The Climate Action Tracker (CAT) has updated its effort sharing methodology to reflect the increase of climate mitigation required to meet the Paris Agreement 1.5°C long-term temperature limit, and the most recent literature published about equitable emissions reductions and the most recent emissions trends.
- The updated CAT rating system has six categories: “Role model,” “1.5°C Paris Agreementcompatible,” “2°C compatible,” “Insufficient,” “Highly insufficient,” and “Critically insufficient:”
- We have now divided our “Sufficient” category into two: “1.5°C Paris Agreementcompatible “and “2°C compatible.” The “2°C compatible” category refers to the 2°C goal adopted in Copenhagen in 2009, now replaced by the 1.5°C limit in the Paris Agreement. This provides an historical reference point and bridge to the Paris Agreement-compatible category rating.
- We have renamed the “Medium” category “Insufficient” because countries rated “medium” would still require others to take considerably more action to keep warming below 2°C, let alone limit it to 1.5°C as required under the Paris Agreement.
- Similarly, so many countries fell into the “Inadequate” category that it was difficult to differentiate between their levels of (insufficient) action. We have therefore divided the “Inadequate” category into two: “Highly insufficient,” (Japan, South Africa), and “Critically insufficient”—reserved for those taking the very least amount of action, such as the US, Russia and Saudi Arabia.
- We find that the main implication of including 1.5°C Paris Agreement-compatible scenarios in fair-share mitigation ranges is that, for many countries, the “Role model” category now requires increased mitigation efforts, as would be expected for moving to a more ambitious target.
- The overall impact of including the most recently-available data varies from country to country. For most countries, the effect of updated allowances in the Fair Share range did not lead to a change in the country’s actual rating.