Consider your morning cup of coffee. Your kettle’s heating element — or flame on a stove — warms up water that you infuse with beans and pour into a mug. Maybe you get busy and the cup of joe sits there for a while, releasing its heat into the atmosphere of the room, until it reaches equilibrium with the indoor temperature. In other words: It got cold.

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Now consider that the expansive Southern Ocean, which wraps around Antarctica, could one day do much the same thing. Since the Industrial Revolution kicked off, humans have dialed up the kettle to its max, adding extraordinary amounts of heat into the atmosphere, more than 90 percent of which has been absorbed by the sea. (It’s also taken up a quarter of our CO2 emissions.) Under climate change, the Southern Ocean has been storing warmth which, like your morning jolt, can’t stay there forever, and will someday return to the atmosphere.

New modeling suggests that this “burp” of heat — the scientists called it that, by the way — could be abrupt. In a scenario where humanity eventually reduces its greenhouse gas emissions and then goes “net negative,” finding ways to remove those planet-warming pollutants from the atmosphere, global temperatures fall. But suddenly the Southern Ocean belches its accumulated heat, leading to a rate of planetary warming similar to what humanity is causing right now. And the thermal burping would continue for at least a century.

Put another way: According to this modeling, at least, humans figure out a way to reverse climate change, only to see the Southern Ocean essentially restart it. While there would be nothing our descendants could do to stop this — since the warming would be driven by already stored heat — the calculations are yet another urgent call to reduce that pollution as quickly and dramatically as possible.

This sudden eructation is not a sure thing, however — it’s the prediction of a model. But it’s a step toward understanding how the planet could respond as humans continue to manipulate the climate, both warming and cooling it. “The question is: How will the climate system, and specifically the ocean, react to scenarios where we remove CO2 from the atmosphere, and when we have a net global cooling effect?” said Svenja Frey, an oceanography PhD student at Germany’s GEOMAR Helmholtz Centre for Ocean Research Kiel and coauthor of the paper.

The Southern Ocean may encircle the frozen continent of Antarctica, but it’s very effective at storing heat: It alone holds around 80 percent of the warmth that’s taken up by all the oceans. Some of this comes from currents that transport relatively toasty waters south, but also lots of upwelling in the Southern Ocean brings cold water to the surface to be warmed up.

The skies above the Southern Ocean are also somewhat less reflective than elsewhere around the globe. Cargo ships and industries in the Northern Hemisphere spew air pollution in the form of aerosols, which themselves bounce solar energy back into the cosmos and help brighten clouds, which reflect still more. That cooling phenomenon has vied, in a sense, with the warming that’s come from the burning of fossil fuels. “That competition hasn’t been as prevalent over the Southern Hemisphere, because it’s this slightly more pristine atmosphere,” said Ric Williams, an ocean and climate scientist at the University of Liverpool, who studies the Southern Ocean but wasn’t involved in the paper.

In the scenario the researchers modeled, the atmospheric concentration of CO2 increases by 1 percent every year until the total amount is double what the planet had before the Industrial Revolution. Then negative emissions technologies reduce the carbon concentration by 0.1 percent annually. (The study didn’t look a specific techniques, but one option is direct air capture of CO2, though this remains expensive and limited in scale.) In response, the atmosphere, land, and oceans cool.

But something starts brewing in the Southern Ocean. Its surface becomes colder, but also saltier due to the formation of new sea ice: When sea water freezes, it rejects its salt, which is then absorbed into the surrounding waters and makes the surface layer heavier. “At the same time, we have these warm, deeper waters,” Frey said. “At some point, the water column becomes unstable, and that’s when we have the deep convection event.”

In other words, a burp. It’s just one way that our planet’s extraordinarily complex and intertwining systems might respond to rising and falling emissions in the centuries ahead. “There’s very large uncertainty in the Earth system response to net-negative emissions — we don’t understand that very well,” said Simon Fraser University climate scientist Kirsten Zickfeld, who studies these dynamics but wasn’t involved in the new paper. “We may well encounter surprises along the way, as this paper shows.”

To be clear, in this scenario, removing atmospheric carbon significantly reduces global temperatures, even factoring in the burp. And the faster we move away from fossil fuels, the less CO2 we’ll have to remove down the line. “Doing negative emissions and reducing our carbon load in the atmosphere is a good thing,” Williams said. “I would just add that, rather than do negative emissions, it’s better not to do the positive emissions in the first place.”

This article originally appeared in Grist at https://grist.org/oceans/hey-so-one-day-the-ocean-might-burp-up-a-bunch-of-heat/.

Grist is a nonprofit, independent media organization dedicated to telling stories of climate solutions and a just future. Learn more at Grist.org

History is unfolding in the Atlantic Ocean right now. Hurricane Melissa has spun up into an extraordinarily dangerous Category 5 storm with maximum sustained winds of 175 mph, and is set to strike Jamaica Monday night before marching toward Cuba. This is only the second time in recorded history that an Atlantic hurricane season has spawned three hurricanes in that category. Melissa has already killed at least three people in Haiti and another in the Dominican Republic.

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The threats to Jamaica will come from all sides. The island could see up to 30 inches of rain as the storm squeezes moisture from the sky, like a massive atmospheric sponge, potentially causing “catastrophic flash flooding and numerous landslides,” according to the National Hurricane Center. Melissa also will bulldoze ashore a storm surge of up to 13 feet — essentially a wall of water that will further inundate coastal areas. “No one living there has ever experienced anything like what is about to happen,” writes Brian McNoldy, a hurricane scientist at the University of Miami.

It will take some time for scientists to determine exactly how much climate change supercharged Melissa, but they can already say that the storm has been feeding on warm ocean temperatures made up to 800 times more likely by global heating. This is how climate change is worsening these tropical cyclones overall: The hotter the ocean gets — the seas have absorbed 90 percent of the extra heat that humans have pumped into the atmosphere — the more energy that can transfer into a storm. “The role climate change has played in making Hurricane Melissa incredibly dangerous is undeniable,” Marc Alessi, a climate attribution science fellow at the Union of Concerned Scientists, said in a statement.

Scientists can already estimate that climate change has increased Melissa’s wind speeds by 10 mph, in turn increasing its potential damage by 50 percent. “We’re living in a world right now where human-caused climate change has changed the environment in which these hurricanes are growing up and intensifying,” said Daniel Gilford, a climate scientist at the research group Climate Central. “Increasing temperatures of the atmosphere is increasing how much moisture is in the atmosphere, which will allow Melissa to rain more effectively and efficiently over the Caribbean, and could cause more flooding than otherwise would have occurred.”

Making Melissa extra dangerous is the fact that it’s undergone rapid intensification, defined as a jump in sustained wind speeds of at least 35 mph in a day, having doubled its speed from 70 to 140 mph in less than 24 hours. This makes a hurricane all the more deadly not only because stronger winds cause more damage, but because it can complicate disaster preparations — officials might be preparing for a weaker storm, only to suddenly face one far worse. Research has shown a huge increase in the number of rapid intensification events close to shore, thanks to those rising ocean temperatures, with Atlantic hurricanes specifically being twice as likely now to rapidly intensify.

At the same time, hurricanes are able to produce more rainfall as the planet warms. For one, the atmosphere can hold 7 percent more moisture per degree Celsius of warming. And secondly, the faster the wind speeds, the more water a hurricane can wring out, like spinning a wet mop. Accordingly, hurricanes can now produce 50 percent more precipitation because of climate change. “A more intense hurricane has stronger updrafts and downdrafts, and the amount of efficiency by which the storm can rain basically scales with how intense the storm is,” Gilford said. Making matters worse, Melissa is a rather slow-moving storm, so it will linger over Jamaica, inundating the island and buffeting it with winds.

As Melissa drops rain from above, its winds will shove still more water ashore as a storm surge. The coastlines of the Caribbean have already seen significant sea level rise, which means levels are already higher than before. (Warmer oceans have an additional effect here, as hotter water takes up more space, a phenomenon known as thermal expansion.) All of this means the baseline water levels are already higher, which the storm surge will pile on top of. “Just small, incremental, marginal changes in sea level can really drive intense changes,” Gilford said.

Jamaica has an added challenge in its mountainous terrain. Whereas water will accumulate on flat terrain, it behaves much more unpredictably when it’s rushing downhill because it easily gains momentum. “When you get a storm like this that is approaching the higher echelons of what we have observed, it’s harrowing, especially because it is pointing at a populated island with complex terrain,” said Kim Wood, an atmospheric scientist at the University of Arizona. “You’re dealing with a funneling effect, where that water, as it falls, will then join other water that’s coming down the mountainside and exacerbate the impacts.”

Maybe the only good news here is that the National Hurricane Center was able to accurately predict that Melissa would rapidly intensify. And in general, scientists have gotten ever better at determining how climate change is supercharging hurricanes, so they can provide ever more accurate warnings to places like Jamaica. But that requires continuous governmental support for this kind of work, while the Trump administration has slashed scientific budgets and jobs. “We couldn’t do this without continued investment in the enterprise that supports advances in not just science, but forecasting and communicating the outcomes of those forecasts,” Wood said.

This article originally appeared in Grist at https://grist.org/extreme-weather/how-hurricane-melissa-got-so-dangerous-so-fast/.

Grist is a nonprofit, independent media organization dedicated to telling stories of climate solutions and a just future. Learn more at Grist.org

In December 2022, Matthew Boyer hopped on an Argentine military plane to one of the more remote habitations on Earth: Marambio Station at the tip of the Antarctic Peninsula, where the icy continent stretches toward South America. Months before that, Boyer had to ship expensive, delicate instruments that might get busted by the time he landed.

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“When you arrive, you have boxes that have been sometimes sitting outside in Antarctica for a month or two in a cold warehouse,” said Boyer, a Ph.D. student in atmospheric science at the University of Helsinki. “And we’re talking about sensitive instrumentation.”

But the effort paid off, because Boyer and his colleagues found something peculiar about penguin guano. In a paper published on Thursday in the journal Communications Earth and Environment, they describe how ammonia wafting off the droppings of 60,000 birds contributed to the formation of clouds that might be insulating Antarctica, helping cool down an otherwise rapidly warming continent. Some penguin populations, however, are under serious threat because of climate change. Losing them and their guano could mean fewer clouds and more heating in an already fragile ecosystem, one so full of ice that it will significantly raise sea levels worldwide as it melts.

A better understanding of this dynamic could help scientists hone their models of how Antarctica will transform as the world warms. They can now investigate, for instance, if some penguin species produce more ammonia and, therefore, more of a cooling effect. “That’s the impact of this paper,” said Tamara Russell, a marine ornithologist at Scripps Institution of Oceanography, who studies penguins but wasn’t involved in the research. “That will inform the models better, because we know that some species are decreasing, some are increasing, and that’s going to change a lot down there in many different ways.”

With their expensive instruments, Boyer and his research team measured atmospheric ammonia between January and March 2023, summertime in the southern hemisphere. They found that when the wind was blowing from an Adelie penguin colony 5 miles away from the detectors, concentrations of the gas shot up to 1,000 times higher than the baseline. Even when the penguins had moved out of the colony after breeding, ammonia concentrations remained elevated for at least a month, as the guano continued emitting the gas. That atmospheric ammonia could have been helping cool the area.

The researchers further demonstrated that the ammonia kicks off an atmospheric chain reaction. Out at sea, tiny plantlike organisms known as phytoplankton release the gas dimethyl sulfide, which transforms into sulphuric acid in the atmosphere. Because ammonia is a base, it reacts readily with this acid.

This coupling results in the rapid formation of aerosol particles. Clouds form when water vapor gloms onto any number of different aerosols, like soot and pollen, floating around in the atmosphere. In populated places, these particles are more abundant, because industries and vehicles emit so many of them as pollutants. Trees and other vegetation spew aerosols, too. But because Antarctica lacks trees and doesn’t have much vegetation at all, the aerosols from penguin guano and phytoplankton can make quite an impact.

In February 2023, Boyer and the other researchers measured a particularly strong burst of particles associated with guano, sampled a resulting fog a few hours later, and found particles created by the interaction of ammonia from the guano and sulphuric acid from the plankton. “There is a deep connection between these ecosystem processes, between penguins and phytoplankton at the ocean surface,” Boyer said. “Their gas is all interacting to form these particles and clouds.”

But here’s where the climate impacts get a bit trickier. Scientists know that in general, clouds cool Earth’s climate by reflecting some of the sun’s energy back into space. Although Boyer and his team hypothesize that clouds enhanced with penguin ammonia are probably helping cool this part of Antarctica, they note that they didn’t quantify that climate effect, which would require further research.

That’s a critical bit of information because of the potential for the warming climate to create a feedback loop. As oceans heat up, penguins are losing access to some of their prey, and colonies are shrinking or disappearing as a result. Fewer penguins producing guano means less ammonia and fewer clouds, which means more warming and more disruptions to the animals, and on and on in a self-reinforcing cycle.

“If this paper is correct — and it really seems to be a nice piece of work to me — [there’s going to be] a feedback effect, where it’s going to accelerate the changes that are already pushing change in the penguins,” said Peter Roopnarine, curator of geology at the California Academy of Sciences.

Scientists might now look elsewhere, Roopnarine adds, to find other bird colonies that could also be providing cloud cover. Protecting those species from pollution and hunting would be a natural way to engineer Earth systems to offset some planetary warming. “We think it’s for the sake of the birds,” Roopnarine said. “Well, obviously it goes well beyond that.”

This article originally appeared in Grist at https://grist.org/science/research-penguin-poop-cooling-antarctica/.

Grist is a nonprofit, independent media organization dedicated to telling stories of climate solutions and a just future. Learn more at Grist.org

With less than a month to go until summer, weather forecasters have been dropping some troubling news about what might be in store. AccuWeather had already predicted an especially active season — which begins June 1 — with up to 10 hurricanes out at sea, and its meteorologists are now forecasting a hotter-than-normal summer on land. Last week, the company warned that the three months could bring “sweltering heat, severe weather, intense wildfires, and the start of a dynamic hurricane season” — an echo of last summer, which was the hottest on record. In some places, like coastal cities along the Gulf Coast, those hazards could combine into dangerous “compound disasters,” with heat waves and hurricanes arriving back-to-back.

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The Trump administration’s cost-cutting crusade could make this summer’s weather all the more perilous. Mass layoffs at the National Oceanic and Atmospheric Administration have hurricane forecasters worried that they’ll lose access to the data they need to make accurate predictions of where storms will make landfall and at what intensity. And as electricity gets more expensive and global warming forces households to run their air-conditioning more, advocates worry that the loss of federal support for people struggling to pay their electric bills could leave a swath of the population especially vulnerable.

President Donald Trump’s proposed 2026 budget, unveiled last week, would cancel the Low Income Home Energy Assistance Program, which provides $4 billion a year to help people pay electricity bills, said Alison Coffey, senior policy analyst at the Boston-based nonprofit Initiative for Energy Justice. “We are about to experience one of the hottest summers on record,” Coffey said. “And this is happening at a time when U.S. households are really, really struggling to pay their utility bills.”

AccuWeather’s summer forecast isn’t the kind you get for your local weather, so they can’t tell you if it will be raining in your town on the Fourth of July. Instead, this seasonal forecast looks at weather trends in March and April, as well as larger phenomena like La Niña and El Niño, the two bands of warm and cold water in the Pacific Ocean that influence the atmosphere above the western U.S. AccuWeather compares all that to how those spring and summer months looked in previous years to get an idea of what might unfold this time around.

AccuWeather says that temperatures could run higher than average across the vast majority of the country this summer. Its forecast also warns of warmer nights, especially in the eastern U.S. These make heat waves all the more unbearable as the human body can’t get the respite of a cool night to bring down the physiological stress.

The eastern U.S. could also suffer through heat waves punctuated by thunderstorms that load the atmosphere with humidity. Those conditions make the human body less efficient at sweating, raising the risk of heat-related illnesses and deaths. Heat kills more people in the U.S. than any other natural disaster, in part because it can aggravate existing conditions like heart disease and asthma.

Out West, the Dakotas, Montana, Idaho, Washington, and Oregon could see temperatures 3 degrees Fahrenheit (or more) higher than average. “The daytime highs are a bigger issue, [records] that could be challenged or broken in parts of the Northern Rockies and in the Northwest coming up this summer,” said Paul Pastelok, a senior meteorologist at AccuWeather.

High temperatures are going to increase wildfire risk, Pastelok added, because a dry, heat-baked landscape is a flammable landscape. Right now almost 40 percent of the U.S. is under drought conditions, double the area of last year. Some parts of the American West actually had a fairly wet winter, but that can also cause problems because strong-growing plants and trees can turn into fuel in the extra-hot summer heat. And as the season wears on, the landscape gets drier, so it’s more liable to burn catastrophically.

Day after day of relentless heat, especially if it’s humid out too, forces people to run the AC more to stay healthy. For the rich, that’s no problem. But lower-income folks suffer a high “energy burden,” meaning a $200 monthly utility bill is a much larger proportion of their income. Americans are also wrestling with an escalating cost-of-living crisis as rent and inflation march higher. With 1 in 6 American households now behind on their utility bills, according to the Initiative for Energy Justice, and 3 million of them having their power shut off each year, the danger is losing power during a heat wave this summer.

City dwellers face added risk here because of the urban heat island effect, the way sidewalks, parking lots, and buildings trap heat and make cities much hotter than surrounding rural areas. Lower-income neighborhoods get 15 to 20 degrees hotter than richer neighborhoods because they have fewer trees, which provide shade and cooling, according to Vivek Shandas, a climate adaptation scientist at Portland State University. “Those neighborhoods and the residents living in them just bear the brunt of that heat wave a lot more acutely than someone living in a more highly invested neighborhood, where tree canopy is lush.”

It will take a whole lot longer to fix the systemic issues that drive heat disparities in cities. But in the meantime, access to air-conditioning will be increasingly crucial as the planet warms. “Having financial assistance for low-income households to make sure that they can keep their electricity and their cooling on during the sweltering summer is more crucial than ever,” Coffey said.

This article originally appeared in Grist at https://grist.org/extreme-heat/summer-record-breaking-heat-hurricanes-liheap/.

Grist is a nonprofit, independent media organization dedicated to telling stories of climate solutions and a just future. Learn more at Grist.org