[protanopia]

Why is a 1.5° maximum a target that should be aimed for? William Nordhaus says a 3.5° maximum is the optimal target. His models show that a 3.5° maximum would result in a net benefit of 30 trillion whereas a 2.5° maximum would be a detriment of 50 trillion[1]. That is to say the reduction in damage would be far less than the cost of implementing such a policy. The cost for a 1.5° maximum target would be even more severe.

[1]W. Nordhaus, “Projections and Uncertainties about Climate Change in an Era of Minimal Climate Policies,” American Economic Journal: Economic Policy, vol. 10, no. 3, pp. 333–360, Aug. 2018, doi: 10.1257/pol.20170046.

edit: This comment is currently sitting at -2. If you think a 1.5° target is optimal, you should explain why you think so rather than just down voting this post. The paper I linked to is by William Nordhaus who won the Nobel Prize for economics in 2018 for his work related to the economics of climate change.

[adrianN]

This is what the IPCC has to say about this: https://www.ipcc.ch/sr15/chapter/chapter-3/