Interview: Tom Lambert on the Social Cost of Carbon
This week on Sustainability Now!, your host, Justin Mog, balances his checkbook with Tom Lambert, an applied economist at the University of Louisville’s College of Business, and the host of Economic Impact on Forward Radio. In 2022, after years of robust modeling and analysis, a multi-institutional team led by researchers from Resources for the Future and UC Berkeley released an updated social cost of carbon estimate that reflects new methodologies and key scientific advancements. The study, published in the journal Nature, finds that each additional ton of carbon dioxide emitted into the atmosphere costs society $185 per ton—3.6 times the current US federal estimate of $51 per ton. Learn more at www.rff.org/news/press-releases…te-new-study-finds/
In his research, Tom uses a tool called IMPLAN, which now helps us calculate damages from greenhouse gases. In preparation for this week’s conversation, Tom used IMPLAN to produce a breakdown for different industries in the Louisville MSA (Jefferson County and surrounding counties). As new climate disclosure mandates roll out across the U.S. and internationally, IMPLAN now equips businesses and institutions with the tools to meet them head-on. Their newest feature brings greenhouse gas emissions data to the IMPLAN experience, capturing carbon outputs by industry and region, and mapping them directly to your economic impact results. Whether you're supporting Environment, Social & Governance (ESG) disclosures, informing climate strategy, or benchmarking emissions in your region, IMPLAN helps you do it with confidence. Learn more about environmental impact reporting, on IMPLAN's blog at blog.implan.com/emissions.
In IMPLAN, GWP20 and GWP100 refer to the Global Warming Potential of greenhouse gases over specific timeframes. See www.epa.gov/ghgemissions/unders…-warming-potentials. GWP measures how much a particular greenhouse gas contributes to global warming, compared to carbon dioxide (CO2), which has a GWP of 1. IMPLAN utilizes greenhouse gas data, including GWP values, to analyze the environmental impacts associated with economic activities. GWP20 indicates the global warming potential over a 20-year timeframe. This timeframe prioritizes gases with shorter atmospheric lifetimes, like methane (CH4). GWP20 highlights the near-term warming effects of these gases. For example, methane has a much higher GWP20 (84-87) than its GWP100 (27-30) because of its shorter lifetime. GWP100 indicates the global warming potential over a 100-year timeframe. This timeframe is commonly used for benchmarking and comparing the environmental impact of various greenhouse gases. It offers a more balanced perspective of both short-lived and long-lived greenhouse gases.
In essence, GWP20 and GWP100 in IMPLAN are important metrics for evaluating the environmental impacts of economic activity by providing insight into the global warming potential of greenhouse gas emissions over different timeframes.
As always, our feature is followed by your community action calendar for the week, so get your calendars out and get ready to take action for sustainability NOW!
Sustainability Now! is hosted by Dr. Justin Mog and airs on Forward Radio, 106.5fm, WFMP-LP Louisville, every Monday at 6pm and repeats Tuesdays at 12am and 10am. Find us at forwardradio.org
Source: Interview: Tom Lambert on the Social Cost of Carbon (Sustainability Now!, Forward Radio 106.5fm, Aug. 25, 2025)
