Environmental Research Letters published a cost analysis of the technologies needed to transport materials into the stratosphere to reduce the amount of sunlight hitting Earth as a means to combat climate change, concluding such technologies are feasible and affordable.
Dr Matt Watson, Principal Investigator on the SPICE Project and Lecturer in Natural Hazards at the University of Bristol, said:
“Research into climate engineering, including costs, is vitally important. However, we must not get drawn into discussion where economics becomes the key driver. Impact on humanity and ecosystems must be, and continue to be, of primary consideration.”
Prof John Shepherd FRS, Chair of the Royal Society’s Geoengineering the Climate report, said:
“Few of us like the idea of taking purposeful action to manipulate the climate of our world, with great uncertainty about the potential side effects. However, it is vital to undertake assessments like this of geoengineering options, given humanity’s current unfettered appetite for burning fossil fuels.
“Greenhouse gas emissions continue to rise and, at present, there is little to suggest that this is likely to change in time to avert serious problems. Should global temperatures start to rise rapidly, we may be forced to find additional ways to moderate climate change.
“As the Royal Society identified in its 2009 report, geoengineering techniques that reflect more of the sun’s energy back into space may provide the swiftest respite and the use of stratospheric aerosol particles may be the most cost-effective option. However, they also may have major undesired impacts, so it is very important that the global community comes together to find effective ways to govern this emerging area of research. Sometime in the future we may need that research to deliver new tools to help us to care wisely for the environment on which we depend.”
Prof Joanna Haigh, Professor of Atmospheric Physics at Imperial College London, said:
“The authors are not advocating deployment of this technology and they are absolutely right to be cautious.
“The technology may be affordable but there is no evidence that it would enable the climate to stabilise in a state similar to that which it would occupy naturally at lower greenhouse gas concentrations. Indeed, what evidence there is suggests that, not only would it fail to address the ocean acidification issue, it could introduce quite different patterns of tropical storms and precipitation.
“If such geoengineering schemes were to be introduced then another very serious consideration would be around when in the future (potentially in a scenario of very high greenhouse gas concentrations) it would be acceptable to switch them off.”