Top science body calls for geoengineering 'plan B'

Catherine Brahic, New Scientist 1 Sep 09;

Take note: the back-up plan for saving the world is no joke. A major scientific institution has published a comprehensive review of possible ways to engineer the climate to reverse global warming.

The UK Royal Society's review of geoengineering will make it difficult for governments to ignore the issue. It says that while reducing emissions of greenhouse gases "absolutely" must remain a priority, there is a serious chance that this will not be enough to stave off global warming of 2 °C.

"My guess would be that there is a 50-50 chance that we can achieve something with emissions reductions," says John Shepherd of the University of Southampton in the UK, chair of the Royal Society group behind the report.

If humanity wants to avoid the worst effects of climate change, it must be ready to safely deploy geoengineering methods as and when necessary, the report says. "We are already staring 1.6 °C in the face," says Shepherd.

He believes we should know some time in the next two decades whether or not efforts to curb emissions will be enough to avoid 2 °C of warming. If not, his personal view is that we should be prepared for a two-step plan B.
Sun shield

Step one: deploy some sort of sun shield to deflect solar energy away from Earth. Reflective technologies could cool the planet within a year, and according to the Royal Society's findings the most promising method in terms of cost and effectiveness would be to pump sulphate particles into the stratosphere (see illustration). However, this will not curb ocean acidification and other side effects of greenhouse emissions, and could disrupt weather patterns, so another method is required.

Step two: enact a means of sucking carbon dioxide out of the atmosphere. Several methods are already being investigated, which fall broadly into two categories: "tech-heavy" solutions, such as artificial trees that filter air and extract CO2 for storage, and "biological" methods, such as planting trees, using biofuels and fertilising the oceans.

According to Shepherd, tech-heavy methods are preferable because they are less likely to interfere with complex ecosystems. "Most of the things that have gone wrong in the past have happened when we've tampered with biological systems," he says.

Geoengineering methods have so far been on the fringe of climate discussions and research. Few, if any, could be developed tomorrow or even tested on a large scale. The Royal Society report calls on the UK government to invest £10 million a year towards an international research effort into geoengineering. This amounts to roughly 10 per cent of the UK climate research budget.

Another unresolved issue is for governments to agree on how to regulate geoengineering efforts. The Royal Society proposes that the UN Commission for Sustainable Development be charged with the task. It also suggests the UN Framework Convention on Climate Change should establish a geoengineering working group.
Bandwagon rolling

Such an international effort is conceivable. There are signs that the field is increasingly being taken seriously at national and international levels. Earlier this month the US National Academies tweaked the remit of its climate panel such that it will now assess geoengineering proposals. The Intergovernmental Panel on Climate Change will decide next month whether or not to do the same.

"It is clear that a lot of people are arguing that the IPCC should include an assessment of geoengineering in its next report," says Ottmar Edenhofer of the Potsdam Institute for Climate Impact Research in Germany and co-chair of one of the IPCC's three working groups. More worryingly, perhaps, military and naval representatives have also taken to attending research and policy workshops on the topic.

The Royal Society gave some reassurance that discussions of geoengineering will not deflate the public will to cut emissions. Results from focus groups suggested that the fact that scientists are giving geoengineering serious thought could be enough to spur people into acting on climate change. Whether this will hold true for politicians remains to be seen.

Investment in geo-engineering needed immediately, says Royal Society
Techniques such as CO2 removal and radiation reflection are 'untested parachutes' until they are rigorously tested, it says
Alok Jha, guardian.co.uk 1 Sep 09;

Experiments on giant sunshades for the Earth and vast forests of artificial trees must begin immediately, according to the Royal Society, to ensure such mega-engineering plans are available as a safety net in case global talks to combat climate change fail.

The scientists spent a year assessing geo-engineering technologies, deliberate planet-scale interventions in the climate system that attempt to counteract global warming. Their report, the most comprehensive to date, concluded that immediate investment is required to discover whether the potential risks outweigh the benefits.

"Unless the world community can do better at cutting emissions, we fear we will need additional techniques such as geo-engineering to avoid very dangerous climate change in the future," said John Shepherd of the University of Southampton, who chaired the RS report.

"However, we are not advocates of geo-engineering - our opinions range from cautious consent to very serious scepticism about these ideas. It is not an alternative to emissions reductions and cannot provide an easy quick-fix to the problem."

Its report, published today, concluded that some approaches – such as capturing CO2 from the atmosphere using artificial trees or shooting tiny particles into the upper atmosphere to reflect away sunlight – looked promising. But all geo-engineering techniques had major uncertainties regarding their own environmental impacts.

The Royal Society considered two main categories of the technology. One involves reflecting a small amount, around 2%, of the solar radiation that reaches the Earth, thus preventing the planet from warming up. The other category involves removing greenhouse gases from the atmosphere.

"CO2 removal methods are preferable because removing greenhouse gases from the atmosphere addresses the problem at its root and is returning the earth's climate system closer to its natural state," said Shepherd.

But he said crucial experimental data in the area was lacking. "We need to initiate research so we can understand the intended and unintended consequences of these methods so that, if we ever do need to deploy them, we can do so in a sensible and effective way."

The report calls for about £10m per year to be spent in the UK as part of a global £100m fund. "That's about 10 times what is being spent now and about 10 times less than what we spend on climate change research," said Shepherd. "And it's only 1% of what we spend on new energy technology."

Ken Caldeira, a climate scientist at the Carnegie Institution in California, said this early-stage research must be carried out as soon as possible. "The worst situation is to not test the options and then face a climate emergency and then be faced with deploying an untested option, a parachute that you've never tested out as the plane's crashing."

Among the most promising technologies identified by the Royal Society are techniques to suck CO2 directly out of the atmosphere. The front-runner in this arena is a design by Klaus Lackner of Columbia University in New York. His artificial trees are not yet cost-effective to produce but Shepherd said it was probably just a matter of time.

Shooting sulphate aerosols into the stratosphere would also work well, said the Royal Society, as previous volcanic eruptions have showed in the past. When Mount Pinatubo in the Philippines erupted in 1991, for example, global temperatures dropped by 0.5C the following year. The costs would be relatively low but the scientists identified questions over potential adverse effects, in particular the destruction of the ozone layer.

Doug Parr, chief scientist at Greenpeace UK, said: "Geo-engineering is creeping onto the agenda because governments seem incapable of standing up to the vested interests of the fossil fuel lobby, who will use the idea to undermine the emissions reductions we can do safely.

"Intervening in our planet's systems carries huge risks, with winners and losers, and if we can't deliver political action on clean energy and efficiency then consensus on geo-engineering is a fantasy."

The Royal Society also pointed out that technical and scientific issues may not be the dominant ones when it came to the actual deployment of geo-engineering technology. Social, legal, ethical and political issues would be of equal significance and implementing global-scale projects would require a pre-existing international agreement.

"When it comes to techniques that need to be field-tested, and where that will occur in places beyond national jurisdiction, such as sulphate aerosols, then inevitably we're looking at some kind of international governance framework," said Catherine Redgwell, a professor of international law at University College London and a member of the Royal Society working group on geoengineering.

At a meeting to launch the report at the Royal Society today, the government's chief scientific adviser John Beddington said the government should be thinking about a modest investment in geoengineering research.

"It is appropriate that the UK continues to support international research in this area including the possibility of considering the types of global governance systems that would be needed for geo-engineering," he said.

World must plan for climate emergency: report
Gerard Wynn, Reuters 1 Sep 09;

LONDON (Reuters) - Humans may have to reset the Earth's natural thermostat and develop new technologies like reflecting sunlight back into space if climate talks fail, Britain's top science academy said on Tuesday.

So-called geoengineering was not a quick fix but may be needed to head off planetary catastrophe and so deserved more research as an insurance policy, the Royal Society said in a report, "Geoengineering the climate."

Such technologies were not an alternative to cutting emissions, however, the report stressed.

Political efforts to curb greenhouse gases are in the spotlight three months before a U.N-led meeting meant to clinch a new climate treaty to replace the Kyoto Protocol.

"Nothing should divert us from the priority of reducing global carbon dioxide emissions and ensuring that the December meeting in Copenhagen does lead to real progress," said Royal Society President Martin Rees.

"But if such reductions achieve too little too late there will be surely pressure to contemplate a plan B," he told an audience at the launch of the report in central London.

Growing interest in geoengineering was partly motivated by a "false hope of a quick fix," Rees said, and Greenpeace's Doug Parr said that it would be seized upon by polluters.

Britain's chief scientific adviser John Beddington supported more research, however. "They are part of the solution," he said of the technology, and painted a bleak picture for the planet.

"There's an enormous 'if' whether there'll be comprehensive action agreed in Copenhagen, whether it's going to be enough. There are also going to be (climate) emergencies and surprises," he said, referring to the "devastating" risk of more acidic oceans as a result of carbon emissions.

MIRRORS

Geoengineering technologies can be divided between those that remove the greenhouse gas carbon dioxide (CO2) from the atmosphere and those which reflect sunlight back into space.

Such technologies are now limited to the laboratory and the Royal Society report called for a 10-year, 100 million pound ($163.2 million) British research program, a 10-fold increase.

People have spewed carbon dioxide (CO2) into the air for thousands of years from burning forests to clear farmland and more recently burn fossil fuels in the industrial revolution.

Reversing that trend of emissions poses an enormous challenge, leading to a growing enquiry into geoengineering.

"Do we need it? I think there is a significant risk that we shall make insufficient progress with emissions reductions and that some support for conventional emissions reductions may be needed," said co-author, James Wilsdon.

The report supported steps to remove CO2 from the air above others, because they addressed the underlying problem of too many heat-trapping gases, and so were more predictable and would fight not only climate change but also acidifying oceans.

In the event of an emergency where the Earth suddenly pitched into a different, hotter climate, however, the world may need to reflect back some sunlight, the report said, for example by shooting highly reflective aerosols into the atmosphere.

That would introduce a new influence on the Earth's climate besides greenhouse gases and so was less predictable, especially if not applied across the whole atmosphere.

"You could actually seriously and adversely impact one of the most critical weather patterns on the planet," said lead author John Shepherd, referring to disruption of the monsoon.

Risky schemes may be only hope for cooling planet: scientists
Richard Ingham Yahoo News 1 Sep 09;

LONDON (AFP) – Sci-fi proposals to cool the planet are laden with risk but may be Earth's only hope if politicians fail to tackle global warming, scientists said on Tuesday in their biggest evaluation to date of "geo-engineering" concepts.

The verdict by Britain's prestigious Royal Society came little more than three months before a UN showdown in Copenhagen on how to reduce the carbon emissions that drive climate change.

John Shepherd, a professor at Britain's University of Southampton, who chaired a 12-member panel which assessed the evidence, said geo-engineering was filling a perilous political void.

"Our research found that some geo-engineering techniques could have serious unintended and detrimental effects on many people and ecosystems -- yet we are still failing to take the only action that will prevent us from having to rely on them," he said.

The report cautiously said some geo-engineering schemes were technically feasible but were shadowed by safety worries and doubts about affordability.

Provided these questions were answered, such projects could be a useful tool as part of a worldwide switch to a low-carbon economy, it said.

But, the report warned, other geo-engineering schemes are so costly or so freighted with risk and unknowns that they should only be considered a last-ditch fix.

Just five years ago, geo-engineering was widely dismissed by mainstream climate scientists as quirky or delusional. As recently as 2007, the UN's Intergovernmental Panel on Climate Change (IPCC) cautioned of its potential risk and unquantified cost.

But the schemes are now getting a serious hearing in many quarters, helped by mounting evidence that climate change is advancing faster than thought while progress towards a carbon-curbing UN treaty is moving at glacial speed.

Supporters say geo-engineering can buy time to let politicians hammer out a deal or wean the global economy off polluting fossil fuels.

The report, "Geoengineering the climate: Science, governance and uncertainty," was based mainly on peer-reviewed literature.

It took a year to carry out, and the Royal Society came under fire from green groups who accused it of handing a cloak of respectability to a once-mocked scientific fringe.

The authors said geo-engineering fell into two main categories.

The most promising entails removal of carbon dioxide, such as by planting forests and building towers that would capture CO2 from the air.

Some of these projects could be harnessed alongside conventional methods to reduce emissions once they are demonstrated to be "safe, effective, sustainable and affordable," said the report.

The other category is called solar radiation management.

Instead of tackling CO2, it would act like a thermostat, turning down the heat that reaches Earth from the Sun.

Concepts in this field include deflecting the Sun's heat away from the Earth through space mirrors, scattering light-coloured particles in the high atmosphere to reflect the solar rays and using ships to spray water that would create reflective low-altitude clouds.

The advantage would be to lower temperatures quickly and could be tempting if global warming suddenly cranked up a gear, the report said.

But these techniques would not curb CO2 emissions that cause dangerous ocean acidification; their costs are unclear but possibly astronomical; and they may end up generating disasters of their own.

Even so, they should not be dismissed out of hand, given their potential in an emergency, said Ken Caldeira, a professor of climate modelling at Stanford University, California.

"We need to think if Greenland were to be sliding into the sea rapidly, causing rapid sea-level rise, or if methane started to de-gas rapidly from the Siberian permafrost, or if rainfall patterns were to shift in such a way that wide-spread famines were induced," he said.

"We would be remiss if we did not do what we could do to understand the potential of these options as well as their uncertainties and risks ahead of time."

Painting roofs white to reflect solar rays -- an idea gaining ground in California and other sunny places -- would provide only limited, local cooling and not affect the rise in global temperature.

"None of the geo-engineering technologies so far suggested is a magic bullet and all have risks and uncertainties associated with them," Shepherd said.

The panel called for funding of around 100 million pounds (162 million dollars) a year to kickstart research into the feasibility of geo-engineering schemes could be feasible -- and, if so, in what circumstances they should be applied and how they would be managed.

Engineering Earth 'is feasible'
Pallab Ghosh, BBC News 1 Sep 09;

A UK Royal Society study has concluded that many engineering proposals to reduce the impact of climate change are "technically possible".

Such approaches could be effective, the authors said in their report.

But they also stressed that the potential of geo-engineering should not divert governments away from their efforts to reduce carbon emissions.

Suggestions range from having giant mirrors in space to erecting giant CO2 scrubbers that would "clean" the air.

Such engineering projects could either remove carbon dioxide or reflect the Sun's rays away from the planet.

Ambitious as these schemes seem, the report concluded that many of them potentially had merit, and research into them should be pursued.

The authors stated, however, that some of the technology was barely formed and there were "major uncertainties regarding its effectiveness, costs and environmental impacts".

One of the technologies considered "too risky" was pouring iron filings into the ocean to grow algae which, the authors said, could cause "substantial damage" to marine life and freshwater, estuary and coastal ecosystems.

Buying time

The study stressed that engineering approaches would only have a limited impact, and that efforts should continue to be focused on reducing CO2 emissions.

"(Governments) should make increased efforts toward mitigating and adapting to climate change and in particular agreeing to global emissions reductions of at least 50% on 1990 levels by 2050 and more thereafter," the authors wrote.

But, they continued, there should be "further research and development" into geo-engineering options "to investigate whether low-risk methods can be made available if it becomes necessary to reduce the rate of warming this century".

Of the two basic geo-engineering approaches, the report concluded that those involving the removal of carbon dioxide were preferable, as they effectively return the climate system closer to its pre-industrial state.

But the authors found that many of these options were currently too expensive to implement widely.

This included "carbon capture and storage" methods, which require CO2 be captured directly from power plants and stored under the Earth's surface.

Current proposed methods also work very slowly, taking many decades to remove enough carbon dioxide to significantly reduce the rate of temperature rise.

Of the carbon removal techniques assessed, three were considered to have most potential:

1. CO2 capture from ambient air: This would be the preferred method, as it effectively reverses the cause of climate change.

2. Enhanced weathering: This aims to enhance natural reactions of CO2 from the air with rocks and minerals. It was identified as a prospective longer-term option.

3. Land use and afforestation: The report found that land-use management could and should play a small but significant role in reducing the growth of atmospheric CO2 concentrations.

So-called solar radiation management methods do not take carbon dioxide out of the atmosphere, and, according to some climate models, may be ineffective in altering shifts in rainfall patterns and storms, the report said.

But the authors said that the door should not be shut to the approach, which could be a faster way to reduce the rate of increase in global temperatures.

Some suggestions include: a giant mirror on the Moon; a space parasol made of superfine aluminium mesh; and a swarm of 10 trillion small mirrors launched into space one million at a time every minute for the next 30 years.

The study also said that many of these approaches had huge logistical demands, and it could take several decades for them to be implemented.

But if temperatures rose to such a level where more rapid action needed to be taken, three techniques were considered to have most potential:

1. Stratospheric aerosols: Previous volcanic eruptions have effectively provided case studies of the potential effectiveness of this method.

2. Space-based methods: These were considered to be a potential technique for long-term use, but only if major problems of implementation and maintenance could be solved.

3. Cloud albedo approaches: These include "cloud ships" which would send sea water into the clouds to make them more reflective.

The report also highlighted an inadequate international legal framework for cross border projects.

"The greatest challenges to the successful deployment of geo-engineering may be to social, ethical, legal and political issues associated with governance rather than scientific issues," it pointed out.

The authors urged an appropriate international body, such as the UN Commission for Sustainable Development, to establish a method for developing treaties to determine who would be responsible for research that might have global risks and benefits.

Professor John Shepherd, a researcher from the University of Southampton, chaired the Royal Society's geo-engineering study.

He said: "It is an unpalatable truth that unless we can succeed in greatly reducing CO2 emissions, we are headed for a very uncomfortable and challenging climate future.

"Geo-engineering and its consequences are the price we may have to pay for failure to act on climate change."