Tom Swinfield and Ben Rifkin

Amidst criticism of carbon markets and the use of static baseline scenarios to determine counterfactuals and the additionality of carbon projects, dynamic baseline approaches emerged as an innovative alternative to the traditional static baseline. These approaches offer opportunities to strengthen the integrity and credibility of credits in the voluntary carbon market because they make use of the same advances in causal inference that have been the basis of the criticism. So, what makes a baseline "dynamic" and why should it be better than a static baseline? What are the challenges and limitations of implementing these approaches, and can they be overcome? Tom Swinfield and Ben Rifkin answer these questions by drawing on experience developing dynamic baselines to independently evaluate project impact and to issue credits.  

Speaker Biographies

Tom Swinfield  –  Senior Researcher at 4C, University of Cambridge and Chief Science Officer, Canopy PACT

With a background in forest ecology and remote sensing, Tom Swinfield co-founded the Cambridge Centre for Carbon Credits (4C), where he has led work on understanding what carbon and biodiversity credits are and how to make them. He has published in leading scientific journals on topics ranging from credit integrity to fungible biodiversity metrics, and has led the development of automated, open-source approaches to assess the real-world impact of conservation and restoration efforts. At Canopy PACT, Dr. Swinfield leads efforts to make scientifically credible nature-based credits a reality. He works closely with project developers, investors, and regulators to ensure that claims about nature’s benefits are rooted in the best available evidence. Dr. Swinfield is passionate about making nature markets work for people, biodiversity, and the climate.

Ben Rifkin  –  Manager, Forestry, TerraCarbon

Ben Rifkin is a forest carbon expert who has supported the design and monitoring of 14+ registered forest carbon projects since he joined TerraCarbon in 2018. He has contributed to innovations in the carbon market by advancing innovations in AFOLU carbon protocols including Verra's VM0045 and VM0047. He provides technical expertise to clients from East Africa to the Pacific Northwest. He is dedicated to improving the integrity of global carbon markets and applying sound scientific principles to develop forest carbon projects around the world. Rifkin earned his MFS degree from the Yale School of the Environment. He is an SAF Certified Forester (CF).

Recommended Readings

Balmford, A., Keshav, S., Venmans, F., Coomes, D., Groom, B., Madhavapeddy, A., & Swinfield, T. (2023). Realizing the social value of impermanent carbon credits. Nature Climate Change, 13(11), 1172–1178. 

Ferraro, Paul J. 2009. “Counterfactual Thinking and Impact Evaluation in Environmental Policy.” New Directions for Evaluation 2009 (122): 75–84.

Rau, E.-P., Holland, J., Swinfield, T., Williams, A., Keshav, S., & Coomes, D. A. (2025). Strengthening the integrity of REDD+ credits: objectively assessing counterfactual methods using placebos. Cambridge Open Engage.

West, T. A., Wunder, S., Sills, E. O., Börner, J., Rifai, S. W., Neidermeier, A. N., Frey, G. P., & Kontoleon, A. (2023). Action needed to make carbon offsets from forest conservation work for climate change mitigation. Science, 381(6660), 873–877.