In the face of dire forecasts for anthropogenic climate change, climate engineering is increasingly discussed as a possible additional set of responses to reduce climate change’s threat. These proposals have been controversial, in part because they – like climate change itself – pose uncertain risks to the environment and human well-being. Under these challenging circumstances of potential catastrophe and risk-risk trade-off, it is initially unclear to what extent precaution is applicable. We examine what precaution is and is not, and make a prima facie case that climate engineering may provide means to reduce climate risks. When precaution is applied to the currently pertinent matter of small to moderate scale climate engineering field tests, we conclude that precaution encourages them, despite their potential risks.
Reprinted in Environmental Law and Climate Change, Jonathan Verschuuren (Ed.), The International Library of Law and the Environment series (Edward Elgar, 2015).