At the Paris climate accord, world leaders promised to keep the global temperature increase this century (relative to pre-industrial levels) "well below 2 ˚C" and if possible below 1.5 ˚C. Many experts are skeptical about this goal being feasible, stating that even if all Paris targets are met, global warming may reach levels up to 3 ˚C above pre-industrial levels. Furthermore, with the coming departure of the United States from the agreement, the meeting of global targets may be in jeopardy.

Will there be at least 2˚C of global warming by 2100?

This question will resolve positively if, by January 1, 2100, there has been a period of at least 5 consecutive years in which the average global temperature in each year was at least 2.0 ˚C greater than the average global temperature in 1880.

(Note that 1880 isn't exactly pre-industrial, but earlier data is highly unreliable, and there should really not have been much warming by then.)

Data for resolution shall come from NASA, if possible. Note that the data in the link is normalised relative to the 1951-1980 baseline, on which 1880 stands at -0.2. Therefore, the critical value to look for with this specific NASA dataset will be 1.8 ˚C. It is likely, though, that the link will no longer be active in a few decades, so a different dataset may have to be used anyway.

The last possible set of 5 years to satisfy the requirement would be 2095-2099, so the last possible resolution date would be around mid-2100, in order to make sure that there are no uncertainties regarding the 2099 climate data.