And we’re now reaching, I think, the point where that physical system is running out of margin.
Take a look at this graph. It shows the temperature of the global sea surface, averaged on a daily basis. Since our planet is 70% ocean, it’s a pretty good gauge of how hot the planet is getting. And what it shows is that in all the decades we’ve been measuring, it’s never been hotter. Given what we know about climate history, it’s almost certainly never been hotter in the history of our species. (Handily, by the way, that 21.1°C line is just about exactly 70°F.) As a Canadian professor wrote, “August 21st likely marked the warmest Sea Surface Temperatures have been for the entire Holocene period, and possibly even as far back as the last Interglacial 125,000 years ago.”
As Damian Carrington chronicled Monday:
The new ocean heat record being set in August is especially remarkable as global sea temperatures are typically highest in March and April, after the austral summer. The Southern Hemisphere has significantly more ocean area than the Northern.
“The record is another clear signal of an ocean under growing stress,” said Dr Samantha Burgess, at the European Union’s Copernicus Climate Change Service (C3S), which produced the new data. “El Niño is adding heat to the system, but it is doing so on top of decades of human-driven warming. The consequences are already visible: The number of marine heatwave days globally has more than tripled since the early 1990s.”
That means many things. Among them, as Ben Noll laid out Monday:
The unusual ocean warmth has fueled powerful storms in the Pacific, such as Hurricane Lala near Hawaii, helped create a reservoir of extra moisture that has contributed to recent rainfall extremes across the United States, and boosted summer heat across Europe.
This is a system that’s being pushed much too hard and much too fast, and it’s breaking.
Forty two percent of the world’s ocean area is now experiencing a “marine heatwave.” This means that wide swaths of coral are already “bleaching,” turning a deadly shade of pale; we don’t have the numbers yet, but it’s entirely predictable. We learned earlier this summer that the last huge coral bleaching event, the fourth this century, ran from 2023 to 2025 and
impacted 84% of the world’s coral reef area in all three coral reef-containing ocean basins (Pacific, Atlantic, and Indian Oceans). Mass bleaching was documented in at least 83 countries and territories.
It’s not just that coral reefs are one of the wildest corners of God’s brain; it’s that they provide food for 500 million human beings and keep waves from destroying shorelines. But still—they’re underwater. We don’t actually see them on a daily basis. It’s hard for us to imagine the damage.
Trees are easier for us to see; think of them as coral reefs but on land. And here’s a completely remarkable account from Eric Niiler on how the hot new wildfires bred by our hot new atmosphere are degrading them in the most obvious possible ways:
On a gentle slope on the western side of the Sierra Nevada Mountains, where a towering green canopy of ponderosa pines had stood for centuries, wildfires have transformed roughly 1,700 acres into brown, bare shrubland.
That forest is gone for good, scientists say. Spiky shrubs and poison oak have replaced the majestic trees. All that is left of the pines are burned logs and dead branches.
It’s part of a wider transformation that’s taking place across the Western United States, from Oregon to New Mexico, as bigger and hotter wildfires sweep through forests that have not evolved to survive such high-intensity blazes and a warmer climate. Recent studies estimate that as much as 40% of Western conifer forests will turn into shrubland by 2100 as a result.
These trees help define the American West. (Google the Oregon license plate). But they also function as part of an ecosystem. To wit:
Researchers say that as trees disappear, winter and spring snow will melt faster, affecting wildlife as well as communities that are already struggling with water shortages. Some Western states get as much as 75% of their water from snowmelt.
“When you remove the forest, that snow is more susceptible to melting earlier,” said Benjamin Hatchett, an interdisciplinary scientist at Colorado State University. And he noted that a warmer, more arid climate dries out soil and pulls moisture from plants, making them more susceptible to wildfire. “That thirstier atmosphere is a big concern,” he said.
Oh, and:
Forests also absorb planet-warming carbon dioxide from the atmosphere. Bigger, older trees store more carbon than younger trees and shrubs. The loss of conifer forests today means a hotter tomorrow.
But again, much of that is invisible—CO2, sadly, can’t be seen. (If it turned the sky smog-brown like carbon monoxide we’d have done something decades ago). And even forests are far away from where most people live as to seem almost unreal. (Once, a visitor looking at the Vermont foliage near my home asked me if we collected the colored leaves when they fell and put them back up next year, as if they were a kind of Christmas decoration).
So let’s think about that water for a moment, the snowmelt that’s disappearing ever faster. Here’s another remarkable account of the American West, this time from Reis Thebault. It begins in the control room of the Central Arizona Project, the vast canal project that supplies water from the Colorado River to Phoenix and its surrounds, which are some of the fastest growing communities in America. The Colorado, though, is drying up, and so big cutbacks are coming:
Short-term reductions, announced by the federal government on Friday, will cost Arizona roughly one-third of its share of river water over the next two years. But beyond that, a range of cutbacks remain possible.
Under the most severe outcome, the system would be cut off entirely during the driest years, setting off a social and economic meltdown Arizonans shudder to even imagine.
“They are threatening to shut down the Southwest,” said Brenda Burman, the project’s general manager. “It’s not possible to picture it.”
There’s a certain poetic justice here, perhaps—communities that have built their identity on the myth of the ruggedly independent Western man overcoming the hostile elements, only to find themselves entirely dependent on the socialized distribution of limited water.
Cave Creek, a picturesque burg steeped in cowboy kitsch in the foothills north of Phoenix, gets 95% of its water from the aqueduct system.
“Without Colorado River water, we would be a dusty little town with dirt roads,” Mayor Robert Morris said.
The town’s leaders have been scrambling to find backup plans. Cave Creek has hired a water consultant and struck deals with neighboring municipalities, cobbling together enough supply for the next five years, Mr. Morris said.
He has sought to prepare residents for higher bills and stricter conservation, working to undo a foundational part of the state’s philosophy in the process.
“The biggest thing for people to overcome is the idea of unlimited, cheap water,” Mr. Morris said.
But even that blow to identity is small compared to the blow that comes when you run out. And not just of affordable water, but of affordable food. And we seem to be nearing that point. We’ve long known, for instance, that yields of staple crops are rising more slowly than they would otherwise, because of higher temperatures. But a new study this week put some fairly remarkable numbers on the future: “Severe water scarcity” events due to global warming could easily triple the price of wheat:
Looking ahead, climate model projections suggest that water scarcity will expand under continued warming. Our results indicate that a temperature increase of about 3°C could triple average global wheat prices relative to 2010.
But we don’t have to wait. As Somini Sengupta pointed out this weekend, in four paragraphs that may set some kind of record for condensed reality, that future is more or less now:
Wheat is at the heart of the modern diet, and this year, it is facing an accumulation of modern dangers. The breadbaskets of the world are getting pummeled by drone strikes and devilish weather, nudging prices higher amid already soaring food costs in the wake of the Iran war.
Heat and drought have diminished harvests in some of the biggest wheat-producing countries, including the United States, which is expected to have its worst wheat harvest in a half-century, spiking prices. Poor countries that agreed to buy American wheat under the threat of Trump tariffs could be stuck paying abnormally high prices.
The Black Sea, a crucial passage for the global wheat trade, is an active theater of the Russia-Ukraine war, while the Houthi militia’s attacks on shipping in the Red Sea have already forced grain shipments to take a longer, more expensive route around South Africa.
Beyond that, a supercharged El Niño further threatens water levels in the Panama Canal, while drought has reduced water levels to perilously low levels in transit routes like the Rhine and Danube rivers in Europe, raising transportation costs. All this at a time when the global atmosphere is hotter than normal because of a century of fossil fuel burning, threatening the livelihoods of small farmers in poor countries.
All of this is down to fossil fuels—the oil we’re fighting over in the Strait of Hormuz, the gas and coal whose methane and carbon emissions have sent temperatures soaring and river levels dropping. It’s reality.
Just to repeat the numbers, this time from Neal Burnette-Irwin and Marion Kilpatrick:
Mark Jankowski with USDA’s Outlook Board is still crunching the numbers for the year, but says the crop is set to break all the wrong records.
“On our balance sheet, we didn’t make any changes to our export or other use forecasts, so all that essentially did was tighten up ending stocks by six million bushels from where we were last month. Now we’re looking at US ending stocks of 717 million bushels, down 203 million bushels from last year, reflecting the fact that this wheat crop is a small crop. It’s historically small.”
US wheat growers can point to a number of challenges this year, but Jankowski says the issues aren’t limited to domestic wheat production. The crop is also suffering globally.
“A fairly sharp reduction in the European Union production estimate. We lowered it by 1.8 million tons this month, reflecting very hot, dry weather that spread across the entire EU region over the summer. Much of that extreme heat hit during the grain-filling stage for wheat, so it is showing up as reduced yield potential. With a 1.8-million-ton reduction in the forecast this month, that would bring the EU’s wheat production forecast down to 134.2 million tons, down just about 11 million tons from last year.”
It’s not just wheat. In Europe, knocked to its knees by an endless stream of heatwaves this summer, we have reports of vegetable harvests collapsing by double digits—60% of France’s broccoli crop, for instance, is gone. Britain could face food shortages within months, one excited newspaper report warns; in Ireland, they’re calling for an emergency food stockpile as harvests run low. The UK government has refused to release an unredacted copy of a report from the country’s intelligence agencies about ecosystem collapse amid rising temperatures, but we do know that it predicts the very real possibility of widespread food shortages by 2030, resulting in “price rises, migration, political destabilisation, and possible war… fueled by the human-induced climate crisis.”
What I’m trying to say is, we are running up against limits. We have made it hot enough on this planet that things are going very wrong. This is not like politics, where you get to say something dumb and change the subject. As I’m writing this, for instance, word has emerged of a court filing where the Trump-appointed board of the Kennedy Center has threatened to tear the building down unless President Donald Trump’s name is carved on the wall. That’s not real; it’s a game, one designed to distract. But wheat is real.
Because we’ve pushed so hard into this new hot world, our margin has been substantially reduced, in some cases to nothing. As one scientist quoted in that excellent article on Western trees and fire said:
“Forests do have innate resilience and under normal circumstances, they can take a hit or two and bounce back,” Dr. Coop said. “But circumstances just aren’t normal anymore.”
Still, there are things we could do. When it comes to forests we could at least not knock more roads into the middle of them, as the Trump administration decided to do last week. (If you want to read a bang-up piece of writing about the Peavine Fire currently devastating Reno, I recommend this from my beloved Third Act colleague B Fulkerson).
When it comes to the Colorado River, we could—as conservationists have suggested for decades—demolish Glen Canyon Dam and let Lake Powell drain downstream to Lake Mead. It wouldn’t solve the problem, but it would give us a little more margin.
And we could deploy lots and lots of solar panels to desalinate enough water to supply some of the needs of places like Phoenix (solar panels that, by the way, shade the desert and conserve some moisture). And we could, you know, stop building water-intensive data centers. (Big victory in New Mexico yesterday, where activists included my Third Act colleagues managed to win a temporary halt to the giant Jupiter project, “in part due to recent revelations about the use of millions of gallons of fresh water for the data center’s construction in recent months.”)
When it comes to food, we may have more margin yet. America’s fertile cropland is filled to an astonishing extent growing corn syrup, feed for cattle, and gasoline—an area the size of Indiana is devoted solely to producing ethanol, an absurd boondoggle. So we’re not without options. Using it to produce solar power and, you know, food people eat would take off some of the pressure.
Above all, of course, we can rapidly deploy renewable energy. At this point it won’t lower the temperature rapidly, but it could keep it from climbing rapidly. And it’s within our technical capacity—the planet possesses the factories capable of turning out solar panels three times as fast as we’re currently going.
I will return next time to politics, because politics is unavoidable. It’s how we will or won’t rise to these challenges. But for now I just want to drive home the reality, the sheer inescapable reality of life on our rapidly overheating planet.
Because we’re pushing the margins, and we’re doing it right now. One of the more remarkable essays I’ve read in recent months comes from Aruna Chandrasekhar, describing modern-day Mumbai as a “city of sweat.” This relates directly to the elevated sea temperatures with which I began this account—Mumbai, as anyone who has had the privilege of visiting the Gateway of India will recall, sits on the edge of the Arabian Sea. The city’s seawalls are already overtopped in storms, but the constant danger is the humidity. Here’s Chandrasekhar (and the whole article is very much worth reading):
In summer, Mumbai’s air holds up to 90% of all the water it can possibly contain, leaving almost no room for sweat to evaporate—which in turn leads to rapid dehydration, exhaustion, and fatal heatstrokes. On a 38°C day in April 2023, 14 people died in an outdoor rally attended by India’s home minister. What has come to be expected of millions upon millions of Mumbaikars, no matter how bad it gets, is resilience. But that resilience is coming up against hard limits of survivability.
Jari Mari is a crazy mosaic of the city’s extremes. Migrant, working-class Muslim and Dalit families live in tin sheds and one-bedroom concrete blocks stacked behind the high-security walls that seal off runway 27. The housing is so dense that the narrow lanes see no sun and feel no wind. But the heat still gets through, and the kids are always sick, many of the mothers in these houses told us: Everyone has to sleep with their doors open, mosquitoes be damned. No one we spoke to could afford air conditioning.
In Sabiya and Sameer Khan’s one-room house, temperatures touch 49°C. When we tell Sameer we’re not here to shoot planes, but to take thermal pictures of his asbestos roof, he looks at us like we’re mad. We show Sabiya how the fan above her stove is pushing hot air back down on her. A couple of blocks away, kids play cricket on concrete that shows a reading of 58.7°C.
58.7°C is 137.66°F. No more need be said.
