EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Assessing ExxonMobil’s global warming projections

Stefan Rahmstorf1,2, Geoffrey Supran3, and Naomi Oreskes3
Stefan Rahmstorf et al.
  • 1Potsdam Institute for Climate Impact Research, Potsdam, Germany (
  • 2Institute of Physics and Astronomy, University of Potsdam; Potsdam, Germany
  • 3Department of the History of Science, Harvard University; Cambridge MA, USA

The performance of mainstream climate models has received extensive scrutiny. By contrast, climate projections by the fossil fuel industry have never been assessed. Based on recent archival discoveries, we quantitatively evaluate all available global warming projections documented by – and in many cases modeled by – Exxon and ExxonMobil Corp scientists between 1977 and 2003. We find that most of their projections accurately forecast warming consistent with subsequent observations. Their projections were also consistent with, and at least as skillful as, those of independent academic and government models. We find that Exxon and ExxonMobil Corp also correctly rejected the prospect of a coming ice age, accurately predicted when human-caused global warming would first be detected, and reasonably estimated the ‘carbon budget’ for holding warming below 2°C. Our results show that ExxonMobil predicted global warming correctly and that by the 1980s, they already knew how much global warming the company’s products were likely to cause.  

How to cite: Rahmstorf, S., Supran, G., and Oreskes, N.: Assessing ExxonMobil’s global warming projections, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-11607,, 2023.