Geoengineering Governance
The controversial technologies that could cool the planet artificially, and why governing geoengineering is one of the hardest challenges in international politics.
Engineering the Climate
Geoengineering refers to deliberate, large-scale interventions in the Earth's climate system to counteract global warming. Two main categories exist. Carbon dioxide removal (CDR) technologies extract CO2 from the atmosphere and store it permanently. This includes direct air capture (using machines to filter CO2 from ambient air), enhanced weathering (spreading minerals that absorb CO2), and bioenergy with carbon capture and storage (BECCS). Solar radiation management (SRM) aims to reflect sunlight back into space to cool the planet, most commonly by injecting sulfate aerosols into the stratosphere to mimic the cooling effect of volcanic eruptions.
CDR is relatively uncontroversial in principle, though current technologies are expensive and operate at tiny scale. SRM is far more contentious because it does not address the root cause of warming (greenhouse gas concentrations), could have severe side effects (altered monsoon patterns, ozone depletion), and would need to continue indefinitely once started, creating a 'termination shock' if suddenly stopped.