Nations are submitting pledges for reductions in emissions – known as “intended nationally determined contributions” – ahead of UN climate talks in Paris at the end of the year which aim to secure a new global deal to tackle climate change.
But analysis of the intended level of emissions in 2030 by some of the world’s largest emitters and assumptions about what other countries might do suggests the pledges will together fail to limit temperature rises to no more than 2C – the threshold beyond which the worst impacts of climate change are likely to be felt.
The authors of the analysis, including Lord Stern who wrote the key report in 2006 on the economics of tackling climate change, have called on countries to find ways to increase ambition for cutting emissions.
Depending on when China’s emissions – which are still growing – reach a peak, the European Union, the US and China are together likely to emit between 20.9 billion and 22.3 billion tonnes of emissions in 2030.
Experts warn that to give the world a better than evens chance of limiting temperature rises to 2C above pre-industrial levels, global emissions would have to be between 32 and 44 billion tonnes in 2030. In order to keep to that limit, either the pledges put forward by the rest of the world must be no more than 23 billion tonnes in 2030, or China, the US and the EU have to cut their greenhouse gases by far more than currently planned, the analysis said.
But current and planned policies from other countries suggest their emissions could be about 35 billion tonnes, meaning there is a gap between the pledges and what is needed to meet the 2C target governments have agreed, the paper warned.
The authors said countries should be considering opportunities to narrow the gap before and after the Paris summit.
“The ambitions and plans agreed at the Paris summit in December 2015 should be regarded as a critical initial step. It is also important that countries make pledges that are credible.
“However, the magnitude of the gap between current intentions and the international target of limiting global warming to no more than 2C clearly shows that an international agreement in Paris will have to include dynamic mechanisms for the assessment of progress and the raising of ambitions.
“Hence the Paris summit should not be regarded as just a one-off opportunity to fix targets,” they said in the paper, published by the Grantham Research Institute on Climate Change and the Environment and the ESRC Centre for Climate Change Economics and Policy at the London School of Economics and Political Science.
The authors, Lord Stern, Rodney Boyd and Bob Ward, urged countries to work hard over the next few months to find credible ways that bigger emissions cuts can be included in pledges submitted before the summit.