One of my pastimes is downloading data and playing around with it on Excel. I’m not kidding myself that doing this means anything in terms of original research, but I do find that I learn quite a lot about the particularities of the data and about the science in general by doing some simple calculations and graphing the numbers. There’s even occasionally a small feeling of discovery, a bit like the kind that you experience when you follow a well-trodden path in the mountains for the first time:

We were not pioneers ourselves, but we journeyed over old trails that were new to us, and with hearts open. Who shall distinguish? J. Monroe Thorington

Anyway, I downloaded some historical emissions data from the CDIAC site and played around with it. To repeat, there’s nothing new to science here, but there were a few things that I found that were new to me. First, let’s look at historical emissions of CO2 from man-made sources from 1850 to 2010. Note that for all of these graphs there are no data shown for 2011-2015.

What immediately struck me—something I hadn’t fully appreciated before—was how small oil consumption was before 1950. Both world wars were carried out without huge increases in oil use, despite the massive mobilizations of armies, navies and air forces. You can make out some downward blips in coal consumption for the Great Depression (~1930) and around the end of WW2 (~1945).

It wasn’t until after 1950 that fossil-fuel consumption went nuts. Some people have taken to calling this inflection point The Great Acceleration, there’s more on this later. Continue reading →