Impact of short-lived non-CO2mitigation on carbon budgets for stabilizing global warming

Abstract

Limiting global warming to any level requires limiting the total amount of CO2emissions, or staying within a CO2budget. Here we assess how emissions from short-lived non-CO2species like methane, hydrofluorocarbons (HFCs), black-carbon, and sulphates influence these CO2budgets. Our default case, which assumes mitigation in all sectors and of all gases, results in a CO2budget between 2011-2100 of 340 PgC for a >66% chanceofstaying below 2°C, consistent with the assessment of the Fifth Assessment Report of the Intergovernmental Panelon Climate Change. Extreme variations of air-pollutant emissions from black-carbon and sulphates influence this budgetby about ±5%. Inthe hypothetical case of nomet..