Even if all signatories to the Paris Agreement meet their climate change commitments, the world will in less than 15 years far exceed the determined carbon emissions cap to limit global warming to 1.5 degrees Celsius, the United Nations Environment Program said in a report Thursday.
The Intergovernmental Panel on Climate Change (IPCC), in its most recent synthesis report in 2014, attempted to determine how much carbon the world could emit while still keeping global temperature rise to 1.5 degrees, 2 degrees, and 3 degrees above pre-industrial levels. The panel found that, to have a 50 percent certainty of limiting global temperature rise to 1.5 degrees, the world could emit 550 gigatons of CO2 equivalent (GtCO2e). To raise that certainly to 66 percent, only 400 GtCO2e could be emitted.
To limit global temperature rise to 2 degrees with 66 percent certainty, the carbon budget is 1,000 GtCO2e; for a 50 percent chance, the cap is 1,300 GtCO2e.
The Paris Agreement on climate change set the goal of keeping global temperature rise as close to the lower end of a 1.5-2-degree range as possible. Nearly 200 nations made commitments under the agreement to take climate action, and 97 nations have as of this week formally joined the accord. However, stakeholders have acknowledged that the national actions will not be sufficient to reach the end goal of the agreement, and thus the commitments will need to be made more stringent as implementation advances.
According to the UNEP report, even if the national commitments are met: “the carbon dioxide budget estimated by the Intergovernmental Panel on Climate Change for limiting warming to below 2°C with at least 66 per cent probability will be close to depleted by 2030, and the similar budget aligned with limiting warming to below 1.5°C with at least 50 per cent probability will already be well exceeded by 2030.”