The 2024 State of Carbon Dioxide Removal report finds that around 7–9 billion tonnes of CO2 per year will need to be removed by mid-century from the atmosphere if the world is to meet the 1.5°C Paris Agreement target. The authors stress that reducing emissions is the primary way to achieve net-zero, but Carbon Dioxide Removal (CDR) has a critical role to play.

Report cover © .

The authors, which this year again includes several IIASA researchers, incorporated sustainability criteria including multiple Sustainable Development Goals into their analysis, and their final figure for a Paris-consistent range of CDR was assessed based on these.

Currently just 2 billion tons of CO2 are being removed by CDR per year, mostly through conventional methods like tree planting. Novel CDR methods – like biochar, enhanced rock weathering, direct air carbon capture and storage (DACCS) and bioenergy with carbon capture and storage (BECCS) - contribute 1.3 million tonnes per year, less than 0.1% of the total. Methods which are effectively permanent account for only 0.6 million tonnes per year – less than 0.05% of the total. 

A diverse range of CDR methods must be rapidly scaled up to address climate change in line with the Paris Agreement. It is important to note here that CDR is not the same thing as Carbon Capture and Storage (CCS). To count as CDR, a method must capture CO2 from the atmosphere. While some CDR methods such as BECCS and DACCS will use the same CO2 transport and storage infrastructure as CCS, CCS usually refers to a set of industrial methods for the capture of CO2 from fossil sources.

CDR has undergone rapid growth in research, public awareness, and start-up companies. Yet there are now signs of a slowdown in development across multiple indicators.

"It is clear that delaying crucial emissions reductions only exacerbates needed mitigation in the future to limit warming well below 2°C, but there are limits to the role sustainable CDR can play the longer the world delays. Our work on the CDR report builds on a recent IIASA paper published in Nature, which also included contributions by former IIASA Young Scientists Summer Program participants Will Lamb and Stephanie Roe and visiting scholar Tomoko Hasegawa," notes coauthor and one of the conveners of the CDR Report, Matthew Gidden, a senior researcher in the IIASA Energy, Climate, and Environment Program.

While investment in CDR research and start-ups is going to an increasing variety of novel methods, few of these methods are currently targeted in government policies and proposals to scale CDR, which accounts for just 1.1% of investment in climate-tech start-ups. The authors say that given the world is off track from the decarbonization required to meet the Paris temperature goal, this shows the need to increase investment in CDR as well as for zero-emission solutions across the board.

The report notes that CDR companies have high ambitions which, taken together, would drive CDR to levels consistent with meeting the temperature goal of the Paris Agreement. However, according to the report, these ambitions have little ground for credibility at present and depend on a much stronger set of policies than currently exists.

The authors urge governments to implement policies that will increase demand for carbon removals. These should include the embedding of CDR policies into countries’ Nationally Determined Contributions (climate action plans under the UNFCCC) and developing better monitoring, reporting and verification systems for CDR. At present, much of the demand for CDR is coming from voluntary commitments by companies to buy carbon removal credits.

“There are some encouraging signs in the growth and diversity of CDR research and innovations. But these are tempered strongly by sparse and precarious long-term demand. Governments have a decisive role to play now in creating the conditions for CDR to scale sustainably,” concludes Steve Smith of the Smith School of Enterprise and the Environment, University of Oxford.

The annual State of Carbon Dioxide Removal report is a combined effort of over 50 international experts. Apart from Gidden, IIASA researcher Thomas Gasser contributed to the report as coauthor of Chapters 7, 8, and 9, and visiting IIASA researcher Gaurav Ganti was a coauthor of Chapter 8. IIASA also hosts the data portal of the State of CDR report. The report is the world-leading scientific assessment of how much carbon dioxide removal will be needed to limit climate change, and whether or not the world is on track to deliver. 

Adapted from a press release prepared by the Smith School of Enterprise and the Environment, University of Oxford. Read the original article.

Further information
Click here to read the full report.


Dehydrated earth or farmland with corn plant struggling for life in dry cracked earth.

25 April 2024

Climate change could become the main driver of biodiversity decline by mid-century

Global biodiversity has declined between 2% and 11% during the 20th century due to land-use change alone, according to a large multi-model study published in Science. The projections show that climate change could become the main driver of biodiversity decline by the mid-21st century.
Green seedlings in various stages of growth

02 April 2024

CROPS: a new EU-funded project to grow citizen science in Europe

In February 2024, a new EU-funded project kicked off. CROPS – short for curating, replicating, orchestrating, and propagating citizen science across Europe – is a three-year project that brings together six partners from six different countries to develop and demonstrate a modern, inclusive mechanism to support the upscaling of citizen science activities in Europe and beyond.
Forestry activity. Trucks transporting tree trunks.

14 March 2024

European forests: how climate change, land ownership, and forest-related policies influence future wood supply

IIASA researchers contributed to a new study analyzing factors affecting future wood supply in Europe such as climate change, land use, and policy developments. The authors propose practical response measures for different stakeholder groups, including the wood-based industry, forest management, and policymakers.