Research

Three enhanced weathering papers landed on CDRXIV in close succession, and read together they give me the clearest snapshot I’ve had of where this pathway actually stands in late 2025. The Suhrhoff et al. systematic review — with a co-author list that reads like a who’s-who of the field — puts a median area-normalized CDR flux of 0.84 tCO₂ ha⁻¹ yr⁻¹ on the table and converges global technical potential at ~0.2–2 GtCO₂ yr⁻¹. Cobo and Guillén-Gosálbez then argue that if you take empirical (rather than theoretical) weathering rates seriously in a life-cycle assessment, inland deployments starting in 2030 face a median 11-year lag before net CDR turns positive. And Gholamahmadi et al. offer the first structured synthesis of how ERW changes the soil’s ability to hold and move water — with mixed results that complicate the “co-benefits” story. ...

Direct air capture is publishing at nearly double last year’s rate. By early July 2026 the CDR Researcher Census had already logged 379 DAC papers - almost the entire 2025 total of 422, in half a year. The run is a clean doubling roughly every two years: 157 papers in 2022, 214 in 2023, 350 in 2024, 422 in 2025. 2026 is indexed only through early July, so the last bar is a floor; annualised it points to about 730 papers, and indexing lag will push the real figure higher. Of the seven census pathways, DAC’s absolute output is mid-pack, but its acceleration is among the steepest - and it is the count most trusted externally. Lück and colleagues’ 2025 map of global CDR research in Nature Communications put 108 DAC papers in 2021 against the census’s 109 - a near-exact match, the tightest of any pathway. ...

Direct air capture gets the magazine covers - the giant fans, the billion-dollar plants, the tech-founder energy. Enhanced rock weathering gets a grinder, a truck, and a field of crushed basalt. Yet in the CDR Researcher Census it is one of the fastest-growing research fronts in the entire field, and almost nobody outside it is watching. Counting papers the census surfaced from OpenAlex and classified as carbon-removal-relevant, enhanced weathering runs 136 papers in 2022, 175 in 2023, 264 in 2024, and 401 in 2025 - a near-tripling in three years (a factor of 2.9), and a plus-52-percent jump from 2024 to 2025 alone. Every year is bigger than the last, and the curve is steepening. ...

The CDR Researcher Census counts 88,708 people. In 2025, 32,047 of them published a carbon-removal paper. The other 56,661 - nearly two-thirds - did not. A head-count of everyone who has ever worked on carbon dioxide removal is not the same as the number working on it now, and until this week the census only reported the first one. So I built the second one. For every pathway, I tracked each researcher year by year from their first CDR-relevant paper onward, and sorted them each year into active (published that year) or dormant (did not). Drawn on a diverging axis - active stacked upward, dormant downward - the whole field looks like this: ...

The carbon-removal industry does not recruit its scientists where the science is biggest. It recruits where the technology is a product. In the CDR Researcher Census, 6.9% of direct air capture researchers work in the corporate sector - the highest share of any pathway. Soil carbon, the largest field with 41,118 researchers, sits at the bottom: 1.7%. The order down the chart is a map of how far each pathway has crossed from science into business. Direct air capture (6.9%) and enhanced weathering (4.4%) lead - both are engineered, measurable, and defensible as products, the kind of thing a company can own. The agronomy-adjacent fields trail: biochar at 2.1%, soil carbon at 1.7%. Where the removal is a machine or a measured mineral reaction, industry shows up. Where it is a farming practice, it mostly stays in the university and the extension service. ...

Biochar research is a Chinese enterprise. Of the 21,978 researchers whose primary pathway is biochar in the CDR Researcher Census, 9,185 - 42% - are in China. The United States has 1,276. That is a ratio of more than seven to one, the most lopsided national concentration of any carbon-removal pathway. No other pathway comes close to this. India is a distant second with 1,766 biochar researchers; the US, so dominant in direct air capture, is third here and barely visible on the chart. Biochar is the one CDR field where a single country holds a near-plurality of the entire global research workforce. ...

Soil carbon is the largest research field in carbon removal, and the one with the least industry behind it. The CDR Researcher Census counts 41,118 researchers whose primary pathway is soil carbon - nearly double the next-largest pathway, biochar, and ten times the size of direct air capture. Yet only 1.7% of them work in the corporate sector, the lowest share of any pathway. Most researchers, least commercialization. That is the paradox. ...

Most social-media advice was written for general B2B marketers. I wanted to know whether any of it actually held up in carbon removal, so last week I pulled together a small study. I scraped the engagement numbers on roughly 900 posts: every recent post from the 25 most-watched carbon-removal company pages on LinkedIn, plus the last few months from the highest-engagement climate voices on X and Bluesky. The list included Climeworks, Heirloom Carbon, Frontier Climate, Mati Carbon, Isometric, Cascade Climate, CDR.fyi, and 18 others on the company side, plus Stefan Rahmstorf, Hannah Ritchie, Johan Rockström, Damian Carrington, Simon Evans, Zeke Hausfather and the rest of the visible climate-science cohort on the personal-account side. ...