Slide 24 of 30
Notes:
Note the logarithmic scale on the forcing. To the extent that this appears to be a linear function of time, it indicates an exponential increase in forcing. In practice there are some signs of a relative slowing down in the 1990’s.
The response is a combination of data from ice cores with (since 1960) direct measurements. Note that the rise started around 1750, before the consumption of fossil fuel was in any way significant. The discrepancy has been attributed to deforestation in Europe, which proceeded rapidly at that time.