Catherine Brahic, New Scientist 18 Mar 09;
HAVE scientists muddied the waters over what needs to be done to stave off dangerous climate change? Have they caused confusion instead of telling politicians how to save the world? That's what many are asking in the wake of a major meeting intended to inform politicians before vitally important negotiations later this year.
This December, the Bella Centre in Copenhagen, Denmark, will play host to thousands of politicians, policy-makers and their entourage as they try to agree on emissions targets. In an attempt to make their mission clearer, last week 2500 scientists gathered in the same halls to deliver the latest findings on how human emissions of greenhouse gases are affecting the environment and how that is likely to evolve over the coming century.
However, some delegates worry the meeting has only created more confusion, leaving policy-makers even less clear about where to set their emissions targets. In 600 talks over three days, researchers presented a complex update on their individual work, the majority of which showed the impacts of climate change would happen faster and be worse than previously thought. The sessions appeared to satisfy the needs of scientists but not the policy-makers present.
This was most obvious in the last session, when Anders Fogh Rasmussen, Denmark's prime minister, struggled to get a firm answer on what emissions targets governments should adopt. He wanted to know whether politicians should still be aiming to limit warming to no more than 2 °C.
This widely accepted target is loosely based on the forecasts of the Intergovernmental Panel on Climate Change (IPCC), but some scientists in Copenhagen suggested 2 °C may not be enough to avert some of the worst impacts of climate change, such as the disintegration of the Arctic ice cap, while others argued the world will get warmer no matter what. "I need some concrete advice now," appealed Rasmussen. "Should we be setting the bar higher? I need to know and I need to know today. The scientific world has to make an agreement with itself - what is the real platform for politicians?"
John Ashton, who is the UK government's special representative on climate change, says it's "wrong and dangerous" for scientists to confuse politicians over the 2 °C target, and this "will make it harder to get the intensity and urgency of effort required".
The problem, says Martin Parry of the Grantham Research Institute on Climate Change and the Environment in London, is that such a large and short meeting was never going to deliver a consensus on climate change. "If you had put another group of scientists on the panel of the plenary sessions, you would have had a different picture," says Parry.
The closest the meeting came to direct advice for politicians was when the organisers published six key messages at the end of the meeting. These messages included a statement that the worst-case scenario IPCC projections are being realised, and an appeal for action. But some conference delegates took issue with the political tone. The messages "carry the authority of the people who drafted them, and no more", says Mike Hulme of the University of East Anglia, UK. "Not the authority of the 2500 expert researchers gathered at the conference, and certainly not the authority of collective global science."
Parry argues that politicians need to ignore the indecision that came out of the meeting and stick to their targets. "Studies continue and there isn't time to take a careful evaluation of all these, let alone get government agreement so science is working back-to-back with policy," says Parry.
Neither Hulme nor Parry doubt that the effects of climate change are being felt more and faster than was forecast by the IPCC, and that limiting global warming is becoming increasingly difficult. "The numbers themselves are not really the message at this stage. There were some mixed messages about these, but what is important is that the Copenhagen climate summit concluded that the IPCC conclusions hold and if anything the challenge is stronger."
Seed clouds to cool the climate
If governments fail to reach a deal on reducing emissions, the option remains to artificially cool the climate. Immediately after the conference in Copenhagen, a small group of climate scientists flew to Edinburgh, UK, where they spent the day discussing the possibility of field testing a proposal to increase the reflectivity of clouds.
The flat sheets of stratocumulus cloud that spread out over the ocean naturally reflect a portion of solar energy out to space. They could be made more reflective by spraying tiny particles of seawater into them, encouraging the formation of smaller water droplets. Clouds that are "doped" in this way should in theory act as sunshades.
Phil Rasch of the US National Center for Atmospheric Research in Boulder, Colorado, presented a modelling study that showed seeding about a quarter of the area above the oceans could conceivably reduce temperatures by enough to counter a doubling of carbon dioxide in the atmosphere.
The group then discussed two methods for atomising seawater in the volumes that would be needed and outlined a potential field trial. US federal funding for geoengineering field tests could be available within five years, the scientists believe, but in the meantime they may need to turn to philanthropic funds in order to get the ball rolling.
None of the attendees advocated artificially cooling the planet instead of reducing greenhouse gas emissions, preferring to see it as a last-resort safety net. "Geoengineering is not a pleasant thought," said one delegate. "I have yet to meet a geoengineer who wants in their heart of hearts to intentionally modify the climate."
On 18 March, an advisory group to the US Defense Advanced Research Projects Agency was due to meet to discuss geoengineering and although some of those present in Edinburgh were attending, most disapproved of using military funding to develop geoengineering. Some emphatically said they would refuse such money.
We need a another kind of scientist to save the world
New Scientist 18 Mar 09;
SCIENCE and politics make uncomfortable bedfellows. Rarely is this more true than in the case of climate change, where it is now time for emergency counselling. One point repeatedly made at last week's climate change congress in Copenhagen was that formulating an action plan to curb climate change is not the job of scientists.
Politicians may be left scratching their heads over what to do (see "'Give us clarity on climate targets'"), but at this stage climate scientists cannot provide more guidance than they did in the 2007 report from the Intergovernmental Panel on Climate Change, for two reasons.
First, models will never provide a straightforward prediction of how the climate will change. As one Copenhagen delegate put it: "Tell me what the stock market will do in 100 years and I will tell you what the climate will do." Second, as most climate scientists will agree, their role is not to formulate policy. They can provide more or less apocalyptic scenarios of what will happen if emissions hit certain thresholds, from burning forests to disappearing islands. But when politicians ask what is the absolute maximum amount of carbon dioxide we should allow to be pumped out, the answer is, invariably, slippery: how much risk do you want to take?
There are ways out of the deadlock. As the major climate negotiations in December approach, scientists need to be able to take off their labcoats sometimes and speak as concerned citizens. Some may feel uncomfortable with blurring the line between science and activism, but they should be aware that no one understands the risks better than they do and no one is better placed to give informed opinions.
Politicians, for their part, should stop begging climatologists for easy answers. What they need instead is a new breed of advisers to descend from the ivory towers of academia and join the climate fray - people who are willing and able to weigh up the risks, costs and benefits of various degrees of action. Risk managers, step up to the plate.
If all else fails, there may still be the safety net of geoengineering. As we have said on several occasions, this option can no longer be dismissed as fantasy. Reputable scientists are discussing options among themselves and with policy-makers, but the fact that we are even considering it should spur governments to cut emissions, cut them deeply and cut them fast. Geoengineering is no get-out-of-jail-free card; it has dangers of its own. The military are already taking an interest (see "Seed clouds to cool the climate"), raising the spectre of climate weapons able to divert rainfall and bring drought. That is the last thing we want.
