This chart tracks Biochar researchers over time on a diverging axis. Above the line are researchers who published a Biochar-relevant paper that year (active); below the line are dormant researchers, split into those who published the previous year and those who published only earlier. New entrants join at the base of the active band each year as a teal block. Biochar is a large, agronomy-adjacent field with a deep pool of one-time contributors. The top envelope is the number actually publishing in the pathway each year.

The useful pattern is how the active band and the dormant floor compare. Biochar currently stands at 7,091 active in 2025 (32% of members). Younger pathways show a steep active band over a shallow dormant floor — the people who arrived are still there — while older or broader ones carry a much deeper dormant pool of past one-time contributors. Watching the top envelope over the years shows whether the pathway is still recruiting and keeping researchers.

Read the active envelope, not the total height. At yearly resolution a skipped publication year reads as “dormant” and a later paper as a return, so the dormant bands overstate permanent exits. The working figure for Biochar is the top line each year, and its slope over 2021–2025 is the real signal.

What the chart shows today

7,091 active biochar researchers in 2025 sounds healthy until you see the denominator: that is just 32% of everyone the field has ever counted, leaving roughly 15,000 members sitting on the dormant floor. That floor is the deepest of any pathway we track, a signature of biochar’s agronomy adjacency - soil scientists drift in for a project cycle, publish, and drift back out. The active line itself has held up through the 2021-2025 window, so this is churn, not decline. For anyone building in the space, the directory tells the same story from the commercial side, with 377 biochar companies out of 969 visible - the deepest bench in CDR. The so-what: hiring and partnership pipelines here should target the dormant pool, because two out of three people who know this field are one relevant grant away from re-entry.

Chart refreshed from our CDR Company Directory. We publish a data-viz read like this twice a week.