Sir David Attenborough: The Truth About Climate Change

The science of climate modeling predicting global warming by anhropogenic emission of CO2 from carbonbased fuels is nicely summarized by the legendary Sir David Attenborough in the Truth About Global Warming:

• The key question is: How can we distinguish between climate variations induced by natural causes and by CO2 emission?
• The key thing that convinced me was a temperature graph prepared by climate scientist Professor Peter Cox showing that a climate model with CO2 emission included can reproduce the temperature during the 20th century better than without.
• So there you have it: It seems little doubt that this recent rise, this steep rise in temperature, is due to human activity.
• It is clear that without the action of human beings there would have been far less temperature change since the 1970s.

The science of climate change is the science of climate modeling. Sir Attenborough became convinced by looking at a graph produced by running a certain mathematical climate model with and without a certain greenhouse effect included. But Sir Attenborough did not ask the natural question: 

• How reliable and accurate are climate models?  
  

Suppose Sir Attenborough was informed that climate models are not reliable, that their accuracy is unknown, would that change his conviction based on a single graph being the output of a climate model? Suppose he was informed that climate models are constructed so as to give the result of the graphs, a graph which is the result of modeling activity of human beings. What would Sir Attenborough then say?

Compare previous blogs on climate simulation.