Sunday was an unprecedented day, and not just because of President Joe Biden dropped out of the presidential race so close to the election. July 21 was the hottest day on record, according to the Copernicus Climate Change Servicewith a global average temperature of 62.76 degrees Fahrenheit, slightly surpassing the previous record set on July 6 of last year.
For 13 straight months now, the planet achieved record temperatures, from hottest year (2023) to hottest month (last July). And what was a daily temperature record eight years ago has now become alarmingly commonplace. “What is truly staggering is how big the difference is between the temperature of the last 13 months and the previous temperature records,” Carlo Buontempo, director of the European Union’s Copernicus service, said in a statement. “We are now in truly uncharted territory and as the climate continues to warm, we will surely see new records being broken in the months and years to come.”
The area may be unknown, but the causes of this heat are very clear. For one, there is the steady rise in global temperatures due to carbon emissions. Since 1850 the earth’s temperature has increased by 0.11 degrees F per decade average, but that rate of warming since 1982 has jumped to 0.36 degrees per decade. Last year was already by far the hottest year on record, while 10 of the hottest years have all occurred in the past decade. Copernicus also notes that the daily global average temperature record prior to July 2023 was 62.24 degrees F, on August 13, 2016. But since July 3, 2023, 57 days have exceeded that mark. Uncharted territory, indeed.
The world may also feel the lingering effects of El Niño this summer. It’s the band of warm Pacific water off the coast of South America, sending additional heat into the atmosphere that raises temperatures and affects weather patterns. The most recent El Niño peaked around the New Year, then faded through this spring. “The atmosphere knows no boundaries,” said Shang-Ping Xie, a climate scientist at the Scripps Institution of Oceanography in San Diego. “We are still under the influence of El Niño. Not to mention that North Atlantic warming is one of the reasons this Atlantic hurricane season is expected to be very active.”
So while July 21st may be sobbing for land crabs, the parts of the Atlantic Ocean where hurricanes form are also extremely warm. Those warm waters is what fuels cyclones like Hurricane Beryl earlier this month, which struck and left Texas hunger in its wake. Scientists have predicted five major hurricanes and 21 named storms this season, thanks in part to those high ocean temperatures.
There may also be some natural variability thrown into the mix this summer: Some years are just warmer than others, even in the absence of human-caused warming. And this time of year is when global average temperatures naturally peak as Northern Hemisphere summer begins to mature. (More land masses in the North absorb and radiate the sun’s energy, versus all that sea area in the South that helps cool things down.
“It just so happened that we had a peak on top of what is typically the warmest climatological week of the entire year,” said Zeke Hausfather, a research scientist at Berkeley Earth, which does its own climate analyses. “This is the hottest day on record, but July is also now – at least in my analysis – almost certain not be the hottest July on record.” That is, the 13-month streak of records may well come to an end. Last July was so hot that it set a very high bar for future Julys to beat.
At the same time, according to Hausfather’s calculations, there is a 95 percent chance that 2024 will surpass 2023 as the hottest year on record. “It was just so warm in the first six months of the year that even if we don’t set new records for the second six months, we’re still very likely going to finish above 2023,” Hausfather said. “We’ve just built up so much of a lead already.”
Back in the Pacific, however, relief may be on the way: With El Niño gone, its cold-water counterpart, La Niña, may take shape in the coming months. This could help reduce global temperatures in 2025, and perhaps even beyond. “The last La Niña was a three-year event,” Xie said. “It is obviously very rare, but has extraordinary effects on the climate.”
Regardless of El Niño and La Niña, however, the past year has been unusually warm—an ominous sign that the planet has entered not just uncharted territory, but an increasingly dangerous one.
