Climate engineering

Climate engineering (or geoengineering) is the intentional large-scale alteration of the planetary environment to counteract anthropogenic climate change.^[1][2] The term has been used as an umbrella term for both carbon dioxide removal and solar radiation modification when applied at a planetary scale.^[3]: 168 However, these two processes have very different characteristics, and are now often discussed separately.^{[3]: 168 [4]} Carbon dioxide removal techniques remove carbon dioxide from the atmosphere, and are part of climate change mitigation. Solar radiation modification is the reflection of some sunlight (solar radiation) back to space to cool the earth.^[5] Some publications include passive radiative cooling as a climate engineering technology. The media tends to also use climate engineering for other technologies such as glacier stabilization, ocean liming, and iron fertilization of oceans. The latter would modify carbon sequestration processes that take place in oceans.

Some types of climate engineering are highly controversial due to the large uncertainties around effectiveness, side effects and unforeseen consequences.^[6] Interventions at large scale run a greater risk of unintended disruptions of natural systems, resulting in a dilemma that such disruptions might be more damaging than the climate damage that they offset.^[7] However, the risks of such interventions must be seen in the context of the trajectory of climate change without them.^[8][7][9]

The Union of Concerned Scientists warns that solar radiation modification could become an excuse to slow reductions in fossil fuel emissions and stall progress toward a low-carbon economy, as the technology does not address these root causes of climate change.^[10]