Carbon Budget

Carbon Budget

Subject: Environment

Context: The world can emit approximately 400 billion tonnes more of carbon dioxide before hitting the 1.5°C limit, as per the IPCC sixth Assessment report.

More about the Report:

• The world currently emits about 40 GtCO2 annually.
• The AR6 showed that the world can emit only about 500 gigatonnes of carbon dioxide (GtCO2) starting January 1, 2020 for a 50 percent chance of limiting warming to 1.5°C. For a 67 percent chance of avoiding 1.5°C, the budget will come down to 400 GtCO2.
• For a 50 percent chance of limiting temperatures to 2°C, the world can emit 1,350 GtCO2; and 1,150 GtCO2 for a 67 per cent chance.
• Current trends also point to wealthy countries like the United States, the European Union and China eating into a disproportionate share of the budget while developing countries are left with negligible ‘carbon space’ to improve their standards of living.
• Economic growth is still inextricably linked to a rise in energy demand, which leads to higher emissions despite dubious claims of ‘green growth’ and decoupling of gross domestic product and energy use / emissions.

Carbon Budget:

• A carbon budget is a cumulative amount of carbon dioxide (CO₂) emissions permitted over a period of time to keep within a certain temperature threshold.
• It is the maximum amount of carbon dioxide (CO2) that can be emitted while still having a chance to limit warming to 1.5°C or 2°C.
• Carbon budgets are constructed on the premise that there is a near-linear relationship between rising global temperatures and the level of cumulative atmospheric CO2.
• Carbon budgets are complex estimates and are typically subject to several uncertainties such as the effect of
  • non-CO2 greenhouse gases (GHG) [methane and nitrous oxide];
  • the cooling effect of aerosols;
  • Earth-system feedbacks such as carbon released by thawing permafrost that were generally not included in climate models.