CREAF Talk with Heather Graven - "Bomb radiocarbon evidence for strong global carbon uptake and turnover in terrestrial vegetation"

TITLE: "Bomb radiocarbon evidence for strong global carbon uptake and turnover in terrestrial vegetation "

DATE: Thursday, 20th March 2025.

TIME & FORMAT: form 12 to 1pm CET - In-person and online.

Seminars will combine in-person and online formats (CREAF, Sala Graus II, Universitat Autònoma de Barcelona, Spain) but in all cases, talks will be always streamed (not recorded), so they can be followed online.

HOW TO CONNECT: direct link to Heather Graven's conference.

SUMMARY OF THE WORKSHOP:

Vegetation and soils are taking up approximately 30% of anthropogenic carbon dioxide emissions because of small imbalances in large gross carbon exchanges from productivity and turnover that are poorly constrained. We combined a new budget of radiocarbon produced by nuclear bomb testing in the 1960s with model simulations to evaluate carbon cycling in terrestrial vegetation. We found that most state-of-the-art vegetation models used in the Coupled Model Intercomparison Project underestimated the radiocarbon accumulation in vegetation biomass. Our findings, combined with constraints on vegetation carbon stocks and productivity trends, imply that net primary productivity is likely at least 80 petagrams of carbon per year presently, compared with the 43 to 76 petagrams per year predicted by current models. Storage of anthropogenic carbon in terrestrial vegetation is likely more short-lived and vulnerable than previously predicted. 

ABOUT THE SPEAKER:

Heather is a professor of Climate Physics at Imperial College London. Her research focuses on the global carbon cycle and its response to human activities and climate change. She uses observations and models of CO₂ and CH₄ and their isotopic composition to investigate their sources and sinks. Heather worked previously with the Scripps CO₂ Program at UC San Diego and with the Environmental Physics group at ETH Zurich.