William D. Nordhaus (born May 31, 1941) is an American economist and professor known for pioneering work that brings greenhouse gas emissions and climate dynamics into long-term economic models. He has been based at Yale University and was a co-recipient of the 2018 Nobel Memorial Prize in Economic Sciences for "integrating climate change into long-run macroeconomic analysis." His research influenced how economists measure the costs and benefits of climate policy.
Overview of contributions
Nordhaus is best known for the development of integrated assessment models (IAMs), especially the DICE (Dynamic Integrated model of Climate and the Economy) family. These models combine economic growth theory with a representation of the carbon cycle and climate damages to estimate optimal mitigation paths, the social cost of carbon, and the timing of policy interventions such as carbon taxes.
Key ideas and impact
- Integrated assessment: linking macroeconomic variables and physical climate processes to evaluate trade-offs between consumption, investment, and mitigation.
- Social cost of carbon: producing estimates used to guide policy on carbon pricing and regulation.
- Policy design: arguing for market-based approaches like carbon taxes to internalize climate externalities.
History and reception
Nordhaus began publishing climate–economy models in the late 20th century and continuously updated them to reflect new data and scientific understanding. His work provoked considerable debate: while many policymakers and economists use his framework to justify pricing carbon, others critique assumptions about damage functions, discounting, and uncertainty. The 2018 Nobel award, shared with Paul Romer, highlighted the importance of embedding long-run environmental factors within macroeconomic analysis.
Works and further reading
Nordhaus wrote books and articles aimed at both specialists and broader audiences, presenting quantitative tools for evaluating climate policy. For background and biographical notes see biographical summary, his Yale profile at Yale University, and material about his birthplace in Albuquerque. Discussions of his climate work and models are available through policy and research summaries at climate economics sources and articles about the 2018 prize at Nobel coverage.
Nordhaus' models remain central to debates on how best to measure and manage the economic risks of a warming world, and they continue to evolve as scientific and economic knowledge advances.