UNEP Emissions Gap

The UNEP Emissions Gap refers to the shortfall between where global greenhouse gas (GHG) emissions are heading under existing pledges and policies and where they need to be to keep warming to 1.5°C or well below 2°C above pre-industrial levels, the temperature limits set out in Article 2 of the Paris Agreement (2015).

The concept is operationalised through the Emissions Gap Report, an annual flagship publication of the United Nations Environment Programme (UNEP) first issued in 2010. Each edition compares three quantities:

• Projected emissions in 2030 (and increasingly 2035) under current policies and under Nationally Determined Contributions (NDCs).
• Benchmark emission levels consistent with least-cost 1.5°C and 2°C pathways drawn from integrated assessment models, broadly aligned with IPCC scenarios.
• The gap between the two, expressed in gigatonnes of CO₂-equivalent (GtCO₂e).

UNEP estimates the gap by aggregating national pledges, comparing them with modelled mitigation pathways, and assessing implementation shortfalls. Reports also evaluate sectoral opportunities (energy, buildings, transport, food systems), the role of methane and other non-CO₂ gases, and equity dimensions such as the disproportionate emissions of high-income households and the G20.

The Emissions Gap Report is widely cited in UNFCCC negotiations, by the IPCC, and in domestic climate policy debates because it translates the abstract Paris temperature goals into concrete tonnage requirements. It typically lands just before the annual Conference of the Parties (COP), framing political pressure on governments to strengthen NDCs. Successive editions have consistently found that current pledges are insufficient: even full implementation of unconditional NDCs leaves the world on track for warming substantially above 1.5°C this century.

The report is complementary to, but distinct from, UNEP's Adaptation Gap Report and the Production Gap Report (co-produced with SEI and others), which track fossil fuel production plans against Paris-aligned pathways.