Emissions from five major economies to double number of countries facing ‘extreme hot’ years, scientists warn

Under current emissions reductions targets

A new scientific paper published today (6 January) in Communications Earth and Environment from scientists at ETH Zurich and Climate Analytics has examined the impacts of the emissions of China, the US, the EU, India and Russia.

The emissions from these five economies account for around 53% of global emissions. According to the study, the emissions that will be emitted from these economies between 1991-2030 look set to double the number of nations that will be exposed to increasingly hot years.

Under current emissions reductions targets, 92% of all countries are expected to experience extreme hot years every second year by 2030, which is twice the number of countries compared to removing emissions from those five economies.

The scientist also examined the estimated emissions of those nations between 2016 and 2030, following the ratification of the Paris Agreement. The study notes that 15% of the estimated increase in nations experiencing extremely hot years is linked to post-Paris emission reduction efforts from the major economies, suggesting that decarbonisation is not happening at a required pace.

“Our work shows that over a relatively short time period, the emissions of these five economies have a strong impact on extreme heat experienced around the globe by 2030. We’re talking about annual mean temperatures that would only be experienced once every 100 years in preindustrial times happening every second year,” ETH Zurich’s researcher Dr. Lea Beusch and lead author of the study said.

The study notes the importance of nations ramping up climate ambitions as part of an agreement in the Glasgow Climate Pact from COP26, which calls on parties to submit updated plans this year.

The state of play going into COP26 was one of renewed optimism. The International Energy Agency’s (IEA) World Energy Outlook, published in October, found that more than 120 nations have unveiled new targets to reduce emissions by 2030, while governments and nations account for 70% of global carbon emissions had made some sort of net-zero pledge.

Experts at Carbon Brief took a deep dive into whether the Glasgow Climate Pact is sufficient in keeping 1.5C alive. It found that current policies will “lead to a best-estimate of around 2.6C to 2.7C warming by 2100”, but this can be reduced to 2.4C if countries meet their nationally determined contributions (NDCs). If national net-zero pledges are met, however, average warming could be reduced to 1.8C by 2100. 1.5C is in touching distance, but nations aren’t dragging themselves over that threshold.

“Our results underscore that the actions of the world’s top emitters will have a huge impact for our global temperature trajectory in this decade. How they respond to the COP26 outcome will be fundamental to whether 1.5°C stays within reach – none of their targets are currently sufficient,” Dr. Alexander Nauels of Climate Analytics, who co-authored the study, added.

Matt Mace

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