The year 2023 is by far the hottest year on record and the World Meteorological Organization reports that it’s not just temperature records that have been broken, ” or even pulverized “. The UN body is publishing its annual report this Tuesday, March 19. The state of the global climate ” which gives ” a new and alarming meaning to the expression “out of the norm” », despite a glimmer of hope.
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Whether carbon dioxide (CO2), methane (CH4) or nitrous oxide (N2O), greenhouse gas emissions reached record levels in 2022, the last year for which the World Meteorological Organization (WMO) has overall data. The first data for 2023 shows “ a continued increase “.
These greenhouse gases trap heat in the atmosphere and are the main culprits of climate change. They result from human activities, notably the combustion of fossil fuels, intensive agriculture or industrial processes, and remain present in the air for several decades (nearly 100 years for CO2, for example). Temperatures will therefore continue to rise for many years even if humanity stopped releasing these gases into the atmosphere.
Last year, the global average temperature approached the limit of +1.5 degrees compared to the years 1850-1900, that is to say before the industrial revolution and the start of massive greenhouse gas emissions. . This limit was set by states around the world during COP21 and the Paris Agreement in 2015. It corresponds, according to scientists, to a threshold beyond which our ways of life are threatened. Fortunately, it is not by taking into account climate records from a single year that this threshold is considered exceeded but by taking an average over a long time. “ The 2014-2023 ten-year average of temperatures is thus +1.2 degrees », Notes the WMO. In 2023, “ the months of June to December all broke heat records “. This is due to climate change but also to the El Niño phenomenon, a natural and cyclical event which further increases global temperatures, the report recalls.
The heat accumulated in the ocean reached its highest level in 65 years of observations in 2023, according to the WMO. Widespread heat waves hit the North Atlantic in particular, especially at the end of the year, with heat considered “severe and extreme” by experts, due to temperatures exceeding the average by 3°C. They were “intense and severe in the Mediterranean for the 12th consecutive year,” the report also notes. Given the immense mass of water that the oceans represent, warming them takes a long time… but so does cooling them. So, even if greenhouse gas emissions stopped immediately, they would take centuries or even millennia to cool down, warns the WMO. The consequences are increased sea levels as well as disrupted or weakened fauna and flora with repercussions for populations living on the coasts and fishing.
Last year, sea and ocean levels rose the highest since satellite records began in 1993. However, “ from July to September 2023, the signing of El Ninoto in this rise is clearly visible “. To understand the effect of climate change, it is therefore necessary to look at long-term trends. Thus, the rate of rise in sea levels increased from 2.13 mm per year during the 1990s to 4.77 mm over the last ten years.
If sea levels rise, it is because warm waters are more expanded (they take up more space) than cold waters, but also because the glaciers of the poles and mountains are melting more and more, which adds a large amount of water in the ocean.
“Preliminary data shows that glaciers worldwide have lost on average the equivalent of 1.2 meters of ice thickness in 2023,” according to the WMO. This was particularly remarkable in Europe and North America, due to a very mild winter. In the Canadian Rockies, glaciers lost three meters in winter, for example. Glaciers are in fact formed from compacted snow. But it is snowing less and less. On the North American continent, the snow cover was 7.47 million km² in May 2023, or 1.57 million km² less than average. This is so much fresh water that is no longer available for populations and ecosystems.
All of this scientific data translates into extreme weather events in 2023, of which the WMO makes a sad list. In the Horn of Africa, floods after years of drought have displaced 1.8 million people. In Libya, they cost the lives of around 10,000 people. Hurricane Otis hit the Mexican resort town of Acapulco, causing economic losses estimated at around $15 billion. Extreme heat waves have swept through many regions of the world with the most significant heatwaves in Europe and North Africa (50.4°C recorded in Agadir in Morocco for example). Droughts are also increasing, causing loss of crops and lack of water in Spain, Uruguay and Argentina. Canada’s fire season was also the worst on record with nearly 15 million hectares of forest going up in smoke.
“ These disasters cost a lot of lives, they devastate economies, associated with other crises such as local conflicts or wars, they aggravate food security problems, population displacements and the repercussions on vulnerable populations. », explains Omar Badour, head of global climate monitoring at WMO.
“ There is a glimmer of hope », notes Omar Badour. The production of renewable energy (solar, wind, water) has been propelled to the forefront of climate action. An energy transition is already underway on a global scale, he believes and, “ very positive thing, technologies are becoming less expensive and accessible to everyone. There are already countries that have crossed 40% of renewable energies » in their electricity production. However, this remains insufficient for a low-carbon planet. As for funding for climate action, “ they reached 1,300 billion dollars in 2021-2022, almost double the previous year ”, according to the report. But here again, this remains largely insufficient: “ They only represent 1% of global GDP ». The needs are “ 9 trillion dollars each year by 2030 and 10 trillion more until 2050 for a world at +1.5°C ». Doing nothing would cost even more, scientists warn.