Sometimes nature does the same: more than 15 million tonnes of sulphur dioxide thrust into the stratosphere by the 1991 eruption of Mount Pinatubo in the Philippines cooled the planet by more than half a degree C for about two years. Volcanic eruptions spew out plumes of aerosols. The 1883 eruption of Krakatoa reportedly lowered global temperatures by 1 degree Celsius. The best modelling suggests SRM would achieve the same result.
Stratospheric aerosol injection is one of a suite of technologies aimed at large-scale manipulation of the climate, known as geoengineering. SRM comes under the category of ‘solar geoengineering.’ But who gets to decide if and when to roll it out? The United Nations Framework Convention on Climate Change (UNFCCC) is the body currently charged with negotiating climate policymaking at the international level. International policymaking of any sort is notoriously difficult, especially for an issue that affects just about every sector of the global economy. Even small national delegations must delicately balance the demands of their governing parties with actors ranging from civil society to industry.
An international agreement around solar geoengineering could mean starting from scratch, beginning with a push to convince the world’s governments that it’s necessary—assuming no rogue actor launches a project on its own, first. But the democratic processes involved here are more about power than psychology—and certain actors exercise a lot of power in the UNFCCC process.
Could a group of low-lying countries, devastated by storms and rising seas, reach a tipping point and pull the trigger for this technology? Could deployment result from a geopolitical power play between the United States and China? Critics believe that the more SRM is legitimized through experiments and positive mainstream attention, the more likely it is that these speculative scenarios become real.
Credit for Image Above: Photo by David McNew/Getty Images