Opens in a new window

Researchers at the Helmholtz Climate Initiative have identified 13 suitable options for CO2 removal in Germany.

© Pixabay

As discussions at COP27 highlighted last week, governments not only need to reduce GHG emissions but also fast-track initiatives to actively remove CO2 from the atmosphere in order to limit global warming to within acceptable levels. There are technological means of CO2 removal known as Direct Air Carbon Capture (DACC), which involve giant filtration systems, but the most effective solutions in the short term will be nature-based.

Now for the first time researchers at the Helmholtz Climate Initiative (HCI) have codified the different options for CO2 removal (or CDR) for Germany achievable by 2050 and identified 13 suitable options. Of the various natural sink enhancement (NSE) techniques mooted, the potential varies from 1.5 to 9.5 tonnes of CO2 removed annually from land or sea through carbon sequestration.

The proposals include growing seagrass meadows in the Baltic Sea (some 62,000 MT of CO2 could be absorbed annually), the rejuvenation of peatlands, afforestation of croplands and an interesting option known as “enhanced weathering of rocks”, which has the highest removal potential per area of all. This involves spreading a finely-ground silicate onto the ground which induces chemical reactions between rocks, water, and air and turns the gas into solid carbonate minerals.

Bioenergy with Carbon Capture and Storage (BECCS) also offers high CDR potential. During the conversion of biogenic residues to energy for heat and power, CO2 is released and immediately captured and stored. It’s proposed that old coal-fired power plants could be converted for wood pellet combustion – the researchers estimate that one 500 MW plant could remove just under 3 MT CO2 per year. But there are drawbacks with this approach, as the demand for biomass is likely to have negative environmental effects on forest ecosystems abroad and cause additional CO2 emissions.