Changes in version 0.1.0 (2026-09-10)                  

  - Initial release.
  - gwp() looks up Global Warming Potential values by gas, IPCC
    Assessment Report (AR4-AR6), and time horizon (20, 100, 500 years).
  - as_co2e() converts a mass of gas to CO2-equivalent.
  - gwp_compare() compares a gas's GWP across assessment reports.
  - standardize_gas() maps non-canonical gas names to canonical gas_id
    values using documented naming variants (no fuzzy matching).
  - Bundled datasets: gwp_values, gases, gas_synonyms, with
    source-by-source provenance in vignette("provenance").