SIf global warming is to be limited to well below two degrees Celsius by the end of the century, as envisaged by the 2015 Paris climate agreement, drastic measures are necessary, and they must be taken as quickly as possible. Global emissions of climate-damaging gases must be reduced quickly, renewable energies expanded, and, above all, huge amounts of carbon dioxide that is already present must be removed from the atmosphere. According to the International Energy Agency (IEA), it should be around 60 million tons (megatons) per year by 2030. The Intergovernmental Panel on Climate Change (IPCC) considers an amount of up to 20 billion tons (gigatons) per year from 2050 to be necessary in order to limit the global rise in temperature to 1.5 degrees. For comparison: global CO₂ emissions in 2021 were around 37 gigatonnes, and in 2022 even 40.6 gigatonnes.
However, the systems for large-scale CO₂ capture are not yet available or are only being tested. Of the two billion gigatonnes of CO₂ that are currently removed from the atmosphere each year, only 0.1 percent is accounted for by capture technologies. The lion’s share is still tied up with biomass and reforestation projects. This is the sober assessment of an international study by the Berlin-based Mercator Institute for Climate Research. The around 20 researchers involved in the study entitled “State of Carbon Dioxide Removal” are calling for significantly more effort to be able to meet the 1.5 degree climate target.
The possibilities of large-scale removal of carbon dioxide from the atmosphere are hardly considered in the climate protection plans of most countries. According to the authors, this is a major reason why separation techniques such as the direct extraction of CO₂ from the ambient air using large filters, known as Direct Air Carbon Capture (DACC), still lead a shadowy existence. The further development of new technologies would therefore only progress slowly. An urgent rethinking of politics is necessary here – above all significantly more investments and research efforts. That has changed slightly in recent years. From 2010 to 2022, around 4.1 billion dollars in public funds flowed into research. “The state of research, development and politics is similarly backward here as it was for renewable energies 25 years ago,” says Jan Minx, head of the MCC working group Applied Sustainability Research and co-author of the report.
The gap between the climate targets set and what can be achieved despite CO₂ savings and the increase in renewable energy is large. According to the authors of the study, in order to close them, the annual carbon dioxide capture worldwide would have to be increased thirtyfold from the current two million tons of CO₂ per year by 2030, and by 2050 even by a thousandfold and more.
But we are still a long way from that, and it will hardly be possible to achieve this through reforestation measures and better soil management alone. Rather, what is needed is separation systems on an industrial scale, each of which can filter several million tons of CO₂ out of the atmosphere.