The Knowledge
2025 was hotter than it should have been – 5 influences and a dirty surprise offer clues to what’s ahead
The past three years recorded unprecedented global heat, with 2025 being particularly warm. Factors such as greenhouse gas emissions and a decline in solar activity influenced temperatures and extreme weather patterns.
Michael Wysession, Washington University in St. Louis
The past three years have been the world’s hottest on record by far, with 2025 almost tied with 2023 for second place. With that energy came extreme weather, from flash flooding to powerful hurricanes and severe droughts. Yet, by most indicators, the planet should have been cooler in 2025 than it was.
So, what happened, and what does that say about the year ahead?
As an earth and environmental scientist, I study influences that affect global temperatures year to year, such as El Niño, wildfires and solar cycles. Some make Earth hotter. Some make it cooler. And one particularly unhealthy influence has been quietly hiding a large amount of global warming – until now.
Factors that made 2025 cooler than 2024
The Earth’s climate is the result of many factors that change from year to year. Some that helped make 2025 cooler than 2024 include:
La Niña’s arrival: La Niña is part of the El Niño-Southern Oscillation, a natural climate pattern that fluctuates between warm El Niño conditions and cooler La Niña conditions. During El Niño, the Pacific Ocean heats up along the equator, influencing the atmosphere in ways that can cause intense storms, droughts and heat waves around the planet. La Niña does the opposite; it’s like putting an ice pack on the atmosphere.
Both 2023 and 2024 were El Niño years, but in 2025 conditions shifted to neutral and then to La Niña starting in September.
The solar cycle: The Sun reached its solar maximum near the end of 2024, the peak of its energy output in an approximately 11-year cycle, and began declining in 2025. So, while the sun’s output was still stronger than average in 2025, it was less than in 2024.
Fewer wildfires: Despite some destructive blazes, the world also saw fewer wildfires during 2025 than 2024, which put less carbon dioxide – a planet-warming greenhouse gas – into the atmosphere.
Despite those points, 2025 still ended up as the third-hottest year in over 175 years of record-keeping and likely one of the warmest in at least several thousand years. It was nearly as warm as 2023, at 2.6 degrees Fahrenheit (1.47 Celsius) above the 1850-1900 average, according to the European Union’s Copernicus Climate Change Service. It also had the second-highest average land temperature recorded, up 3.6 F (2 C) compared to preindustrial years, with more than 10% of the land experiencing record-high temperatures.
Factors that made 2025 warmer than expected
Several other factors made 2025 warmer than expected, and some are likely to continue to increase in 2026. They include:
Greenhouse gas emissions: The big driver of global warming is excess greenhouse gas emissions, largely from burning fossil fuels, and 2025 had plenty.
Greenhouse gases trap heat near Earth’s surface like a blanket, raising the temperature. They also linger in the atmosphere for years to centuries, meaning gases released today will continue to warm the planet well into the future. The levels of carbon dioxide, methane and nitrous oxide in the atmosphere all increased in 2025.
Rising energy demand drove an increase in fossil fuel use. About 80% of the increasing electric power demand came from emerging economies, largely for rising air conditioning demands as the world gets hotter. In the U.S., the rapid growth of data centers for AI and cryptocurrency mining helped boost U.S. carbon dioxide emissions by 2.4%.
Earth’s energy imbalance: Other sources can disrupt the natural balance between the amount of sunlight that reaches Earth and the lesser amount radiated back to space. A recent study found that Earth’s energy uptake surged and temperatures rose quickly when a rare three-year La Niña in 2020-2022 shifted to El Niño in 2023-2024.
Declining polar ice, which efficiently reflects sunlight back into space, also affects the energy balance. As sea ice declines, it leaves dark ocean water that absorbs most of the sunlight that reaches it. In a spiraling feedback, warmer water melts sea ice, allowing more sunlight into the ocean, warming it faster; 2025 had the lowest winter peak of Arctic sea ice on record and the third-lowest minimum extent of Antarctic ice.
https://datawrapper.dwcdn.net/t0SSd/1
Air pollution: Sulfate aerosol pollution from coal combustion and burning heavy fuel oil in shipping has also been affecting Earth’s energy balance. It has been masking the full effects of human-caused greenhouse gases for years by reflecting sunlight back into space, creating a cooling effect. But sulfate aerosol pollution is also a serious health hazard, blamed for about 8 million human deaths per year from lung diseases.
Recent reductions in sulfate pollution – now 40% less than 20 years ago – have meant about a 0.2 F (0.13 C) increase in global temperatures. Much of the reduction was from China’s efforts to reduce its notoriously bad air pollution in recent years and international shipping rules in effect since 2020 that have reduced sulfur emissions from large ships by 85%.
Taking all factors together, humans are now warming the planet at a faster rate than at any point in human history: at about 0.5 F (0.27 C) per decade. That extra heat can fuel extreme weather, including flash floods, heat waves, extended droughts, wildfires and coastal flooding, affecting human lives and economies.
Predictions for 2026
Most climate models predict 2026 will be about as hot as 2025, depending on whether a Pacific El Niño develops, which forecasters give about a 60% chance of happening. The planet is already starting the year out warm, even if it doesn’t feel like that everywhere. While January was very cold in parts of the U.S., globally, Earth saw its fifth-warmest January on record, and much of the western U.S. saw one of its warmest winters on record.
Solar output will continue to decrease slowly in 2026. However, the International Monetary Fund projects strong global economic growth at about 3.3%, suggesting electricity demand will also continue to grow. The International Energy Agency expects global electricity demand to increase by 3.6% per year through at least 2030.
Even though global renewable energy use is growing quickly, it isn’t growing fast enough to meet rising demand, meaning more fossil fuel use in the coming years. More fossil fuels burned means more emissions and more warming, while the ability of the ocean and land to absorb carbon dioxide continues to decrease. As a result, the atmosphere and oceans heat up, increasing the risks of passing tipping points – glaciers disappear, Atlantic Ocean circulation shuts down, permafrost thaws, coral reefs die.
If greenhouse gas emissions continue at a high rate, humanity may look back at 2025 as one the coolest years globally in the rest of our lives.
Michael Wysession, Professor of Earth, Environmental, and Planetary Sciences, Washington University in St. Louis
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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The Knowledge
When Did Water Vending Machines Become a Thing?
When did water vending machines appear in America? Explore their history from a 1908 penny water vendor to the refill machines of the 1970s and 1980s.
You’ve probably seen them hundreds of times.
They sit outside supermarkets, convenience stores and shopping centers—or sometimes stand alone in small roadside kiosks. You bring an empty bottle, usually one, three or five gallons, put in some money, push a button and watch purified water pour into your container.
For many people in California, Arizona and other parts of the American West, water vending machines seem like they’ve simply always been there.
But when did we actually start buying water this way?
The answer takes us back more than a century, although the machines we recognize today didn’t really arrive until the 1970s.
The Water Vending Machine’s Surprising Ancestor
The story begins in Boston in 1908 with a man named Lawrence Luellen.
Luellen was working on something that sounds surprisingly modern: a machine that would allow someone to pay a penny and receive a clean drink of water in an individual disposable cup.
At the time, public drinking water was often consumed from a communal cup or metal dipper—a practice that increasingly worried public-health officials because of the potential spread of disease.
Luellen developed a paper drinking cup along with what became known as the Luellen Cup & Water Vendor. The porcelain machine contained water, ice, disposable cups and a place for discarded cups.
For one penny, a customer could get a drink of cold water in a fresh cup.
Historical records at Lafayette College’s Hugh Moore Dixie Cup Company Collection show that Luellen completed work on the vending apparatus in early 1908. His company, the American Water Supply Company of New England, was incorporated on April 4 of that year.
There was just one problem.
The complete water machine was expensive to manufacture.
The company eventually concentrated on selling the disposable cups and cup dispensers instead. Those cups ultimately evolved into one of America’s most recognizable household products—the Dixie Cup.
So although Luellen’s machine wasn’t the five-gallon refill station we know today, the basic idea was already there:
Put money into a machine and receive drinking water.
The Modern Water Vending Machine Arrives
The next major chapter didn’t occur until roughly 65 years later.
According to histories of the water-vending industry, the first practical machines designed to sell purified water in bulk appeared during the mid-1970s.
These were fundamentally different from Luellen’s machine.
Instead of giving customers a cup of water, the new machines treated water—typically municipal tap water—and allowed customers to fill their own reusable containers.
And we have unusually strong evidence that these machines were operating by 1976.
On July 26, 1976, the U.S. Environmental Protection Agency issued a memorandum specifically addressing the regulatory status of water vending machines.
The EPA described machines that filtered and disinfected water with ultraviolet light and then dispensed the treated water into a customer’s own container using a coin-operated mechanism.
In other words, by the summer of 1976, the basic water-refill machine many of us recognize today was already operating in the United States.
Why the 1970s?
The timing wasn’t accidental.
Americans had become increasingly concerned about pollution and drinking-water quality during the 1960s and 1970s.
Congress passed the Safe Drinking Water Act in 1974, establishing a federal framework for protecting public drinking-water supplies. National drinking-water regulations followed during the decade.
Meanwhile, technologies such as filtration, activated carbon treatment, ultraviolet disinfection and eventually reverse osmosis made it practical to build relatively compact systems capable of treating municipal water at the point where it was sold.
The result was a new business opportunity:
Instead of transporting thousands of bottles of water to a store, a vending company could connect a machine to the local water supply, purify that water on site and sell it by the gallon.
Customers supplied the bottle.
California Helps Turn It Into a Business
California became one of the industry’s most important early markets.
One company that would eventually become a major player was founded by Robert G. Miller.
In 1983, Miller established Bottle Water Vending Inc., the predecessor of Glacier Water Services.
The company manufactured water vending machines and placed many of them outside supermarkets. Customers brought their own containers, while participating stores often sold reusable plastic jugs nearby.
The machines treated municipal water using combinations of filtration, reverse osmosis, carbon treatment and ultraviolet sterilization.
The idea caught on quickly.
In 1984, the company expanded from California into Arizona.
Nevada followed in 1986.
By 1987, the company reportedly had nearly 900 water vending machines operating.
Texas and Florida followed in 1988.
The familiar supermarket water-refill station was becoming a significant business.
Then Came the Drive-Up Water Kiosk
Another variation appeared at almost exactly the same time.
In 1984, Lani and Don Dolifka developed what became Watermill Express in Colorado.
Their idea was an automated stand-alone purification kiosk capable of taking municipal water, processing it through multiple purification stages and selling the finished drinking water directly to customers.
Instead of walking into a supermarket, customers could pull up to the kiosk with their bottles.
Later Watermill Express systems were designed to accommodate reusable containers ranging from one to five gallons, using treatment processes including sediment filtration, activated carbon, reverse osmosis, ultraviolet disinfection and ozone treatment.
That basic concept remains familiar today.
Why Five-Gallon Bottles?
The five-gallon container was already well established through traditional bottled-water delivery services.
But refill vending changed the economics.
Instead of purchasing another filled bottle—or waiting for a delivery—a customer could keep the same container and refill it repeatedly.
That eliminated much of the packaging and transportation involved with conventional bottled water.
It also made purified drinking water relatively inexpensive.
Bring the jug.
Buy the water.
Take the same jug home.
Bring it back when it’s empty.
More than four decades later, that’s still essentially how the system works.
So Who Invented the Modern Water Vending Machine?
That’s where the story gets complicated.
There doesn’t appear to be a single universally recognized inventor of the modern bulk purified-water vending machine.
Lawrence Luellen developed an important early coin-operated water vending concept in 1908, but his machine dispensed an individual drink and disposable cup—not gallons of purified water into a customer’s reusable bottle.
The modern bulk-water machine emerged much later, apparently during the mid-1970s, as water-treatment technology and consumer concern about drinking-water quality converged.
By 1976, the EPA was already dealing with the regulatory implications of machines that treated municipal water and sold it through coin-operated dispensers into customers’ own containers.
Entrepreneurs and companies then refined and expanded the idea during the 1980s.
From a Penny Cup to Five Gallons at a Time
The evolution is remarkable.
1908: Put in a penny and receive a cup of cold water.
Mid-1970s: Machines begin treating municipal water and selling purified water in bulk.
1976: The EPA documents coin-operated machines dispensing treated water into customers’ containers.
1983: Bottle Water Vending, the predecessor of Glacier Water Services, begins operations in California.
1984: Glacier’s predecessor expands into Arizona, while Watermill Express develops its automated purification kiosk in Colorado.
Late 1980s and beyond: Water refill machines become increasingly familiar outside supermarkets and at stand-alone locations throughout the United States.
Today, paying a few coins—or tapping a card—and filling a five-gallon jug might seem thoroughly ordinary.
But the machine sitting outside your neighborhood supermarket represents more than a century of evolution in how Americans buy something that once seemed almost unimaginable to sell from a vending machine:
a drink of water.
Sources and Further Reading
U.S. EPA — Status of Water Vending Machines Under Public Law 93-523
Lafayette College — Hugh Moore Dixie Cup Company Collection
U.S. EPA — Safe Water Research Milestones
Glacier Water Services Company History
World Vision — History of Watermill Express
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High Speed Rail
Brightline West Construction Advances, But Opening Timeline Shifts Beyond the 2028 Olympics
Construction continues to expand along Interstate 15 as Brightline West moves closer to connecting Southern California and Las Vegas with 200 mph electric trains, though the opening timeline has shifted to late 2029.
The vision of traveling between Southern California and Las Vegas in about two hours by high-speed rail is steadily becoming more tangible as Brightline West expands construction activity along the Interstate 15 corridor.
Since construction officially began in 2025, work has continued to ramp up in both California and Nevada. Motorists traveling I-15 may have noticed increased construction activity, survey crews, utility work, and periodic lane closures as the project moves from planning into full-scale development.
Construction Is Becoming More Visible
Brightline West’s 218-mile all-electric high-speed rail line will connect Rancho Cucamonga, California, with Las Vegas, Nevada, using the median of Interstate 15 for much of the route.
Current work includes:
- Utility relocation
- Geotechnical investigations
- Site preparation
- Early civil construction
- Continued work around future station locations
As construction progresses, travelers should expect additional traffic impacts along portions of I-15 while crews prepare for bridges, guideways, track installation, and station construction.
A New Timeline
One of the biggest developments since construction began is a revised completion schedule.
While Brightline West was once expected to open before the 2028 Los Angeles Olympic Games, current projections now place passenger service in late 2029.
Large infrastructure projects frequently experience schedule adjustments due to inflation, labor availability, permitting, and supply chain challenges. Although the delay means Olympic visitors are unlikely to ride the line, construction continues to move forward.
Four Passenger Stations Planned
The line will include stations at:
- Las Vegas
- Apple Valley
- Hesperia
- Rancho Cucamonga
Passengers traveling from Los Angeles will transfer to Brightline West using Metrolink at Rancho Cucamonga, creating an important connection between Southern California’s commuter rail network and the new high-speed line.
Fast, Electric Travel
When complete, Brightline West trains are expected to operate at speeds approaching 200 mph, reducing travel time between Rancho Cucamonga and Las Vegas to approximately 2 hours and 10 minutes.
The fully electric trains are being manufactured by Siemens and are designed to offer a comfortable alternative to one of America’s busiest highway corridors.
Looking Ahead
The next major milestones will likely include visible bridge construction, elevated guideways, station buildings, track installation, electrical systems, and eventually testing of the first trainsets.
While passengers will have to wait a bit longer than originally hoped, Brightline West remains one of the most ambitious passenger rail projects currently under construction in the United States.
For Southern California, it represents more than a faster trip to Las Vegas—it could signal the beginning of a new era for high-speed passenger rail in the American West.
Have you driven the I-15 corridor recently? Have you seen any Brightline West construction? Share your observations in the comments below, and subscribe to the STM Daily News newsletter for more transportation and infrastructure updates.
Source and Related Links
- Brightline West – Construction:Construction Plan & Current Project Details — breakdown of the Nevada and California construction segments, stations, track/electrification and maintenance facility.
- Brightline West – Construction Advisories:Current Construction Advisories — useful for ongoing field investigations, lane impacts and work-zone updates.
- Brightline West – Project Overview:Official Project Overview — confirms the 218-mile Las Vegas–Rancho Cucamonga route and overall project scope.
- Nevada Department of Transportation:Brightline West High-Speed Rail Project — government source covering the route, stations, $3 billion federal award and construction background.
- Siemens Mobility:American Pioneer 220 Manufacturing Facility — details on the U.S.-built high-speed trainsets and Siemens’ Horseheads, New York manufacturing facility.
- Brightline West – Official Groundbreaking:April 2024 Groundbreaking Announcement — useful background on the project’s infrastructure, bridges, rail, electrification and Buy America commitments.
Transportation
LAX SkyLink Is 99% Complete — But New Financial and Legal Questions Cloud October Opening
Last Updated on August 16, 2026 by Daily News Staff
LOS ANGELES — After years of delays, construction disputes and rising costs, the long-awaited train that promises to transform how passengers move through Los Angeles International Airport appears tantalizingly close to the finish line.
But there’s still a catch.
LAX SkyLink — formerly known as the Automated People Mover — is more than 99% complete and trains are running along the elevated guideway as part of testing. Yet passengers still can’t climb aboard, and new financial and legal concerns are adding uncertainty as the project approaches critical deadlines this fall.
The latest estimates point toward passenger service beginning no earlier than October 2026, with October 6 emerging as a target date in project documents and recent reporting. However, Los Angeles World Airports (LAWA) has not announced October 6 as a firm public grand-opening date.
For travelers who have watched empty trains glide above LAX for months, the obvious question remains:
If SkyLink is essentially finished, what’s taking so long?
Trains Are Running — Just Without Passengers
SkyLink entered a major new phase in April when extensive operational testing began on the 2.25-mile elevated system.
The testing isn’t simply about determining whether the trains move. The entire automated system — trains, signaling, stations, platform doors, communications and other components — must demonstrate that it can operate reliably and safely before passengers are allowed aboard.
One major requirement calls for the system to operate for 30 consecutive days without a significant problem before passenger operations can begin. As of late June, that milestone had not yet been achieved.
That explains why travelers at LAX can see what looks like a functioning railroad while still being directed to buses, cars and shuttles.
The trains may be moving, but the system hasn’t completed the certification process required for public service.
October 6 Is a Target — Not Yet a Grand Opening
Recent reporting based on project scheduling information has identified October 6, 2026, as an estimated date for passenger service availability.
That’s an important distinction.
Until LAWA announces an official opening date, travelers shouldn’t necessarily start planning an October 6 SkyLink ride.
And developments reported in August suggest there is still reason for caution.
A New Financial Warning
The latest wrinkle involves the financing behind the project.
Fitch Ratings recently placed approximately $1.2 billion in senior bonds associated with the project on negative watch and downgraded the bonds deeper into speculative-grade territory, according to reporting published in August.
Fitch cited the increasingly limited amount of time available before important contractual deadlines.
According to the ratings agency, the project’s lenders face a longstop date of October 8, 2026, while the overall project has another critical longstop date of December 8, 2026. Further delays could create increasingly serious contractual and financial complications.
That doesn’t mean SkyLink is about to be abandoned.
But it does demonstrate just how little breathing room remains after years of delays.
The Legal Battle Isn’t Over Either
Meanwhile, the relationship between LAWA and the consortium responsible for building and operating SkyLink remains strained.
LAX Integrated Express Solutions, better known as LINXS, filed a lawsuit against the City of Los Angeles in July alleging breaches of its project agreement.
LINXS contends that airport-related actions contributed to delays and that the consortium is entitled to additional compensation and schedule extensions.
LAWA has maintained that its focus remains getting SkyLink completed and safely opened to passengers.
The dispute is the latest chapter in a project that has experienced years of disagreements between the airport and its contractor.
From a 2023 Opening to Late 2026
It’s worth remembering just how late this project has become.
SkyLink was originally expected to enter service in 2023.
Subsequent schedules moved the opening into 2024, 2025 and then early 2026. LAWA announced in 2024 that it expected passenger service to begin in January 2026.
That didn’t happen either.
Testing finally accelerated in spring 2026, but additional technical work and project disputes pushed expectations deeper into the year.
The project’s reported construction cost has climbed to roughly $3.34 billion, making SkyLink both one of LAX’s most important modernization projects and one of its most troubled.
Why SkyLink Matters So Much
Despite the delays, SkyLink could dramatically improve the passenger experience at LAX once it opens.
The fully automated electric train will operate along a 2.25-mile elevated guideway serving six stations.
Three stations will serve the Central Terminal Area, while the remaining stations provide connections to ground transportation, parking, rental cars and regional transit.
Most importantly for public transportation riders, SkyLink will connect airport terminals with the LAX/Metro Transit Center, finally creating the missing rail link between LAX terminals and Metro’s C and K Lines.
Currently, Metro passengers reaching the Transit Center must transfer to shuttle buses to reach their terminals.
SkyLink is designed to eliminate that final shuttle ride.
According to LAWA, trains will operate 24 hours a day, seven days a week. During peak hours between 9 a.m. and 11 p.m., trains are expected to arrive approximately every two minutes.
Each four-car train can carry as many as 200 passengers and their luggage, while the complete end-to-end journey is expected to take approximately 10 minutes. Trains can reach speeds of up to 47 mph.
The Finish Line Is Finally Visible
For anyone who has followed the SkyLink saga, skepticism about another projected opening date is understandable.
The project has been “almost finished” for a remarkably long time.
But there is an important difference in 2026: the trains are now running across the actual system.
Construction has largely given way to testing, certification and final completion work.
That makes the current situation considerably different from previous years when major construction and systems integration remained unfinished.
Still, the combination of reliability testing, financial pressure, contractual deadlines and litigation means October shouldn’t be written in permanent ink just yet.
For now, October 2026 remains the target rather than a guaranteed opening.
And after waiting three years beyond the original opening schedule, Southern California travelers may want to wait until LAWA officially announces the first day of passenger service before celebrating.
When that day finally arrives, however, it will mark a major milestone not just for LAX but for Los Angeles transportation.
For the first time, travelers will be able to step off a Metro train, transfer to SkyLink and reach the airport terminals without sitting in LAX’s infamous horseshoe traffic.
After all the delays, disputes and billions of dollars spent, that first passenger trip can’t come soon enough.
Official Project Information
For the latest official information about the project, visit the Los Angeles World Airports SkyLink project page.
STM Daily News will continue following SkyLink as the project moves toward passenger service.
Related Links
- Los Angeles World Airports — LAX SkyLink — Official project page with system details, stations, train capacity, operating plans and project information. LAX SkyLink Official Project Page
- LA Metro — LAX/Metro Transit Center — Information about the transit center that will connect Metro’s C and K Lines with SkyLink. LAX/Metro Transit Center
- LA Metro — Getting to LAX — Current information for travelers using Metro to reach LAX, including the shuttle connection that will eventually be replaced by the direct SkyLink transfer. Go Metro to LAX
- LA Metro — C and K Line Schedules — Current rail schedules for the lines serving the LAX/Metro Transit Center. LA Metro Rail Schedules
- Los Angeles World Airports — Transforming LAX — Overview of the airport’s broader modernization program, including SkyLink and other major LAX infrastructure projects. Transforming LAX
