An interactive introduction to climate change detection


We begin by plotting global average temperatures recorded for each of the past 153 years. Colder years are blue and warmer years red.


Click on the wide button below to compare these observations with temperature changes caused by a combination of human and natural factors, averaging over 100 climate model simulations of the same period.


Press the button again to see how the models warm in response to human influences alone.


Press it again to see the models' response to natural factors like volcanoes. Press it a 3rd time to show human and natural influences combined.

The models seem to get the overall shape about right when we include both human and natural influences. But they seem to be slightly warmer than the observations in the final few years. We're going to investigate why.