Storing CO2: what’s possible and what works?

7 May 2020

Can we reduce the concentration of CO2 in the air by capturing and storing it? An Academy fact sheet summarises what the Advisory Board of the European Academies of Science (EASAC) writes about this. The conclusion: don’t expect too much in the short term.

CO2 emissions from factories and from coal- and gas-fired power stations can be captured and stored in empty gas fields This process is referred to as Carbon Capture and Storage (CCS). The costs involved are high, and governments are reluctant to invest in it.

CO2 emitted by biomass-fired power stations can also be captured and stored. This is called Bio Energy CCS (BECCS). During the production and processing of biomass, however, a lot of CO2 'leaks' into the atmosphere, sometimes more than is eventually stored underground by means of BECCS. Moreover, production of sufficient biomass would take up 7 to 25% of all farmland and grassland worldwide.

The simplest way to extract CO2 from the air is to plant billions of trees. But then it will take decades before those new trees are able to absorb significant quantities of CO2. It would also require a great deal of space.

An entirely different technique involves crushing rock and scattering the powder in the oceans, where it weathers and binds CO2. It’s not yet possible to determine whether this can work on a large scale. The European Academies of Science conclude that more research will first be needed.