The 2015 Paris climate agreement was a major milestone, but the truth is, achieving its ambitious goal of keeping temperatures to within 1.5 °C to 2 °C of preindustrial levels would require rates of mitigation far in excess of what’s been achieved—or even what’s been planned.
Because of this, more people are contemplating geoengineering—notably solar radiation management, which involves reflecting a portion of the sun’s radiation back into space. The idea raises many questions. We don’t know how effective it would be, and we don’t fully understand its potential impacts. There are also ethical issues about its use and its governance.
We need to acknowledge that the aggregate environmental and socioeconomic risks of solar radiation management would probably be small in comparison with the benefits of reducing global temperatures. But those benefits and harms would be unequally spread among regions of the world, and between current and future generations.
In the absence of multilateral agreements, there’s no way of controlling who might execute such a geoengineering plan. It’s possible that a small group of countries, or a single country, or a large company, or even a wealthy individual might take unilateral action on geoengineering. Others might subsequently engage in their own climate engineering strategies to counter such action.
To avoid such a future, we should establish global governance frameworks. Currently there’s really only one forum that could give legitimacy to any such framework for geoengineering: the United Nations General Assembly.
Here are the kinds of questions such a framework would have to address: Who controls the “global thermostat”? How would decisions be made to balance the need to reduce the global temperature with the inequality of regional and local impacts across the globe? How would trans-border and trans-generational ethical issues be addressed? How would the required governance frameworks withstand potentially substantial geopolitical changes over the decades, and possibly centuries, over which they would need to be deployed? How might such techniques be deployed without undermining the will to cut emissions (which will continue to be necessary no matter what)? How would decisions relating to the rate of starting, continuing, and stopping those techniques be governed?
This last issue is of particular concern, as suddenly stopping a geoengineering scheme would result in a rapid and probably catastrophic rise in temperatures. Many of these governance issues might turn out to be unresolvable and thus might keep us from attempting this kind of fix in the first place.
The research community has been addressing many of these issues, but the global policy community and the public have not. It’s time to begin doing so.
Janos Pasztor is executive director of the Carnegie Climate Geoengineering Governance Initiative.