Climate engineering, which is the intentional cooling of the Earth by modifying its radiation balance, may pose legitimate concerns, but some argue that it is nonetheless crucial to begin considering.
Climate engineering — cooling Earth intentionally by modifying its radiation balance — worries many people. We know little about the effectiveness of these technologies or their side effects. The unintended consequences could be profound. One country’s interventions will affect others and could distract from climate-change mitigation efforts, and there is no international mechanism for regulating such deployments. These are legitimate concerns.
But interventions may need to be considered in the future. The 2013 report of the Intergovernmental Panel on Climate Change suggested that even if the world almost eliminates greenhouse-gas emissions by mid-century, decades of climate engineering — such as removing carbon dioxide from the atmosphere or injecting reflective particles into the stratosphere — might be required to control global temperatures and preserve vulnerable populations and ecosystems1.
Yet the climate-science community has largely avoided the subject. Government-funded research has been restricted to modelling and social-science investigations. The few outdoor experiments that have tested concepts were either funded privately or performed as pure climate science without making the climate engineering intent clear. Such experiments fail to ensure two fundamental principles of good governance of climate-engineering research: transparency and that the research is for the public good.