One way to think about the issue of mitigating climate change is to consider three binary variables:
By these I mean:
- Is there a perception that all major emitters are making a fair contribution to addressing the problem?
- Is mitigation to a sustainable level highly expensive?
- Are obvious and unambiguous climatic disasters occurring?
These interact in a few different ways.
It is possible to imagine moderate levels of spending (1-5% of GDP) provided the first condition is satisfied. Especially important is the perception within industry that competitors elsewhere aren’t being given an advantage. Reduced opposition from business is probably necessary for a non-ideological all-party consensus to emerge about the need to stabilize greenhouse concentrations through greatly reduced emissions and the enhancement of carbon sinks.
It is likewise possible to imagine medium to high levels of spending in response to obvious climatically induced disasters. For instance, if we were to see 1m or more of sea level rise over the span of decades, causing serious disruption in developed and developing states alike. Such disasters would make the issue of climatic damage much more immediate: not something that may befall our descendants, but something violently inflicted upon the world in the present day.
Of course, if things get too bad, the prospects for cooperation are liable to collapse. Governments facing threats to their immediate security are unlikely to prioritize greenhouse gas emission reductions or cooperation to that end with other states.
We must hope that political leaders and populations will have the foresight to make cooperation work. It may also be hoped that the cost of mitigation will prove to be relatively modest. The issue of disasters is more ambiguous. It is probably better to have a relatively minor disaster obviously attributable to climate change, if it induces serious action, than the alternative of serious consequences being delayed until it is too late to stop abrupt or runaway change.