When Hurricane Ida battered Louisiana with catastrophic flooding and powerful winds in August 2021, more than 1 million people lost power. Then came the heat wave. Temperatures rose above 90 degrees Fahrenheit — a sucker punch to those sweltering in their homes, unable to turn on air conditioning as power outages stretched on for days.

It was the heat that proved deadliest in New Orleans, responsible for at least nine of the city’s 14 hurricane-related deaths.

The combination of a hurricane, heat wave and a multi-day power outage is a nightmare scenario, but it’s one set to become more common as humans continue to warm the planet, fueling devastating extreme weather. And it reveals an uncomfortable truth about the vulnerability of humanity’s ultimate protection against heat: Air conditioning.

Air conditioning is far from perfect. It gobbles up energy, most of which still comes from planet-heating fossil fuels, meaning it exacerbates the very problem it’s used to mitigate. Plus, it’s only available to those who can afford it, further widening social inequality.

But it is also a lifeline against increasingly brutal heat, the deadliest type of extreme weather. It allows people to live in places where temperatures push close to the limits of survivability and where extreme heat persists even at night.

Demand for AC is exploding, expected to triple worldwide by 2050, as global temperatures soar and incomes grow.

The problem is, without electricity, access to air conditioning is lost. And many electrical grids are being pushed to a breaking point due to increasingly frequent extreme weather and soaring demand for cooling.

Hippos can get airborne when moving at high speeds over land, according to a new study.

This is the first time that the animals, which can weigh more than 2,000 kilograms (2.2 tons) and spend much of their time in water, have been found to lift all four limbs off the ground when moving quickly, according to a statement from the Royal Veterinary College (RVC) in the UK.

After analyzing videos showing 169 movement cycles from 32 hippos, researchers found that the fastest-moving animals spend around 15% of each stride off the ground.

John Hutchinson, study lead author and a professor of evolutionary biomechanics at the RVC, told CNN that very little was known about the way that hippos move on land.

“Hippos were a big missing part of the puzzle,” he said. “They’re really hard to study.”

Not only do they spend a lot of time in water, they are “very aggressive and dangerous” and are more active at night, said Hutchinson.

In the videos studied by researchers, hippos tended to move fast when something motivated them, such as chasing a rival hippo or being chased by lions or rhinos, he said.

President Joe Biden told Democratic governors during a meeting at the White House on Wednesday that part of his plan going forward is to stop scheduling events after 8 p.m. so that he can get more sleep, according to three sources briefed on his comments.

Three House Democratic lawmakers say they have been besieged with hundreds of texts, phones ringing off the hook and numerous video calls as the party looks to blunt the fallout from President Joe Biden’s disastrous debate performance last week and determine what’s next ahead of November.

The lawmakers, speaking on the condition of anonymity, painted a feverish mood within the House Democratic Caucus as Biden has privately acknowledged that the next stretch of days is crucial to his campaign as he faces a growing number of calls to step aside as the party’s presumptive presidential nominee or risk the party’s chances of keeping the White House and winning back control of the House.

“The phones don’t stop ringing. Everyone is talking,” one House Democrat told CNN’s “The Lead,” pointing to polling that shows the president’s waning popularity and the prevailing fear that Biden remaining at the top of the ticket could negatively affect House races.

Humans aren’t the only ones capable of performing amputations to save lives.

Florida carpenter ants have been observed biting off the injured limbs of nestmates, depending on the location of the wounds, to help their counterparts survive, according to a new study.

About 90% to 95% of the ants receiving amputations make it through the process and continue with their duties within the nest just fine despite losing a leg, researchers found.

The study, published Tuesday in the journal Current Biology, builds on previous findings released in 2023 by the same international team of scientists.

That research found a different ant species called Matabele ants, or Megaponera analis, use their mouths to secrete antimicrobial compounds to cleanse injuries and prevent potential infections. The compounds are produced by what’s known as metapleural glands.

Most ants have these glands. But over time, some species — including Camponotus floridanus, also known as carpenter ants — have evolutionarily lost them.

Vice President Kamala Harris’ camp is digging in and dismissing calls for her to replace President Joe Biden on the ticket amid escalating calls for the president to step aside and new polling showing the vice president outpacing Biden in a hypothetical race against Donald Trump.

The mandate among Harris campaign staff is to remain firm, stay in line and keep the focus on the Biden-Harris ticket, one source told CNN. The vice president’s staff received similar guidance in a virtual staff meeting Monday to follow the vice president’s lead and keep heads down, another source told CNN.

The internal marching orders echo the message Harris is taking on the trail. On Tuesday, Harris again batted down the idea of running in Biden’s place during a brief interview with CBS.

“Look, Joe Biden is our nominee. We beat Trump once and we’re going to beat him again, period,” she said.

“I am proud to be Joe Biden’s running mate,” she later added.

Denisovans survived and thrived on the high-altitude Tibetan plateau for more than 100,000 years, according to a new study that deepens scientific understanding of the enigmatic ancient humans first identified in 2010.

Researchers analyzed thousands of animal bone fragments unearthed at Baishiya Karst Cave, 3,280 meters above sea level near the city of Xiahe in China’s Gansu province — one of only three places the extinct humans were known to have lived. Their work revealed that Denisovans could hunt, butcher and process a range of different large and small animals, including woolly rhinos, blue sheep, wild yaks, marmots and birds.

The team of archaeologists working at the cave also uncovered a rib bone fragment in a layer of sediment that dates back between 48,000 and 32,000 years, making it the youngest of the handful of known Denisovan fossils — a clue that the species was around more recently than scientists previously thought.

Due to a dearth of fossil evidence, details on how these archaic human ancestors lived have been scarce. But the new study reveals Denisovans who lived in Baishiya Karst Cave were incredibly resilient, surviving in one of Earth’s most extreme environments during warmer and colder periods and maximizing the diverse animal resources available in the grassland landscape.

“We know that the Denisovans lived, occupied the cave and this Tibetan plateau for such a long time, we really want to know, how did they live there? How did they adapt to the environment?” said Dongju Zhang, an archaeologist and professor at Lanzhou University in China and co-lead author of the study published Wednesday in the journal Nature.

“They used all these animals available to them, so that means their behavior is flexible,” Zhang added.

The US Food and Drug Administration will no longer allow the use of brominated vegetable oil in food products, the agency said Tuesday.

Brominated vegetable oil (BVO) is vegetable oil modified with the chemical bromine and has been used in small amounts to keep citrus flavoring from floating to the top in beverages, according to an FDA statement.

Dozens of products — mostly sodas — use BVO as an ingredient, according to the Eat Well Guide by the Environmental Working Group, a nonprofit research and advocacy group that focuses on consumer health, toxic chemicals and pollutants.

The rule that no longer allows BVO in food will go into effect August 2, but companies will have one year after that date to reformulate and relabel their products as well as deplete their BVO inventory, according to the FDA statement.

The food additive was removed from the FDA’s list of Generally Recognized As Safe or “GRAS” substance list in 1970 and has been regulated since then, the agency said.

Because of the past restrictions, there are only a small number of products that still contain BVO, the FDA said.

Ramen isn’t the first food to come to mind when you think of sweet treats. Cup Noodles is trying to change that — with a new s’mores-flavored instant ramen.

The limited-edition offering combines microwavable noodles with a sauce-based flavor blend of chocolate, marshmallow and graham crackers, plus additional mini marshmallows to sprinkle on top. The result: a sweet and gooey dessert you can prepare in just five minutes.

While this marks Cup Noodles’ first foray into dessert territory, the noodle maker is no stranger to non-traditional ramen pairings. “Cup Noodles Campfire S’mores” is the latest in a series of seasonal flavors aimed at shaking up how consumers perceive the brand.

Nissin Foods USA Senior VP of Marketing Priscila Stanton pointed to previous limited offerings as Cup Noodles’ efforts to expand beyond a “pantry staple.” That lineup of flavors includes Pumpkin Spice, Everything Bagel and Breakfast (a mixture of the classic breakfast combination of maple syrup pancakes, sausage and eggs).

“Ramen is eaten at all parts of the day during all times,” she said. “We believe that ramen can play in all of these different areas, and sweet is definitely one of those areas that we’ve had some success in.”

On a strip of land in northern Sweden, not far from the Arctic Circle, a new facility is taking shape which could help revolutionize one of the planet’s dirtiest industries: steelmaking.

By 2026, if all goes to plan, the site just outside Boden will be filled with industrial buildings painted white, silver and black – colors to reflect the region’s mountains and lakes – and huge, brick-red towers.

This complex will be world’s first large-scale “green steel” project, according to H2 Green Steel, the Swedish company behind the multi-billion-dollar mill.

Instead of burning coal, it will use “green hydrogen” produced with renewable electricity. The company says its process will cut carbon pollution by 95% compared to traditional steelmaking, and is aiming to produce 5 million metric tons of green steel by 2030.

It will mark another step toward overhauling the steel sector, but the path to cleaning up this polluting industry is a challenging one.

Steel is one of the world’s most commonly used materials, critical for everything from buildings, bridges, cars and fridges to renewable energy infrastructure like wind turbines. The world consumes a huge amount – nearly 2 billion metric tons each year.

The problem is steelmaking is incredibly energy-hungry and remains heavily reliant on coal, the most polluting fossil fuel. The industry accounts for between 7% to 9% of global carbon pollution, and its impact looks set to worsen, with demand projected to jump 30% by 2050.

The industry is under huge pressure to clean itself up. Many hopes are pinned on new technologies, with a particular focus on replacing coal with green hydrogen.

While projects like H2 Green Steel show momentum is growing, experts say the pace is far too slow.

New coal-powered steel plants are still being approved and developed globally, potentially locking in decades more emissions, even as the world scrambles to avoid catastrophic climate change.

“The sector is not on track,” said Mohamed Atouife, a researcher Princeton University who specializes in the use of green hydrogen in heavy industry.

Diego Cardeñosa has loved sharks ever since he was a child. The Colombia native was never afraid of them when he visited his beloved beach. Instead, he was fascinated with how sharks move through water using their multiple fins. It’s no surprise he became a marine biologist.

“As soon as I realized they were going through a conservation crisis, I wanted to help what I love the most,” said Cardeñosa.

Sharks need him more than ever. The International Union for the Conservation of Nature reports 35% of all shark species are threatened with extinction. That number has grown nearly 50% in a decade’s time.

The primary reason is overfishing; shark meat and fins are highly sought.

“They are being killed at a rate that cannot be sustained in the future,” said Cardeñosa.

Scientists worry the sharks’ dwindling numbers could bring ecological collapse as they play a number of key roles in the ocean.

President Joe Biden’s campaign insisted Friday he will not drop out of the 2024 race, but fractures between those in the president’s orbit insisting on trudging forward and the broader Democratic world seeking a last-minute change were growing after Biden’s disastrous debate performance.

Biden acknowledged the weak performance while giving a much more animated speech in North Carolina on Friday, saying, “I know I’m not a young man. I don’t walk as easily as I used to. I don’t talk as smoothly as I used to. I don’t debate as well as I used to, but i know what I do know: I know how to tell the truth. I know right from wrong. And I know how to do this job, I know how to get things done. And I know what millions of Americans know: When you get knocked down, you get back up."

From the West Wing to Wilmington, Biden advisers spent Friday morning calling Democratic members of Congress, donors and other key supporters in hopes of allaying some of the widespread panic about the debate with former President Donald Trump on CNN Thursday night.

Biden’s performance — rife with a raspy voice, an often mouth-agape facial expression and one painful moment in which the president lost his train of thought and suddenly stopped speaking — laid bare the potential political costs of nominating the oldest-ever president for a second term.

Asked whether Biden would exit the race, Biden campaign spokesperson Seth Schuster responded: “No.”