Reality Check: The Missing Pieces of New York’s “Climate Math” Debate

This briefing by RMI examines the debate over emissions accounting methods in New York State, specifically focusing on the shift to a 20-year global warming potential (GWP20) timeframe and the inclusion of upstream and biogenic emissions. The author argues that this 'new climate math' increases climate benefits without necessarily increasing costs, as physical emissions remain constant regardless of the accounting timeframe used.

• New York's updated emissions accounting includes three primary changes: the inclusion of out-of-state emissions from imported energy and exported waste, the counting of biogenic gross emissions from plant-based fuels, and the adoption of a 20-year global warming potential (GWP20) timeframe to prioritize short-lived pollutants like methane and hydrofluorocarbons (HFCs).
• Using the new accounting method instead of the old method (based on the June 2020 decarbonization study) would improve avoided temperature rise benefits by 66 percent by 2050, while potentially avoiding up to $240 billion in damages.
• The author contends that the shift to a 20-year GWP timeframe does not inherently increase costs because physical emissions are unaffected by the accounting timeframe; it merely changes how short-lived pollutants are expressed in tons of carbon dioxide equivalent (CO2e).
• Affordability of climate action in New York can be supported by the Inflation Reduction Act, which could reduce costs by up to 19 percent, and the state's cap-and-invest program and NY HEAT legislation. Meeting New York's targets is estimated to provide at least $115 billion in net benefits for climate and health.
• Other US states including California, Washington, Massachusetts, Rhode Island, and Maryland have also considered or used 20-year timeframes to address underappreciated emissions.

APA

RMI (2023). Reality Check: The Missing Pieces of New York’s “Climate Math” Debate. https://rmi.org/resources/reality-check-the-missing-pieces-of-new-yorks-climate-math-debate/

Chicago

RMI. Reality Check: The Missing Pieces of New York’s “Climate Math” Debate. 2023. https://rmi.org/resources/reality-check-the-missing-pieces-of-new-yorks-climate-math-debate/.

Wikipedia

{{cite report |author=RMI |title=Reality Check: The Missing Pieces of New York’s “Climate Math” Debate |date=22 June 2023 |url=https://rmi.org/resources/reality-check-the-missing-pieces-of-new-yorks-climate-math-debate/ |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{rmi2023reality, author = {{RMI}}, title = {{Reality Check: The Missing Pieces of New York’s “Climate Math” Debate}}, institution = {RMI}, year = {2023}, month = jun, url = {https://rmi.org/resources/reality-check-the-missing-pieces-of-new-yorks-climate-math-debate/}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }