About the Contrail Impact Counter:

The purpose of the Contrail Impact Counter is to give an indication of the magnitude of the climate problem of contrails and to show how much CO2 equivalent we could potentially save if we avoided warming contrails. It is important to keep in mind that there is considerable uncertainty around the climate impact of contrails, so the counter can only estimate the potential climate savings so far this year. This is how we arrived at the numbers:

In 2019, the aviation industry released 1.03 billion metric tons of CO2 from burning jet fuels. According to the widely quoted Lee et al. (2021) study, we need to multiply that number by 0.63 (using the GWP100 metric) to find the contrail impact expressed as CO2 equivalent (CO2e). That is roughly 650,000 million tons of CO2e in contrail warming. However, as a rule of thumb, it is only the most warming 80% of contrails that it is realistic to target in the near future. Which brings us to about 500,000 million tons of CO2e.

The Contrails Impact Counter starts at 0 tons of CO2e at the beginning of the year and counts up to reach 500 million tons of CO2e by the end of the year.

A typical passenger vehicle emits 4.6 metric tons of carbon dioxide per year (in the US). Removing 500 million tons of CO2e from contrails would then be the equivalent of taking 108 million cars off the roads for a year.

A typical coal-fired power plant in the US emits 3.5 million tons of CO2 per year. Removing 500 million tons of CO2e from contrails would then be the equivalent of shutting down 142 coal-fired power plants for a year.

Here are the yearly consumption-based CO2 emissions per country.