A few days ago, I posted an article concluding that climate change is an optimization problem to be solved calmly and rationally, not an emergency to be prioritized above all else.

There were many enthusiastic comments from which I got an important takeaway: a more extensive evaluation of fat-tail risks is required. I had only partially covered that important point in my original article by discussing uncertainties in climate sensitivity.

For that reason, I now present a follow-up article weighing low-likelihood high-impact risks from climate change against equivalent risks from drastic climate action. My conclusion remains that a moderate target of 2.5 °C is better supported by current evidence than a 1.5 °C target.

Specifically:
- Fat-tail risks involved in an additional 1 °C of warming are comparable to those involved in attempting a complete overhaul of the foundation of our society within a single generation. 
- The risks of additional warming from a 2.5 °C pathway will only emerge after 2050, giving us several decades to put risk mitigation measures in place. 
- If a fat-tail risk does manifest itself, our response may be decidedly more united in a climate crisis scenario than in an economic depression caused by a damaged energy-industrial system. 
- A 2.5 °C target is actually achievable, whereas the 1.5 °C carbon budget may well already be exhausted by the time global emissions peak. 
- The continued pursuit of extreme targets such as 1.5 °C increases polarization, excludes many solutions, and distracts from other important global problems.
 
I hope the discussion can continue from here!