Our remaining CO2 budget: Car is over

Zuletzt geändert am 29. May 2022

The other day I was walking with someone (TM) in the Tiergarten. We talked about climate issues. One point was the new IPCC report and the remaining CO2 budget for achieving the 1.5° target. The IPCC report is compiled by leading scientists as a summary of scientific articles. This was done with professional articles from 2020 in 2021. The report was translated in 2022 and then made available to the public in March and April. Almost all political parties in Germany agreed before the election last year that they were aiming for the 1.5° target. The following table shows the remaining budget of CO2 emissions we had in 2020 depending on certain temperature increases coupled with a certain probability. The first line shows the 1.5° target with a probability of 17%, 33%, 50%, 67%, 83%. If we want to reach 1,5° with a probability of 17% we had 900 Gt left, for 33% we had 650 Gt and so on.

Table with the remaining CO2 quantities and the corresponding temperature increases and probabilities. Source: IPCC, 2021. 6. IPCC Assessment Report. p. 27

The development of the climate is complex. The climate is like weather. Depending on the type of weather situation, it is not possible to predict whether it will rain tomorrow or not. But you can predict it with a certain probability. This is also the case with climate developments. If we emit 650 Gt of CO2 from 2020, we will reach the 1.5° target with a 33% probability. This means that in one out of three cases, what we expect will happen. We all learned this in school with dice. So: works, crap, crap, works, crap, crap. At 50% it would be: work, crap, works, crap and at 67% it would be: works, works, crap, works, works, crap. Someone once compared this to crashing planes at an event. One in three crashes. This is not entirely correct, because there are a lot of options for the value above 1.5°. 1.52° is also a miss of the 1.5° target. What happens in the remaining third is again a question of probabilities. I don’t know the details because I’m not an expert, but with a certain probability we will end up in a 2° world, with a different probability in a 3° world and so on. All these probabilities together for the range above 1.5° give 33%. One thing is clear: we don’t want to go there. It’s bad enough now. So we have to push the probability of getting there as low as possible. The table shows us the case for reaching the 1.5° target with 83% probability. That would be: works, works, works, works, crap. Much better, isn’t it? At least better than 1 out of 3 (67%), because the probabilities in the range we want to avoid also shift in our favor if we emit less CO2. If we want 83% certainty, we have to assume 300Gt remaining CO2 emissions in 2020. In the meantime, however, humanity has unfortunately continued to emit CO2. This amounted to 34,807 million tonnes in 2022 (source: Statista). In 2021, we reached almost the level of 2019 again (source: Deutschlandfunk), i.e. 36,702 million tonnes. Together, this is about 70 Gt for 2020 and 2021. This means that we still have 300–70 = 230 Gt left to reach the 1.5° target with an 83% probability. For all of humanity. We can now consider how to allocate this remaining budget. One could simply look at who has emitted how much since the beginning of industrialization and divide the quantities fairly. If we do that, … Oh. Not possible for the western world, because then we have nothing left.

Countries represented by CO2 emissions instead of their real size. Source: The Carbon Map, 13.05.2022.

Then let’s try the second best: we take what’s left and divide that by the number of people living in this world. Since Germans are 1% of the world’s population, we have 1% of 230 Gt = 2.3 Gt. A former environment minister once said: “Nobody can understand what these tons mean.” That’s why we break it down even further. This country is home to 83 million people (source: Wikipedia). 2.3 t * 10^9 / 83 * 10^6 = 27.7 t per person.1

At this point, we should now be thoughtful. Extinction Rebellion has occupied the bridge in front of the ARD capital studio in Berlin and summarized it as follows:

Bridge decoration during a blockade of Extinction Rebellion: We are fucked, Berlin, 05.03.2022, Image: Stefan Müller, CC-BY

The average annual output of a person in Germany is 10.78t. In other words, we will have used up everything in three years.2 All of it! Oh.

Average German CO2 emissions according to the Federal Environment Agency, 2022

Note that the US and Australia are twice as bad as Germans, so if they continue as if there was no tomorrow, they would have used up their share in a year and a bit.

My interlocutor has now pointed out an interesting fact: If you buy a car with a combustion engine today, then it will emit so much CO2 during the time cars are registered in Germany (10.1 years in average; Kraftfahrt-Bundesamt, 2022: 7), that the remaining budget of the respective person is used up. According to Atmosfair, a mid-range car that drives 12,000km a year emits 2t. SUVs have a correspondingly higher output. It follows that actually not a single combustion car should be registered anymore. I hear you say, “Well, ok, convinced. I buy an electric car and drive only with green electricity.” But no. Fiddlesticks! A 100% electric small car only needs up to 11t CO2 of our remaining budget for production (Of course, the combustion engine also has a CO2 impact in production! I had ignored that for the sake of the punchline. For combustion engines, the CO2 impact of production is: small cars: up to 4 tons of CO2, mid-range cars: up to 8 tons of CO2, mid-range cars hybrid: up to 12 tons, CO2 luxury SUV: up to 25 tons of CO2. Source: Carbon connect, 2020)

The overall conclusion is that cars are not a solution for private transport. At the moment it may be difficult in the countryside without a car, but this problem must be solved politically as soon as possible. A continuation of this is simply impossible if we want to continue living. Car is over!

Family at Fridays For Future Demonstration at the Brandenburg Gate in Berlin, 20.09.2019, Photo: Stefan Müller CC-BY


Broken down to one person, 27.7t of CO2 remain. According to atmosfair, this is less than 14 years of driving a car if 12.000 km are driven per year with a mid-range combustion engine car (without manufacturing the car). Or less than 6 flights from Berlin to LA and back (5,095t each) or less than three flights to Sydney Economy Class (10,683t). You can only do Business Class (20t) or First Class (26.7t) once. In many other types of consumption, the energy mix plays a role. This is not the case with combustion cars and airplanes, because it is clear that fossil fuels are burned. That’s why individual decisions are really decisive here. Maybe you should just avoid these things. At least from time to time. Please!


I would like to thank Cornelia Huth of Scientist Rebellion for food for thought and help with the numbers and sources and someone (TM) for the point concerning the personal remaining budget and the CO2 emissions of cars.


carbon-connect AG. 2020. The CO2 footprint of a new car: electric versus combustion engine: the not so easy climate balance. Volketswil. https://www.carbon-connect.ch/de/co2-emissionen-autoproduktion/.

IPCC, 2021. Summary for policy-making. In the contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)] (ed.), Scientific basics. https://www.de-ipcc.de/media/content/AR6-WGI-SPM_deutsch_barrierefrei.pdf.

Federal Motor Transport Authority. 2022. Vehicle registrations (FC) Stock of motor vehicles and their trailers by vehicle age 1 January 2022. Flensburg: Kraftfahrzeugbundesamt. https://www.kba.de/SharedDocs/Downloads/DE/Statistik/Fahrzeuge/FZ15/fz15_2022.pdf?__blob=publicationFile&v=5.

German Council of Environmental Experts. 2020. For a determined environmental policy in Germany and Europe (environmental assessment). (https://www.umweltrat.de/SharedDocs/Downloads/DE/01_Umweltgutachten/2016_2020/2020_Umweltgutachten_Entschlossene_Umweltpolitik.html)