Geoengineering

Geoengineering (also known as climate engineering or climate intervention) is the deliberate large-scale interventions in the Earth’s climate system intended to counteract human-caused climate change. The term commonly encompasses two broad categories: large-scale carbon dioxide removal (CDR) and solar radiation modification (SRM). CDR involves techniques to remove carbon dioxide from the atmosphere and is generally considered a form of climate change mitigation. SRM aims to reduce global warming by reflecting a small portion of sunlight (solar radiation) away from Earth and back into space. Although historically grouped together, these approaches differ substantially in mechanisms, timelines, and risk profiles, and are now typically discussed separately. Some other large-scale engineering proposals—such as interventions to slow the melting of polar and alpine ice—are also sometimes classified as forms of geoengineering. Some types of geoengineering present political, social and ethical issues. One common objection is that focusing on these technologies could undermine efforts to reduce greenhouse gas emissions. Effective governance and international oversight are widely regarded as essential. Major scientific organizations have examined the potential, risks, and governance needs of geoengineering, including the US National Academies of Sciences, Engineering, and Medicine, the Royal Society, the UN Educational, Scientific and Cultural Organization (UNESCO), and the World Climate Research Programme.