Impact of Current Climate Proposals by Bjorn Lomborg.
In return for a mere $1.5 TRILLION per year…

…if we measure the impact of every nation fulfilling every [carbon reduction] promise by 2030, the total temperature reduction will be 0.048°C (0.086°F) by 2100.

Even if we assume that these promises would be extended for another 70 years, there is still little impact: if every nation fulfills every promise by 2030, and continues to fulfill these promises faithfully until the end of the century, and there is no ‘CO₂ leakage’ to non-committed nations, the entirety of the Paris promises will reduce temperature rises by just 0.17°C (0.306°F) by 2100.

US climate policies, in the most optimistic circumstances, fully achieved and adhered to throughout the century, will reduce global temperatures by 0.031°C (0.057°F) by 2100.

EU climate policies, in the most optimistic circumstances, fully achieved and adhered to throughout the century, will reduce global temperatures by 0.053°C (0.096°F) by 2100.

China climate policies, in the most optimistic circumstances, fully achieved and adhered to throughout the century, will reduce global temperatures by 0.048°C (0.086°F) by 2100.

The rest of the world’s climate policies, in the most optimistic circumstances, fully achieved and adhered to throughout the century, will reduce global temperatures by 0.036°C (0.064°F) by 2100.

http://onlinelibrary.wiley.com/…/1758-5899.12295/full

http://bishophill.squarespace.com/blog/2015/11/10/the-size-of-the-prize.html

https://www.manhattan-institute.org/sites/default/files/R-OC-0318.pdf

https://www.scientificamerican.com/article/climate-change-will-not-be-dangerous-for-a-long-time/