Reducing CO2 emissions alone won’t be enough to limit global warming to 1.5°C or even 2°C. A landmark report released Tuesday reveals that we must remove four times more CO2 from the atmosphere by 2050 than we currently do.
This involves not only relying on forests but also embracing cutting-edge technologies that are still in their early stages.
Quantifying the CO2 Removal Challenge
The second edition of an interdisciplinary report coordinated by the University of Oxford sets clear targets. Depending on global warming scenarios, we need to capture and permanently store between “7 and 9 billion tons of CO2” annually by 2050. The first edition of this report, “The State of Carbon Dioxide Removal,” concluded last year that we currently remove about two billion tons, primarily through reforestation. This is a stark contrast to the 40 billion tons emitted globally in 2023.
CO2 Removal: A Necessary Complement to Emissions Reduction
Over 50 researchers, some of whom are also part of the UN’s Intergovernmental Panel on Climate Change (IPCC), emphasize that while rapidly reducing emissions remains the most critical strategy, removing CO2 from the atmosphere is also essential to achieve the Paris Agreement goals.
The Urgency of Addressing Fossil Fuel Emissions and Deforestation
“If we fail to reduce emissions from fossil fuels and deforestation, the Paris Agreement goals will be unattainable, even with strong action to increase CO2 removal,” warned William Lamb, one of the report’s authors, during its presentation.
CO2 removal has recently seen “rapid growth in research, public opinion, and start-ups.” However, experts warn of “early signs of a slowdown” as policies and public funding lag behind. They urge governments to incorporate CO2 removal tracking into their national reduction plans (NDCs) under the Paris Agreement.
The Role of Carbon Credits and the Funding Challenge
The market is currently expanding due to corporate demand for carbon credits, controversial financial instruments that allow companies to offset their emissions by funding CO2 removal or emission reduction projects. Climeworks, a start-up with CO2 capture facilities in Iceland, exemplifies this. Their two plants currently capture and store 10,000 tons of CO2 annually, supported by private funds and carbon credit sales. However, reaching one million tons will require billions of euros, a funding level that remains “uncertain” for Climeworks and other start-ups.
Environmental Risks and the Need for Sustainable Development
The Center for International Environmental Law (CIEL) sees this report as illustrating “a worrying trend to increasingly sell CO2 removal as a solution to climate change.” They argue that it distracts from the priority of phasing out fossil fuels.
Diverse CO2 Removal Techniques and Their Potential Impacts
CO2 removal focuses on CO2 already in the atmosphere. This involves restoring or creating natural carbon sinks (forests, soils, peatlands) and new techniques like direct air capture with large compressors (DACCS), capturing CO2 after biomass combustion (BECCS), converting biomass to biochar, and spreading crushed CO2-absorbing rocks on land or sea.
CIEL raises concerns about the potential risks of some techniques (DACCS, geoengineering, and BECCS) for ecosystems and communities. The report’s authors acknowledge these risks, emphasizing the need for rapid but sustainable and regulated development of CO2 removal. They also point out that even traditional techniques, if poorly executed, can harm biodiversity and food security.