The emissions gap

Abstract

The emissions gap is defined as the difference between the estimated total global greenhouse gas (GHG) emissions resulting from the full implementation of the nationally determined contributions (NDCs), and the total global GHG emissions from least-cost pathways consistent with the Paris Agreement long-term goal of limiting global average temperature increase to well below 2°C, and pursuing efforts to limit it to 1.5°C relative to pre-industrial levels. Or in other words, the gap between promised and needed emission reductions. The key questions assessed in this chapter are, what is the current best estimate of the emissions gap for 2030 considering the latest NDCs? What levels of global emissions are in line with the climate mitigation goals of the Paris Agreement? Where are we headed under current policies and various mitigation pledge scenarios in terms of global warming over the course of the century?