(Paris) Almost all countries in the world could experience one in two particularly hot years from 2030, according to a study published on Thursday which underlines the major responsibility for the greenhouse gas emissions of the main global polluters.
The study, published in the journal Communications Earth and Environment, crosses historical emissions data and the commitments made before the recent world climate conference COP26 by the world’s five largest emitters – China, United States, European Union, India and Russia – to establish global warming predictions by region of ‘by the end of the decade.
One in two summer heat waves
Result: 92% of the 165 countries studied are expected to record once every two years a year of extremely hot temperatures. Those years being defined as reaching the all-time high expected once every hundred years in the pre-industrial era, before the exponential increase in emissions from human activity responsible for climate change.
A conclusion “which underlines the urgency and shows that we are moving towards a much warmer world for everyone”, according to Alexander Nauels, from the NGO Climate Analytics, co-author of the study.
To highlight the contribution to the phenomenon of the largest emitters, the researchers then modeled the situation by withdrawing their emissions since 1991, the year following the publication of the first report of the UN climate experts (IPCC). , which highlighted the responsibility for emissions caused by human activity.
The proportion of countries affected by these years of extreme heat then drops to 46%.
For Lea Beusch, from ETH University Zurich, the study highlights the “clear footprint” of large emitters in different regions.
“I think that’s very important, because usually we’re talking about the abstract amounts of emissions, or global temperatures, that we know but can’t feel,” she explains.
The more fragile tropical areas
The upheaval would be particularly marked in the African tropics. “As this is a region where the variations from one year to the next are generally quite small, even the moderate increase it will undergo, compared to other regions, really pushes it out of its way. known climate pattern ”, emphasizes the researcher.
In absolute value, the strongest temperature increases affect the high latitudes of the northern hemisphere, a phenomenon that has already been observed.
The consequences could be mitigated through significant reductions in countries’ emissions, the authors insist.
However, according to the UN, current commitments would see emissions increase by 13.7% by 2030, far from the halving necessary to keep within reach the ideal objective of the 2015 Paris Agreement, namely contain global warming to +1.5 ° C compared to the pre-industrial era.