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Reopening the Strait of Hormuz won’t make summer any cooler.

If you happened to be watching the popular Thai morning show Wanmai Thai earlier this month, you may have come across an odd segment on workplace attire. In it, the three hosts demonstrated that by removing your business jacket, you can stay comfortable at the office and conserve electricity. “People who are addicted to cool air conditioners — well, now you don’t have to,” the disrobed hosts told their viewers from their shirtsleeves.
The segment was designed to encourage more than just common-sense fashion choices. Thailand is one of many Southeast Asian countries that rely heavily on the Middle East for fuel, with about 74% of its oil sourced from the Persian Gulf. The vast majority of that must pass through the Strait of Hormuz, which has been effectively closed to tanker traffic since the U.S. and Israel attacked Iran in late February. In some places, the situation is even more dire: 87% of Vietnam’s oil comes from the Persian Gulf. For the Philippines, it’s 96%.
These countries, along with others in the region, have been among the first to experience the cascading effects of the Iran War. Most have only modest emergency reserves, which will buy them a month, or maybe two. “We’re definitely in an environment where every step you can take to maximize energy conservation significantly counts,” Clara Gillispie, a senior fellow for climate and energy at the Council on Foreign Relations, told me. “The challenge is, we don’t know how bad the supply crunch is going to get.”
What we do know is that summer is approaching, and it’s likely to be another hot one. “We have heard this year could be a bad El Niño,” Jason Lee, a leading heat expert at the National University of Singapore and the chair of the Global Heat Health Information Network’s Southeast Asia Hub, told me. “We are expecting a warmer summer.” In fact, this year and next could be the hottest in human history.
Southeast Asia is particularly vulnerable: Cambodia, Myanmar, and Thailand are disproportionately affected by climate change, and could experience temperatures of 105 degrees or higher on more than 138 days a year by the end of the century. Those kinds of temperatures put a strain on the grid even in the best of times; if they arrive this spring and summer against the backdrop of a worsening energy crisis and electricity rationing, they could kill people whose survival depends on access to working AC.
Unsurprisingly in a warming world, a third of Southeast Asia’s growth in electricity use is attributable to cooling-related infrastructure, per the International Energy Agency. “Air conditioning is increasingly not a luxury in some of these places, where it makes a real, meaningful difference in terms of the livability of cities,” Gillispie told me.
But because of the energy crisis, Thailand is asking all sectors to keep air conditioners set to 80 degrees Fahrenheit — a temperature that may offer limited relief, especially given a forecasted heat index of 140 degrees in parts of the country by early April. (Health experts say that 75 degrees is the ideal temperature for the body to recover during episodes of extreme heat, especially in urban areas, where cities tend to hang onto the heat overnight.) Governments of other countries in the region, meanwhile, have instituted four-day workweeks and work-from-home policies in the name of conserving energy.
It’s a matter of life and death. One of the leading ways lower-middle-income countries have adapted to prevent temperature-related mortality is by investing in AC. “If your community has money, then you have options, and one of those options is to increase access to air conditioning,” Emily Grover-Kopec, the director of energy and climate practice at Rhodium Group and the author of a new report on heat-related mortality from the University of Chicago’s Climate Impact Lab, told me. For example, though though Djibouti and Kuwait are countries with similar climates, heat-related deaths are projected to increase by 55 deaths per 100,000 in Djibouti by 2050, “on par with the current death rate of HIV/AIDS,” the report found, while the richer country, Kuwait, is projected to see only 25 additional deaths per 100,000, or “less than half the current death rate of heart disease.”
The Climate Impact Lab’s numbers for Southeast Asia might not immediately jump off the page as particularly scary, in part because the data is designed to capture a net change in mortality. Southeast Asia’s topography varies widely, and in the more mountainous regions of the countries, researchers project a net decrease in deaths due to milder winters.
But the report also measures changes on top of a baseline that is already bad. South and Southeast Asia combine to account for half of global heat-related deaths. Counterintuitively, this baseline can sometimes dissuade governments from investing in adaptation-related measures because extreme heat is pervasive and normalized. It’s like the “effect of a smelly room,” said Lee, the GHHIN Southeast Asia chair. “After you are in the room for a long time, the stench disappears.” Similarly, many of the “most vulnerable regions are not taking serious action because [the heat] is perpetual. It was always warm and uncomfortable in Southeast Asia.”
As incomes improve, though, adaptation via air conditioning remains one of the most effective ways to save lives. In Indonesia, for example, less than 15% of households had ACs in 2024; around half are expected to have them by 2035. But it is also air conditioning that is most immediately threatened by unreliable and unaffordable energy. As fuel costs go up, utilities may ration electricity, as is already the case in Sri Lanka, another Asian country that relies heavily on imported Middle Eastern fuels.
Rationing, in turn, can lead to blackouts, meaning that even people who can afford air conditioning will lose access to it. What we know from previous extreme heat disasters is that it’s often prolonged exposure to indoor temperatures — which don’t even necessarily need to be that high — that turns deadly. That is especially true for elderly populations, which are highly concentrated in Southeast Asian countries.
What’s more, e a short war in the Middle East will have consequences for Southeast Asia at this point, Teevrat Garg, an associate professor of economics at the University of California, San Diego, who specializes in environmental policy and energy transitions in low- and middle-income countries, told me. Many nations in Southeast Asia are now backing away from their plans to phase out coal — Thailand, for example, has ordered its plants to run at full capacity, an about-face for a country that had previously explored decommissioning some of its biggest polluters. “Decarbonization goals are likely to be pushed back when you have an energy crisis of this kind,” Garg said. “The first priority is providing electricity to everybody” — especially when lives are at stake.
Running air conditioning less, or not at all, can also make keeping schools open unsafe. Pakistan, Sri Lanka, and Bangladesh have already reduced in-person classes to conserve energy. “Even when schools can stay open, there are questions about the impacts that [heat] has on students — their cognitive processes and the quality of the teaching and learning,” Gillispie of CFR told me, echoing Garg by adding that the crisis is “not a one-off. It’s something that’s going to have ripple effects for years to come.”
It’s precisely these ripples and cascades that make the energy crisis so difficult to respond to, Lee added. In Singapore, for example, where he lives and works, there are currently haze warnings due to nearby wildfires, advising people to stay indoors with the windows closed — where they’ll inevitably have to run AC. (Coal-fired plants and diesel generators will also add to regional air pollution, prompting more air quality warnings across Southeast Asia.) At the same time, the government is telling people to keep their windows open for ventilation and go to cooling malls and water fountains to deal with the heat.
“And now we have an energy crisis” on top of everything else, Lee said. Looking ahead to the summer, when temperatures will spike, and load-shedding is possible, he added, “I hope the governments are thinking about this, because if that scenario plays out, this will be devastating.”
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Timber companies think of them as pests, but new research indicates that stands of the slender tree can act as barriers against raging flames.
Colorado’s Aspen Acres Fire is named after a quiet RV campground located high in the San Isabel Mountains, about a five-hour drive due southeast of the state’s better-known Aspen. Both places, however, are named after the iconic deciduous tree known for its golden leaves in the fall. While the start of monsoon season may yet prevent the Aspen Acres Fire — the seventh-largest in Colorado’s history — from joining Utah’s Babylon Fire as the second 100,000-acre “megafire” of the season, the conflagration has been aided in its rampage not by aspens, but rather by dead, downed, and blighted ponderosa pines, spruce, and Douglas firs. The wildfire has now burned over 98,000 acres and nearly 300 homes, and is only 36% contained due to steep terrain that has hampered firefighting efforts, along with extreme drought conditions and beetle infestations that have greatly degraded the forest health of the region.
But what about its aspens? Though the extent of the damage at the campground remains unknown, according to a recent study of Populus tremuloides, Colorado’s iconic golden trees could be one of the keys to more wildfire-resistant forests in the future.
Flavie Pelletier, a recent PhD graduate of McGill University’s Natural Resource Sciences program, told me she first became interested in aspens while working as a tree planter in British Columbia. “The historical assumption on aspen is that stands are very good at stopping fire progression. But the paradox is that if you take an aspen by itself, it’s going to burn at high severity,” Pelletier, who published her findings in Forest Ecology and Management, told me.
By creating near-real-time maps of fires using satellites and comparing them against the Canadian Forest Service’s newly available maps of dominant tree species in the boreal, Pelletier and her colleagues discovered that aspen were almost two and a half times more common at the perimeter of a burned area than inside it. The finding suggests that despite the flammability of a single aspen with its thin bark, stands of aspen act as a kind of barrier when wildfire ran up against them, likely because they lack the flammable resins of conifers and their high foliage helps force running crown fires back toward the ground. Pine and spruce, by contrast, showed a near-zero or even negative effect.
When aspen stands did burn, Pelletier found they did so more slowly: A tree cover of 50% aspen burned at about 224 hectares per day, compared to 717 hectares per day in areas where aspen made up less than 10% of the cover. That’s the equivalent of about 1,000 FIFA-regulation soccer pitches per day in places where aspen are sparser — like Aspen Acres.
Even more surprising, though, was that the pattern held true in the early season, when the trees are still twiggy and have yet to grow their moisture-filled leaves, and despite the severity of fire weather. “Aspen still showed resilience even when the fire weather was very intense, [like in 2023, when] we had all the fires,” Pelletier said.
But she was also the first to admit that seasons are getting more extreme, and that there’s no guarantee the pattern will hold for the next 10 or 20 years.
Pelletier was reluctant to make a policy recommendation based on her research, noting that she’s not a forest manager. But in Alberta and British Columbia, timber companies spray hundreds of thousands of acres of timber with glyphosate, an herbicide, to kill off aspens because the trees outcompete the more commercially valuable conifers. Her findings are “a big argument to stop the spreading of herbicides because you’re increasing the risk of fire in your forest by removing aspen,” Pelletier said.
Despite her hesitation, Pelletier is explicit in her paper about one thing: that aspens “should be encouraged — specifically around key landscape positions, such as population centers” — given that they are a proven means of hardening the wildland-urban interface against wildfires. It might be too late for the idyllically named Aspen Acres, of course; any of the aspens that once drew tourists to the area are likely now ash.
But this not be Colorado’s last fire, either.
Current conditions: More than two dozen locations across the Mountain West and Midwest broke temperature records Sunday as the nation’s heat wave roasted the Central United States • At least 12 people died fleeing a sweeping wildfire in Spain as hundreds of firefighters battled the flames • In Colorado, the ongoing Aspen Acres Fire has destroyed 780 structures.
During President Donald Trump’s first term, his administration’s big fight over public lands centered on the last two national monuments approved by Barack Obama on the way out of office. In 2017, Trump signed executive orders slashing the size of Bears Ears National Monument by 85% and nearby Grand Staircase-Escalante, both located in Utah, by half. Legal challenges were still pending when President Joe Biden restored the reserves to their initial size in 2021. But ABC4 in Utah reported last week that Trump planned to announce a new executive order to shrink the boundaries of the monuments yet again, likely this afternoon. “The Antiquities Act was a one-way statute when Teddy Roosevelt signed it into law. It was a one-way statute when President Trump tried to ignore it in 2017. It’s still a one-way statute today,” Aaron Weiss, the executive director of the Center for Western Priorities, said in a statement. “Just last month, Congress had a chance to weaken the management plan for Grand Staircase-Escalante and declined.”
In April, the Senate approved a House resolution using the Congressional Review Act to clear the way for a mining operation near Minnesota’s Boundary Waters, in what my colleague Jeva Lange called a declaration of “open season on public lands.”
Over the past 12 months ending in July, 56 fusion companies raised a total of $4.5 billion, a 69% jump over 2025’s total. That’s according to the latest data from the Fusion Industry Association’s annual report. Total funding since 2021 now stands at $14.2 billion, a sevenfold increase. Twice as many companies are now competing as when the report was first published six years ago. This year’s figures include major financing rounds from Commonwealth Fusion Systems, which raised $863 million last August; Inertia Enterprises, which brought in $450 million in February; Helion Energy, which raked in $456 million last month; and the European champion Proxima Energy, which netted $518 million this month.

Back in January, I told you when the price of copper hit a record high. We kept track, too, of Chilean miners’ plans to ramp up production last month. But Chile’s output of copper fell sharply in May, according to a Mining.com analysis of data from Codelco, the country’s national miner. Production from major miners such as BHP dropped over 18% year-on-year to 106,300 metric tons. The fall comes as key mines in the South American nation face declining ore quality.
The move comes right as one of China’s biggest solar manufacturers switched from using silver to copper in its panels in response to what Bloomberg described as the surging prices of the precious metal.
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The world’s first commercial satellite powered by nuclear energy has launched into space after escaping the Earth’s atmosphere on a SpaceX Transporter-17 vessel. Miami-based City Labs, the company behind the launch, specializes in designing, developing, and manufacturing micro power technology based on the radioisotope tritium. The technology is meant to provide long-lasting, maintenance-free power for medical, industrial and space applications. “This is a historic step for commercial nuclear power in space,” City Labs CEO Peter Cabauy told World Nuclear News. The system “demonstrates that safe, compact, and regulatory-approved nuclear power systems are ready for routine commercial deployment.” The technology “enables persistent, always-on” operations “that are not constrained by sunlight or battery life.”
New York is behind on its development of clean energy. Its offshore wind buildout has stagnated. The state has limited space and sunlight for large-scale solar. And while Albany is positioning itself as the state leader on nuclear power with plans to construct more reactors upstate, those efforts are long term, and only just began. But one source of green power is expanding faster than expected: rooftop solar. New Yorkers installed 8 gigawatts of distributed solar capacity, putting the state ahead of schedule moving toward its legally-binding goal of 10 gigawatts by 2030. “New York continues to set the bar high as we mark another milestone for solar within our communities across the state,” New York Governor Kathy Hochul, a Democrat, said in a statement. “This is low-cost, reliable clean energy that is delivering cost savings for families and businesses while expanding the availability of renewable energy which benefits our environment, our economy and contributes to New York’s diverse energy resource mix.” That’s optimistic. But as Heatmap’s contributor Jesse Jenkins explained on our Shift Key podcast in 2023, there are limits to how big an impact rooftop solar can have on emissions.
China, as I told you last week, has been investing heavily in green hydrogen. The statement in Beijing’s latest Five-Year Plan confirms that green hydrogen, ammonia, and methanol “will play a significant role in decarbonizing China,” Hydrogen Insight reported.
Building a data center is also quite carbon-intensive.
When I helped start Heatmap News three years ago, I didn’t think I would be writing this much about big tech companies.
I knew that, sure, they were crucial to America’s ability to develop and scale some next-generation emissions-reducing technologies. (By then, Microsoft had already started its huge carbon removal purchasing program.) And, yes, I knew they bought a lot of renewables. But I still understood their clean energy programs chiefly as an employee perk — a way for some of the economy’s richest firms to show their largely urban, college-educated, and liberal employees that they cared.
Perhaps that was true once. It’s not true anymore. Over the past several years, the tech companies have become major electricity consumers and producers in their own right. Artificial intelligence has turned their electricity procurement and development businesses into core operational competencies. (Meta and Microsoft have even considered entering the electricity trading business.) Some of the thorniest questions in climate policy were first encountered by these tech companies.
More importantly, their hunger for electricity has transformed them into quasi-industrial companies — and given them enough heft in the market to sometimes counterbalance (and sometimes collaborate with) the utilities and fossil fuel firms that previously steered the sector. As such, they’re now crucial parts of the U.S. decarbonization story.
Three companies in particular dominate the artificial intelligence cloud business: Google, Amazon, and Microsoft.
The country’s best-known frontier labs, such as OpenAI and Anthropic, rely on these companies to provide their compute power; Amazon Web Services is the backbone of virtually the entire online software industry. Amazon, Google, and Microsoft account for more than half of the country’s data center power capacity, according to the investment firm Jeffries.
So these companies’ emissions are, in a sense, not only their own; they also give us a view into the AI industry’s carbon footprint more broadly.
Over the past two weeks, all three of these cloud providers released their energy and emissions data for the past year, and we’ve looked at the top line findings from these reports in past editions. Today I want to briefly dive into what they could mean together.
Let’s handle the part you already know: Everyone’s emissions are up.
Microsoft’s emissions grew by 25% last year, their largest year-over-year leap since the pandemic. Amazon’s emissions leapt by 16%, its largest one-year increase ever. Google’s emissions increased by 18%, rising above their pre-pandemic level.
This surge will make the companies’ climate goals increasingly difficult to meet — and some of them are coming up fast. Microsoft has pledged to become ‘carbon negative’ by 2030, meaning it must remove more climate pollution from the atmosphere than it emits in that year. Google has pledged to achieve net zero by 2030, a goal that requires — by its own estimate — cutting its emissions in half by that year, as compared to their 2019 level. Amazon, meanwhile, has pledged to achieve net-zero in its operations by 2040.
All three firms’ greenhouse gas emissions are up because of the AI data center boom. Microsoft consumes nearly four times as much electricity as it did before the pandemic; Google’s electricity use has more than doubled.
These companies’ energy use has swelled, too, but at least as of last year, nearly all of their energy demand still took the form of electricity. When we think about “electrification” in the national context, perhaps we should think at least as much about these AI megalodons as we do about heat pump or battery manufacturers.
Amazon, to its shame, does not publish recent electricity usage data, so it doesn’t appear on either of these charts.
But outsiders have estimated its power consumption based on the numbers it does publish. Hendrik Rood, an IT researcher and consultant in the Netherlands, calculates that Amazon’s data center business used 78,000 gigawatt-hours in 2025. That would mean it consumes nearly as much electricity as Microsoft and Google combined.
As I cautioned yesterday, some of these figures are already outdated. Although all three companies just released their 2025 sustainability data, Microsoft brackets its report to the fiscal year, which ended on June 30, 2025. Google and Amazon’s data covers the calendar year.
In what might be a quirk inherent to the genre, all three sustainability reports have a somewhat defensive tone (or at least a writing style that tries to anticipate quibbles). These companies know that their sustainability pledges, embraced in the heady flush of 2020 and 2021, have become much more difficult to fulfill in the AI era. And they want you to know that all of their emissions could be worse — if not for their corporate policies, pollution might be much higher.
I can’t say I find these counterfactuals entirely believable. We don’t know what Google or Microsoft or Amazon would do if, say, computing were more energy intensive or a certain process more environmentally damaging. And Jevon’s paradox suggests that every gain in efficiency — especially for a service as in-demand as AI — will make it cheaper to use AI, therefore raising its energy demand.
But I do think it’s worth sharing these claims to get some perspective. Google, for its part, says that its corporate emissions would be five times higher than they are if not for its total slate of policies:

Microsoft takes a more clinical approach. It selects four of its corporate policies: “carbon-free electricity, sustainable fuels, XBOX console efficiency,” as well as efforts to decarbonize its Surface tablet production. If not for these interventions, it says, it would have emitted 34 million tons of greenhouse gas into the atmosphere last year, not the 21 million tons that it did produce.
For all the focus on the difficulty of powering data centers (including by Heatmap), electricity does not drive most of these companies’ emissions — or it didn’t in the first half of last year, at least. The majority of Microsoft, Google, and Amazon’s greenhouse gas emissions came from what are dubbed “scope 3” emissions, a somewhat nebulous category that includes buildings, employee travel, and the full carbon footprint of their supply chain. This category reflects the AI boom in its own way.
(Skip this if you’re a sustainability nerd: In the classic schema used for corporate emissions accounting, “scope 1” emissions are direct fossil fuel pollution from an asset that the company owns or controls, “scope 2” emissions are pollution associated with the electricity, steam, or chilled water purchased by the company, and “scope 3” emissions are everything else — pollution from the company’s upstream supply chain and its downstream product use. I find this scheme makes somewhat more sense for businesses like airlines and automakers than it does for technology conglomerates. But that’s a different newsletter.)
It makes sense, then, that Amazon should have huge scope 3 emissions. The scope 3 subcategory called “Purchased Goods and Services” drives the largest share of its emissions; these include pollution from goods and services that Amazon buys for its employees to use, as well as all the embodied carbon in its line of Amazon Basics products.
But the biggest driver of scope 3 emissions — and thus for emissions overall — for Microsoft and Google came from “capital goods,” a category that covers new construction, physical assets and other fixed infrastructure used to produce products and services. More than 40% of Microsoft’s total emissions came from capital goods, and they made up more than 9 million metric tons of the company’s greenhouse gases. Google doesn’t fully aggregate out its “capital goods” category, combining it with the “use of sold products” subcategory, but it was responsible for almost 9 million tons as well.
These capital goods include the new data centers themselves: all the cement, steel, server racks, and silicon that actually make up the physical infrastructure supporting the AI boom. Here at Heatmap, we often focus on the electricity sector because it’s where so much change. But it’s good to remember that construction remains enormously carbon-intensive, and the literal buildings that house AI are, in many cases, still driving a disproportionate amount of emissions.