In our political life, reality hardly matters any more. On Tuesday the president of the United States, in a fit of pique, proposed renaming Lake Ontario “Lake America.” He hides in a food cart and sends journalists out as decoys to be killed on his behalf. His winsome aide hands him an endless stream of flattering tweets. And yet the world stumbles on. People die, obviously, as a result of this folly—in the Middle East, and in middle America, where suddenly measles is a serious threat again. (Hell, the deaths attributable to Elon Musk’s decision to destroy the US Agency for International Development put him in the Stalin and Mao category for negligent manslaughter.) But human societies are for a while resilient; we assume that there’s always a chance for a reset. After the next election normal service will resume. If you start with a rich country like the US, it can absorb a lot of decline.

But that’s not how physical systems work. You push them and then past a certain point things change. If the temperature drops below 32°F water freezes, and if it rises above 212°F then it boils, more or less. This newsletter spends a lot of time in the world of politics, because that’s where we need to make changes. But sometimes we need to remind ourselves that ultimately that political world is a subset of the physical one, simply because that’s how things work.

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.

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........

© Common Dreams