CO2, CO2e or CO2eq – yes, what now?

Translated by Emma Finney

Different greenhouse gasses have different effects. To compare different greenhouse gasses, there are CO2 equivalents: CO2e or CO2eq for short. Which greenhouse gasses have which share in the climate crisis?

Greenhouse gases are the most important factor in global warming. CO2 is the main contributor. We use CO2e or CO2eq to compare different greenhouse gases with CO2.

What is the greenhouse effect?

Every day, the sun sends rays of light to Earth. When these touch the earth’s surface, they are reflected and converted into heat rays. The heat rays then make their way back into space. But the greenhouse gasses prevent them from making the return journey. Similar to a glass roof, they trap the heat in the atmosphere. The more greenhouse gasses we artificially produce now, the denser the roof and the greenhouse effect becomes.

anthropogenic greenhouse effect explained in a graph
Image: studyflix. Natural and human-made greenhouse effect: how industry intensifies the greenhouse effect.

What greenhouse gasses are there – and why should we be afraid of cow burps?

On 11 December 1997, the United Nations Framework Convention on Climate Change, or Kyoto Protocol for short, defined six climate-damaging greenhouse gasses: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrogen-containing hydrofluorocarbons (HFCs), perfluorocarbons (HFCs) and sulfur hexafluoride (SF6). Since 2015, nitrogen trifluoride has also been added (NF3).

In Germany, 87.1 percent of the release of greenhouse gasses is attributable to carbon dioxide, 6.5 percent to methane, 4.6 percent to nitrous oxide and around 1.7 percent to F-gasses (as of 2020).

Many greenhouse gasses have a stronger climate impact than CO2 but are present in the atmosphere in smaller quantities. Here is a comparison:

Greenhouse Gas Greenhouse Gas Equivalencies
Methane 25 CO2e
Nitrous oxide 298 CO2e
CFCs up to several 1000 CO2e

This means that one ton of methane contributes 25 times more to climate change than one ton of CO2.

What does all this have to do with cow burps?

Every three minutes at the latest, gas escapes a cow – totalling an annual average of over 100 kilograms of methane. In terms of its climate-damaging effect, this corresponds to CO2 emissions of 18,000 kilometers driven by car. A further 90 kilograms of methane per year are produced by their feces.

How do we prevent the greenhouse effect and save our climate?

Our goal at ForTomorrow is to reduce greenhouse gas emissions in such a way that we in Europe will be climate-neutral by 2040 – so we can stop the climate crisis. To this end, we use the European Emissions Trading Scheme.

THE EU Emissions Trading scheme is THE climate protection tool for the European Union. Large CO2e emitters must buy CO2 rights in the EU. If they do not, there will be massive penalties and the emission rights will have to be submitted later. By buying these EU emission allowances and shutting them down unused, we at ForTomorrow are reducing the amount of CO2e that can be emitted by the industry as a whole. Put simply: We buy the rights that the coal-fired power plants need to emit CO2e in the EUso they can emit less.


Sources and further information (all German):

Umweltbundesamt. (11.08.2021). Wie funktioniert der Treibhauseffekt. [accessed on 03.05.2022].

Umweltbundesamt. (23.04.2021). Klima und Treibhauseffekt. [accessed on 03.05.2022].

Umweltbundesamt. (05.07.2021). Die Treibhausgase. [accessed on 03.05.2022].

Brockhaus, S. (18.05.2019). CO2-Äquivalente: Was diese Angabe bedeutet. [accessed on 03.05.2022].

studyflix. Treibhauseffekt einfach erklärt. [accessed on 04.05.2022].

br. (08.04.2022). Rülpser und Pupse setzen Methan frei. [accessed on 04.05.2022].