+0.26°C
This is the average increase in temperature between 2014 and 2023, a level never reached before. This is what the second update of the key indicators of climate change (IGCC) reveals, published Wednesday June 5 by a consortium of around fifty researchers in the journal Earth System Science Data. This warming is the result of the combination of greenhouse gas emissions which remain high, and the reduction in the cooling effect of pollution particles, due to the continuous improvement in air quality. Human-caused warming thus reached 1.19°C over the last decade (2014-2023), an increase compared to the 1.14°C observed between 2013 and 2022.
+1.43°C
This is the warming measured for the year 2023 alone, the hottest year ever recorded, in particular due to the El Niño effect, this meteorological phenomenon which consists of the warming of part of the equatorial Pacific Ocean with consequences on the whole world. According to the researchers, warming caused by human activity reached 1.3°C in 2023, showing that natural climate variability, notably due to El Niño, also played a role in the record temperatures. According to the World Meteorological Organization (WMO), La Niña, associated with colder episodes, is expected to take over in the second half of the year.
What is there to hope for a respite? Not necessarily. “The end of El Niño does not mean a pause in long-term climate change, as our planet will continue to warm due to greenhouse gases,” said Ko Barrett, Deputy Secretary General of WMO, quoted in the press release. The WMO also recalls that the last nine years have been the hottest on record, despite the cooling effect of a long La Niña, which lasted from 2020 to early 2023. In addition, with the arrival of La Niña, the National Oceanic and Atmospheric Administration (NOAA) projects an “extraordinary” 2024 hurricane season in the North Atlantic, with four to seven Category 3 or higher hurricanes possible.
200 billion tonnes of CO2
These are the emissions that the world can theoretically emit to have a 50% chance of staying below 1.5°C of warming. This is called the remaining carbon budget. 200 billion tonnes of CO2 is equivalent to five years of current emissions since the world emits around 50 billion tonnes of CO2 per year. In other words, this means that we have a one in two chance of reaching the symbolic threshold of 1.5°C, enshrined in the Paris Agreement, before 2030. While this is very worrying, we must also have in mind head that this excess may only be temporary, but then we will have to accelerate the reduction of greenhouse gas emissions. For comparison, in 2020, the Intergovernmental Panel on Climate Change (IPCC) calculated that the remaining carbon budget to stay below 1.5°C was between 300 and 900 gigatons of carbon dioxide, with a central estimate of 500. But since then, CO2 emissions and global warming have continued, still eating into the remaining carbon budget.
