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Geoengineering should not be used as a climate fix yet, says US science academy

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That word 'yet' is truly alarming.

Geoengineering should not be used as a climate fix yet, says US science academy

That extreme planet-hacking fixes for climate change have become a future possibility is a wake up call to reduce emissions now, say top US scientists

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‘The likelihood of eventually considering last-ditch efforts to address damage from climate change grows with every year of inaction on emissions control,’ says US National Academy of Science report. Photograph: ISS/NASA

Suzanne Goldenberg

The Guardian Tuesday 10 February 2015 11.12 EST

Climate change has advanced so rapidly that the time has come to look at options for a planetary-scale intervention, the National Academy of Science said on Tuesday. But it was categorical that such ‘geoengineering’ should not currently be deployed at scale or considered as an alternative to cutting emissions now.

The much-anticipated report from the country’s top scientists strongly endorsed the idea of further research into a topic it admitted had once been taboo: proposed high-tech fixes for climate change.

Cutting the carbon pollution that causes climate change was still the main solution, the scientists said, but they conceded they could see the day when desperate governments would turn to geoengineering.

“That scientists are even considering technological interventions should be a wake-up call that we need to do more now to reduce emissions, which is the most effective, least risky way to combat climate change,” Marcia McNutt, the committee chair and former director of the US Geological Survey, said.

“But the longer we wait, the more likely it will become that we will need to deploy some forms of carbon dioxide removal to avoid the worst impacts of climate change.”

The two-volume report, produced over 18 months by a team of 16 scientists, was far more guarded than a similar British exercise five years ago which called for an immediate injection of funds to begin research on climate-altering interventions.

But the two US reports – Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration and Climate Intervention: Reflecting Sunlight to Cool the Earth – could boost research efforts at a limited scale.

Bill Gates, among others, argues the technology, which is still confined to computer models, has enormous potential and he has funded research at Harvard. The report said scientific research agencies should begin carrying out co-ordinated research.

But geoengineering remains extremely risky and relying on a planetary hack – instead of cutting carbon dioxide emissions – is “irresponsible and irrational”, the report said.

Rafe Pomerantz, a climate official in the Clinton administration said: “The hostility has diminished a lot about the need to research. It has made it more politically possible for the academy to come out like this. The atmosphere has changed.”

The shift was prompted by the growing awareness that the climate measures in the pipeline to date will fall far short of keeping the world within the 2C limit for avoiding dangerous climate change, Pomerantz said.

“There is no risk-free path here,” he said. “The question is: do we need this to help us manage the risks while we are reducing the concentration of greenhouse gases in the atmosphere? That is the question and nobody knows whether we have a tool or not.”

The scientists looked at two broad planetary-scale technological fixes for climate change: sucking carbon dioxide emissions out of the atmosphere, or carbon dioxide removal, and increasing the amount of sunlight reflected away from the earth and back into space, or albedo modification.

But even with such technologies on the horizon it was far better to fight climate change by reducing greenhouse gas emissions, the report concluded.

The report also warned that offering the promise of a quick fix to climate change through planet hacking could discourage efforts to cut the greenhouse gas emissions that cause climate change.

“The message is that reducing carbon dioxide emissions is by far the preferable way of addressing the problem,” said Raymond Pierrehumbert, a University of Chicago climate scientist, who served on the committee writing the report. “Dimming the sun by increasing the earth’s reflectivity shouldn’t be viewed as a cheap substitute for reducing carbon dioxide emissions. It is a very poor and distant third, fourth, or even fifth choice. |It is way down on the list of things you want to do.”

But geoengineering has now landed on the list.

Climate change was advancing so rapidly a climate emergency – such as widespread crop failure – might propel governments into trying such large-scale interventions.

“The likelihood of eventually considering last-ditch efforts to address damage from climate change grows with every year of inaction on emissions control,” the report said.

If that was the case, it was far better to be prepared for the eventualities by carrying out research now.

The report gave a cautious go-ahead to technologies to suck carbon dioxide out of the air, finding them generally low-risk – although they were prohibitively expensive.

The report discounted the idea of seeding the ocean with iron filings to create plankton blooms that absorb carbon dioxide.

But it suggested carbon-sucking technologies could be considered as part of a portfolio of responses to fight climate change.

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Carbon-sucking technologies, such as these ‘artificial forests’, could in future be considered to fight climate change - but reducing carbon dioxide emissions now is by far the preferable way of addressing the problem. Photograph: Guardian

It would involve capturing carbon dioxide from the atmosphere and pumping it underground at high pressure – similar to technology that is only now being tested at a small number of coal plants.

Sucking carbon dioxide out of the air is much more challenging than capturing it from a power plant – which is already prohibitively expensive, the report said. But it still had a place.

“I think there is a good case that eventually this might have to be part of the arsenal of weapons we use against climate change,” said Michael Oppenheimer, a climate scientist at Princeton University, who was not involved with the report.

The other, far more riskier planetary-scale climate interventions involves proposals to increase the amount of sunlight reflected back into space by injecting sulphur dioxide into the atmosphere to increase the amount of reflective particles.

But the report expressed deep misgivings about tinkering with the reflectivity of the atmosphere on a planetary scale. “Albedo modification techniques mask the effects of greenhouse warming; they do not reduce greenhouse gas concentrations,” the report said.

The two technologies have very different downsides, said Ken Caldeira, an atmospheric scientist at Carnegie Institution’s Department of Global Ecology and a geoengineering pioneer.

“The primary concern about carbon dioxide removal is how much does it cost,” he said. “There are no sort of novel, global existential dilemmas that are raised. The main aim of the research is to make it more affordable, and to make sure it is environmentally acceptable.”

In the case of albedo reflection, however, the issue is risk. “A lot of those ideas are relatively cheap,” he said. “The question isn’t about direct cost. The question is, What bad stuff is going to happen?”

There are fears such interventions could lead to unintended consequences that are even worse than climate change – widespread crop failure and famine, clashes between countries over who controls the skies.

But Caldeira, who was on the committee, argued that it made sense to study those consequences now. “If there are real show stoppers and it is not going to work, it would be good to know that in advance and take it off the table, so people don’t do something rash in an emergency situation,” he said.

Spraying sulphur dioxide into the atmosphere could lower temperatures – at least according to computer models and real-life experiences following major volcanic eruptions.

But the cooling would be temporary and the risks enormous, the report said. The interventions would do nothing to reduce the greenhouse gas emissions that are in the atmosphere – but merely mask some of the symptoms. It would do nothing to right ocean chemistry, which was thrown off kilter by absorbing those emissions.

“My view of albedo modification is that it is like taking pain killers when you need surgery for cancer,” said Pierrehumbert. “It’s ignoring the problem. The problem is still growing though and it is going to come back and get you.”

Dr Matthew Watson, reader in Natural Hazards at the University of Bristol and who was the lead scientist on a UK geoengineering project that was cancelled due to a perceived conflict of interest, said: “This latest report builds on previous discussion and captures a centrist position that many scientists and publics will feel comfortable with. It highlights the need for careful, engaged and holistic thinking and strongly echoes the messages of UK researchers from the recent Royal Society meeting in London.”

http://www.theguardian.com/environment/2015/feb/10/geoengineering-should-not-be-used-as-a-climate-fix-yet-says-us-science-academy

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