A counterfactual is an object or scenario that has not happened or is not a current actuality. Counterfactuals are speculative reference cases that can be compared to existing realities. Climate scientists and climate-communications researchers use counterfactual models as “baselines” against which to measure the effects of anthropogenic activity on the environment. For instance, one increasingly common application of counterfactuals within climate-change communications involves the use of models that quantify what the magnitude and frequency of a certain type of extreme weather event (such as a heatwave or hurricane) would have been if anthropogenic carbon emissions had been curbed. The use of such models allows scientists to disentangle the effects of anthropogenic impacts from naturally variable fluctuations in weather.

A very large-scale counterfactual would be a representation of the world we know today but without the effects of the elevated carbon emissions from human activities over the last two centuries. Counterfactuals are not utopic visions. They are visions of a different status quo.

Defined by Andrew Michael Gorin