Article published in Politiken on 13 October 2019, Af Kåre Press-Kristensen, senior advisor specializing in air quality at the Ecological Council. He is an environmental engineer with a Ph.D. from DTU and has HD(A) from SDU.

We fly more and more. Video meetings do not provide the same closeness as traditional face-to-face business meetings. And Lalandia just can't keep up with the southern sun. The airports' passenger records clearly testify to this. Not only the Danes are affected by travel fever. It is a global trend that comes with increasing prosperity and more and cheaper air routes. A quick search shows that I can fly Copenhagen-London round trip for DKK 229.

Air traffic is responsible for 3-5 percent of man-made global warming. Under half of this is due to CO2 emissions, while the rest is caused by jet streaks and high-altitude emissions of nitrogen oxides (NOx). If targeted efforts are not made to reduce aircraft's climate impact, in 2050 aircraft may contribute to more than 20 percent of man-made global warming.

At the Ecological Council, we get a lot of inquiries from people who want to reduce the climate impact from their flights. The only safe way is not to fly, but this is not always possible. In an ideal world, the EU would just levy a fixed tax on jet fuel equivalent to what real climate compensation costs, and invest the money in controlled real climate projects in poor countries and the development of cleaner aircraft. Because even more energy-efficient planes and cleaner fuels are just around the corner. But while we wait for politicians and technology, there are still more opportunities to act ourselves. You can purchase cleaner biofuels from some airlines or find compensatory projects.

Here's how you do it
Finding the climate impact of travel is a challenge. Here it must be remembered that most airlines only disclose the CO2 load of the flight, but not that from jet streaks and NOx. Therefore, we at the Ecological Council recommend using the German website Atmosfair.de to calculate the total climate burden.

Here are a number of options and drop-in groups if you want to compensate for the climate:

First option: More and more airlines (SAS, KLM and Lufthansa) offer passengers to buy a mixture of biofuels based on waste, e.g. used frying oil, and SAS is experiencing increasing interest. In a few years, biofuels can be replaced by so-called electro-fuels, which are produced via electricity from wind and solar energy. However, to avoid the heating effect from jet streaks and NOx, the planes have to fly lower. The purchase of cleaner aviation fuels helps to promote a green transformation of air traffic.

Another option: Climate compensation for flights, where you invest money yourself or via the airline in projects that absorb an amount of CO2 equivalent to the climate impact from the flight, continues to receive more attention. The critics believe that it is buying indulgence and thereby buying the opportunity to continue to pollute. The proponents believe that air traffic is here to stay and that good compensation projects are better than doing nothing.

Pitfalls: Climate compensation does not change the aviation sector's increasing climate burden, and is therefore not an argument for free flying either. At the same time, climate compensation must be real. You really have to keep your tongue in your mouth here.
If afforestation projects are chosen as compensation, it must be ensured that the project is carried out and that trees are replanted if they die. At the same time, the planted trees must absorb CO2 that corresponds to the climate impact from the flight within 3-5 years, so that CO2 is quickly removed from the atmosphere and problematic accumulation of CO2 is avoided.

The afforestation must also be beyond what would have been planted anyway, and the forest must of course not be felled, unless the wood is used in buildings and the forest is replanted. Finally, double counting must be avoided: If a forest is planted on Danish fields, the Danish state will automatically also report the forest's CO2 absorption in the national climate account, so it is counted in two places. Similar challenges apply to other compensation projects.

One of the solutions is to invest in afforestation projects in developing countries without their own climate obligations, e.g. in Ethiopia. Here, afforestation can also contribute to e.g. increased biodiversity and erosion control. On the other hand, there may be greater risk with projects in developing countries due to political unrest, unstable climate, insufficient control, etc.

Providers: When purchasing afforestation via the website GoldStandard.org minimizes the risk that the projects do not produce the desired effect.

Credible climate compensations can also be obtained via Atmosfair. Both Atmosfair and Gold Standard are experiencing an explosively increasing interest in compensating.

Price: Even if you include the total climate impact from CO2, jet streaks, etc., and the most expensive climate compensations are purchased, the extra price is usually only a few percent of the total price of the trip (flight, food, taxi, hotel, experiences, etc.).

Of course, climate compensation must not become an excuse for not reducing our CO2 emissions.
We all have a responsibility. We are the first generation to see the consequences of global climate change, and the last generation that can seriously do something about it.