(This article is also available in German)
Unsurprisingly, the current efforts to reduce CO₂ emissions are far from sufficient to keep the Paris climate target of less than 1.5 degrees Celsius. That also shows Climate Action Tracker in its 2022 tally. Even reaching the 1.5 degree limit is dangerous, because then several Climate tipping points be triggered, as the Potsdam Institute for Climate Impact Research warned in September 2022. With around 40 billion tons of CO₂ that humanity emitted in 2022, it will only take eight years before the 1.5 degrees could be reached, calculated the Global Carbon Project.
Should even the improbable happen that the limit is not exceeded through massive emission reductions, then there still remain the unavoidable releases from agriculture, heavy industry and shipping, which must continue to be retrieved from the air for decades to come.
The recently published report entitled “The State of Carbon Dioxide Removal (CDR)” now gives a precise insight into the potential of approaches to extracting the amounts of CO₂ from the atmosphere and storing it permanently. Methods for capturing and storing carbon from the combustion of coal, oil and gas (CCS) are not considered because they do not contribute to a reduction, but only prevent the increase in CO₂.
Clean up the atmosphere
The extensive analysis reveals a large gap between what governments are planning to do to remove CO₂ from the atmosphere and what is required to meet the Paris Climate Agreement target.
The plans of the states do not go beyond 2050 anyway. One of the authors, Jan Christoph Minks from Mercator Research Institute on Global Commons and Climate Change (MCC), points out: “In the long term, we may have to start thinking about cleaning up the atmosphere today, because the climate damage is already really considerable. But to do that, we really have to remove CO₂ from the atmosphere.”
Of course, now, in the first half of the 21st century, the focus is still on avoiding and reducing greenhouse gases. In the second half of the 21st century, active CO₂ removal should then dominate climate protection. “Of course we have to think about it today: what do we have to do to make it really possible,” said Minks.
Currently, around two gigatonnes of CO₂ of the 40 gigatonnes produced annually by humans are removed from the atmosphere, primarily through reforestation and the management of existing forests. The newer methods contribute just two million tons, 0.1 percent. Among these newer methods, the scientists include, for example, bioenergy with CO₂ capture (BECCS), biochar, or the direct capture of CO₂ from the air (DAC) with chemical air filters.
Three scenarios: how much CO₂ actually needs to be removed
The report uses three scenarios to show how big the gap is between current efforts and the necessary reductions.
If the focus of climate policy is on generating energy from renewable energies, an additional 5.4 gigatonnes of CO₂ must still be removed in 2030 and 7.6 gigatonnes in 2050. If one relies on the currently common natural disposal methods (such as forests and moors), there will still be 3.9 gigatonnes in 2030 that will have to be eliminated elsewhere. For example, because forests cannot be expanded at will, the gap would be 9.8 gigatonnes in 2050. However, if the world focused its focus on reducing its consumption and demand for goods, there would only be 3.5 gigatons to be eliminated in 2030, but still 4.7 gigatons of CO₂ in 2050.
Novel CDR processes such as direct atmospheric deposition, improved weathering and new carbon-rich materials are still in an early stage of development. They therefore need a significant push, says the report. A carbon price incentive and an appropriate regulatory framework are required for the expansion of known conventional CDR methods on land and the introduction of new techniques on a large scale. This is also important so that companies and society do not put off efforts to further reduce and avoid greenhouse gases.
But there is also hope. ‘Innovation in CDR has increased significantly in recent years,’ the authors state. Evidence of this is the more than four billion US dollars for publicly funded research, an increase in patents, but also more investments in new CDR capacities of around 200 million US dollars between 2020 and 2022.
China’s progress in CO₂ removal
China is the world leader here: It registered 36 percent of all patents for these new methods, especially for the direct separation of greenhouse gases from the air. The state also leads in research, as the authors of the report can show based on the number of scientific and peer-reviewed publications.
China is also well advanced in practice and is using biochar for CO₂ removal across the board, as co-author Oliver Geden from German Institute for International Politics and Security of the Science and Politics Foundation reports: “In the province of Nanjing, rice straw can no longer be burned. That’s why they make biochar out of it, which they either use in building materials or simply use as fertiliser.”
The status report on carbon dioxide removal from the atmosphere is to be published annually from now on. Because the CO₂ concentrations are changing, the level of knowledge about the CO₂ removal methods is increasing, and access to data sources is also improving.
(jle)
