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“Temperature blankets” are the new hot crafting craze.

Trina Messer knew the weather in Dallas-Forth Worth had been unusually warm this year, but she hadn’t anticipated needing her clay-colored yarn in February. “Today we are expecting a high in the 90s!!!,” she marveled in a Facebook update last week, adding regretfully, “I was hoping for more blues, but it is what it is.”
Messer, a retired educator of 30 years, started crocheting in 2022, the natural evolution of a knitting habit she’d picked up while bored during the pandemic. So far, she has made several scarves and hats, a big cardigan “almost like a coat,” and even a couple of throw blankets. Then, in January, she began work on her biggest project yet: a temperature blanket.
Temperature blankets aren’t always blankets — they can be scarves, shawls, and even crocheted snakes. The basic premise, though, is the same: Over the course of a year, knitters, crocheters, and embroiderers add a new row, stitch, or square to their project every day, with the color of yarn corresponding to the temperature of the location where they live. In recent years, this community has grown massive, in essence creating a de facto visual record of climate change for thousands of locations around the world. “From December 1 until today, I’ve had over 26,000 people join,” Sarah Moerdyk, the creator and moderator of Facebook’s largest temperature blanket group, told me in February. For most of its existence, beginning in 2017, the group wasn’t “super active,” hovering around a few hundred members. “In a matter of three months, it’s really blown up.”
Messer chose to break her earth-toned palette into 10-degree intervals, ranging from a white yarn that represents temperatures below 19 degrees Fahrenheit to “chili red” for days over 110. She even has a special yarn, “silver sparkle,” to log days with snowfall. Thankfully, she’d already purchased the clay-colored yarn she’d designated for temperatures between 90 and 99 degrees, even though she hadn’t expected to need it until late March or April.
According to the National Oceanic and Atmospheric Administration, the contiguous United States just concluded its warmest meteorological winter in recorded history. Across the country, temperatures were 5.4 degrees above average; in some states, like Wisconsin, it was nearly 10 degrees above what it should have been for the period between December and February. “This is not normal,” Messer told me a couple weeks ago, when her phone showed it was 91 degrees near Dallas. “Don’t think it’s like this all the time.”
Despite temperature blankets’ resemblance to climatologist Ed Hawkins’ famous warming stripes, the concept predates his 2018 graphics. Perhaps more surprisingly, it wasn’t initially conceived as a commentary on climate change. As far as I — and others — have been able to gather, Kristen Cooper, a craftsperson and beekeeper living in northern British Columbia, was the first to come up with the concept that evolved into the modern temperature blanket challenge when she described a similar scarf pattern in a 2013 blog post. “You record the day’s highest temperature by knitting one row in the color designated for each temperature,” she wrote. By the end of the year, “you will have a visual, colorful graph of the temperatures of your area.”
Cooper told me she, in turn, had been inspired by knitter and author Lea Redmond’s “sky scarf,” a project from 2008 (and later, a book) that involved knitting a row a day in a color that “best captures the essence of the sky out your window.” Redmond was slightly skeptical of the idea that she could be the temperature blanket’s progenitor. Her project tried to capture “the embodied experience of looking at this beauty of the sky every day,” she told me. Temperature projects, by contrast, rely on numbers that people retrieve from a thermometer in their kitchen — or, “I’m guessing, a lot of people just check the internet.”

Internet data doesn’t have the immediacy of events unfolding in real-time, outside your window. But representing temperature data at all requires a level of emotional remove that Redmond, personally, was a little wary of: For example, when wildfires turned day to night in California in 2020, “temperature-wise, that would not have shown up in a temperature scarf, but in a sky scarf, that stripe would have looked like shit.”
Cooper, for her part, never finished the first temperature scarf because she realized that if she missed a day, she couldn’t accurately make it up — her rural town didn’t have its own weather station — which would defeat the whole point of the project. But while she eventually moved on, swept up by life with a new baby, the knitting world took the concept and ran with it. “I hadn’t really been following along, but every now and then, a completely random post by strangers on Facebook or Instagram will pop up showing a temperature blanket,” Cooper told me. “And I’m always so amazed at how far the concept has traveled.”
Only recently have artists started using conceptual knitting and crocheting projects as explicit commentaries on climate change. In 2017, after the inauguration of President Trump, yarn shop owner Emily McNeil and data scientist Asy Connelly launched the Tempestry Project — which uses standardized colors and ranges to create historic temperature records — half as a joke and half out of real anxiety over the possibility of climate information disappearing from government websites. “We weren’t really thinking about temperature blankets,” McNeil told me. “I guess I knew that they existed, but it wasn’t really on my radar when we started it.”

Admittedly, sifting through all that climate data can take an emotional toll during the hours or days it takes to complete a tapestry. In addition to tapestries representing individual years, which rely on historical data rather than real-time observations, the Tempestry Project also facilitates multi-year “New Normal” tapestries that are directly inspired by Hawkins’ warming stripes. “The first one that I knit had me in tears as the colder colors just fade out, and you are never going to get those again,” McNeil said. (When I asked how they deal with the feelings brought up by the project, McNeil and Connelly told me dryly, “A lot of wine.”)
Temperature blanket knitters and crocheters can similarly feel alarmed by what’s unfolding in their hands. Moerdyk told me the warm weather in the northern hemisphere has been a big topic in the Facebook group, with some people having to quick-order summer colors or make special trips to the store to accommodate the winter heat in their projects. Perversely, the weirdness becomes kind of thrilling. “It’s fun to hear people say, ‘My colors are going nuts right now,’” Moerdyk said. Especially this early in the year, “to put all of a sudden this really warm temperature color in — it’s memorable. You’ll look back and say, ‘Oh my gosh, remember that time in February we had a 70-degree day? That was crazy.’”
The result is that temperature blankets become an accessible way of discussing climate change, without any of the political baggage. Moerdyk originally started the Facebook group for her friends but has since recorded participants from 1,114 different locations, including every state and over a dozen countries. She said the community has remained surprisingly civil despite all that diversity — some of it surely ideological. But temperature blankets are “not really a controversial topic,” Moerdyk said. “No matter what you believe in, temperature changes.”

For the thousands of hobbyists who’ve taken on temperature blanket projects, the craft becomes a way to witness the immediate changes in their environment that aren’t necessarily wholly negative. “If you’re looking at temperature blankets as a climate marker, that can get heavy,” Heather Walpole, the owner of Ewe Ewe Yarns, which sells temperature blanket starter bundles, told me. “But we’re still living our lives and we have a desire to create.”
Redmond, the sky scarf creator, finds this kind of creative intentionality to be the key. “It’s not like I invented stripes having meaning,” she joked. “But I do think most stripes on most garments in most stores in the United States today are meaningless. That just seems like such a missed opportunity.” It’s not that having a throw blanket or a scarf with weather-coordinated stripes will change the world. But displaying or wearing a beautiful object inspires others to ask questions: Where did you get that? Did you make it yourself? “They’re story sparks,” Redmond said. “They’re excuses to tell your story.”
This already weirdly warm year is still in its relatively chilly opening chapters, but the savviest knitters are already hurrying to stock up on yarns for June and July. As Messer, the Texas-based knitter, told me, “If this summer is anything like last summer,” then her blanket will have “a whole lot of burnt orange and red.”
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Just as demand for batteries is intensifying.
The energy impacts of the continued crisis in the Persian Gulf are obvious. Countries that rely on the natural gas and oil from the region are dealing with higher prices, and in some cases are trying to tamp down their demand for fuel and electricity to keep prices under control, not to mention maintain basic energy availability.
But it’s not just gas-fired power plants and internal combustion engines that are feeling the pinch.
The consequences of the effective closure of the Strait of Hormuz go well beyond the set of energy commodities typically associated with the Persian Gulf, including a vast array of minerals and petrochemicals, including many necessary to produce clean energy. We’ve already covered aluminum, a key component of solar panels, cars, and batteries, which requires so much energy for processing that almost 10% of it is produced in the Middle East, where fuel is abundant.
Now another chemical essential to the battery supply chain is seeing price hikes and supply reductions: sulfuric acid.
Sulfuric acid is used in refining and processing several metals and minerals key to the energy transition, including copper, cobalt, nickel, and lithium. Copper is used throughout EVs and other clean technologies, while nickel and cobalt are used in cathodes in lithium-ion batteries — which, of course, also contain lithium. Shortages or higher prices of sulfuric acid could lead to shortages or higher prices for batteries and electric vehicles, just as consumers flock to them to help mitigate the impacts of rising fossil fuel costs.
Sulfur is a byproduct of oil and natural gas refining, hence about half of seaborne sulfur comes from the Middle East, according to Argus Media, but only a handful of sulfur-bearing vessels have transited the Strait of Hormuz since the war began. In response to the disruption, China, the world’s top exporter of sulfuric acid, began restricting shipments abroad, according to S&P.
Sulfuric acid “is an irreplaceable input in the manufacture of renewable energy materials, such as silicon wafers in solar panels; the nickel, cobalt, and rare earths in wind turbine magnets and electric vehicle (EV) motors; and the copper wiring in every grid connection and transformer,” wrote Atlantic Council fellow Alvin Camba in an analysis for the think tank.
“Most elemental sulfur comes from the Middle East,” Camba told me, “and it goes to places like Indonesia,” where metals are processed to “produce the batteries for a lot of vehicles for companies like Tesla, BYD, and Honda.”
Shortages of sulfuric acid will likely hit Indonesia especially hard. The country produces about 60% of the world’s nickel, but has only about a month’s inventory of sulfur, according to a team of Morgan Stanley analysts. “We believe the energy shock is reverberating and will sustain beyond the reopening of the Strait of Hormuz,” the analysts wrote of China’s export restrictions. “It will keep fuel markets tighter, lift the cost curve for Indonesian nickel, and raise refining margins in Asia. Higher energy prices will show up in food, tech and battery supply chains.”
Already, according to Morgan Stanley, “several” Indonesian nickel producers have reduced their output by at least 10% from last month. In the Democratic Republic of Congo, copper and cobalt miners are reducing their use of chemicals in their operations and considering cutting output.
Battery manufacturers are already seeing higher costs for their materials. The Chinese battery giant (and Tesla supplier) CATL saw its profit margins decline quarter-over-quarter revenue growth due to “cost pressure,” Morningstar analyst Vincent Sun wrote last week in a note to clients — and that’s despite greater sales volumes as consumers attempt to escape fossil fuel-dependency. As sulfuric acid rises in price, the battery companies will also be competing with agribusiness, who use sulfuric acid to produce phosphate fertilizers, Camba told me.
Even Ivanhoe Mines chief executive and metal and mining mega-bull Robert Friedland said in a statement last week, “If the closure of the Straits of Hormuz continues … second-derivative effect will be on global copper production due to the shortage of the world’s most important industrial chemical, sulfuric acid.” Friedland described the market for sulfur and sulfuric acid as “extremely tight.”
That also spells bad news for lithium, the namesake mineral used in EV batteries. Around half of global lithium production comes from spodumene, a hard rock mined largely in Western Australia. Refining that rock requires a “shitload’ of sulfuric acid, Nathaniel Horadam, the founder and president of Full Tilt Strategies, told me, through an energy intensive process known as “acid baking.”
Australian mines were already suffering from high diesel prices and shortages due to the conflict in Iran, according to Argus Media. The high price of sulfuric acid could put a squeeze on margins for lithium refining, which largely occurs in China.
“If their production costs go up, that’s going to be factoring into their market pricing,” Horadam said. “I would expect all those prices to go up in the short to medium term until this stuff kind of settles.”
The other major threat to battery makers specifically, Horadam said, was shortages of petrochemicals like ethylene, which is used in the production of plastics, and polyethylene, a polymer often used in plastic bags.
Ethylene is often made from ethane, a natural gas liquid, or naphtha, a refined petroleum product and production in the Persian Gulf has been severely disrupted by the Hormuz crisis. As of March, Asian petrochemical producers had already reduced their output in anticipation of shortages.
Polyethylene is also a crucial component in lithium-ion batteries, where it’s often used in the “separator,” which physically divides the cathode from the anode. Even the Trump administration has thrown its support behind polyethylene in battery manufacturing A $1.3 billion loan from the Department of Energy’s in-house bank to finance a separator manufacturing facility in Indiana survived the Trump administration’s gutting of that office, with $77 million getting disbursed last September. (Notably, the Trump-era announcement dropped a reference to electric vehicles and instead enumerated separators’ uses in “data centers, energy storage, and consumer electronics.”)
Over 40% of lithium-ion separators are produced in China with the “bulk” of them produced in Asia, according to the DOE, which makes support for domestic production paramount to maintaining international competitiveness and domestic supply chains.
“We’re relying on the Chinese and Japanese to produce all our separators and electrolytes and such,” Horadam said. “This sulfuric stuff is getting all the attention because it’s pretty obvious in terms of visible, salient minerals that are directly impacted, but I wouldn’t sleep on separators and binding agents.”
The opinion covered a host of actions the administration has taken to slow or halt renewables development.
A federal court seems to have struck down a swath of Trump administration moves to paralyze solar and wind permits.
U.S. District Judge Denise Casper on Tuesday enjoined a raft of actions by the Trump administration that delayed federal renewable energy permits, granting a request submitted by regional trade groups. The plaintiffs argued that tactics employed by various executive branch agencies to stall permits violated the Administrative Procedures Act. Casper — an Obama appointee — agreed in a 73-page opinion, asserting that the APA challenge was likely to succeed on the merits.
The ruling is a potentially fatal blow to five key methods the Trump administration has used to stymie federal renewable energy permitting. It appears to strike down the Interior Department memo requiring sign-off from Interior Secretary Doug Burgum on all major approvals, as well as instructions that the Interior and the Army Corps of Engineers prioritize “energy dense” projects in ways likely to benefit fossil fuels. Also struck down: a ban on access to a Fish and Wildlife Service species database and an Interior legal opinion targeting offshore wind leases.
Casper found a litany of reasons the five actions may have violated the Administrative Procedures Act. For example, the memo mandating political reviews was “a significant departure from [Interior] precedent,” and therefore “required a ‘more detailed justification’ than that needed for merely implementing a new policy.” The “energy density” permitting rubric, meanwhile, “conflicts” with federal laws governing federal energy leases so it likely violated the APA, the judge wrote.
What’s next is anyone’s guess. Some cynical readers may wonder whether the Supreme Court will just lift the preliminary injunction at the administration’s request. It’s worth noting Casper had the High Court’s penchant for neutralizing preliminary injunctions in mind, writing in her opinion, “The Court concludes that the scope of this requested injunctive relief is appropriate and consistent with the Supreme Court’s limitations on nationwide injunctions.”
On China’s H2 breakthrough, vehicle-to-grid charging, and USA Rare Earth goes to Brazil
Current conditions: In the Atlantic, Tropical Storm Fernand is heading northward toward Bermuda • In the Pacific, Tropic Storm Juliette is active about 520 miles southwest of Baja California, with winds of up to 65 miles per hour • Temperatures are surging past 100 degrees Fahrenheit in South Korea.
Nearly two weeks ago, Vineyard Wind sued one of its suppliers, GE Vernova, to keep the industrial giant from exiting the offshore wind project off the coast of Nantucket in Massachusetts. Now a U.S. court has ordered GE Vernova to finish the job, saying it would be “fanciful” to imagine a new contractor could complete the installation. GE Vernova had argued that Vineyard Wind — a 50/50 joint venture between the European power giant Avangrid and Copenhagen Infrastructure Partners — owed it $300 million for work already performed. But Vineyard Wind countered that the manufacturer remains on the hook for about $545 million to make up for a catastrophic turbine blade collapse in 2024, according to WBUR. “The project is at a critical phase and the loss of [Vineyard Wind]’s principal contractor would set the project back immeasurably,” the Suffolk County Superior Court Judge Peter Krupp wrote in his decision, repeatedly using the name of GE Vernova’s renewables subsidiary. “To pretend that [Vineyard Wind] could go out and hire one or more contractors to finish the installation and troubleshoot and modify [GE Renewables’] proprietary design without [GE Renewables’] specialized knowledge is fanciful.”
Charlotte DeWald fears the world is sleepwalking into tipping points beyond which the Earth’s natural carbon cycles will render climate change uncontrollable. By the time we realize what it means for global weather and agricultural systems that there’s no sea ice in the Arctic sometime in the 2030s, for example, it may be too late to try anything drastic to buy us more time. Much of the discourse around what to do concerns a specific kind of geoengineering called stratospheric aerosol injections, essentially spraying reflective particles into the sky to block the sun’s heat from permeating the increasingly thick layer of greenhouse gases that prevent that energy from naturally radiating back into space. That’s something DeWald, a former Pacific Northwest National Laboratory researcher and climate scientist by training who specialized in modeling aerosol-cloud interactions, knows all about. But her approach is different, using a technology known as mixed-phase cloud thinning, a process similar to cloud seeding. “The idea is that you could dissipate clouds over the Arctic to release heat from the surface to, for example, increase sea ice extent or thickness or integrity,” she told me. “There’s some early modeling that suggests that it could yield significant cooling over the Arctic Ocean.”
With all that context, you can now appreciate the exclusive bit of news I have for you this morning: DeWald is launching a new nonprofit called the Arctic Stabilization Initiative to “evaluate whether targeted interventions can slow dangerous” warming near the Earth’s northern pole. So far, ASI has raised $6.5 million in philanthropic funding toward a five-year budget goal of $55 million to study whether MCT, as mixed-phase cloud thinning is known, could help save the Arctic. The nonprofit has an advisory board stacked with veteran Arctic scientists and put together a “stage-gated” research plan with offramps in case early modeling suggests MCT won’t work or could cause undue environmental damage. The project also has an eye toward engaging with Indigenous peoples and “will ground all future work in respect for Indigenous sovereignty, before any field-based research activity is pursued.” The statement harkens to Harvard University’s SCoPEx trial, a would-be outdoor experiment in spraying reflective aerosols into the atmosphere over Sweden that ran aground after researchers initially failed to consult local stakeholders and a body representing the Indigenous Saami people in the northern reaches of Nordic nations came out against the testing. (By repeatedly invoking ASI’s nonprofit status, DeWald also seemed to draw a contrast with for-profit stratospheric aerosol injection startup Stardust Solutions, which last year Heatmap’s Robinson Meyer reported had raised $60 million.) “We are continuing to move toward critical planetary thresholds without a viable plan for things like tipping points,” DeWald said. “That was the inflection point for me.”

China just took yet another step closer to energy independence, despite its relatively tiny domestic reserves of oil and gas, kicking off the world’s largest project to blend hydrogen into the natural gas system. As part of the experiment, roughly 100,000 households in the center of the Weifang, a prefecture-level city in eastern Shandong province between Beijing and Shanghai, will receive a blend of up to 10% hydrogen through existing gas pipes. The pilot’s size alone “smashes” the world record, according to Hydrogen Insight. Whether that’s meaningful from a climate perspective depends on how you look at things. A fraction of 1% of China’s hydrogen fuel comes from electrolyzer plants powered by clean renewables or nuclear electricity. But the People’s Republic still produces more green hydrogen than any other nation. Last year, the central government made cleaning up heavy industry with green hydrogen a higher priority — a goal that’s been supercharged by the war in Iran. Therein lies the real biggest motivator now. While China relies on imports for natural gas, swapping out more of that fuel for domestically generated hydrogen allows Beijing to claim the moral high ground on emissions and air pollution — all while becoming more energy independent.
Meanwhile, China’s container ships are the latest sector to experiment with going electric and forgoing the need for costly, dirty bunker fuel. A 10,000-ton fully electric cargo vessel capable of carrying 742 shipping containers just started up operations in China this week, according to a video posted on X by China’s Xinhua News service.
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The ability of electric vehicles to serve as distributed energy resources, charging in times of low demand and discharging back onto the grid when demand peaks, has long been a dream of EV enthusiasts and DER advocates alike. California’s PG&E utility launched a small bi-directional charging program in 2023, allowing owners of Ford F-150 Lightnings to use their trucks as home backup power, and eventually feed energy back onto the grid. The utility added a host of General Motors EVs to the program back in 2025. On Monday, it announced its latest vehicle participant: Tesla’s Cybertruck. The Tesla vehicle will be the first in the program to run on alternating current, which simplifies the equipment necessary and lowers costs for consumers, according to PG&E’s announcement.
In January, I told you about the then-latest company to benefit from President Donald Trump’s dabbling in what you might call state capitalism with American characteristics: USA Rare Earth. The vertically integrated company, which aims to mine rare earths in Texas, took big leaps forward in the past year toward building factories to turn those metals into the magnets needed for modern technologies. For now, however, the company needs ore. On Monday, USA Rare Earth announced plans to buy Brazilian rare earth miner Serra Verde in a deal valued at $2.8 billion in cash and shares. The transaction is expected to be complete by the end of the third quarter of this year. The company pitched the move as a direct challenge to China, which dominates both the processing of rare earths mined at home and abroad. “The world has become too dependent on a single source and it’s high time to break that dependency,” USA Rare Earth CEO Barbara Humpton told CNBC’s “Squawk Box” on Monday.
As if we needed more evidence that the data center backlash is “swallowing American politics,” here’s Heatmap’s Jael Holzman with yet another data point: According to tracking from the Heatmap Pro database, fights against data centers now outnumber fights against wind farms in the U.S. That includes both onshore and offshore wind developments. “Taken together,” Jael wrote, “these numbers describe the tremendous power involved in the data center wars.”