ABSTRACT
One broad framing of geoengineering is that it could be used to try to avoid a "climate emergency". The fundamental problems with the "emergency-use" framing of geoengineering are that the parts of the climate system which may pass a tipping point are lagging behind anthropogenic forcing, and that passing a tipping point can lead to irreversible change. As for geoengineering to "avoid reaching a climate 'tipping point'" there is a glimmer of hope in that systems approaching bifurcations carry generic early warning signals, such as becoming more sluggish in their recovery from natural fluctuation. So, those suggesting geoengineering to avoid reaching a tipping point would do well to focus their attention on fast-responding systems which should carry the best early warning prospects, for example, monsoons or the Arctic sea-ice. In summary, "emergency-deployment" framings of geoengineering to avoid or reverse climate tipping points could be seriously flawed.
