Editing Global warming potential (section)

=== GWP in policymaking ===
As governments develop policies to combat emissions from high-GWP sources, policymakers have chosen to use the 100-year GWP scale as the standard in international agreements. The [[Kigali Amendment]] to the [[Montreal Protocol]] sets the global phase-down of [[hydrofluorocarbon]]s (HFCs), a group of high-GWP compounds. It requires countries to use a set of GWP100 values equal to those published in the IPCC's Fourth Assessment Report (AR4).<ref name=":5">'''[https://treaties.un.org/doc/Treaties/2016/10/20161015%2003-23%20PM/Ch_XXVII-2.f-English%20and%20French.pdf Amendment to the Montreal Protocol on Substances that Deplete the Ozone Layer] (the "Montreal Protocol"), adopted at Kigali on October 15, 2016, by the Twenty-Eighth Meeting of the Parties to the Montreal Protocol (the "Kigali Amendment").'''</ref> This allows policymakers to have one standard for comparison instead of changing GWP values in new assessment reports.<ref>{{Cite web |date=August 8, 2024 |title=Understanding Global Warming Potentials |url=https://www.epa.gov/ghgemissions/understanding-global-warming-potentials |access-date=August 26, 2024 |website=US EPA, Greenhouse Gas Emissions}}</ref> One exception to the GWP100 standard exists: [[Government of New York (state)|New York state]]’s [[Climate Leadership and Community Protection Act]] requires the use of GWP20, despite being a different standard from all other countries participating in phase downs of HFCs.<ref name=":5" />