Fair Share
A nation's overall fair share of the global climate effort is calculated as a percentage of that global effort -- whether mitigation or adapation related -- and is based on the country's share of the global responsibility for causing climate change and capacity for addressing it. These are expressed in a Responsibility and Capacity Index, which is calculated based on user's own preferred interpretation of national responsibility and capacity. These preferences are set in the panel to the left labeled Calculator Settings, and a core subset of them are also accessible in the Equity Settings panel.
Critically, a nation's fair share is not seen in domestic terms, though its mitigation potential of course is. The CERP views climate as a global commons problem that can only be solved within a high-cooperation international regime. Such a regime can only be established if each Party sees others to be doing their fair shares in the face of the common challenge. In practice, of course, each country will decide, on the basis of its own specific considerations (e.g. it’s own view of costs, co-benefits and political-economic tradeoffs) what fraction of its fair share of the global effort it will attempt domestically, and what fraction it will make off shore” by supporting action in other countries.