Subsidizing failure

In its sixth assessment report, released in March 2023, the Intergovernmental Panel on Climate Change (IPCC), the United Nations body that regularly assesses the current state of climate science, points out that “biological CDR methods like reforestation, improved forest management, soil carbon sequestration, peatland restoration[,] and coastal blue carbon management can enhance biodiversity and ecosystem functions, employment[,] and local livelihoods.”

On the other hand, notes the IPCC, the implementation of mechanical DAC along with underground sequestration of CO2 “currently faces technological, economic, institutional, ecological-environmental and socio-cultural barriers.” Further, the current global rates of mechanical carbon capture and storage “are far below those in modeled pathways limiting global warming to 1.5°C to 2°C.”

In a study published in the journal PLOS Climate in February 2023, a team of American scientists analyzed the benefits and downsides of the two pathways in detail. They used three criteria: effectiveness (“[d]oes the process achieve a net removal of CO2 from the atmosphere” once all inputs and outputs are accounted for?), efficiency (“[a]t a climate-relevant scale… [of a billion metric tons of CO2 per year], how much energy and land are required?”), and impacts (“[w]hat are the significant co-benefits or adverse impacts [on nature and society]?”).The team gathered data and crunched the numbers. The lead author, June Sekera, a carbon researcher and visiting scholar at the New School for Social Research in New York, concluded:

“[B]iological sequestration methods, including restoration of forests, grasslands, and wetlands and regenerative agriculture, are both more effective and more resource efficient in achieving a climate-relevant scale of CO2 removal than are techno-mechanical methods – which use machinery and chemicals to capture CO2. Additionally, the co-impacts of biological methods are largely positive, while those of technical/mechanical methods are negative. Biological methods are also far less expensive.”

In this comparative study, the scores for natural versus mechanical carbon removal methods were not close: Natural methods won in every category – and by a significant margin. The problem with machine-based carbon removal is not just that current technologies are immature (with the hope of getting better with more research and investment), but also that using machines is inherently inefficient, costly, and risky. On the other hand, removing carbon by restoring nature costs less, is more effective at reducing atmospheric carbon, and offers numerous side benefits.The American study also noted that its findings “that biological methods exhibit superior effectiveness in comparison to DAC are consistent with data reported in the 2022 IPCC study.” It added in plain terms: “According to the IPCC, not only are biological methods of CDR more effective than DAC…, but their effectiveness is projected to increase significantly over time.”

As if to underscore that conclusion, a separate study published in March 2023 in the journal Nature Climate Change concluded that the protection and rewilding of even a small targeted group of wildlife species would help facilitate the capture and storage of enough carbon to keep the global temperature below the tipping point of warming 1.5 degrees Celsius above pre-industrial levels.

Excerpted: ‘Capturing Carbon With Machines Is a Failure – So Why Are We Subsidizing It?’.

Courtesy: Counterpunch.org