Why CO2 is often more emphasized than other greenhouse gases
CO2 (carbon dioxide) is considered the main cause of anthropogenic climate change, i.e. climate change caused by humans. For this reason, the term “CO2 emissions” was established as a collective term for greenhouse gas emissions.
However, it is important to understand that climate change is influenced by a variety of greenhouse gases.
Climate impact (Global Warming Potential, GWP):
The gases differ in their climate impact, i.e. their influence on the greenhouse effect. The GWP is a measurement that compares the effectiveness of gases, their residence time in the atmosphere and their ability to store heat.
In the table you can see the different climate impacts (Global Warming Potentials, GWPs) of the gases:
The graphic shows that CO2 has a climate impact of 1, while SF6 has a GWP of 23,900. This means that one SF6 molecule impacts the climate 23,900 times more than one CO2 molecule.
Then why do we always talk about “CO2” and not “SF6”?
Because of its frequency: CO2 is by far the gas that is emitted the most.
In Austria, CO2 accounts for 85% of total greenhouse gas emissions.
More reasons why CO2 is more emphasized than other greenhouse gases:
- Dominance of emissions:
CO2 is the most commonly emitted greenhouse gas caused by human activities. The main source of CO2 emissions is the burning of fossil fuels such as coal, oil and natural gas for energy production, transport and industry. - The Kyoto Protocol:
The Kyoto Protocol, also known as the Kyoto Agreement, is an international environmental agreement that was first adopted in the Japanese city of Kyoto in 1997 and came into force in 2005. The aim of the protocol is to reduce global greenhouse gas emissions and combat climate change. In order to simplify the complexity of the topic and make it understandable and accessible to a larger group of people, science has agreed on a collective name, namely CO2. The decision was made to use the gas that occurs most frequently. - Long residence time in the atmosphere:
CO2 has a comparatively long atmospheric residence time, meaning it remains in the atmosphere for many centuries. This causes CO2 emissions to accumulate over long periods of time and have a lasting impact on the climate. - Measurability:
Compared to other gases, CO2 emissions can be easily measured and quantified, both at a national and global level. This makes it possible to monitor progress in reducing emissions and develop policy measures. - Responsibility:
The burning of fossil fuels, such as coal, oil and natural gas, is the main source of man-made CO2. These fossil fuels are used in many areas including energy production, transportation and industry. Therefore, CO2 emissions are closely linked to human activities and economic processes. - Global influence:
CO2 has a global impact on climate change because it is evenly distributed throughout the atmosphere. Other greenhouse gases, such as methane (CH4) and nitrous oxide (N2O), have a shorter atmospheric residence time and may show regional or sectoral differences. - Cumulative emissions:
The total amount of CO2 released into the atmosphere since the start of the Industrial Revolution is significant and continues to grow. The long residence time of the gas has led to a drastic accumulation of atmospheric CO2 concentrations, which in turn drives global warming.
However, it is important to note that other greenhouse gases, particularly methane, also contribute significantly to climate change. In recent years there has been increased attention on methane emissions because methane is a much more potent greenhouse gas per molecule than CO2, even though it is present in the atmosphere in smaller quantities.
The emphasis on CO2 emissions therefore does not mean that other greenhouse gases are neglected, but rather reflects the historical importance of CO2 in efforts to combat climate change. Science and politics take into account the role of all greenhouse gases in the development of climate protection strategies.
With our work at pro local, we also want to make a contribution to climate protection and help reduce greenhouse gas emissions through local value chains. We hope that through our label we can educate consumers about the origin of products and thus encourage environmentally friendly decisions.
You can find more information about this in Part IV of this series.
Sources: Umweltbundesamt