A counterfactual

Philosophers like to use counterfactuals as a way to assess principles. Wikipedia provides this example:

If Oswald had not shot Kennedy, then someone else would have.

In particular, there is a close connection between asserting the truth of a counterfactual proposition and asserting a causal connection between events rather than just a correlation. Claiming that

If atmospheric CO₂ had been maintained at average levels of the 1950s, global average temperature would now be about 1.5°C lower.

requires accepting a causal connection between levels of atmospheric CO₂ and global average temperature. Those who deny the causal connection, James Inhofe for example, would deny the counterfactual.

Counterfactual history can also be entertaining, as Saturday Night Live reminds us.

(This is an old clip, but I only discovered it today. Sheril at The Intersection pointed the way.)