According to the abstract (I haven't tried to access the full article), the researchers take standard academic climate models (for instance, HadCM3 [1]), plug i

According to the abstract (I haven't tried to access the full article), the researchers take standard academic climate models (for instance, HadCM3 [1]), plug in some assumptions about future CO2 emissions, and compare the results to what is known about Eocene and Pliocene climates. If these academic models reflect reality (and several generations of climate scientists have tried to ensure that they do), then human-made climate change is "real". But if for some reason you believe that all these climate models are incorrect, then you will probably find this article to be of little interest. [1] https://en.wikipedia.org/wiki/HadCM3 https://en.wikipedia.org/wiki/HadCM3