The oceans broke a new world temperature record this week, raising fears of harmful consequences for marine life and climate balances.
The surface temperature of the oceans “reached 20.96°C on July 30” 2023 according to the ERA5 database, while “the previous record was 20.95°C in March 2016”, said a spokeswoman from the European Copernicus service to AFP.
These data relate to the oceans between the 60th parallel north and south, thus excluding only the polar regions.
The US Oceanic and Atmospheric Observation Agency (NOAA), which uses a different database, also notes the same trend of ocean warming in recent months, with a record temperature reached on April 4, at 21.06 degrees. On August 1, the temperature of the oceans was almost at the same level (21.03 ° C) and still above the previous record of 2016.
The oceans absorb 90% of the excess heat from the Earth system caused by human activity during the industrial era and this energy accumulation continues to increase as greenhouse gases accumulate in the atmosphere.
Piers Forster of the University of Leeds in the UK called the Copernicus data “very robust”.
“The ocean heat wave poses an immediate threat to some marine life, we are already seeing signs of coral bleaching in Florida as a direct result and I expect further negative consequences,” said this professor specializing in climate change.
This overheating of the oceans will have other chain effects on biodiversity, such as the migration of species or the arrival of invasive species threatening fish stocks and therefore food security in certain parts of the globe.
In addition, warmer waters have less capacity to absorb CO2 thereby reinforcing the vicious circle of global global warming of the planet.
This temperature record follows a series of others for several weeks. And others cannot be ruled out as the El Niño phenomenon, which tends to warm the waters, has only just begun. According to experts, its full effects will only really be felt towards the end of this year and will continue for years to come.
“While there are certainly other short-term factors, the primary long-term cause is undoubtedly the buildup of greenhouse gases in the atmosphere caused by human activities, primarily burning fossil fuels,” said Rowan Sutton of the University of Reading.
The use of coal, oil and gas will undoubtedly be at the heart of painful debates at the next COP28, the major international meeting on the climate which will be held at the end of the year in Dubai.
Last week, North Atlantic waters already reached an average temperature never before measured, with a record average surface water temperature of 24.9°C observed on July 26, according to data. NOAA drafts. The North Atlantic generally peaks in temperature in September.
Since March, which is the month in which the North Atlantic begins to warm after winter, the temperature curve has been moving well above that of previous years, with a gap having widened further in recent weeks. The North Atlantic has thus become an emblematic observation point for the overheating of the planet’s oceans.
A few days earlier, it was the Mediterranean Sea which had beaten its daily heat record, with a median temperature of 28.71°C, according to the main Spanish maritime research center.
A record temperature of 38.3°C was even recorded on Monday, July 24 off the coast of Florida. A temperature that corresponds to that of a bath or a jacuzzi, and which could potentially represent an absolute world record in terms of point measurement, if its accuracy is confirmed.
According to a 2019 IPCC report, sea heat waves have been twice as frequent since 1982. And their intensity could be 10 times greater in 2100 than at the beginning of the 20th century if emissions do not drop.
08/04/2023 20:02:49 – Paris (AFP) – © 2023 AFP
