Guest essay by David Bennett Laing
In 1900, Knut Ångström concluded from a famous experiment that very little warming results from a doubling of atmospheric CO2. Although no similar experiment has been performed since, there is a simple and accurate way to tell by observing hard data from the real world. My approach in this is synthetic and not analytic, and I feel strongly that the integration of a variety of empirical data from the Earth system is essential for a good understanding of how things actually work in Nature.
Here in figure 1 is the Keeling curve, showing the steady increase in CO2 from 1959 to the present, as measured at the observatory on Mauna Loa, Hawaii:
Notice that there is an annual cycle (small squiggles) superimposed on the general increasing trend. If you average the monthly records for…
View original post 1,046 more words