How your carbon footprint is calculated
The ClimateHero Carbon Calculator estimates your carbon footprint in units of carbon dioxide equivalents (CO2e). This is the unit that climate researchers commonly use to deal with the fact that all greenhouse gases do not have the same strength in the greenhouse effect. As an example, 1 ton of methane gas has the same climate impact as 28 tons of carbon dioxide (over a 100-year period). This means that 1 ton of methane equals 28 tons carbon dioxide equivalents (CO2e).
ClimateHero uses about 30 public sources to calculate your carbon footprint. Based on these sources and your answers in the climate calculator, we can estimate the emissions from your private consumption, which amounts to about 10 tons of CO2e per person per year for many of us. The world average, including those living in abject poverty, is around 5 tons CO2e per person per year.
ClimateHero uses the Exponential Roadmap which tells us that climate emissions must be halved by 2030 at the latest. That leads us to a personal climate budget for the average global citizen of about 2.5 tons per year. But since the world population continues to grow, we round off downwards to a climate budget of 2 tons CO2e per person per year.
That is where we have obtained the four archetypes that we use to categorize your climate footprint:
- Climate Hero (<2 tons) – Already today living within the 2030 global climate budget
- Climate Friend (2-5 tons) – Already helping to decrease the world average
- Climate Consumer (5-10 tons) – Increasing the global average
- Climate Villain (>10 tons) – Exceeding the average among wealthy individuals
Out of the estimate of 10 tons CO2e per capita, you can affect about 80% as a private individual. The remaining 2 tons is associated with public investments that you as an individual can’t change through your way of life. These 2 tons must be halved before 2030, which is why we single out 1 ton of these when we calculate your footprint. That means you can’t get a lower footprint than 1 ton CO2e in the climate calculator.
It is important that your carbon footprint is calculated as accurately as possible. But to us it is even more important that there is a quick and easy way for you to estimate your footprint and learn from the important lessons in the test. This is why the calculation contains some general assumptions, enabling us to limit the number of questions and estimate your carbon footprint in five minutes. As a rule of thumb, we have chosen to exclude/simplify questions if the outcome is less than 0.1 tons CO2 per year.
Your carbon footprint should therefore not be interpreted as being precisely correct down to the decimal point. That being said, you will most likely end up in the correct category from the four archetypes we use to portray the carbon footprint (Climate Hero, Climate Friend, Climate Consumer, and Climate Villain).
As ClimateHero aims to help everyone on the planet to reduce their footprint, we use data sources that are internationally viable as much as possible, but supplement with country-specific data where necessary.
Click here to see a list of the data sources that the climate calculator relies upon.