Iris on science · June 25th

The most solid proof comes from two randomized trials. The Finnish FINGER study (2015) and the U.S. POINTER trial (2025) tested a bundle of habits—exercise, a MIND‑style diet, cognitive‑social activity, and vascular monitoring—and both showed modest but reliable gains in memory and thinking scores.

Observational work backs this up, noting that people who move more, eat leafy greens and berries, keep blood pressure low, and stay mentally and socially active tend to develop dementia less often. Those numbers are larger than the trial effects, but they can’t prove cause.

So the “one thing” doesn’t exist. Instead, stack four simple habits: regular movement (especially strength), a MIND‑type eating pattern, good heart‑health numbers, and ongoing mental challenges plus social contact.

Start tiny—a short walk, a serving of greens, a quick blood‑pressure check, or a puzzle—and let each habit become automatic before adding the next. The combined effect is what the evidence points to.

Today, we have a guest essay from our friend Susan Wind, a mom and environmental advocate, who has been bringing attention to public health problems associated with toxic coal ash since her daughter was diagnosed with thyroid cancer at age 16. When she learned that most of her neighbors had cancer too, she decided to do something about it.

Positivity is everywhere these days. You can’t go more than a mile without seeing a bunch of posters extolling the benefits of always looking up, or having an activewear-clad smiler tell you that all you need to do is put a smile on your face and the world will improve. This is not helped by the now-debunked—but still common—belief that simply smiling would make you feel more happy. People love the idea of positivity. If all you need is a sunny outlook to make your life improve, that makes everything so much easier.

In brief: Today’s post takes advantage of a quiet tropics to explain what ridge riding thunderstorms are, as you may be hearing a bit about those in addition to heat next week across a swath of the Central and Eastern U.S. There’s nothing to report in the Atlantic tropics, so today we’ll talk about a topic that will become more relevant in the coming peak summer heat: Ridge-riding thunderstorms. What are they? Well, the name tells you everything. They are thunderstorms that develop and ride the periphery of high pressure in the upper atmosphere.

A recent observational analysis of insurance data shows premiums are already climbing steeply because of climate‑related risks. In the United States, homeowner insurance went up about 29 % and auto insurance roughly 25 % between early 2021 and early 2026. Similar jumps are seen in France, Australia and many low‑income countries, where insurance coverage often stays below 10 %. The pattern signals that climate damage is feeding directly into household costs and broader inflation.

A separate report from risk analysts maps climate exposure for global data centres. It finds more than half of capacity sits in regions facing chronic heat or drought, and nearly four‑fifths are vulnerable to acute hazards like floods, wind or wildfires. The authors argue that, for many markets, climate risk should be treated as a baseline factor rather than a rare shock.

Observational research on food prices in the UK projects that heat‑related “climate‑inflation” could add 11 % to the cost of the top twenty fruits and vegetables by 2035 and up to 68 % by 2050. When combined with ordinary inflation, the total price of fresh produce could be 170 % higher than today. Similar trends are emerging elsewhere: extreme weather is already pushing up costs for growers such as a major banana supplier, which now spends more on shade cloth, reflective sprays and cooling upgrades.

A quasi‑experimental study of London’s low‑emission zone provides a concrete health benefit. After the zone was introduced, emergency hospital admissions for heart and breathing problems fell by about 8 % and 6 % respectively, reversing a prior upward trend. The reduction in sick‑leave and medical visits translates into real savings for families and the health system.

All of these strands point to a growing economic burden from fossil‑fuel‑driven climate change—higher insurance bills, pricier food, and added health costs—while clean‑energy policies, like the three free electricity hours now being rolled out across much of Australia, illustrate how cheaper, abundant power can start to offset those pressures. The evidence suggests that staying on the fossil

The investigation by HEATED, based on public tax filings and board disclosures, shows that Switch Energy Alliance isn’t a neutral nonprofit—it’s funded by major methane‑gas and oil companies, including a $200,000 grant from the Ovintiv Foundation and smaller gifts from Shell USA and the Energy Corps network.

Their free lesson‑plan platform, used by thousands of teachers and tens of thousands of students, frames fossil fuels as essential, downplays their climate harms, and never even names “climate change.” The curriculum highlights oil and gas as “necessary” while emphasizing the limits of renewables, mirroring the talking points of the industry sponsors.

Because the content reaches classrooms across the U.S. and Canada, the bias can shape how a whole generation perceives energy and the climate, making the hidden funding a serious concern for science education.

I’m thinking of the weekend under that 400‑year‑old oak, the heat, the mix of bright minds and the uneasy feeling that settled when two young AI leaders gave their pitch. Their script sounded familiar: the technology is insanely powerful, it could be dangerous, and we’re all scared together. The point was less about data and more about the moral question they left hanging—why keep pushing something that might wipe us out?

The piece walks through the usual answers we hear. “We need to stay ahead of China or Russia,” which treats the race as a grim necessity but never asks if the race itself is ethical. “AI will solve problems we can’t handle,” which sounds hopeful but feels hollow when the leaders aren’t actually prioritising those goals. And the “you’re responsible for how you use it” line, which shifts blame onto users the same way Big Oil once shifted it onto consumers.

What really sticks is the critique of the more seductive narrative: that AI is a spiritual upgrade, a mirror for humanity’s moral failings, a step toward a higher consciousness. The author calls that a kind of gaslighting—packaging a massive, top‑down rollout as a cosmic rite of passage, while ignoring who’s actually shaping the mirror: mostly wealthy, Western, male voices. The result is a sense that the conversation is already over, that the horse has bolted, and any moral questioning is moot.

In the end, the article asks us to look past the rehearsed justifications and notice the gap between the hype and the real stakes. It’s a reminder that, before we accept AI as inevitable, we need to ask whether we should be building it at all, and who gets to decide what “should” looks like.

Twenty-nine Hotshot Crews are now on incidents in the Great Basin, with fires burning across Utah, Nevada, and Wyoming. The largest now being the Cottonwood Fire outside Beaver, Utah, updated this morning at nearly 60,000 acres. The fire remains active this afternoon, but there is a very small chance of precipitation moving through; that system will also bring dry lightning and heavy winds, so a double-edged sword. Fire weather conditions are expected to return full force going into this weekend. Fire managers have said the cause of the fire is human related, but no further details were provided while an investigation is ongoing. Great Basin Team 5 assumed control of the fire today at 6 a.m. Yesterday, extreme fire behavior was fueled by drought conditions, high temperatures, and low fuel moistures. Last night, dozers and hand crews created fire line in the City Creek area. Crews on the east side will engage in structure protection today, as well as fire line construction where they can. On the west side of the fire, firefighters worked around the backside of the fire to build fire line which they will use as an anchor to build continual line from. Today, firefighters will continue establishing fire line and engage in structure protection. Crews will be working day shifts and night shifts, establishing 24- hour fire coverage. Crews from Rocky Mountain Power are working to clear downed power lines from Highway 153 and will be brushing around power lines ahead of the fire on the east side. Several aircraft have been assigned to the incident and will be utilized across the fire. A structure assessment team is being established to assist the county with structure inventories. Fishlake National Forest The Iron Fire has seen some containment put on the map, mostly around the town of Eureka. Firefighters have brought that 37,720-acre fire to 17% containemt. There are 519 personnel on that Utah fire with 15 crews, 2 helicopters, 10 engines, and heavy equipment. The cause of the Iron Fire is under investigation. Last night, firefighters engaged in a firing operation on the Eastern flank of the Iron Fire. Crews successfully utilized this tactic to stop an eastern run the fire was making through the Pinyon Canyon area. Today, crews will continue direct extinguishment activities throughout the fire area, with an emphasis on the Eastern flank firing containment line. Additionally, crews will continue to improve the work that has been accomplished in proximity to the town of Eureka, better solidifying the safety of the community moving forward. Crews will continue to be present during the dry lighting and high windstorm that is predicted to enter the fire area in the afternoon. Great Basin Team 3 Over in Nevada, the 23,187-acre Grapevine Fire remains problematic, while significant progress has been made on the 17,036-acre Kane Springs Fire, now 40% contained. The terrain in the Clover Mountain Wilderness Area, where the Grapevine Fire is, is unforgiving. Crews have conducted multiple firing operations to bring the fire into more favorable ground for containment. The Grapevine Fire remains active in steep, rugged terrain within the Clover Mountain Wilderness Area. Firefighters continue suppression efforts using a combination of direct and indirect tactics, including strategic firing operations, aviation support, and strengthening existing containment features. Over the last several operational periods, firefighters completed significant burnout operations near the Bunker Pass, Mud Springs, and Pine Wash Road areas to remove fuels ahead of the fire and improve containment opportunities. Crews continue to secure those completed operations while scouting additional opportunities to strengthen containment in difficult terrain. Nevada Type 3 Incident Management Team 4 will assume command of the Grapevine Fire tomorrow morning. Incoming personnel are currently participating in transition briefings to ensure continuity of suppression efforts and firefighter safety. Nevada Type 3 Incident Management Team 4 Wyoming popped the Kinky Creek Fire in the Gros Ventre Wilderness of the Bridger Teton National Forest. About as scenic as it gets. The fire ordered a Type 3 Team, and smokejumpers were able to lock in an anchor point last night. The fire is estimated at 350 acres, and the Tallac and Vale Hotshots are en route. Yesterday, smokejumpers were able to create an anchor point at the heel of the fire and are working to keep the fire on the west side of the Gros Ventre River. Other resources began setting up structure protection around Darwin Ranch. Firefighting resources include a type 3 helicopter, air attack, smokejumpers, fire engines, and other support staff, with over 50 firefighters working to suppress the fire. Additional resources have also been ordered and will arrive today. Fire managers are implementing direct extinguishment and indirect confinement strategies on the Kinky Creek Fire.

The Forest Service and the U.S. Wildlife Service are adding a few concrete steps to cut down the health risks firefighters face on the line. First, they’ll make N95 masks widely available during active fire work, and every crew will get mandatory training on how and when to wear them. Second, they’re standardizing decontamination: after a shift, crews will have access to showers and a specific cleaning routine for their Nomex gear, which should clear out soot and chemicals more reliably than ad‑hoc rinses.

Erin Phelps, the agency’s deputy director of risk management, explained that these changes are based on internal reviews of past incidents where inadequate protection led to respiratory and skin issues. The new protocols are being rolled out as a uniform policy, so every federal firefighter gets the same level of protection, regardless of the region.

Finally, the agencies are tightening rules around mop‑up work, limiting how long crews stay in low‑intensity smoke without a break. The goal is to keep exposure times short enough to avoid the cumulative inhalation problems that have shown up in health monitoring data. All of this should start reducing the long‑term health burden for firefighters in the coming fire seasons.

Solar now beats coal in the United States: for the first time on record, solar accounted for 12.8 % of national electricity generation last month, while coal fell to 12.2 %. That’s a reversal from five years ago, when coal produced roughly three times as much power as solar. The numbers come straight from the U.S. Energy Information Administration, which tracks hourly generation across the grid.

China’s renewable rollout is even more striking. Annual installations of wind and solar there now exceed the combined additions of the rest of the world, and the country is hitting its renewable‑energy targets ahead of schedule. The United Kingdom, too, has shut down its final coal plant and gets almost half its electricity from wind and sun.

Meanwhile, NOAA confirmed El Niño conditions on June 11, with sea‑surface temperatures already 1 °C above average and a 63 % chance of a “very strong” or “super” event later this year. Historical super El Niños (1982‑83, 1997‑98, 2015‑16) have been linked to severe heatwaves, floods, wildfires and economic losses that can double the risk of civil conflict in tropical regions.

Because solar is now the cheapest electricity source on record, new projects are being installed roughly every minute in the U.S. The trend is moving forward despite federal policies that have tried to slow renewables, suggesting the market dynamics are outpacing political resistance.