Modeling Human Impact on Global Warming

This data on global temperature and efforts to model it is from Emanuel , MIT climatologist, published in the Boston Review. Since global warming is evident, the question of whether that warming is driven by human activities is of utmost importance. The data above show the observed temperature along with two computer simulations of that temperature, one including those influences arising from human activity and the other not. It can be seen that the two computer models diverge in the 1970s and now do not overlap. Emanuel comments "almost all climate scientists today believe that man's influence on climate has emerged from the background noise of natural variability."

This illustration is constructed with data from Collins, et al., which in turn comes from the IPCC 2007 report. It is clear that the observed warming affects all continents, and that the models that include radiative forcing from human activities predict the observations better.