Dr. James Glynn:

The point was about radiative forcing which is ultimately what drives up temperatures. I agree with what I am interpreting the Senator as saying about intensity. What matters for short-lived gases is the flow rate, which is similar to what the Senator said about intensities, compared with long-lived gases so it is the accumulation that matters. The slow rate of temperature increase is driven by long-lived gases such as carbon dioxide. When one gets very close to achieving temperature stabilisation, say within 15 years of stabilising temperature, that intensity or flow rate becomes very important. When further from temperature stabilisation, those short-lived gases might not be as important but when very close to temperature stabilisation, significantly reducing those intensities and the radiative forcing from those gases becomes very important. It is the last mile effect.