The summer of 2024 will surpass last year’s as the hottest on record

The summer of 2024 will surpass last year’s as the hottest on record

By Saima S. Iqbal

In Japan, more than 70,000 people visited emergency rooms with heatstroke in July and August alone. Iran is experiencing a relentless heat wave. Closed Government buildings, banks and schools were damaged, and US cities such as Phoenix, Arizona and Las Vegas endured weeks of temperatures exceeding 100 degrees Fahrenheit (38 degrees Celsius). These are just some of the indicators that European and US weather agencies are showing as the hottest June through August on record, offering a glimpse into how a warmer world could change.

This summer’s new record average temperature of 62.2 degrees Fahrenheit (16.8 degrees Celsius) is just 0.05 degrees (0.03 degrees Celsius) higher than last summer’s unusually high average. Both are the highest summer averages in almanac records going back to 1850. But ancient tree-ring studies suggest that 2023, and therefore 2024, will be the hottest in the past 2,000 years. And some meteorologists have calculated that the two-year average could be the hottest in 125,000 years of Earth’s history, when hippos swam in the waters around Britain and forests dotted the Arctic. The National Centers for Environmental Information at the National Oceanic and Atmospheric Administration now say there’s a 97% chance that 2024 will surpass 2023 as the hottest year on record.

Scorching hot June and August contributed greatly to this summer’s record heat. Both months broke or matched the 2023 record, with the global average surface temperature at least 2.7 degrees Fahrenheit (1.5 degrees Celsius) above pre-industrial levels. In 2016, under the Paris Agreement, countries agreed to try to limit global warming below this threshold, but the target takes into account multi-year averages rather than single months. If July had been a little warmer, the planet could have had 14 consecutive months with temperatures above the threshold. (July was the hottest month on record.) recordHowever, the global average temperature on July 22 reached 62.89 degrees Fahrenheit (17.16 degrees Celsius), about 3 degrees Fahrenheit (1.7 degrees Celsius) warmer than the pre-industrial average. Fifteen countries, from Mexico to Chad, recorded their hottest temperatures on record this year, and monthly records were broken in 130 countries.

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The accumulation of these records reflects the magnitude of anthropogenic climate change. Global temperature records are concentrated around El Niño events, with the latest one beginning in late 2023 and ending in May 2024. This complex weather pattern causes significant heat to be released from tropical oceans into the atmosphere. But El Niño only changes global temperatures by 0.36 degrees F (0.2 degrees C), and by itself cannot cause the rapid changes the Earth is currently experiencing. “Human greenhouse gas emissions are essentially permanently adding an El Niño equivalent of heat every decade,” says Zeke Hausfather, a climate scientist at the nonprofit Breakthrough Institute. He points out that other unknown factors also seem to be at play, because scientists believe that up to one-third of the global warming observed from 2023 to 2024 cannot be explained by anthropogenic climate change or El Niño.

Earth has endured extreme temperatures in the past, but those extremes have increased gradually. “These are geological trends that usually happen over millions or thousands of years,” says Ángel Fernández Bou, a biological systems engineer at the University of California, Merced. [same] “The increase in temperature will occur over decades.” As a result, scientists worry that the planet will warm too quickly for organisms and their environments to adapt.

For example, modern sewer systems may not be able to withstand increasingly intense rains. As heat waves become more intense and frequent, our bodies will not be able to withstand longer periods of time outdoors, or indoors without air conditioning. Increased wildfires are expected to burn thousands of acres of crops and pastures. And past adaptation strategies are proving to be longer and more costly than expected, Hausfather notes.

Global and national temperature records clearly show the amount of excess heat that greenhouse gases have trapped in the atmosphere, but humans do not live in average temperatures. These measurements can hide wide regional variations and extreme temperatures. A series of summer heat domes in the southwestern United States created one of the hottest places on Earth. As of September 4, Phoenix had reached 100 degrees Fahrenheit for more than 100 consecutive days, far surpassing the city’s previous record of 76 consecutive days set in 1993. July’s heatwaves caused suffering for Olympic athletes in Paris, sparked wildfires in Portugal and Greece, and exacerbated water shortages in Italy and Spain. Even in the Southern Hemisphere, where winter was, sweltering heat continued from June to August. Australia experienced summer-like weather throughout August, with the national average temperature being 5.4 °F (3 °C) higher than normal, with remote areas of Western Australia reaching a record high of 107 °F (41.6 °C). In July, temperatures in the Antarctic winter regions were 50 °F (28 °C) higher than normal.

Texas A&M University climate scientist Andrew Dessler says the planet will continue to break record heat unless humanity stops emitting greenhouse gases. Now that renewable energy is cheaper than fossil fuels, he says the biggest obstacle to meaningful action is political, not technological. That means, Dessler emphasizes, “the solutions are within our grasp.”

Greenhouse gas emissions have stabilized over the past decade, at least preventing further acceleration of warming. But to prevent global temperatures from rising any further, emissions from other sources, such as burning fossil fuels, deforestation and agriculture, must stop. Climate scientists currently predict that the Earth will exceed the 1.5-degree threshold set by the Paris Agreement later this decade or early next.

“But we don’t go from climate stability to crisis as soon as we exceed 1.5 degrees,” Hausfather stressed. “Even a tenth of a degree is a problem. The more we warm, the bigger the impacts will be.”