Need to catch up

Techniques for removing CO2 from the air are still in their infancy

Plants like this can be used to suck CO2 out of the air.

(Bild: Climeworks)

Carbon dioxide emissions continue to rise. Many countries have started to remove the greenhouse gas from the atmosphere. However, according to a major report, this is still not enough to sufficiently protect the climate. Reducing carbon dioxide (CO2) emissions remains the most important aspect of climate protection, emphasizes the team led by first author Stephen Smith from the University of Oxford.

However, CO2 removal and storage must increase to seven to nine billion tons of CO2 per year by the middle of the century, according to the report, which has now been presented. Only then will it be possible to limit global warming to 1.5 degrees, as agreed in Paris, or at least to well below two degrees.

According to the international report "State of Carbon Dioxide Removal 2024", only 2.2 billion tons of CO2 per year are currently being removed from the atmosphere worldwide, mainly through conventional methods such as afforestation and reforestation. To date, modern methods only remove 1.3 million tons of CO2 from the air each year - less than 0.1 percent of the total amount removed.

These include CO2 extraction from the air with subsequent storage or the combustion of plants, whereby the resulting CO2 is also stored. Plants extract CO2 from the atmosphere as they grow. Another method produces biochar from plants, which is placed in the soil.

Still at the very beginning
"We are a bit where we were with renewable energies 30 years ago," said Daniela Thrän from the Helmholtz Center for Environmental Research in Leipzig. "Today, we have to think about how to get the new technical solutions on the road, so to speak." It is necessary to build demonstration plants, as the USA is already doing, and to select storage facilities for CO2.

According to the report, there is currently still a considerable gap between the countries' national proposals for CO2 removal and most scenarios that are compatible with the Paris temperature target. However, the exact size of the gap has not been determined. "A critical uncertainty is how to account for the fact that global emissions have not declined in recent years as projected in the scenarios," the report states.

It is good that the report presents the most important message right at the beginning, said Simon Wolf from the organization Germanwatch: "Reducing emissions remains the key lever against global warming and the efforts made so far are far from sufficient." At the same time, Wolf also believes it is important "to reach the level of negative emissions that we need for a 1.5-degree-compatible pathway in good time".