The first three weeks of July have been the warmest three-week period on record so far, according to the Copernicus Climate Change Service. And the month we are in is on track to be the hottest July ever (and the hottest month on record now in absolute terms). Since May, the global mean sea surface temperature has been well above previously observed values for the time of year, contributing to this period as well. The record-breaking succession has scientists thinking the planet is heading into "uncharted territory."
“We don't have to wait until the end of the month to know this. Unless there is a mini-Ice Age in the coming days, July 2023 will break records across the board," said United Nations Secretary-General António Guterres.
The extreme temperatures recorded in the northern hemisphere have been the fuel for heat waves, experienced in much of North America, Asia and Europe, and forest fires in countries such as Canada, Greece as well as in other areas of the Mediterranean. All this is having an impact on people's health, the environment and economies. Climate change and some effects of El Niño (cyclical warming phenomenon driven in the Equatorial Pacific with an impact on the entire planet) are largely responsible.
“For vast parts of North America, Asia, Africa and Europe, it is a cruel summer. For the entire planet, it's a disaster. And for scientists, it is unequivocal: humans are to blame. All this is fully consistent with predictions and repeated warnings. The only surprise is the speed of change,” Guterres said.
"The temperature records are part of the trend for dramatic increases in global temperatures. Human-caused emissions are ultimately the main driver of these rising temperatures," says Carlo Buontempo, director of the Service. of Copernicus Climate Change.
“The extreme weather that affected many millions of people in July is unfortunately the harsh reality of climate change and a foretaste of the future,” said Petteri Taalas, Secretary General of the World Meteorological Organization. For him too "the need to reduce greenhouse gas emissions is more urgent than ever", since "climate action is not a luxury but an obligation".
Here are eight new extreme weather tests.
On July 6, the average daily air temperature at the planet's surface exceeded the record set so far, which dates back to August 2016. It thus became the hottest day ever recorded, followed by two dates of the same streak, on July 5 and 7.
Specifically, according to the data set managed by Copernicus, the global average surface air temperature reached its highest daily value on July 6 (17.08 °C). As shown in the graph, every day since July 3 has been hotter than the previous record of 16.80°C on August 13, 2016.
The Copernicus Climate Change Service considers that "it is very likely that July 2023 will be the hottest July" of those recorded so far and that it is also "the hottest month on record". All this occurs after last June had also been considered the hottest June.
Specifically, the global average surface air temperature averaged over the first 23 days of July 2023 was 16.95 °C. This figure is well above the 16.63°C recorded for the entire month of July 2019, ranked so far as the warmest July and the warmest month ever recorded. “It is virtually certain that the full monthly average temperature for July 2023 will exceed that of July 2019 by a significant margin,” says the Copernicus report. This will make July 2023 the warmest July and the warmest month on record.
The first three 3 weeks of July (July 3-23) have been the hottest 3 weeks on record. If you compare the average temperature of the first 23 days of July 2023 with the same average for all Julys since 1940, July 2023 clearly stands out as the warmest month on record.
During the first and third weeks of July, the global average temperature temporarily exceeded the threshold of 1.5°C above the pre-industrial level (according to a Copernicus estimate.
Specifically, this threshold was exceeded between July 3 and 12 and then again from July 17 to 22, although it had already been exceeded on previous occasions in other months (especially during the winter of 2015-2016 and the spring of 2016). ), this is the first time the threshold was exceeded in July. It is also the first time that it was exceeded in early June 2023 (the daily global temperature).
This does not necessarily mean, far from it, that the level of 1.5 °C specified in the Paris Agreement will be permanently exceeded as a goal to stop the increase in temperatures, since this agreement refers to long-term warming over many years.
Average daily sea surface temperatures over oceans outside the polar zones (60°S–60°N) have been at record values for the time of year since April 2023. In particular, since mid-May , these temperatures have risen to unprecedented levels for the time of year. According to these data, on July 19, the daily value reached 20.94 °C, only 0.01 °C below the highest value recorded on March 29, 2016 (20.95 °C), according to the service. of Climate Change of the UN.
However, the heat in the North Atlantic is alerting scientists in a particular way. “We have never had a marine heat wave in this part of the Atlantic. I didn't expect this,” Daniela Schmidt, professor of Earth sciences at the University of Bristol, UK, said last week.
In June, temperatures off the coast of Ireland were 4-5C above average, which the National Oceanic and Atmospheric Administration classified as a category 5 marine heatwave, or "beyond extreme".
National meteorological and hydrological services have reported record temperature records to WMO and now it will be time to verify any new national temperature records. Thus, China set a new national temperature record of 52.2°C on July 16 (Turpan city, Xinjiang province of China), according to the China Meteorological Administration. WMO's interim State of the Global Climate 2023 report, to be presented at COP28 in December, will incorporate details of the new national temperature records.
In contrast, the temperature record for continental Europe of 48.8°C, measured in Sicily on August 11, 2021, was not broken during the July heat waves, according to provisional information.
As the air and surface layers of the sea experience above-average temperatures, new records are being set for Antarctic sea ice extent. The loss of sea ice seems to mark a new trend; and a new record has been set several times in recent years.
Satellite data from the National Snow and Ice Data Center at the University of Colorado at Boulder, USA, show that not only is 2023 a significant outlier, but that 2022 ended some of the world's largest sea ice extents. registered casualties. But the gap from the long-term average for this time of year appears to be widening.
The area covered by sea ice in Antarctica is at record lows in July. It would have to cover an area around 10 times the size of the UK, compared to the 1981-2010 average.
"As a backdrop we have, of course, climate change" but, in addition to seasonality, other factors are present, such as El Niño or the effects of aerosols, Kim Reid of Monash University tells the BBC. These tiny particles like sulfur dust, sea salt, can reflect incoming solar radiation. "And all of this can control the temperature of the planet," says Reid.
