Status: 01/19/2023 02:34 am
Limiting carbon emissions will not be enough to combat climate change. Instead, CO2 must also be “captured” from the atmosphere in the long term – especially with new technologies.
“CO2 removals are a necessity, they will not fall out of the sky,” says climate researcher Jan Minx. The expert is certain that a lot of carbon dioxide will have to be removed from the atmosphere in the future. Germany not only wants to be climate-neutral from 2045, but also wants to remove CO2 from the atmosphere a few years later. The German Climate Protection Act says: “Negative greenhouse gas emissions” are to be achieved from 2050.
“A lot of people overlook this, but by the middle of the 21st century, CO2 removal will dominate climate protection,” predicts Minx. We should think about that today.
Experts say it is one of the greatest challenges facing humanity. “But we’re just at the beginning,” says climate researcher Minx, co-author of the first Report on the global inventory of CO2 removals (“The State of Carbon Dioxide Removal”). According to the report, significantly more carbon dioxide must be removed from the atmosphere than is the case today thanks to new technologies.
Forests and moors cannot store enough CO2
Currently, CO2 from the atmosphere is mainly stored through reforestation, i.e. new forests, and through rewetted moors – around two gigatonnes per year. However, according to the report, twice as much CO2 would have to be bound from the atmosphere by 2050 if the climate target of a maximum warming of 1.5 degrees is to be met.
If the two-degree target were to be reached, 50 percent more CO2 would have to be removed from the atmosphere than today. That cannot work with new forests and moors alone, says climate researcher Minx and sees even small increases as a major challenge: “We don’t have a plan for it at the moment.”
However, if really large amounts of CO2 could be removed from the atmosphere in the future, this could help to mitigate climate change. According to the report, even most climate models would count on it. And if the goals of the Paris climate agreement are to be met, new technologies that can store much more carbon dioxide must be deployed in the long term, according to the report.
Filter out CO2 with fans?
Many new technologies are still being tested in the laboratory. But according to the report, there has been a major surge in innovation, especially in the past two years. So-called direct air capture systems are getting a lot of attention. The CO2 is extracted from the air with fans and filters and then later reacts in the ground together with water and basalt – solid rock is formed.
“Currently it’s only a few thousand tons that are caught every year,” says researcher Minx. An existing plant in Iceland can just about offset the annual CO2 emissions of 500 Germans. The Icelandic company Carbon Engineering is planning a one-million-ton power plant for 2025, says Minx: “It would be the first on such an industrial scale.”
Many technologies are still in their infancy
The systems for direct CO2 removal are still very expensive and require a lot of energy from renewable sources. But in the future, a lot of carbon dioxide could also be bound with biochar or bioenergy plants with CO2 storage. Currently, however, most of the methods are only tested in the laboratory: “They hardly exist yet,” says Minx. Only two million tons of CO2 could currently be stored by all new technologies.
If you want to be climate neutral, you have to reduce CO2
Even the most ambitious country in the world will not be able to completely do without greenhouse gas emissions by the middle of the century. But the states still have no plans at all, says Oliver Geden from the German Institute for International Politics and Security: “Governments, especially those that have decided on net zero targets, have to clarify and say publicly how much CO2 removal they want to make .” But this question has not yet been answered.
CO2 storage banned in Germany
Many storage technologies are currently banned in Germany by the carbon dioxide storage law, and that will probably not change any time soon, says social scientist Geden. Therefore, Germany will have to export carbon dioxide extracted from the atmosphere in the first phase. “So far, it’s difficult to say how this debate will develop in the long term. From a scientific point of view, it doesn’t matter where the CO2 is stored,” says Geden.
In the long term, Germany could also store its own CO2 waste in its own country. Overall, however, there are still many reservations in Germany, says Christine Merk from the Institute for the World Economy at the University of Kiel: “Today, most people are still put off by the methods.” In the future, we could at least partially buy our way out of debt with CO2 measures: “It will be interesting to observe the development over the next few decades,” says Merk.
Hoping for innovations
According to the report, innovations in the field of CO2 removal have increased significantly over the past two years. But it still needs a large political start-up aid. About 120 governments want to be carbon neutral in the long term. However, nobody will be able to do without CO2 emissions completely in this century.
Reforestation is all the more important, but also the promotion of new technologies to bind carbon dioxide in the long term. The research team hopes that every tonne of less CO2 will help to slow down climate change at least a little.