Global Carbon Budget

The Committee on Climate Change, UK, has set out its proposals for the Fifth Carbon Budget to the UK government but added that new policies will be required in order to hit the targets. The statutory advice covers the period between 2028 and 2032, and now the government has until June next year to respond to plans and confirm whether it will back the plan into law. The findings state the UK should set a target to cut emissions by 57% compared to 1990 levels for the period 2028 to 2032.

What is Carbon Budget? In 1992, the United Nations Framework Convention on Climate Change (UNFCCC) decided the objective of global climate policy should be to stabilise humans’ influence with the climate below the level at which it can be considered “dangerous”. The most widely accepted threshold is two degrees of warming relative to pre-industrial times – this is the limit recommended by the UK’s Committee on Climate Change, for example.

In its new report, the the Intergovernmental Panel on Climate Change (IPCC) includes a calculation of how much carbon we can emit and still have a reasonable chance of staying below 2 degrees celsius. It calls this amount a Carbon Budget. The Budget is an upper limit on total human emissions, from the beginning of the industrial revolution until the day we stop burning carbon.

The IPCC’s first analysis was included in its fifth scientific assessment of climate change, published in September 2013. It suggested that a two-thirds chance of keeping warming below two degrees required the world to limit its total carbon emissions since 1860 to no more than a trillion tonnes of carbon. Of this grand all-time total, 515 billion tonnes had already been emitted by 2011. So, according to the IPCC, we have just under 500 billion tonnes of our budget left. Then we have to stop. TOTALLY.

The report said that fossil-fuel power generation would have to be “phased out almost entirely by 2100" — unless the largely untried technology of capturing CO2 emissions and burying them out of harm’s way could be deployed on a massive scale. Without a drastic slowdown in emissions within the next decade, the phase-out date could happen much earlier, probably before 2050, writes Fred Pearce in Yale Environment 360 is a publication of the Yale School of Forestry & Environmental Studies, US.