There are two reasons even CDN readers ought to be concerned about rising global CO2 emissions. First, climate is complicated and despite our view that the problems are overstated and models are alarmist, it is nonetheless possible that by adding a lot of CO2 to the air in a short period of time we might cause changes we later regret, so the slower the process the lower the risk. Second, and perhaps more worrisome, there is a robust statistical correlation between rising atmospheric CO2 and panicky politicians promoting disastrous climate policies, which is unambiguously harmful for the world. Fortunately this week’s cheerful chart shows global per capita CO2 emissions, and a few minutes spent with those numbers will show you why the IPCC emission scenarios are hopelessly overstated and can be safely ignored, along with their apocalyptic forecasts of the impacts.

Here are global average CO2 emissions per capita since 1950:

Notice that the numbers rise dramatically from 1950 to around 1970 then leveled off at just over 4 tonnes of CO2 per person. Then from 2000 to 2010 the rate grew again to just under 5 tonnes then backed off again to the current level of 4.7 tonnes per person.

The stability of the line since 1970, despite global economic growth including in the Third World, suggests that thanks to greater energy efficiency, which is a good thing regardless of your attitude to CO2, the global average will likely remain between 4 and 5 tonnes per capita even as the world and especially its poorer inhabitants get richer. There are currently about 8 billion total inhabitants, so an average of 4.7 tonnes per person means there are about 37,600 million metric tonnes (MMt) of CO2 emissions annually.

OK, some may say, but what of population growth? However, the big story in modern demographics is how rapidly the birthrate is falling around the world. Midrange UN projections now show population peaking at around 10.3 billion by 2080 then falling thereafter. If emissions average 4-5 tonnes per capita that means peak emissions of 41,200 to 51,500 MMt of CO2 per year at most. Which might sound like a lot, but in comparison to IPCC projections it is not, as we can see by marking that range on a chart recently compiled by Dr. Roy Spencer at the University of Alabama in Huntsville:

The 2080 levels indicated in red, a line not a dot because they span a range of emissions, are roughly what you get if 10.3 billion people emit 4 to 5 tonnes per person. The lines labeled “SSP1-2.6” through “SSP5-8.5” are the IPCC emission projections, while the straight green dotted line that extends from the present up to 2050 is the Energy Information Administration forecast. You can see that if you extend it out in a straight line it hits the red line as of 2080, and since population declines after that so would the emissions trajectory.

Comparing the red 2080 range to the IPCC projections, we can see right away that only SSP2-4.5 comes close. It looks OK up to 2060 then goes down too quickly after that. But SSP3-7.0 and SSP5-8.5 are far too high, and not just decades hence. Instead they are already way out of bounds compared to known data.

Now take a guess as to which IPCC emission scenario is used in almost all the climate impacts research, and especially all the papers you hear about on the news? Yes, SSP5-8.5, the follow-on to RCP8.5 which we’ve discussed many times before. 150,000 MMt as of 2080 would require reaching about 14.5 tonnes per capita over the next 50 years, three times the level of between 4 and 5 tonnes that has held over the past 50 years. The people peddling this implausible storyline have never provided a sensible rationale for it.

We, meanwhile, are justified in assuming the pattern of the past 50 years will hold for the next 50 years. Total CO2 emissions will follow a low path that does not look like the IPCC’s scare stories. And so there is no climate emergency or disaster looming even if CO2 does a lot more to the weather than we think probable. Which is a cheerful thought.