A new study published on Wednesday by renowned researchers warns that human-caused global warming has reached an “unprecedented pace,” with the window to limit temperature rise to 1.5°C rapidly closing.
Record-Breaking Warming Trend
“Human-induced warming has increased at an unprecedented rate in instrumental measurements, reaching 0.26°C per decade in 2014-2023,” the scientists state.
This finding, published in the journal Earth System Science Data, is the result of the work of nearly sixty renowned researchers who rely on the methods of the IPCC, the UN-mandated climate experts. The study’s significance lies in providing updated indicators based on the IPCC’s latest report, without waiting for the next cycle in several years.
Compared to the pre-industrial era, this human-induced warming reached 1.19°C over this decade, a significant increase from the figures in the last report published a year ago (+1.14°C over 2013-2022).
For 2023 alone, human-caused warming reached 1.31°C. The total observed warming reached 1.43°C, as natural climate variability also played a role, starting with the El Niño phenomenon.
Urgency for Climate Action
Scientists aim to provide updated data annually to inform negotiations at global climate conferences (COP) and political debates, as the current decade is considered decisive for achieving the goals of the 2015 Paris Agreement, which aims to limit warming well below 2°C and, if possible, to 1.5°C.
This publication comes as representatives from around the world gather in Bonn to advance climate negotiations ahead of COP29 scheduled for Baku at the end of the year (November 11-22).
“For us, this is a reminder of the urgency and importance of negotiations and agreements to reduce greenhouse gas emissions,” emphasized Pierre Friedlingstein of the University of Exeter and CNRS in a press conference.
“Climate action is important because each increment of additional warming due to human activities increases serious risks,” reminds climatologist Valérie Masson-Delmotte, citing recent heatwaves, droughts, and extreme rainfall worldwide.
She also highlights “the success of collective actions,” such as the protection of the ozone layer. All scientists quoted participated in the study.
Factors Driving Warming
The warming is the result of greenhouse gas emissions – mainly caused by the massive use of fossil fuels (oil, gas, coal) – which are at record levels: about 53 billion tons of CO2 equivalent per year from 2013-2022.
Another factor has also played a role, scientists point out: reduced cooling caused by polluting particles in the air, which reflect sunlight and allow for the formation of certain clouds.
“The main reason is air pollution reduction, first in Europe and the United States, and more recently in Asia, particularly in China,” explained Glen Peters of the Center for International Climate Research in Oslo to AFP.
A Glimmer of Optimism
The remaining carbon budget – the margin of maneuver, expressed as the total amount of CO2 that could still be emitted while maintaining a 50% chance of limiting global warming to 1.5°C – is shrinking.
This “budget” is now only around 200 billion tons, the equivalent of about five years of emissions at the current rate, compared to 250 billion in the last edition of the study a year ago.
“This is a critical decade,” the authors write. “We could expect global warming of 1.5°C to be reached or exceeded in the next 10 years” in the absence of cooling caused by a major volcanic eruption.
“But it is also the decade when we could expect global emissions to peak and begin to decline substantially,” they emphasize.
Despite record levels, the rate of increase in CO2 emissions has slowed this decade compared to the 2000s. The report contains “a bit of optimism,” says Piers Forster of the University of Leeds, lead author of the study.