Climate

Heat-related deaths in the United States are on the rise. But how bad will it be 20, 30 or 40 years from now? Scientists now have a clue.

Currently, an estimated 8,000-plus deaths in the United States every year are associated with extreme temperatures, both hot and cold. Within the next few decades, that number could double or even triple, largely due to heat, researchers report September 20 in JAMA Network Open.

“As the climate warms, the frequency, duration and intensity of heat waves is increasing. Understanding how this will impact our health is crucial,” Sameed Khatana, a cardiologist at the University of Pennsylvania, says. Our bodies are capable of bearing sweltering temperatures, but as temperatures rise, this ability is pushed to its limit (SN: 6/21/24). More

Over the last 485 million years, Earth has been both a lot colder and a lot hotter than once thought.

A new temperature timeline that combines geologic data with computational simulations reveals a rich, detailed and dramatic picture of the ebb and flow of icehouse and greenhouse conditions on Earth throughout this span of time, which includes most of the Phanerozoic Eon. The timeline shows Earth’s average temperature dropping to as low as 11° Celsius and rising to as high as 36° C, researchers report in the Sept. 20 Science. More

Transcript

James McCall: Solar production in the US really started to pick up around 2012. As solar really became mainstream, there was a lot more concerns of land use changes.

Ravi Sujith: If you look at the type of land that’s been converted for solar installations, over 60 percent of those landscapes are converted croplands.

Chong Seok-Choi: They both require flat areas with a lot of sun, and that’s close to transmission infrastructures. So in this context, it is important for us to figure out how to combine farming and solar power production so that both can exist in harmony. More

It’s winter in the Southern Hemisphere — but you wouldn’t know it from the thermostat.

On August 26, a remote stretch of the coastline in Western Australia experienced the highest winter temperature ever recorded anywhere in the country: a blistering 41.6° Celsius (107° Fahrenheit).

In Bidyadanga, an Aboriginal community in Western Australia, the overnight low temperature on August 28 was a staggering 27.2° C (81° F). That’s in winter, when the long-term average nighttime temperature has been around 15° C (59° F). Such heightened nighttime temperatures can disrupt sleep, leading to decreased cardiovascular and mental health (SN: 8/6/23). More

In its latest global climate report, the National Oceanic and Atmospheric Administration confirmed that July was the 14th straight month of record-breaking heat. That, in and of itself, is a new record.

In the last 175 years, there has been only one other hot streak that comes close in terms of longevity. According to NOAA, the second longest hot streak on record spanned the 12 months from May 2015 to May 2016 (SN: 1/20/16; SN: 1/14/21). Then things drop off: The third and fourth longest recorded streaks were six months each, and subsequent stints are shorter still.

Many of these streaks occurred during an El Niño, a natural phenomenon in which warm surface waters spread across the tropical Pacific Ocean, temporarily elevating the global average temperature (SN: 8/21/19). Its cyclical counterpart, La Niña, involves those warm surface waters receding to the western side of the Pacific, causing a transient global cooling effect. More

An extraordinary heat wave last week toppled thousands of temperature records across Asia, from Iran to Japan. In Iran’s highlands, the city of Isfahan, at the foothills of the Zagros Mountains, sweltered in temperatures up to 43.8° Celsius (110.8° Fahrenheit). Japan, which saw at least 120 deaths due to heatstroke in July, issued more heat stroke warnings August 9, as temperatures climbed to 39° C (102.2° F).

As what’s “normal” for temperatures continues to tick upward, it’s important to note that we can’t just adapt our way out of climate change, scientists have warned (SN: 2/28/22). A concerted, global effort to curb carbon emissions is what’s needed to stave off more disastrous climate consequences, researchers say. More

Australia’s Great Barrier Reef faces critical danger from back-to-back bouts of extreme ocean heat.

Ocean heat in the Coral Sea is at its highest in four centuries, scientists report in the Aug. 8 Nature. The researchers drilled into coral skeletons from in and around the region and analyzed the chemical makeup of those samples to reconstruct sea surface temperatures from 1618 to 1995, alongside modern instrumental sea surface measurements spanning 1900 to 2024.   

Before 1900, ocean temperatures in the region were relatively stable. But from 1960 to 2024, those temperatures have climbed relentlessly. That upward climb is linked to humans’ greenhouse gas emissions, the team found.

Five of the six hottest years in the record were in the last decade: 2016, 2017, 2020, 2022 and 2024, with temperatures as much as 1 degree Celsius hotter than average. Each year had a mass bleaching event during the warmest months, from January to March (SN: 4/29/24).

Scientists drilled into corals in the Great Barrier Reef (shown) to collect core samples. The chemical makeup of the corals reveals changing water conditions, including temperature, over the corals’ lifetime.Tane Sinclair-Taylor

Researchers have long sounded the alarm about mass bleaching, in which corals stressed by extreme heat or pollution expel symbiotic algae living in their tissues, leaving them stark white (SN: 8/9/23). Corals can bounce back, given time. But back-to-back bleaching can ultimately kill a reef.

“The Great Barrier Reef is iconic,” climate scientist Benjamin Henley of the University of Melbourne in Australia said at an Aug. 6 news conference. UNESCO designated the reef as a World Heritage Site in 1981. More

Il fait trop chaud. The Paris Olympics officially opened on July 26, just in time for athletes to compete in a hellish heat wave.

Last week, Olympians in the French capital faced daytime temperatures reaching 35° Celsius (95° Fahrenheit), and in southern France temperatures climbed up to 40° C (104° F). Other countries in the Mediterranean region also felt the heat wave. In Spain, the city of Barcelona recorded its highest-ever temperature — 40° C — on July 31. And in Italy, the sweltering weather helped fuel a wildfire in the Monte Mario natural reserve in Rome. 

This extreme heat would not have happened without climate change, researchers from the World Weather Attribution Network reported on July 31.  “If the atmosphere wasn’t overloaded with emissions from burning fossil fuel, Paris would have been about 3 [degrees] C cooler and much safer for sport,” said climatologist Friederike Otto of the Imperial College London in a statement. 

“Yesterday, climate change crashed the Olympics.“The world watched athletes swelter in 35°C heat. If the atmosphere wasn’t overloaded with emissions from burning fossil fuel, Paris would have been about 3°C cooler and much safer for sport” – @FrediOtto— World Weather Attribution (@WWAttribution) July 31, 2024

Other parts of the world sweltered, too. In California, Death Valley set the record for the hottest month ever recorded on Earth, averaging 42.5° C (108.5° F) across July. A major heat dome also settled in over the southern United States (SN: 6/21/24). The extreme heat swept across much of the country by the end of the week, with the National Weather Service placing more than 150 million people under extreme heat advisories on August 1. Antarctica’s eastern region also experienced a major heat wave, with ground temperatures rising beyond 28° C. More