, we can compensate for global warming.
"The size distribution of the particles is critical," Turco said. "If the particles are too large, that will actually create a warming effect, a greenhouse warming. Small particles are not useful because they don't reflect much radiation; you need something in between, and we have shown that is hard to achieve reliably."
Turco and Yu have simulated, for the first time, the actual injection processes that might be used, focusing on the early evolution of the injection plumes created from aircraft or balloon platforms. They used an advanced computer model developed by Yu to calculate the detailed microphysical processes that ensue when reactive, particle-forming vapors are emitted into the atmosphere. They also accounted for the photochemical reactions of the injected vapors, as well as the mixing and dilution of the injection plume.
"We found that schemes to emit precursor gases in large quantities would be extremely difficult to design and implement within the constraints of a narrow tolerance for error, and in addition, the outcomes would be very sensitive to variables over which we would have little control, such as the stability and mixing conditions that occur locally," Turco said.
"Advocates of geoengineering have tried to make climate engineering sound so simple," he added. "It's not simple at all. We now know that the properties and effects of a geoengineered particle layer in the stratosphere would be far more unpredictable, for example, than the physics of global warming associated with carbon dioxide emissions. Embarking on such a project could be foolhardy."
How can global warming be combated?
"We must reduce carbon emissions," Turco said. "We need to invest big-time in alternative energy sources with minimal carbon footprints."
The research is federally funded by the National Science Foundation.
Last edited by Sore Throat on Fri Jan 02, 2009 5:28 pm; edited 1 time in total |
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Sore Throat
Joined: 01 Sep 2000
Posts: 1798
Location: x |
| Climate scientists: it's time for 'Plan B'
Fri Jan 02, 2009 5:15 pm
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http://www.independent.co.uk/environment/climate-change/climate-scientists-its-time-for-plan-b-1221092.html
Climate scientists: it's time for 'Plan B'
Poll of international experts by The Independent reveals consensus that CO2 cuts have failed – and their growing support for technological intervention
By Steve Connor, Science Editor and Chris Green
An emergency "Plan B" using the latest technology is needed to save the world from dangerous climate change, according to a poll of leading scientists carried out by The Independent. The collective international failure to curb the growing emissions of carbon dioxide (CO2) in the atmosphere has meant that an alternative to merely curbing emissions may become necessary.
The plan would involve highly controversial proposals to lower global temperatures artificially through daringly ambitious schemes that either reduce sunlight levels by man-made means or take CO2 out of the air. This "geoengineering" approach – including schemes such as fertilising the oceans with iron to stimulate algal blooms – would have been dismissed as a distraction a few years ago but is now being seen by the majority of scientists we surveyed as a viable emergency backup plan that could save the planet from the worst effects of climate change, at least until deep cuts are made in CO2 emissions.
What has worried many of the experts, who include recognised authorities from the world's leading universities and research institutes, as well as a Nobel Laureate, is the failure to curb global greenhouse gas emissions through international agreements, namely the Kyoto Treaty, and recent studies indicating that the Earth's natural carbon "sinks" are becoming less efficient at absorbing man-made CO2 from the atmosphere.
Levels of CO2 have continued to increase during the past decade since the treaty was agreed and they are now rising faster than even the worst-case scenarios from the Intergovernmental Panel on Climate Change, a United Nations body. In the meantime the natural absorption of CO2 by the world's forests and oceans has decreased significantly. Most of the scientists we polled agreed that the failure to curb emissions of CO2, which are increasing at a rate of 1 per cent a year, has created the need for an emergency "plan B" involving research, development and possible implementation of a worldwide geoengineering strategy.
Just over half – 54 per cent – of the 80 international specialists in climate science who took part in our survey agreed that the situation is now so dire that we need a backup plan that involves the artificial manipulation of the global climate to counter the effects of man-made emissions of greenhouse gases. About 35 per cent of respondents disagreed with the need for a "plan B", arguing that it would distract from the main objective of cutting CO2 emissions, with the remaining 11 per cent saying that they did not know whether a geoengineering strategy is needed or not.
Almost everyone who thought that geoengineering should be studied as a possible plan B said that it must not be seen as an alternative to international agreements on cutting carbon emissions but something that runs in parallel to binding treaties in case climate change runs out of control and there an urgent need to cool the planet quickly.
Geoengineering was dismissed as a distraction a few years ago but it has recently become a serious topic of research. Next summer, for example, the Royal Society, in London, is due to publish a report on the subject, led by Professor John Shepherd of the National Oceanography Centre at Southampton University. Professor Shepherd was one of the scientists who said that a plan B was needed because he was now less optimistic about the prospects of curbing CO2 levels since Kyoto was agreed, and less optimistic about the ability of the Earth's climate system to cope with the expected CO2 increases. "Geoengineering options... must not be allowed to detract from efforts to reduce CO2 emissions directly," said Professor Shepherd, who studies the interaction between the climate and oceans. In answer to the question of whether scientists were more optimistic or less optimistic about the ability of the climate system to cope with increases in man-made CO2 without dangerous climate change, just one out of the 80 respondents to our survey was more optimistic, 72 per cent were less optimistic, and 23 per cent felt about the same.
Professor James Lovelock, a geo-scientist and author of the Gaia hypothesis, in which the Earth is a quasi-living organism, is one of those who is less optimistic. He believes that a plan B is urgently needed. "I never thought that the Kyoto agreement would lead to any useful cut back in greenhouse gas emissions so I am neither more nor less optimistic now about prospect of curbing CO2 compared to 10 years ago. I am, however, less optimistic now about the ability of the Earth's climate system to cope with expected increases in atmospheric carbon levels compared with 10 years ago," he told The Independent. "I strongly agree that we now need a 'plan B' where a geoengineering strategy is drawn up in parallel with other measures to curb CO2 emissions."
Among those who oppose geoengineering is Professor David Archer, a geophysicist at Chicago University and expert on ocean chemistry. "Carbon dioxide released to the atmosphere will continue to affect climate for many millennia," he said. "Relying on geoengineering schemes such as sulphate aerosols would be analogous to putting the planet on life support. If future humanity failed to pay its 'climate bill' – a bill that we left them, thank you very much – they would bear the full brunt of climate change within a very short time."
Gummer set for green role
The former Tory cabinet member who publicly fed his daughter a beefburger during the outbreak of so-called "mad cow disease" is in line for a leading role in helping the Government fight against global warming, writes Nigel Morris.
John Gummer, who served as Environment Secretary in the previous Conservative government, has been shortlisted for the post of chairman of the Committee on Climate Change. He is one of three candidates being discussed in Whitehall to succeed Baron Turner of Ecchinswell. The others are Rachel Lomax, a former Treasury official who has recently retired as a deputy governor of the Bank of England, and Sir John Harman, former chairman of the Environment Agency.
Mr Gummer, 69, has been a Conservative activist for almost half a century and has spent 34 years as an MP. He represents the safe seat of Suffolk Coastal. A 16-year spell in government culminated with his promotion by John Major to Environment Secretary, when he was regarded as a pioneering minister, introducing the landfill tax and the fuel-price escalator.
Mr Gummer said last night he knew nothing about the vacant post.
Fixing the planet Could technology help save the world?
Injecting the air with particles to reflect sunlight
Volcanic eruptions release huge amounts of sulphate particles into the upper atmosphere, where they reflect sunlight. After Mount Pinatubo erupted in 1991, sulphates reflected enough sunlight to cool the Earth by 0.5C for a year or two. The Nobel Laureate Paul Crutzen suggested in 2006 that it may be possible to inject artificial sulphate particles into the upper atmosphere – the stratosphere. However, the idea does not address ocean acidification caused by rising CO2 levels. There may be side-effects such as acid rain and adverse effects on agriculture.
Creating low clouds over the oceans
Another variation on the theme of increasing the Earth's albedo, or reflectivity to sunlight, is to pump water vapour into the air to stimulate cloud formation over the sea. John Latham of the United States National Centre for Atmospheric Research in Boulder, Colorado is working with Stephen Salter of Edinburgh University and Mike Smith at Leeds to atomise seawater to produce tiny droplets to form low-level maritime clouds that cover part of the oceanic surface. The only raw material is seawater and the process can be quickly turned off. The cloud cover would only affect the oceans, but still lower global temperatures.
Fertilising the sea with iron filings
This idea arises from the fact that the limiting factor in the multiplication of phytoplankton – tiny marine plants – is the lack of iron salts in the sea. When scientists add iron to "dead" areas of the sea, the result is a phytoplankton bloom which absorbs CO2. The hope is that carbon taken up by the microscopic plants will sink to deep layers of the ocean, and be taken out of circulation. Experiments support the idea, but blooms may be eaten by animals so carbon returns to the atmosphere as CO2.
Mixing the deep water of the ocean
The Earth scientist James Lovelock, working with Chris Rapley of the Science Museum in London, devised a plan to put giant tubes into the seas to take surface water rich in dissolved CO2 to lower depths where it will not surface. The idea is to take CO2 out of the short-term carbon cycle, cutting the gas in the atmosphere. Critics say it may bring carbon locked away in the deep ocean to the surface.
Giant mirrors in space
Some scientists suggest it would be possible to deflect sunlight with a giant mirror or a fleet of small mirrors between the Earth and the Sun. The scheme would be costly and prompt debate over who controls it. Many scientists see it as contrary to the idea of working with the Earth's systems. |
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Sore Throat
Joined: 01 Sep 2000
Posts: 1798
Location: x |
| Field of Gleams - Shinier crops could cool the earth
Sun Jan 18, 2009 4:36 am
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http://journalwatch.conservationmagazine.org/2009/01/16/field-of-gleams/
Field of Gleams - Shinier crops could cool the earth
Farm fields with bling may be the next big thing in agriculture, if scientists from the University of Bristol have their say. In Current Biology, they propose that farmers fight climate change by planting crops that reflect more sunlight back to space.
The authors note that some varieties of corn, wheat, and barley have leaves that are especially reflective. So why not genetically engineer crops to maximize this effect? Farmers already pick seed strains that yield the juiciest tomatoes and wheat that’s good for making bread. All they’d have to do is add another criteria to their list.
Inserting such a change into a global climate model, the authors found that glimmering fields could cool summertime temperatures in much of Europe, North America, and Asia by up to one degree Celsius–enough to relieve the worst droughts and heat waves. The reduction is equivalent to offsetting one-fifth of the seasonal regional warming expected by the end of the century. In other words, this “bio-geoengineering” approach might be a relatively cheap and simple way to beat the heat.
Source: Ridgwell, A. et al. 2009. Tackling Regional Climate Change By Leaf Albedo Bio-geoengineering. Current Biology DOI: 10.1016/j.cub.2008.12.025 |
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Sore Throat
Joined: 01 Sep 2000
Posts: 1798
Location: x |
| Ocean climate fix remains afloat
Tue Feb 03, 2009 12:33 am
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http://news.bbc.co.uk/2/hi/science/nature/7856144.stm
Ocean climate fix remains afloat
By James Morgan
Science reporter, BBC News
Plans to curb climate change by using plankton to draw carbon dioxide into the world's oceans have been boosted.
A spectacular natural algal bloom in the Southern Ocean helped to "lock" carbon away into deep sea sediments, according to a study in Nature journal.
But the amount of carbon stored was not nearly as high as some artificial "geo-engineering" schemes had predicted.
Plans to "seed" plankton blooms by adding iron to oceans are strongly opposed by many green groups.
The international research team behind the Crozex study say their findings have "significant implications" for plans to mitigate climate change.
They come as scientists resume a controversial ocean fertilisation experiment in the Scotia Sea, east of Argentina.
The Lohafex study had been suspended by the German government after environmental groups protested that it violates the terms of the UN Convention on Biological Diversity.
They fear that adding iron to oceans may damage ecosystems.
Ocean commotion
Using algae as a "biological carbon pump" has been touted as one of the more promising "geo-engineering" schemes for mitigating global warming.
Plankton act as a natural sponge for carbon dioxide - drawing the greenhouse gas down out of the atmosphere and into the sea.
When plankton die, they sink to the bottom of the ocean, locking away some of the carbon they have absorbed.
Experiments suggest that "seeding" oceans with iron can stimulate the growth of plankton - particularly waters which are rich in nutrients.
But exactly how much carbon sinks to the sea floor, and how long it remains locked away, is still unknown.
In the Crozex experiment, an international research team sailed to the Crozet Islands, in the Southern Ocean, about 2,200km (1,400 miles) southeast of South Africa.
These waters experience a spectacular annual plankton bloom the size of Ireland, 120,000 sq km (46,300 sq miles) fertilised by iron naturally supplied from the islands' volcanic rocks.
The researchers used sediment traps to follow the passage of carbon from the sea surface to the ocean floor.
They found that seawater and sediment samples taken directly beneath the bloom were two-to-three times richer in carbon, compared to samples from a nearby ocean region which was rich in nutrients, but not in iron.
"Our results have significant implications for proposals to mitigate the effects of climate change through purposeful addition of iron to the ocean," said lead author Professor Raymond Pollard, of the National Oceanography Centre, Southampton.
"Our findings support the hypothesis that increased iron supply...may have directly enhanced carbon export to the deep ocean.
"[However] our estimate of carbon sequestration for a given iron supply still falls 15-50 times short of some geo-engineering estimates."
Next steps
"This is a significant result," said Professor Peter Burkill, director of the Sir Alister Hardy Foundation for Ocean Science, Plymouth (SAHFOS).
"It suggests that ocean iron fertilisation might work for reducing atmospheric CO2 through export of carbon into the ocean's interior.
"But the next step from natural experiments to artificial ones is crucial.
"We now need to know what the ecological impacts of artificial fertilisation experiments are."
Many scientists doubt whether adding iron artificially will ever seed plankton blooms as successfully as natural iron.
To test the technique, the German government has just re-authorised one of the largest ocean fertilisation experiments to date.
The Lohafex expedition had been suspended, after concerns that it violated the terms of the Convention On Biological Diversity.
But researchers on board the vessel RV Polarstern have now begun seeding six tonnes of iron sulphate over 300 square kilometres of the Scotia Sea, east of Argentina.
"As this paper shows, much larger amounts of iron are being added daily by natural processes around the Crozet Island," said Professor Andrew Watson, University of East Anglia.
"And that doesn't seem to have done the Antarctic ecosystem any harm."
Crucial experiment
"Legitimate experiments like [Lohafex] are crucial to learning more about the effects of iron fertilisation," said Dr Gary Fones, University of Portsmouth, who was part of the Crozex team.
"They will help scientists evaluate the merits of such a scheme."
However, the environmental impact of Lohafex was questioned by Kristina Gjerde, high seas policy advisor, the International Union for Conservation of Nature (IUCN).
She said: "The fundamental question remains, should this activity be allowed to proceed unregulated?
"I am not against research in this area; however, it should follow internationally agreed rules and procedures.
"The Convention on Biological Diversity's call for a defacto moratorium on ocean fertilisation reflects the will of the international community that this activity should not proceed until certain basic requirements have been satisfied.
"The government ministries that authorised the Lohafex experiment did not comply with the rules for [environmental] impact assessments as they currently exist under the London Convention [on the Prevention of Marine Pollution]."
Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/7856144.stm |
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Sore Throat
Joined: 01 Sep 2000
Posts: 1798
Location: x |
| Every silver lining has a cloud
Sun Feb 08, 2009 7:36 pm
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http://www.economist.com/science/displaystory.cfm?story_id=13013035
Every silver lining has a cloud
From The Economist print edition
Plans to engineer the climate may be less effective than had been hoped
IF PEOPLE can warm the Earth, they can probably cool it too. That is the idea behind geo-engineering, which holds that besides cutting the rate at which it is turning fossil fuels into climate-changing carbon dioxide, humanity should also consider planet-wide engineering projects intended to reduce the side-effects of this combustion. All sorts of ideas have been proposed, from filling the stratosphere with reflective particles to giant space-borne parasols designed to shade the Earth from the sun. The idea of such a technological last chance, even if it sounds implausible, is a secret comfort to many of those frustrated by the lack of progress around the world in cutting emissions of greenhouse gases. Two papers published this week suggest, though, that those hopes may be misplaced.
The first, by a group of researchers from Britain’s National Oceanography Centre, led by Raymond Pollard, looked at the idea of dumping iron in the oceans to promote huge blooms of phytoplankton—tiny algae that consume carbon dioxide as they grow. This approach has received a lot of interest. Though much of the carbon thus absorbed returns to the atmosphere when the plankton die, around 8-9% ends up locked away beneath the waves for decades or more. Dr Pollard’s paper, which appeared in Nature, outlined the results of an experiment that looked at the effects of iron on the growth of phytoplankton near the Crozet Islands in the Southern Ocean.
Every year, as the days lengthen, the seas near these islands produce an enormous bloom of plankton, roughly the size of Ireland. Erosion of the islands dumps large quantities of iron in the water. The prevailing currents then carry most of this iron north, leaving the waters to the south with less. That makes the seas around the Crozet Islands an ideal natural laboratory. Dr Pollard and his colleagues found, as geo-engineers would hope, that phytoplankton blooms in the waters north of the islands were bigger and longer-lived than those to the south. More plankton means more carbon dioxide sucked from the air.
The researchers reckon that the extra iron boosted growth rates and carbon-dioxide consumption between two- and threefold. They also found the first evidence of a similar boost in the amount of carbon locked away in the deep ocean. But while the theory of iron fertilisation seems sound, the practice may be tricky: the team’s results suggest that geo-engineers have overestimated the amount of carbon removed per tonne of iron by between 15 and 50 times.
Similarly sobering conclusions are reached in the second paper, by Tim Lenton of the University of East Anglia and Naomi Vaughan of the Tyndall Centre for Climate Change Research, and published in Atmospheric Chemistry and Physics Discussions. This study attempts to rank the likely effectiveness of various geo-engineering proposals.
Because geo-engineering is a new field, the researchers chose to ignore trifles such as cost or practicality, and focused instead on the sheer physical limits on what can be done and how much good the different schemes would do. Top of the list is a solar shade, a gigantic umbrella in space that would shield the Earth from the sun’s rays. This is both the most effective option and the most “scalable”, since a hotter Earth would simply require a bigger or more opaque parasol.
The other ideas suffer from fundamental limits that stop them being scaled up indefinitely. Injecting sulphate particles into the stratosphere, for instance, would cool the Earth by reflecting more sunlight into space. (Nature has already shown that this concept can work, since volcanic eruptions that send sulphur-rich plumes into the stratosphere can temporarily alter the world’s climate.) However, Dr Lenton notes that the method becomes less effective as the atmosphere becomes more saturated with particles. At most, he reckons, the sulphate-injection approach could counteract half of the warming the world is expected to suffer over the next 100 years if carbon-dioxide emissions continue to rise unchecked.
Other options seem even less effective. Encouraging cloud formation over the oceans by spraying seawater into the air would be roughly as helpful as pumping the stratosphere full of particles. Its effects, though, would be geographically patchy. And dumping nutrients such as iron into the sea would be only one-sixth as effective as either sulphate injection or promoting the formation of clouds.
Moreover, effectiveness is only one way to rank the ideas. In theory, a solar shade could provide any amount of cooling, but the researchers estimate that it would have to have an area of 4.1m square kilometres (half the size of Brazil) to offset half the warming expected over the next century, assuming no cuts in carbon-dioxide emissions occur. A polite critic of such a plan might describe it as “ambitious”. Sulphate particles, meanwhile, survive only a few years in the atmosphere. For the sulphate-injection method to remain effective they would need to be replenished constantly for centuries—longer than the lifetime of most countries.
Then there are the side-effects. Any geo-engineering project would necessarily be enormous, and would therefore cause plenty of disruption to ecosystems. Plans to suck carbon from the air by growing trees conflict with the need to grow crops. Creating gigantic algal blooms risks using up all the oxygen in large parts of the ocean, killing anything else that lives there. These sorts of things are unlikely to go down well with environmentalists. Indeed, a group of researchers hoping to conduct more experiments on ocean fertilisation was recently ordered to stop by the German government. Ministers were worried that the experiment might have been illegal under international laws designed to protect marine wildlife, although they eventually gave the go-ahead. When it comes to the environment, there are no perfect answers. |
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Sore Throat
Joined: 01 Sep 2000
Posts: 1798
Location: x |
| Geoengineering is risky but likely inevitable, so we better
Tue Feb 10, 2009 2:47 am
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http://gristmill.grist.org/story/2009/2/8/22587/75724/
Geoengineering is risky but likely inevitable, so we better start thinking it through
The following is a guest essay from Jamais Cascio, a cross-disciplinary futurist specializing in the interplay between technology and society. He co-founded Worldchanging.com, and now blogs at OpenTheFuture.com.
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With the recent release of a detailed comparison between different geoengineering strategies and the launch of a German-Indian joint experiment in ocean-iron-fertilization, the debate over whether geoengineering will have any place in our efforts to combat global warming is one again churning. I've been writing about the geoengineering dilemma since 2005, and Grist's David Roberts -- no big fan of geoengineering -- asked me to give my take on where the issue stands today. My top-line summary?
Geoengineering is risky, likely to provoke international tension, certain to have unanticipated consequences, and pretty much inevitable.
Just to be clear, here's what I want to see happen over the next decade: An aggressive effort to reduce carbon emissions through the adoption of radical levels of energy efficiency, a revolution in how we design our cities and communities, a move away from auto-centered culture, greater localism in agriculture, expanded use of renewable energy systems, and myriad other measures, large and small, that reduce our footprints and improve how we live.
This plan, or something very much like it, is required for us to have the best chance of avoiding disastrous climate disruption. Could we make it happen within the next decade? Definitely. Are we likely to do so? I really want to say yes ... but I can't.
And that's a real problem, because we're not exactly overburdened with global warming response plans that have a solid chance of actually doing something about it in time. We all know that half-measures and denial masquerading as caution certainly won't be enough to avoid disastrous warming; unfortunately, neither will the kinds of ideas still coming out of the world's capitals. Although clearly better than nothing, they simply won't get carbon emissions down far enough fast enough to avoid a catastrophic climate shift.
Here's why: No matter what we do, even if we were to suddenly cut off all anthropogenic sources of carbon right this very second, we are committed to at least another two to three decades of warming, simply due to thermal inertia. Add to that the feedback effects from environmental changes that have already happened: ice cap losses increasing polar ocean temperatures, accelerating overall warming; melting permafrost in Siberia releasing methane, which can be up to 72 times more powerful a greenhouse gas than carbon dioxide; overloaded carbon sinks in oceans and soil losing their ability to absorb CO2. These factors combine in a way that could make even our best efforts too slow to avoid disaster.
So what would we do?
Now I know some of you are saying "stop right there -- you're giving up before we've even really tried." I understand the sentiment, but I strongly disagree. In a complex environment, with myriad uncertainties (not about the science, but about how quickly and how thoroughly we can respond), thinking through the alternatives in case we aren't successful is absolutely critical. Arguments that we shouldn't even think about whether or not geoengineering will be necessary remind me of Condoleezza Rice's argument for why there were no backup plans for Iraq: "It's bad policy to speculate on what you'll do if a plan fails when you're trying to make a plan work." I take the opposite view -- the only ethical choice is to have alternative plans ready, because no plan ever works the way you intend.
No matter what, we would have to continue with emission reductions, even if we don't work fast enough to escape serious problems. Carbon dioxide sticks around in the atmosphere for centuries; the more we add, even slowly, the longer the crisis will last. But we'd also have to decide on a more immediate strategy.
The conventional response would be to focus on mitigation, building the kinds of projects needed to lessen the very worst impacts of global warming. Even in the best scenario, we'd still see disastrous events, and many deaths; in time, however, we'd learn how to deal with the new climate. Hopefully, we'd be able to do so before too many people died from heat waves, drought, opportunistic diseases, storms, resource wars, forced migration, and the like. But make no mistake: the mitigation scenario would still be catastrophic for many around the world.
That's why the geoengineering option appeals to many: systems that cool the planet a bit over the short run could suppress many of the more disastrous effects of warming temperatures, even as we continue with emissions reductions. Geoengineering projects are generally within our current technological and financial capabilities, and most emulate well-known natural processes. The goal would be to give us time to make the social, political, economic and technological changes needed to stop building up greenhouse gases.
Varieties of geoengineering
There are two chief forms of geoengineering under consideration: albedo management, which reduces heat in the short term by blocking or reflecting a small portion of the sunlight hitting the Earth; and carbon management, which uses a variety of techniques to gradually sequester large amounts of atmospheric carbon. Albedo management techniques include cloud brightening, stratospheric particle injection (mimicking the effects of large volcanic eruptions), and the infamous orbiting space mirrors. Carbon management techniques include biochar burial, trees and other plants engineered to absorb more CO2, and "air capture," which uses a chemical process to remove CO2 from the atmosphere.
Of the two, albedo management would be most likely to be used to give the short-term "stay of execution" to allow carbon emission reductions to take hold. Enhanced carbon sequestration, while ultimately more effective, would be too slow to make a difference in a time scale measured in months and years rather than decades and centuries.
A variety of albedo management techniques have been suggested. Some, such as putting reflective sheets in the desert to launching thousands of square kilometers of mirror fabric into orbit, don't pass the plausibility test, either due to cost or clear draw-backs. The two approaches that seem most likely to be considered are stratospheric injection of sulfates and cloud-brightening via seawater pumps.
The sulfate injection plan is explicitly modeled on the effects of massive volcanic eruptions, such as Mount Pinatubo; global temperatures dropped by half-a-degree celsius in the months after the 1991 eruption. The favorable aspects of this plan are reasonably solid: the cooling effect would start within weeks of the injection process; the technology is readily available; and because of the historical record around volcanic eruptions, we actually have a decent idea of what kinds of impacts this kind of geoengineering would have. The less-favorable aspects are also fairly clear: likely damage to the ozone layer (as happened after Mt. Pinatubo); the potential for health and ecological damage should the sulfate injections fail to reach the stratosphere; and a temperature "spike" if sulfate injections are stopped abruptly.
Cloud-brightening has a similar temperature impact, but is less eco-mimetic. It appears to have fewer potential drawbacks and would be used over a smaller area than sulfate injection (which is necessarily global). Its likely problems include bigger uncertainties about the technologies required, questions about the potential for as-yet unknown consequences, and the same temperature bounce-back as sulfate injection if the process is halted suddenly.
Albedo management of any kind also faces the probability of altering rainfall patterns, with the potential for inducing droughts and triggering storms in places that wouldn't necessarily have been hit in a no-geoengineering scenario. And, of course, moderating temperatures does nothing to stop ongoing ocean acidification.
Sociopolitical issues
Any kind of geoengineering would also face a variety of non-technical issues that at best add complexity to their use. Most prominent are the political concerns. With geoengineering being global in impact, who determines whether or not it's used, which technologies to deploy, and what the target temperatures will be? Who decides which unexpected side-effects are bad enough to warrant ending the process? Given that the expense required for sulfate injection (and likely cloud-brightening) would be low enough for a single country to undertake, what happens when a desperate "rogue nation" attempts geoengineering against the wishes of other states? And with the benefits and possible harm from geoengineering attempts being unevenly distributed around the planet, would it be possible to use this technology for strategic or military purposes? That last one may sound a bit paranoid, but it's clear that any technology with the potential for strategic use will be at the very least considered by any rational international actor.
There are also more mundane questions of liability. If (for example) South Asia experiences an unusual drought during cyclone season after geoengineering begins, who gets blamed? Who gets sued? Would all "odd" weather patterns be ascribed to the geoengineering effort? If so, would the issue of what would have happened absent geoengineering be considered relevant?
The broad push-back against geoengineering from many environmentalists tends to focus upon other issues, however. Some people argue that geoengineering is at best a distraction from making the necessary cuts to carbon emissions, and at worst a temptation to delay or abandon those cuts entirely. Others argue that geoengineering is simply dangerous, as the Earth's geophysical systems are far too complex to "engineer," and any attempt to manipulate the climate in this way is bound to have enormous unanticipated consequences.
Both are possible. I'm less concerned about the first, as geoengineering would most likely be a controversial reaction to a desperate need to avoid catastrophe, and the inevitable loud debate over the value of geoengineering would drive home the point that carbon emissions have to continue. The question of complexity and unintended results can't be so easily set aside, however. Frankly, I would go so far as to say that problems of complexity and dangerous surprises are close to certain in any geoengineering scenario.
The bottom line
But none of those concerns matter.
If we start to see faster-than-expected increases in temperature, deadly heat waves and storms, crop failures and drought, the pressure to do something will be enormous. Desperation is a powerful driver. Desperation plus a (relatively) low-cost response, coupled with quick (if not necessarily dependable) benefits, can become an unstoppable force.
If we don't want to see geoengineering deployed, we have to get our carbon emissions down as rapidly and as widely as possible. If we don't -- if our best efforts aren't enough against decades of carbon growth and temperature inertia -- we will see efforts to do something, anything, to avoid global catastrophe.
The choice remains ours ... but time is quickly running out. |
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Sore Throat
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| Hacking the planet: The only climate solution left?
Sat Feb 28, 2009 8:27 pm
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http://www.newscientist.com/article/mg20126973.600-hacking-the-planet-the-only-climate-solution-left.html
Hacking the planet: The only climate solution left?
by Catherine Brahic
N A room in London late last year, a group of British politicians were grilling a selection of climate scientists on geoengineering - the notion that to save the planet from climate change, we must artificially tweak its thermostat by firing fine dust into the atmosphere to deflect the sun's rays, for instance, or perhaps even by launching clouds of mirrors into space.
Surely the scientists gave such a heretical idea short shrift. After all, messing with the climate is exactly what got us into such trouble in the first place. The politicians on the committee certainly seemed to believe so. "It is not sensible, is it? It is not a serious suggestion?"
Had the question been posed a few years ago, most climate scientists would have agreed. But the mood is changing. In the face of potentially catastrophic climate change, the politicians and scientists all agreed that since cuts to carbon emissions will likely fall short we need to be exploring "Plan B". Climatologists have hit a "social tipping point" says Tim Lenton of the University of East Anglia, UK.
What's more, respected scientists, including Nobel laureate Paul Crutzen, and groups such as the UK's Royal Society, are already assessing the risks and benefits. Are we ready to try to turn down the thermostat? Who will have the authority to push the button? And what would happen if one nation or well-intentioned "green finger" individual decided to go it alone?
Geoengineering schemes range from the low-tech, such as planting trees, to sci-fi, such as placing mirrors in orbit between Earth and the sun. All would work either by diverting solar energy away from Earth or by sucking carbon dioxide out of the atmosphere to dampen the greenhouse effect (see diagram).
Previously, the idea of tweaking the climate in this way was anathema to most scientists. Apart from the technical challenges and environmental risks, many argued that endorsing the concept might scupper international negotiations for a post-Kyoto protocol to reduce global emissions. But it's becoming clear that moves to cut global carbon emissions are too little and too late for us avoid the worst effects of climate change. "There is a worrying sense that negotiations won't lead anywhere or lead to enough," says Lenton. "We can't change the world that fast," says Peter Liss, who is scientific adviser to the UK parliamentary committee investigating geoengineering. Extraordinary measures may now be the only way of saving vulnerable ecosystems such as Arctic sea ice.
What's more, geoengineering could turn out to be relatively cheap. Early estimates suggest some schemes could cost a few billion dollars, small change compared to the cost of slashing emissions - estimated by former World Bank chief economist Nicholas Stern to be at least 1 per of global GDP per year. In his testimony to the UK politicians last year, John Latham of the National Center for Atmospheric Research in Boulder, Colorado, argued that all of the above reasons make it "irresponsible" not to examine geoengineering.
While no one advocates deploying fleets of ships or launching space mirrors tomorrow, we need to know how Plan B is going to work, which means doing field tests. "If you wait for a climate catastrophe then you need to deploy fairly full-scale fairly quickly which means you won't have time to look at the risks," says Ken Caldeira of the Carnegie Institution of Washington in Stanford, California.
Yet, as with genetically modified crops, field testing has already sparked public resistance. This has been made clear with the various attempts in recent years over ocean fertilisation experiments. In 2007, a commercial firm called Planktos announced a plan to dump iron filings into the ocean off the Galapagos Islands. More recently, a research ship set off to seed iron in the Southern Ocean. Both generated protests from environmentalists, such as ETC group, which feared they would damage ocean ecosystems.
In many ways ocean fertilisation shows how other geoengineering schemes might be regulated. After the Planktos furore, the London Convention on marine pollution - ratified by over 80 countries - extended its remit to include geoengineering, and imposed a ban on commercial fertilisation. It has also announced its intention to strictly regulate scientific experiments. On 9 February, interested parties met to begin setting up experimental standards.
Yet how we would implement geoengineering schemes on a global basis is less obvious, says lawyer David Victor of Stanford University's programme on energy and sustainable development. "Whether all governments would need to OK a scheme in international waters or outer space is unclear," he says. "Who would decide? And who would be responsible for redressing any unintended consequences?"
For an example of the problems that would need to be ironed out, take a look at one of the more mature geoengineering schemes that could provide us with instant cooling today - pumping sulphate particles into the atmosphere to reflect the sun's rays back into space. If one country forged ahead, it could have detrimental effects on others. A 2007 study suggested sulphate sunshades could trigger catastrophic drought in some regions. "There would inevitably be winners and losers, as there is not a single global thermostat which will bring about universal and consistent cooling," says David Santillo, senior research scientist at Greenpeace Research Laboratories in Exeter, UK. "By its very nature, if there is to be any purpose in geoengineering, it would have to exert an impact over a vast proportion of the planet."
There is no single global thermostat which will bring about universal cooling
Victor estimates only a handful of nations or groupings - including Australia, Brazil, China, India, Russia, the European Union and possibly Japan - have the capability to unilaterally deploy atmospheric sunshades. Only one of these has come close so far. In November 2005, Yuri Izrael, former vice-chair of the Intergovernmental Panel on Climate Change and head of the Russian Global Climate and Ecology Institute, tried to persuade his president, Vladimir Putin, that Russia should release 600,000 tonnes of sulphur aerosol particles into the atmosphere immediately.
If any nation seriously considered going it alone, "there would almost certainly be an international diplomatic incident", says Santillo. If a sunshade triggered drought elsewhere, this could be interpreted as "hostile use" of weather modification, in which case the action would fall foul of the UN Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques (ENMOD). During the Vietnam war, the US experimented with rain seeding to disrupt the Ho Chi Minh trail, which eventually led 70 nations, including the US, to ratify the treaty. But for it to be of any use, a drought-stricken nation would have to prove that a stratospheric sunshade was to blame and this could be difficult at best.
"Almost everyone agrees that some form of international regulation and authorisation is necessary," says John Shepherd, a deputy director of the UK Tyndall Centre for Climate Change Research and chair of the Royal Society working group investigating geoengineering. But as for how, "we just don't know", he says.
The obvious choice would be for the UN to regulate geoengineering. However, when New Scientist enquired, the UN Framework Convention on Climate Change was unable to comment. According to Joan Ruddock, a UK minister serving in the Department of Energy and Climate Change, a powerful UN treaty on geoengineering in the wake of failed emissions talks is unlikely. "If we have entirely failed to bring the world community together to do the rather simpler things which we already understand very well," she says, then devising a geoengineering agreement would be even more difficult.
Even if no nation did go it alone and governments couldn't agree on global action, that still leaves the alarming possibility of an individual deciding to modify the climate on their own - a so-called "green finger". Science historian James Fleming of the Wilson Center in Washington DC describes a gathering he attended at NASA's Ames Research Center in California in November 2006. Astrophysicist Gregory Benford of the University of California, Irvine, announced that he wanted to "cut through red tape and demonstrate what could be done" by injecting a chalk-like substance into the Arctic stratosphere to reflect sunlight, using private funding. And Planktos would have forged ahead with ocean fertilisation had no one stepped in.
There is little doubt that planetary tinkering presents governments with huge challenges. But living in a much warmer world will be even more unpleasant (see "Surviving in a warmer world"). For now we have time. It will be a couple of decades before we know if international negotiations to wean ourselves off high carbon fuels have had any success.
If not, we may have no choice but to start tweaking the climate ourselves. "Only fools find joy in the prospect of climate engineering," says Caldeira. "There is a sense of despair that we are not seeing deep emissions cuts quickly, and that is pushing us to consider these things."
Only fools find joy in the idea of climate engineering. There is a sense of despair
Dump the Sunshade at our Peril
What happens if we tinker, then change our mind? Will all of humanity be doomed? Not necessarily. Most methods that absorb carbon dioxide would take decades to work so stopping them is unlikely to have sudden undesired effects.
In the most worrying scenario, sunshades would be deployed then removed. Preliminary results suggest aerosols would naturally have a stratospheric life of about one year, making them reversible if needed. But there is a big catch.
If they were deployed as an excuse to continue burning fossil fuels, the masked greenhouse effect would build up and other effects such as ocean acidification would continue. Sunshades would have to be replenished or the planet would be hit with the full force of pent-up warming. Victor Brovkin of the Max Planck Institute for Meteorology in Hamburg, Germany, calculates that if a sunshade were kept up for 200 years, then dismantled, the planet could warm by between 5 °C and 10 °C within decades. Such an event would trigger massive belches of methane from thawing permafrost and the breakdown of entire ecosystems.
From issue 2697 of New Scientist magazine, page 8-10. |
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Sore Throat
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| Rogue Shades: Geoengineering and the Climate Fight
Wed Mar 04, 2009 2:12 am
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http://blogs.wsj.com/environmentalcapital/2009/02/27/rogue-shades-geoengineering-and-the-climate-fight/
Rogue Shades: Geoengineering and the Climate Fight
Posted by Keith Johnson
One of the biggest challenges in fighting global warming is getting countries to act. One of the biggest risks may be that countries do act—with unilateral geoengineering schemes to stave off climate change.
Geoengineering, the idea of raising giant sunshades or seeding the atmosphere with sun-blocking particulates, is taking a lot of heat lately. New scientific research suggests the potential benefits from geoengineering may be wildly overstated, or a very short-term solution at best. Eminent climate-change types like Ralph Cicerone, the president of the U.S. National Academy of Sciences, doubts it will ever be a climate-change solution.
The problem is that nobody really knows for sure. As Foreign Affairs notes this month , geoengineering as a discipline is still well outside the mainstream: Nearly the entire community of geoengineering scientists could fit comfortably in a single university seminar room, and the entire scientific literature on the subject could be read during the course of a transatlantic flight.”
Bringing geoengineering “out of the closet,” Foreign Affairs suggests, should be a global priority—not as a climate solution necessarily, but as an insurance policy against rogue states or even rich individuals:
An effective foreign policy strategy for managing geoengineering is difficult to formulate because the technology involved turns the normal debate over climate change on its head […]Geoengineering is an option at the disposal of any reasonably advanced nation. A single country could deploy geoengineering systems from its own territory without consulting the rest of the planet…
Although it is hardly wise to mess with a poorly understood global climate system using instruments whose effects are also unknown, politicians must take geoengineering seriously because it is cheap, easy, and takes only one government with sufficient hubris or desperation to set it in motion […] Although it may sound like the stuff of a future James Bond movie, private-sector geoengineers might very well attempt to deploy affordable geoengineering schemes on their own.
The bottom line: Some people still see geoengineering as perhaps the only way to stave off the worst impacts of climate change, given the difficulties of securing global cooperation to roll back emissions. Critics see the remedy as worse than the cure, given that a geoengineering hole card could erode political will to curb emissions, not to mention the unpredictable knock-on effects of mucking further with the climate. |
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Sore Throat
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| Geoengineering’s Drawbacks
Sat Apr 04, 2009 12:08 am
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http://ieet.org/index.php/IEET/more/cascio20090316/
Geoengineering’s Drawbacks
Jamais Cascio
Open The Future
Because I’m not reflexively opposed to geoengineering research, and because I increasingly suspect that some level of albedo-management geoengineering will be necessary simply due to climate disruption happening faster than previously expected, some people tend to assume that I’m a geoengineering advocate. I’m not—but as I’ve noted before, I do believe that it would be less disastrous than climate-driven depopulation. Nonetheless, geoengineering is all-but-certain to have undesirable consequences, both politically (see next post) and environmentally.
This week we got an excellent example of the latter.
Using well-established data on the light-diffusing effects of aerosol particles, Daniel Murphy [at the National Oceanic and Atmospheric Administration’s (NOAA’s) Earth System Research Lab] calculated that the geoengineering scheme currently envisioned could reduce incoming sunlight by about 3%. That squares with data from the Mount Pinatubo eruption.
The geoengineering scheme would also mean 3% less sunlight reaching flat photovoltaic collectors that generate electricity. But the aerosols would cut the available solar radiation even more to dish- and tube-shaped collectors that use mirrors to concentrate sunlight. Murphy’s research shows that for every watt per square meter of sunlight diffused by the aerosols, as much as 5 watts per square meter would be made unavailable to mirrored collectors on the ground.
This is a problem, but not a fatal one. Commercially-available photovoltaic cells remain painfully inefficient, so one of the best ways to increase the energy returned from a solar array is to use concentration. High-atmosphere particles tend to scatter light, however, and diffuse light doesn’t concentrate as well as direct sunlight.
There are a few caveats:
Solar isn’t the only renewable option, and concentrated solar—while the best energy-producer per square meter—isn’t likely to be the dominant form, at least once cheap solar plastics become more widely available.
Concentrated solar doesn’t become useless, just less-efficient.
Most importantly, the leading proposal for stratospheric sulphate injection geoengineering would have it happen primarily at the poles; warming at the poles has a much greater feedback effect than equatorial warming, and is much more critical to prevent.
Solar, concentrated or otherwise, isn’t likely to be a critical energy source at the poles, so the reduction in solar efficiency resulting from stratospheric sulphate geo would be less important if the geo focuses on polar regions.
Even if this turns out to be a minor drawback, it’s an important indicator that no one response to global warming is perfect. Even carbon emission reduction has negative repercussions—up-front expense in some cases, time required in others, and even the possibility of a short-term increase in warming due to the removal of atmospheric particulates (shutting down coal plants means more than reducing CO2, it also reduces soot and other pollutants—yay for our lungs, but clearer skies mean warmer Earth). Still, geoengineering, because of its scale and the complexity of its subject, is highly likely to offer up more of these dilemmas.
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Jamais Cascio is a fellow of the IEET, and a professional futurist. He writes the popular blog Open the Future. |
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Sore Throat
Joined: 01 Sep 2000
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| Geoengineering Our Way Out of Global Warming
Sat Apr 04, 2009 12:13 am
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http://voices.washingtonpost.com/capitalweathergang/2009/04/anyone_following_the_issue_of.html
Geoengineering Our Way Out of Global Warming
By Steve Tracton | April 2, 2009; 11:00 AM ET
An increasing number of prominent climate scientists and environmentalists (e.g., here and here) are expressing concerns that the point of no return -- when even the most extreme measures to reduce greenhouse gas emissions will be inadequate to reverse many consequences of global warming -- is rapidly approaching.
Speculation on the exact nature of the consequences ranges from coastal cities being submerged under rising seas, more severe floods and droughts, longer and more extreme heat waves, food and water shortages that spark civil unrest, and the reversal of ocean currents leading (ironically) to an ice age, to name a few. Then there's the ultimate doomsday scenarios -- extinction of the human race, or merely the decline of civilization as we know it.
Some of the speculation is based on the latest peer-reviewed science and assessments by the Intergovernmental Panel on Climate Change. The more dramatic end-of-the-world predictions smell more of scaremongering to force policymakers to act, and act now, to reduce emissions of carbon dioxide and other greenhouse gases.
Some of those who believe the tipping point is near -- the point beyond which some impacts of climate change, be they catastrophic or less so, are inevitable -- are giving serious consideration to the idea of geoengineering, deliberate actions taken to slow or reverse global warming by either removing carbon dioxide from the atmosphere or by reducing the amount of sunlight reaching Earth. In other words, Plan B.
Keep reading for more on what geoengineering is all about...
The topic of geoengineering has gained enough traction that the U.S. National Academies is hosting a workshop on the subject this summer, and the UK's national academy of science is preparing a report on the feasibility of climate geoengineering. A recent article in the journal Foreign Affairs states that, "As climate change accelerates, policymakers may have to consider 'geoengineering' as an emergency strategy to cool the planet. Engineering the climate strikes most as a bad idea, but it is time to start taking it seriously." And an advisory group to the Defense Advanced Research Projects Agency recently convened a meeting to discuss geoengineering -- not withstanding concerns expressed by some that military involvement might lead to the use of climate geoengineering as a weapon.
Among the approaches being considered to reduce the solar radiation reaching the ground are firing plumes of fine dust or pumping sulfur dioxide into the atmosphere to deflect the sun's rays in a manner that mimics the cooling effects of volcanic eruptions, and deploying large arrays of land-based mirrors and/or launching mirrors into orbit around Earth (e.g., see here).
Among the schemes for removing carbon dioxide from the atmosphere is dumping tons of iron into the ocean. Iron is necessary for algae photosynthesis, a process that sucks carbon dioxide from the air but is relatively rare in the ocean. In principle, the iron would supercharge the growth of algae, which when it dies would sink to the ocean bottom carrying the carbon with it. A recent iron-fertilization experiment off the coast of Argentina indeed produced a massive algae bloom, but it turned out to be a different kind of algae than anticipated, and one that was quickly devoured by tiny shrimp and other sea life, leaving experts scratching their heads on what the experiment's results mean for iron fertilization as a strategy to sequester carbon. Another approach being discussed is creating plantations of fast-growing trees, which absorb carbon dioxide from the air and convert it into wood, then converting the wood into charcoal (by burning it in the absence of oxygen) and burying the charcoal to prevent the carbon from ever returning to the air.
I've written previously of smaller-scale weather (as opposed to climate) modification programs, including China's efforts to avoid rain during the 2008 Olympics and to induce drought-relieving snowfall by seeding clouds with silver iodide. As I indicated in those posts, neither the Chinese nor anyone else has demonstrated that such weather modification programs produce meaningful changes in overall precipitation patterns. For one thing, it's not possible to know for sure what might have occurred in the absence of cloud seeding. Additionally, it's extremely difficult, maybe impossible, to anticipate unintended consequences -- for example, a seeding-induced increase in precipitation in one place could result in less precipitation somewhere else. In such situations, the legalese of responsibility and liability becomes a major concern.
This classic illustration of the law of unintended consequences -- solving one problem but inadvertently creating another -- is likewise a concern when it comes to geoengineering the climate, but on a much larger scale. This includes addressing questions such as which nation or nongovernmental entity should decide whether the potential benefits outweigh the risks, and who is responsible for correcting (if possible) unintended consequences?
Aside: To the best of my knowledge there's been very little coverage of climate geoengineering and its implications in mainstream newspapers and TV news broadcasts. There are obviously many important issues and events to cover these days, but I'm surprised that geoengineering has not been judged more newsworthy given what's currently happening in the field.
See also our previous post highlighting a new documentary on geoengineering. |
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Sore Throat
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| Obama to Look at Climate Engineering
Thu Apr 09, 2009 12:02 am
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http://online.wsj.com/article/SB123920773503201665.html
Obama to Look at Climate Engineering
Associated Press
WASHINGTON -- The president's new science adviser said Wednesday that global warming is so dire, the Obama administration is discussing radical technologies to cool Earth's air.
John Holdren told the Associated Press in his first interview since being confirmed last month that the idea of geoengineering the climate is being discussed. One such extreme option includes shooting pollution particles into the upper atmosphere to reflect the sun's rays. Mr. Holdren said such an experimental measure would only be used as a last resort.
"It's got to be looked at," he said. "We don't have the luxury of taking any approach off the table."
Mr. Holdren outlined several "tipping points" involving global warming that could be fast approaching. Once such milestones are reached, such as complete loss of summer sea ice in the Arctic, it increases chances of "really intolerable consequences," he said.
Twice in a half-hour interview, Mr. Holdren compared global warming to being "in a car with bad brakes driving toward a cliff in the fog."
At first, Mr. Holdren characterized the potential need to technologically tinker with the climate as just his personal view. However, he went on to say he has raised it in administration discussions.
Mr. Holdren, a 65-year-old physicist, is far from alone in taking geoengineering more seriously. The National Academy of Science is making climate tinkering the subject of its first workshop in its new multidiscipline climate challenges program. The British parliament has also discussed the idea.
The American Meteorological Society is crafting a policy statement on geoengineering that says "it is prudent to consider geoengineering's potential, to understand its limits and to avoid rash deployment."
Last week, Princeton scientist Robert Socolow told the National Academy that geoengineering should be an available option in case climate worsens dramatically.
But Mr. Holdren noted that shooting particles into the air -- making an artificial volcano as one Nobel laureate has suggested -- could have grave side effects and would not completely solve all the problems from soaring greenhouse gas emissions. So such actions could not be taken lightly, he said.
Still, "we might get desperate enough to want to use it," he added.
Another geoengineering option he mentioned was the use of so-called artificial trees to suck carbon dioxide -- the chief human-caused greenhouse gas -- out of the air and store it. At first that seemed prohibitively expensive, but a re-examination of the approach shows it might be less costly, he said. |
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Sore Throat
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| Scientists weigh geoengineering in global warming battle
Sun Apr 19, 2009 5:36 pm
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http://www.usatoday.com/tech/science/columnist/vergano/2009-04-19-geoengineering_N.htm
Scientists weigh geoengineering in global warming battle
By Dan Vergano, USA TODAY
Not every crazy idea, say dropping out of Harvard to start a software firm, is a bad one. But you don't have to be Bill Gates to place your bets that way.
Consider atmospheric geoengineering — pumping reflective particles into the stratosphere to reflect sunlight — seen as a way to cut the effects of global warming. In 1991, the eruption of Mt. Pinatubo in the Philippines cooled the atmosphere's average temperature worldwide almost one degree Fahrenheit, a kind of "global dimming," serving as an inspiration for the idea. Such high-altitude aerosols, different from the ones found in spray cans, can play a big role in climate.
A 2006 paper in the journal Science, for example, written by the eminent atmospheric scientist Tom Wigley of the National Center for Atmospheric Research, suggested that annually blasting roughly 500,000 tons of sulfur (about 7% of yearly sulfur production) into the stratosphere every year for three decades would prevent global warming. But there is that acid rain issue.
Earlier this month, White House science adviser John Holdren found himself at the center of a brouhaha over remarks to the Associated Press that geoengineering of all sorts was "mentioned" as the administration pondered means of limiting global warming. Holdren later downplayed geoengineering schemes, after news stories appeared linking atmospheric geoengineering to drought, ozone depletion and acid rain, among other concerns.
A pair of recent papers point to some unintended consequences of atmospheric geoengineering, ones that add to the sense that it might not be such a good idea.
In a study in the journal Environmental Science and Technology, federal scientist Daniel Murphy of the National Oceanic and Atmospheric Administration looked at what stratospheric aerosols would do for solar cells and mirrored solar power collectors. He turned to 1991 data from the Mt. Pinatubo eruption for an answer.
In the study, calculations of sunlight scattering combined with records from Hawaii's Mauna Loa observatory showed that for every one watt's worth of sunlight reflected away from Earth by stratospheric aerosols, another four watts were converted from direct sunlight to diffuse sunlight. Such sunlight is bad news for the large power-generating solar collectors that rely on mirrors to concentrate power. Even though total direct sunlight fell only 3% in 1991, power generated by these collectors dropped by 20%. "It turns out that any systems using mirrors to concentrate direct sunlight are much more sensitive than one-for-one," Murphy says, by e-mail.
"Among all of the possible side effects of geoengineering, the effect on solar power is probably not the most important. It is one of the most certain," Murphy adds.
A second paper, out Sunday in the journal Nature Geoscience, points to another problem with stratospheric aerosols. "We are really uncertain about their role in the climate system," says study lead author Dan Cziczo of Pacific Northwest National Laboratories in Richland, Wash. Ice condenses around aerosol particles, a process that scientists know leads to high-flying cirrus clouds. Those clouds in turn reflect sunlight, a cooling effect in the global warming equation.
But how this happens exactly isn't clear, Cziczo says. "So, what we were really trying to do was look at what particles helped to form the clouds," he says. "What really cropped up was lead."
In a series of field measurements of ice crystals combined with cloud chamber experiments, Cziczo and colleagues found that lead makes a great ice condenser in stratospheric aerosols, a first report of this effect.
"Most of the lead in the atmosphere is not natural," Cziczo notes, but was spewed out in leaded gasoline in previous decades and is still used in light aircraft engines. Lead is one of the worst pollutants of the industrial age, linked to lowered intelligence scores, nerve damage and high blood pressure, among many other ills.
But plugging lead into a series of climate models, the Nature Geoscience study shows that high stratospheric lead levels would lead to ice clouds whose sunlight reflection would cut current global warming in half. "These are the kinds of emissions we might have seen in the late 1970's," Cziczo says. In past decades, lead pollution may have helped keep global warming at bay.
"The study helps to highlight why talk of geoengineering is something we shouldn't pursue now," he adds. "It's a bit arrogant to presume we understand aerosols so well we could not expect unintended consequences." |
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| Geoengineering, a 'Poor Option' for Earth
Sat May 16, 2009 4:02 am
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http://news.softpedia.com/news/Geoengineering-a-039-Poor-Option-039-for-Earth-111057.shtml
Geoengineering, a 'Poor Option' for Earth
Studies reveal it does little good
Over the past few years, engineers and scientists from several universities and research institutions have argued that geoengineering – as in using artificial substances to change natural feats of the oceans, such as the production of plankton, and also to boost the water's ability to store carbon dioxide – is the best way of deterring global warming, and climate change, implicitly. However, according to a new study, which will appear in a forthcoming issue of the journal Global Biogeochemical Cycles, the scheme may not be nearly as effective as advertised.
In short, experts at the US Department of Energy's (DOE) Lawrence Berkeley National Laboratory (LBNL) have announced that the Iron Hypothesis doesn't work. Simply put, this line of thought holds that, by fertilizing waters with iron particles, in areas where the metal is missing, but other nutrients exist, could directly bring the evolution of global warming to a stand-still, and even stop the phenomenon. Iron helps plankton – the basic life form in the ocean – bloom, and plankton consumes more carbon dioxide from the surface.
When the organisms die, they take all the CO2 they've consumed over their life down to the ocean floor, where it gets trapped. Following this line of reasoning, the more organisms live, the more greenhouse gases get sucked in, and the clearer the atmosphere becomes. But the LBNL team, using data from the Carbon Explorer floats, which are deep-diving sensors, has determined that the effect of ocean fertilization in designated test areas around the Southern Ocean is null, and that the amounts of carbon dioxide have not increased at all.
“Just adding iron to the ocean hasn't been demonstrated as a good plan for storing atmospheric carbon. What counts is the carbon that reaches the deep sea, and a lot of the carbon tied up in plankton blooms appears not to sink very fast or very far,” LBNL Oceanographer Jim Bishop, who is also a University of California in Berkeley (UCB) professor of Earth and Planetary Sciences and a member of the Earth Sciences Division at the Berkeley Laboratory, explains. “We would never have made these surprising observations if the autonomous Carbon Explorer floats hadn't been recording data 24 hours a day, seven days a week, at depths down to 800 meters or more, for over a year after the experiment's original iron signature had disappeared,” he adds.
“Assumptions about the biological pump – the way ocean life circulates carbon – are mostly based on averaging measurements that have been made from ships, at intervals widely separated in time. Cost, not to mention the environment, would have made continuous ship-based observations impossible in this case. Luckily, one Carbon Explorer float costs only about as much as a single day of ship time,” Bishop goes on to explain.
“Iron is not the only factor that determines phytoplankton growth in HNLC regions. Light, mixing, and hungry zooplankton are fundamentally as important as iron. You can grow a lot of Brussels sprouts, but kids won't eat it. The same appears to be the case with diatom phytoplankton and zooplankton. It's the zooplankton community that determines carbon sedimentation,” the expert concludes. |
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Sore Throat
Joined: 01 Sep 2000
Posts: 1798
Location: x |
| Pressing the Case for Geoengineering
Tue Jun 23, 2009 5:05 am
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http://greeninc.blogs.nytimes.com/2009/06/22/pressing-the-case-for-geoengineering/
Pressing the Case for Geoengineering
By STEVE LOHR
David G. Victor got a spirited reaction to his article about geoengineering in Foreign Affairs a few months ago. “I fielded a lot of hate mail,” he said.
Mr. Victor, the director of Stanford University’s Energy and Sustainable Development Program, is a leading voice in the effort to get governments and policymakers to start thinking seriously about the possibility of technological tinkering with the atmosphere, as a weapon of last resort in the battle against global warming.
In the March/April edition of Foreign Affairs, Mr. Victor was the lead author of an article that candidly acknowledged the challenge. “Fiddling with the climate to fix the climate strikes most people as a shockingly bad idea,” he wrote.
I watched Mr. Victor make his case before a small group of mainly government policymakers from nine nations at a private gathering north of San Francisco earlier this month, organized by the Institute for Large Scale Innovation, a nonprofit group. He is an engaging, even cheerful bearer of bad news.
In his analysis, there are three ways of coping with climate change: controlling emissions, adapting to the altered climate and geoengineering, which he concedes, is the most drastic, even desperate. “It is Dr. Strangelove, but it is entirely doable,” said Mr. Victor, who is also a law professor at Stanford.
Geoengineering, he said, needs to be brought in from the mad-scientist fringe. Governments, he said, should finance research, weigh policy options and discuss geoengineering in international climate-change organizations. “It may be we never use this option, but is needs to be ready,” he said.
John Holdren, the chief science adviser in the Obama administration and an environmental policy specialist, recently suggested that geoengineering has to be taken seriously. “It’s got to be looked at,” he told The Associated Press in April. “We don’t have the luxury of taking anything off the table.” Mr. Holdren later clarified that the White House was not strongly considering pursuing geoengineering as a policy.
At the California meeting, Mr. Victor’s pitch was greeted with polite skepticism, as he reviewed ideas like spraying tiny reflective particles into the upper atmosphere to help block the sun’s rays and cool the planet.
Francelino Grando, a senior government official from Brazil, worried that geoengineering might be seen as a solution instead of a stop-gap. “It may give people the impression that we don’t have to worry about climate change because we can solve it through engineering,” he said. “But the only real answer is that we have to fundamentally change the pattern of energy use.”
For his part, Mr. Victor declared himself optimistic that technologies to curb emissions — from alternative fuels to carbon capture — will be the long-term answer. But he worries about making it to the long term without environmental disaster, especially during transition years, he said, from 2050 to 2070 or so. “So I think we’ll need to have the geoengineering option,” he said. |
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Sore Throat
Joined: 01 Sep 2000
Posts: 1798
Location: x |
| It’s Time to Cool the Planet
Tue Jun 23, 2009 5:16 am
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http://online.wsj.com/article/SB10001424052970204771304574181522575503150.html
It’s Time to Cool the Planet
Cutting greenhouse gases is no longer enough to deal with global warming, says Jamais Cascio. He argues that we also have to do something more direct—and risky.
By JAMAIS CASCIO
If we’re going to avoid climate disaster, we’re going to have start getting a lot more direct. We’re going to have to think about cooling the planet.
The concept is called geoengineering, and in the past few years, it has gone from being dismissed as a fringe idea to the subject of intense debates in the halls of power. Many of us who have been watching this subject closely have gone from being skeptics to advocates. Very reluctant advocates, to be sure, but advocates nonetheless.
What has changed? Quite simply, as the effects of global warming have worsened, policy makers have failed to meet the challenge. As a result, if we want to avoid an unprecedented global catastrophe, we may have no other choice but to reduce the impact of global warning, alongside focusing on the factors that are causing it in the first place. That is, while we continue to work aggressively to reduce the amount of carbon released into the atmosphere, we also need to consider lowering the temperature of the Earth itself.
To be clear, geoengineering won’t solve global warming. It’s not a “techno-fix.” It would be enormously risky and almost certainly lead to troubling unforeseen consequences. And without a doubt, the deployment of geoengineering would lead to international tension. Who decides what the ideal temperature would be? Russia? India? The U.S.? Who’s to blame if Country A’s geoengineering efforts cause a drought in Country B?
Also let’s be clear about one other thing: We will still have to radically reduce carbon emissions, and do so quickly. We will still have to eliminate the use of fossil fuels, and adopt substantially more sustainable agricultural methods. We will still have to deal with the effects of ecosystems damaged by carbon overload.
But what geoengineering can do is slow the increase in temperatures, delay potentially catastrophic “tipping point” events—such as a disastrous melting of the Arctic permafrost—and give us time to make the changes to our economies and our societies necessary to end the climate disaster.
Geoengineering, in other words, is simply a temporary “stay of execution.” We will still have to work for a pardon.
Nothing New
Altering the Earth’s temperature, of course, is hardly anything new. Human civilization has been changing the Earth’s environment for millennia, often to our detriment. Dams, deforestation and urbanization can alter water cycles and wind patterns, occasionally triggering droughts or even creating deserts. On a global scale, industrial activity for the past 150 years or so has changed the Earth’s atmosphere, threatening to raise average world temperatures to catastrophic levels, even if we were able to stop releasing carbon into the atmosphere immediately.
What we’re talking about with geoengineering, however, is something new. It’s a more deliberate manipulation of the environment, rather than a byproduct of other activities. And while we know more than we did just a few years ago about how it might work, there are still plenty of unknowns.
Geoengineering mainly takes two forms: temperature management, which moderates heat by blocking or reflecting a small portion of the sunlight hitting the Earth; and carbon management, which gradually removes large amounts of carbon from the atmosphere (as opposed to simply reducing the amount of additional carbon we’re releasing into the atmosphere). Temperature management is the more likely course of action, as it has the advantage of potentially quick results, while carbon-management techniques that would have a global impact might take decades or centuries to show results.
Sun Block
Temperature-management proposals boil down to increasing how much sunlight the Earth reflects, rather than absorbs. (Increasing the planet’s reflectivity by 2% could counter the warming effects of a doubling of CO2 emissions.) While a variety of techniques have been suggested, some don’t pass the plausibility test, either due to cost, clear drawbacks, or both.
For instance, one proposal would place thousands of square miles of reflective sheets in the desert to reflect sunlight—an interesting plan, until you realize that this would effectively destroy desert ecosystems. Another proposal calls for launching millions of tiny mirrors into orbit, where they would block some sunlight from reaching the atmosphere. But one study of the orbiting-mirror plan concluded that, to keep pace with the continual warming, we’d need to launch one square mile of sunshade into orbit every hour.
Two approaches hold the most promise: injecting tons of sulfates—essentially solid particles of sulfur dioxide—into the stratosphere, and pumping seawater into the lower atmosphere to create clouds. A recent report in the journal Atmospheric Physics and Chemistry Discussions identified these two approaches as having a high likelihood of being able to counter global temperature increases, and to do so in a reasonably short amount of time.
The sulfate-injection plan, which has received the most study, is explicitly modeled on the effects of massive volcanic eruptions, such as Mount Pinatubo in the Philippines; in the months after the 1991 eruption, global temperatures dropped by half a degree Celsius.
To trigger a drop in global temperatures, we’d need to loft between two million and 10 million tons of sulfur dioxide (which combines with oxygen to form sulfate particles) into the lower stratosphere, or at about 33,000 feet. The tiny particles suspended in the atmosphere act like a haze, reflecting a significant amount of sunlight—though not enough to notice at ground level (except for some superb sunsets).
While this seems like a large amount, several studies have shown it could be done using some combination of high-altitude balloons, dispersal in jet-aircraft exhaust, and even more exotic platforms such as artillery shells. As with volcanic sulfates, the particles would eventually cycle out of the atmosphere, so we’d have to refresh that two to 10 megatons of sulfur dioxide roughly every year.
Stratospheric sulfate injection appeals to many geoengineering proponents for a few reasons. It doesn’t require a massive leap in technology to carry out successfully; arguably, we could start doing it this year, if we needed to. It’s relatively cheap, probably costing just a few billion dollars a year. And because stratospheric sulfate injection emulates an effect of volcanic eruptions, we already have some idea of what to expect from it—for better and worse. We know, for example, that the cooling effect could start within weeks of the injection process.
We also know that stratospheric sulfates will likely damage the ozone layer (as happened after Mount Pinatubo erupted), potentially resulting in more skin cancer and damage to plants and animals. In addition, the scattering of sunlight will reduce the efficiency of some kinds of solar power, and some studies have suggested that it could disrupt monsoonal rain cycles.
A Higher Chance of Clouds
The other high-impact proposal, cloud brightening, increases the amount of reflected sunlight by making more clouds and thickening existing ones. One idea is to use ships to propel seawater thousands of feet in the air, where it would form or increase cloud cover.
The technique has both advantages and disadvantages compared with the sulfate-injection method. Lofting seawater into the air to seed cloud formation would have fewer environmental side effects than the sulfates, and may allow for targeted use to counter droughts. Because it would be relatively low altitude, it wouldn’t have the same scattering effect on sunlight as sulfate injection.
But increasing the extent and thickness of cloud cover could also have at least as powerful an effect on rainfall patterns as sulfate injection, increasing downpours in one area or contributing to unexpected droughts in others. Finally, the technologies required for cloud brightening are still experimental, though initial proposals look to be markedly more environmentally benign than those used for sulfate injection.
Both solutions could present a more dramatic problem if the geoengineering was to stop abruptly. According to some studies, global temperatures would spike once the geoengineering steps were ended, actually exceeding for a short time where they would have been without any geoengineering. Afterward, the temperature increase would continue as if nothing had been done to slow it. While this doesn’t mean we’d have to undertake geoengineering indefinitely, it underscores why geoengineering must be accompanied by carbon cuts.
Also, neither would do anything to solve other problems that arise from excessive levels of carbon dioxide, such as oceans becoming more acidic from increased carbon loading.
The Political Impact
Any kind of geoengineering would also face other issues. Most prominent are the political concerns. Since geoengineering is global in its effects, who determines whether or not it’s used, which technologies to deploy, and what the target temperatures will be? Who decides which unexpected side effects are bad enough to warrant ending the process? Because the expense and expertise required would be low enough for a single country, what happens when a desperate “rogue nation” attempts geoengineering against the wishes of other states? And because the benefits and possible harm from geoengineering attempts would be unevenly distributed around the planet, would it be possible to use this technology for strategic or military purposes? That last one may sound a bit paranoid, but it’s clear that any technology with the potential for strategic use will be at the very least considered by any rational international actor.
There are also more mundane questions of liability. If, for example, South Asia experiences an unusual drought during cyclone season after geoengineering begins, who gets blamed? Who gets sued? Would all “odd” weather patterns be ascribed to the geoengineering effort? If so, would the issue of what would have happened absent geoengineering be considered relevant?
Consider the Alternative
With all of these drawbacks, why would I consider myself an advocate of geoengineering, no matter how reluctant? Because I believe the alternative would be worse.
The global institutions we rely on to deal with a problem like climate change seem unable to look past short-term roadblocks and regional interests. At the same time, climate scientists are shouting louder than ever about the speed and intensity of environmental changes coming from global warming.
In short, although we know what to do to stop global warming, we’re running out of time to do it and show no interest in moving faster. So here’s where geoengineering steps in: It gives us time to act.
That’s if it’s done wisely. It’s imperative that we increase funding for geoengineering research, building the kinds of models and simulations necessary to allow us to weed out the approaches with dangerous, surprising consequences.
Fortunately, the deployment of geoengineering need not be all or nothing. Though it would have the greatest impact if done globally, some models have shown that intervention just in the polar regions would be enough to hold off the most critical tipping-point events, including ice-cap collapse and a massive methane release.
Polar-only geoengineering strikes me as a plausible compromise position. It could be scaled up if the situation becomes more dire and could be easily shut down with minimal temperature spikes if there were unacceptable side effects.
Still, we can’t forget: Geoengineering is not a solution for global warming. It would simply hold temperatures down temporarily, doing nothing about the causes of climate change, let alone ocean acidification and other symptoms of a carbon overdose. We can’t let ourselves slip back into business-as-usual complacency, because we’d simply be setting ourselves up for a far greater disaster down the road.
Our overall goal must remain the reduction and then elimination of greenhouse-gas emissions as swiftly as humanly possible. This will require feats of political will and courage around the world. What geoengineering offers us is the time to make it happen.
--Mr. Cascio, based in the San Francisco Bay area, is a futurist and Senior Fellow at the Institute for Ethics and Emerging Technologies. He can be reached at reports@wsj.com. |
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