Geoengineering

Climate change geoengineering, defined by the Royal Society as “deliberate large-scale manipulation of the planetary environment to counteract anthropogenic climate change” was until recently considered outside the mainstream of climate policymaking.

However, the mode of response by the world community in addressing climate change has dramatically changed the landscape. While there is a solid consensus among scientists and policymakers that temperature increases of 3.6 degrees F (2 degrees C) or greater above pre-industrial levels will cause extremely serious impacts on human institutions and ecosystems, the current commitments made by the world community to reduce greenhouse gas (GHG) emissions are projected to put the globe on track for temperature increases of 4.5–7.5 degrees F (2.5–4.2 degrees C) by the end of the 21st century, with further increases thereafter.

As a consequence, there is increasingly serious consideration of the potential role of geoengineering as a means to avoid a climate emergency, such as rapid melting of the Greenland and west Antarctic ice sheets, or as a stopgap measure to buy time for effective emissions mitigation responses. 

However, little research has been conducted on potential geoengineering options, and no major research programs are currently in place. Climate geoengineering options can be divided into two broad categories: solar radiation management (SRM) methods and carbon dioxide (CO2) removal (CDR) methods.