the big Climate Change report is coming out this month
The long awaited 5th assessment report from the IPCC is being published this month, so expect lots of news stories about it.
As a sneak preview, here's one rather telling illustration from it:
What the illustration shows is the result of running climate models under two different assumptions.
The blue shaded area is what the models predict for different parts of the world's land and oceans, over the last 100 years, if you only take into account the natural cycles (eg the ones that cause ice ages).
The pink shaded area is the prediction if you take into account both the natural cycles AND the effect of human activities such as burning lots of oil.
The dark line isn't a prediction. It is the chances we've actually observed over the last 100 years. As you can see, the observed changes are compatible with the models that take human activity into account (they stay in the pink area), but they are increasingly incompatible with the predictions you get if you only take natural cycles into account (they leave the blue area further and further behind in the second half, as you go from 1960 to 2010).