Climate change indicators in red after year of record heat, warns UN

Published on: 03/19/2024 – 2:17 pm

8 minutes

Carbon dioxide (CO2), methane (CH4) or nitrous oxide (N2O), greenhouse gas emissions are set to reach record levels in 2022, for which last year World Meteorological Organization (WMO) Contains aggregate data. The first data for 2023 shows “ constant increase “

These greenhouse gases trap heat in the atmosphere and are the main culprits of climate change. They result from human activities, especially the combustion of fossil fuels, intensive agricultural or industrial processes, and remain present in the air for several decades (for example about 100 years for CO2). Even if humanity stopped releasing these gases into the atmosphere, temperatures would continue to rise for many years.

Last year, the global average temperature reached a limit of +1.5 degrees compared to 1850-1900, that is, before the industrial revolution and the beginning of large greenhouse gas emissions. These limits were set by states around the world during COP21 and the Paris Agreement in 2015. According to scientists, it corresponds to the threshold beyond which our way of life is threatened. Fortunately, this threshold is not considered exceeded by considering a single year’s climate record but by taking a long-term average. ” The 2014-2023 ten-year average temperature is thus +1.2 degrees

», notes WMO. In 2023, “ Heat records were broken in all months from June to December “This is due to climate change but also to the El Niño phenomenon, a natural and cyclical phenomenon that further increases global temperatures, the report recalls.

According to the WMO, in 2023 accumulated ocean warming reached its highest level in 65 years of observations. Widespread heat waves hit the North Atlantic, especially late in the year, with temperatures exceeding 3°C on average, with heat considered “severe and extreme” by experts. They were “intense and severe in the Mediterranean for the 12th consecutive year,” the report also noted. Given the amount of water that the oceans represent, it takes a long time to heat it up… but it also takes a long time to cool it down. So, even if greenhouse gas emissions were to stop immediately, cooling would take centuries or even millennia, the WMO warns. A rise in sea levels results in disturbed or weakened fauna and flora for coastal populations and fisheries.

Last year, sea and ocean levels rose the most since satellite records began in 1993. However, “ From July to September 2023, signing Al Ninoto This increase is clearly visible ” To understand the impact of climate change, it is therefore necessary to look at long-term trends. Thus, the rate of sea level rise has increased from 2.13 mm per year in the 1990s to 4.77 mm in the last ten years.

If sea level rises, it’s because warm water expands more than cold water (they take up more space), but also because the poles and mountain glaciers are melting more and more, which puts more water in the oceans. adds. .

“Preliminary data shows that glaciers worldwide have lost an average of 1.2 meters of ice thickness in 2023,” according to the WMO. This was particularly notable due to the very mild winters in Europe and North America. For example, in the Canadian Rockies, glaciers lose three meters in winter. Glaciers are actually formed from compacted ice. But the snow is falling less. On the North American continent, snow cover in May 2023 was 7.47 million km², or 1.57 million km² below average. This is so much fresh water that is no longer available to populations and ecosystems.

All this scientific data translates into extreme weather events in 2023, of which the WMO makes a sad list. In the Horn of Africa, floods following years of drought have displaced 1.8 million people. In Libya, they lost about 10,000 lives. Hurricane Otis struck the Mexican resort town of Acapulco, causing an estimated $15 billion in economic damage. Extreme heat waves have swept many regions of the world, with Europe and North Africa (for example 50.4°C recorded in Agadir in Morocco) the most notable heat waves. Droughts are also increasing, causing crop damage and water shortages in Spain, Uruguay and Argentina. Canada’s fire season was also the worst on record with nearly 15 million hectares of forest gone up in smoke.

“ These disasters cost a lot of human lives, they devastate economies, are associated with other crises such as local conflicts or wars, they exacerbate food security problems, population displacement and consequences for vulnerable populations. », Omar Badour, head of global climate monitoring at the WMO, explains.

“ There is a ray of hope », Omar Badour notes. Production of renewable energy (solar, wind, hydro) is at the forefront of climate action. A global energy transition is already underway, he believes, and, “ On a very positive note, technologies are becoming less expensive and accessible to everyone. There are already countries that have surpassed 40% renewable energy » in their electricity generation. However, this remains insufficient for a low-carbon planet. To fund climate action, “ They reached $1,300 billion in 2021-2022, nearly double the previous year. “, according to the report. But here again, this remains largely inadequate: ” They represent only 1% of global GDP ». needs are ” 9 trillion dollars per year by 2030 and 10 trillion more for a world at +1.5 degrees Celsius by 2050 ». Scientists have warned that doing nothing will cost more.