Thanks for the chart. To me it still seems like we are missing something. If you look at the period of 1940 - 1980, then there was not really an upward or downward trend. But in the 36 years after 1980, the global temperature has been going up like crazy. Should all of that be attributed to statistical noise? To me it looks like some new factor has started to influence the climate in the recent years, whatever that factor may be.
The standard explanation is that aerosol emissions (soot and SO2) masked the warming during 1940-1980. Once environmental protections in the West kicked in, the warming due to CO2 has taken up.
If you compare the rate of fossil fuel use over time, you'll find that that has also been accelerating tremendously. There are other factors involved, including particulate emissions (mostly from coal) which tended to repress warming trends.
From 1945 - 1975, fuel consumption was roughly doubling every decade. The rate of increase moderated slightly during the 1970s oil crises, but picked up afterward, with China's growth since 2000 being particularly troubling.
Rather than eyeballing it, why not do a proper regression?
To me, it looks like a line going up from 1900 with a bump in 1940. But you don't have to take my word for it, there's piles and piles of data out there.
I'm not denying that the world has been heating up since 1900. I'm saying that during the last ca. 36 years it is suddenly going very much faster than it did before.
World CO2 emissions in 2014 were about 9.8 gigatonnes. The current concentration of atmospheric CO2 is about 400 parts per million. In 1980, the relevant figures were about 5.3 gigatonnes and 340ppm.
We've got the accelerator to the floor. It's no wonder that we're getting all the speeding tickets now.
