Planetary securitySaving the planet: Plan B
Top U.K. science organization calls for coordinated geoengineering efforts as Plan B for protecting the planet from the negative consequences of climate change
What if, as countries eager to develop their industries and more people buy car, it would prove impossible to cut CO2 emissions in a manner which would meaningfully affect global warming trends? Not to worry: Catherine Brahic writes that there is back-up plan for saving the world. A major scientific institution has published a comprehensive review of possible ways to engineer the climate to reverse global warming.
The U.K. 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 United Kingdom, chair of the Royal Society group behind the report.
If humanity wants to avoid the worst effects of climate change, it must be ready safely to 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. This, however, 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 fertilizing 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.
Brahic writes that 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 U.K. government to invest £10 million a year toward an international research effort into geoengineering. This amounts to roughly 10 percent of the U.K. 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
Brahic notes that 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 U.S. 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.
