4. How reliable and accurate are climate models?
Modern climate models can generally be considered reliable tools for predicting climate. A recent study (Hausfather et al., 2020) evaluated the performance of various climate models published between the early 1970s and the late 2000s. They looked at how well models project global warming in the years after they were published by comparing the model projections to actual observed temperature changes. 14 out of the 17 model projections were consistent with observation, especially when mismatches between projected and observationally-informed estimates of forcing were taken into account. This means that the actual climate physic models were generally accurate and mismatches between output model temperatures and observed climate data occurred mainly due to uncertainties in future forcing estimates, i.e. estimates of future climate gas emissions, which need to be put into the climate model (also see “What are the inputs and outputs for a climate model?”).
Hausfather, Z., Drake, H. F., Abbott, T., and Schmidt, G. A., 2020, Evaluating the Performance of Past Climate Model Projections: Geophysical Research Letters, v. 47, no. 1, p. e2019GL085378.