INFOGRAPHICS. Heat waves, record temperatures, sea heat waves, melting ice… when climate indicators get carried away

The records are linked since the beginning of the year and global warming is becoming more and more noticeable all around the world.

How far will climate indicators continue to climb? Heat waves in the northern hemisphere, world temperature record, overheating of the oceans, record melting of the ice in Antarctica… For several weeks, meteorological measuring instruments have been panicking. So much so that the UN Secretary General, Antonio Guterres, sounded the alarm at the beginning of July. “The current situation is proof that climate change is out of control”alerted the leader of the United Nations.

However, the situation is not surprising, according to THE climatologists. “Everything that is happening at the moment was expected given our greenhouse gas emissions. We are more on a trajectory than on a break”precise Christophe Cassou, one of the main authors of the sixth IPCC report, with franceinfo. The planet is actually witnessing human influence on global warming, which is becoming more and more noticeable. Franceinfo takes stock in four infographics.

The northern hemisphere is burning in heat waves

Throughout the week, heat waves have suffocated several regions of the northern hemisphere: in North America, in eastern Asia and around the Mediterranean. All these heat waves have in common that they constitute extreme phenomena made more frequent and more intense by climate change. The thermometer has climbed very high in Europe, where it was recently demonstrated that the climate is warming twice as fast as for the whole planet, according to a joint report by the World Meteorological Organization and the European observatory Copernicus.

Absolute records have been broken in the south-east of France, mainly at altitude in the Alps, the Pyrenees and in Corsica. In Spain, temperatures reached 45.3°C on Tuesday in Figueras (Catalonia), while a massive fire ravaged nearly 2,900 hectares on the island of La Palma, in the Canary archipelago. Greece was also plagued by flames throughout the week, with numerous fires starting around Athens and on the island of Rhodes. In Italy, the thermometer rose to 44°C on Tuesday in Ragusa (Sicily). The island holds the heat record for Europe, with 48.8°C measured on August 11, 2021.

World temperature records

The heat waves come as the planet’s average temperature hits record highs. In early July, the World Meteorological Organization, attached to the UN, said it had recorded the hottest week ever measured on Earth. Previously, June temperatures had already been record high too. And the month of July is already on the way to becoming the hottest ever measured, according to the European climate change observatory Copernicus (C3S). Data from the United States Oceanic and Atmospheric Observation Agency (NOAA), in the graph below, shows that the average temperature in 2023 stands out very clearly compared to previous years.

If the year 2023 stands out, it is because the warming due to human influence is amplified by the return of El Niño, a warm anomaly in the waters of the Pacific which occurs on average every two to seven years. It most often results in a rise in global temperatures. “We also tend to see a ‘staircase’ type effect when El Niño occurs. Global warming then increases suddenly without returning to the previous level. This is what happened for the last two big El Niños. This can also explain the runaway effect we are currently feeling”specifies Christophe Cassou.

Oceans in the grip of extreme heat

Less visible than the temperature of the atmosphere, but no less worrying, the ocean has also been in a state of suffocation since mid-March. The northern part of the Atlantic Ocean, off the coast of Ireland, is the most affected area with a sea surface temperature measured at 24.5°C on Monday July 17, or 1.41°C above the historical average for this period, according to NOAA data.

The warming of the oceans is an essential indicator for measuring climate change, given their vast extent and their ability to absorb and transport heat. This unprecedented rise in temperatures worries researchers who compare it to an “underwater fire” because of its devastating effects on marine fauna and flora, which in places reach their physiological limits. “We reach adaptability thresholds, i.e. the temperature and drought levels beyond which living systems are no longer able to adapt and disappear”explains Christophe Cassou.

The historic melting of Antarctic sea ice

The poles are not spared. In Antarctica, the sea ice experienced a historic melt in February. There ice then reached its lowest extent for 45 years, according to the European observatory Copernicus. Since then, the sea ice has been struggling to recover despite the arrival of winter in the southern hemisphere. At the end of June, the Copernicus teams calculated that some 2.5 million km² of sea ice was missing, the equivalent of five times the size of mainland France.

The World Meteorological Organization has warned of “the unprecedented rhythm” the melting of the Antarctic sea ice as well as the consequences of this phenomenon “not only for the poles of the Earth (…) but also for global weather and climate”. The ice cap, a thick freshwater glacier that covers Antarctica, contains enough water to cause a catastrophic rise in sea levels if it were to melt. Moreover, the white pack ice reflects the sun’s rays more than the ocean, and its loss accentuates global warming. “We are in something never seen” oceanographer and climatologist Jean-Baptiste Sallée told AFP on July 10. “With an ice floe that is not growing at the natural rate. The question is: have we entered a new regime? But it is still too early to answer that.”

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