June 22, 2018
A new report from Climate Advisers makes the case that natural solutions are abundant, well-understood, and readily-available carbon dioxide removal options that exist today. They should be deployed fully and without delay.
Scientists and other experts increasingly believe that nations will need to proactively deploy planetary-scale solutions to remove carbon dioxide (CO2) and other greenhouse gases (GHGs) from the atmosphere in addition to rapidly decarbonizing the global industrial economy in order to limit the impacts of climate change. The 2015 Paris Agreement recognizes this dual challenge. In addition to limiting temperature rise to well below 2ºC (and striving for 1.5ºC), its long-term goals commit signatories to balancing emissions from sources and removals in sinks in the second half of the century.
Carbon Dioxide Removals (CDR) include both natural and technology-based methods to capture and either store or use CO2. Natural approaches use photosynthesis to absorb atmospheric CO2, storing it in above-ground biomass, as well as in roots and soil. Technological approaches use man-made methods to remove CO2 from point sources such as power plants and industrial facilities, as well as from the atmosphere.
The table below provides a summary of the most prevalent CDR approaches.
Our new report attempts to bring CDR into the mainstream climate conversation by identifying powerful solutions that are ready and cost-effective to deploy today.
- Natural solutions are the most readily-available CDR options. Most are very well-understood and have been deployed on a large scale for decades. Technological solutions are still largely immature, most exist only at the laboratory or demonstration stage.
- Natural solutions are currently a far more cost-effective option to capture carbon dioxide, with a price tag that is an order of magnitude lower per ton of CO2 captured than technological solutions.
- Natural CDR also offers numerous co-benefits, including more resilient ecosystems, increased wildlife habitat and biodiversity, improved water quality and erosion control. With some minor exceptions, technological CDR would be deployed purely for its climate mitigation benefits. This might make it more difficult to obtain buy-in from a diverse group of stakeholders.
- Natural CDR may not be enough to meet the goals of the Paris Agreement. There are significant limiting factors to Natural CDR through both saturation effects—the natural limit of biomass to store carbon—and land constrains will cap the mitigation potential of solutions such as afforestation/reforestation and make them costlier.
- The cost of technological approaches will likely decrease in the decades to come while their mitigation potential will remain largely unchanged.
- Encouraging large-scale deployment of CDR should be a component of all truly visionary international climate action agendas and national long-term emissions strategies, with a strong early emphasis on natural CDR over the next few decades and continued research and development of technological CDR as an insurance policy over the long term.
Summary of CDR Approaches, by Factor
To meet the climate challenge, we must achieve a balance between GHG sources and sinks, through actions to reduce emissions and increase removals. However, attention to the latter half of the equation has not kept pace. Therefore, governments, companies and advocates should:
- Deploy mature natural solutions as early as possible to the greatest extent possible. Natural, biological sinks offer the best combination of benefits for the climate at the lowest cost today. Vegetation also takes time to reach its full sequestration potential.
- At the same time, invest in continued research, development, and demonstration of technological CDR options so that they can be deployed by mid-century. New technology takes time to become cost-effective and reach commercial scales.
- Focus on forests and land as a near term solution to galvanize international action and create more climate ambition in the short term.
Click here to read the full report.