Using the figures. Hover any mark for its value. Hover a legend chip, a line, a bar or a label to follow it across the panels;
click to keep it, and click again or show all to release. Each figure's data downloads as a table.
Fair shares and carbon debt. Each region receives a share of the carbon budget
under a fairness principle. A region whose cumulative emissions exceed its allocation carries a carbon debt. It can pay the
debt down by cutting emissions faster at home, by removing emissions at home, or by financing action in other
regions.
The two corners. Under unlimited transfers (U, up-pointing triangle in
the paper figures) finance between regions is unlimited, the physical transition matches the cost-effective
source pathway, and the fair share is settled by financial transfers. Under lowest transfers (L,
down-pointing triangle) finance is held to the lowest level at which the model remains feasible, the higher-responsibility
regions cut fossil fuels faster at home, and the regions with less historical responsibility gain room relative
to the source pathway. A cross marks the source pathway.
The fair-share variants. ECPC shares the budget by equal cumulative emissions
per person, CAPC adjusts that share for capability, and the year is when responsibility starts to count (1990,
2015 or 2025). The default pair is ECPC 2015 on the SSP2 narrative. ECPC 2015* is ECPC 2015 with a ten-year
delay before transfers begin. Further pairs change the narrative (SSP1), the cooperation channel (novel carbon
removal only) or the discount rate (1%). Each pair has both corners.
The carbon budgets. Two budgets, both counted from 2020 and both allowing
overshoot: one consistent with about 2 °C at a two-in-three chance and one with 1.5 °C at an even chance. The
budget binds the emissions the fair-share rules cover. Land use, international shipping and aviation sit
outside it, so total CO₂ over 2020 to 2100 lands within a few percent of the budget for every line.
Transfers, investment and consumption. Transfers and investment are present
values at 2025 of flows from 2026, in market exchange rate dollars. Consumption changes are the same present
value against the no-new-policy baseline or against the source pathway.