Access Carbon Market Data from Emissions Trading Systems and Voluntary Registries // Unified access to carbon market data from compliance emissions trading systems ('EU ETS', 'UK ETS', 'RGGI', California Cap-and-Trade) and voluntary carbon markets (Verra, Gold Standard, American Carbon Registry, Climate Action Reserve, via the Berkeley Voluntary Registry Offsets Database and the 'CarbonPlan' 'OffsetsDB' API). Includes cross-market price data from the 'International Carbon Action Partnership' ('ICAP') Allowance Price Explorer https://icapcarbonaction.com/en/ets-prices, global carbon pricing from the World Bank Carbon Pricing Dashboard https://carbonpricingdashboard.worldbank.org/, and the historical 'RFF' World Carbon Pricing Database following Dolphin, Pollitt and Newbery (2020) doi:10.1038/s41597-022-01659-x. Data is downloaded from public sources on first use and cached locally.