co2e - Global Warming Potential Lookups and CO2-Equivalent Conversion

Provides curated Global Warming Potential (GWP) values from IPCC Assessment Reports 4 through 6, gas name standardization across documented naming variants (IUPAC/common names, per-report naming changes, and EPA/data.gov naming), and CO2-equivalent conversion utilities. Values are drawn from official IPCC source tables, with corrections applied for two substances where the published table is known to contain errors; see the package vignette for details and source-by-source provenance notes.