Technologies

As a ‘Sea Ice Free’ Arctic Looms, the Climate Consequences Are Mounting

Research points to a milestone in the 2030s, but sea ice is already disappearing at an unprecedented rate. And that affects all of us.

The sound of ice cracking underneath the hull of a 25,500-ton icebreaker is unmistakable. No matter where you are — shuffling along the lunch line in the galley or sitting on the observation deck with a pack of cards — the wincing of steel and crunching of ice can shriek through the ship. It’s almost ghostly; undeniably haunting.

The sight of the ice? That’s mesmerizing. From the deck of Australia’s icebreaker, the RSV Nuyina, on which I sailed to Antarctica for more than five weeks at the start of 2022, it’s like looking out over a Martian landscape that’s been covered in a coat of stark white paint. In the distance, castles of ice rise from the vast, unbroken ice sheet. At the foot of one fortress, a battalion of King penguins lurks, unfazed by the freezing temperatures. Behind the ship, smaller Adelie penguins avoid a scrap with a leopard seal by climbing onto an island of ice and scurrying away.

Sea ice is vital to the Antarctic ecosystem. It’s not just a refuge for penguins and other animals, but a fundamental facet of life for creatures further down the food chain too, like Antarctic krill. It means life. The ice is also critical for heat because it’s more reflective than water, bouncing back more sunlight than the ocean, and it can act as a physical barrier, impacting the exchange of gases between the ocean and the atmosphere and protecting the continent’s ice shelves.

The Antarctic is currently experiencing the lowest level of sea ice since satellites began taking measurements in 1979. It’s an anomaly scientists are concerned about and monitoring closely. It was just a decade ago that sea ice in the Antarctic reached record highs, but generally low extents have been observed since 2016. It’s worrying, and could signal a shift in the sea ice dynamics down south, but the situation is more dire at the opposite end of the planet.

There, at the Earth’s northern extreme, the Arctic is experiencing an increase in temperatures two to four times higher than anywhere else in the world, and sea ice has decreased by about 12% per decade since the beginning of the satellite era. About 548,000 square miles of sea ice has been lost since 1979, equivalent to losing an area of ice roughly half the size of India. It’s seen a more rapid decline since 2000.

It’s one of the most obvious signs that greenhouse gas emissions are shifting the planet’s equilibrium. Researchers say we can take steps to slow the changes, but we need to act with urgency.

The 4 million people who call the Arctic home rely on the Arctic Ocean for food and transportation. The Indigenous peoples of the Arctic, who make up about 10% of the population, have a vibrant and longstanding cultural connection to the region that is slowly dripping away as regions become free of sea ice for the first time in millennia.

Meanwhile, the distribution of wildlife is shifting and behaviors are changing, altering the interactions between predators and prey. The Arctic’s famous polar bears rely on the ice to hunt and now have to travel further to eat, whereas the narwhal, a near-mythic, tusked whale, faces increased threats from killer whales lingering in exposed, warmer waters and disruptions to its migratory patterns.

Our best models currently predict the Arctic will be «sea ice free» within the next few decades, perhaps as soon as the 2030s. Antarctica’s sea ice is more of a mystery. But at both poles, sea ice is disappearing at an unprecedented rate.

And when the ice ends it’s not just the ends of the Earth that will change. It’s the entire planet.

An already changed Arctic

The Arctic Ocean’s sea ice expands during the winter, peaking in March, before retreating toward the North Pole. It typically reaches its lowest extent in mid-September. It never completely melts away — the North Pole itself is typically surrounded, and up to a fifth of the ice in the Arctic is so-called multiyear ice, persisting for more than a year.

Our understanding of this rhythmic pulse in the Northern Hemisphere stretches back for millennia. Indigenous peoples of the Arctic have passed down knowledge of the sea ice’s extent for thousands of years, particularly around coastal communities. Iceland’s government has been keeping detailed records since the 1600s, while log books and diaries kept during early exploration by ship provide a surprising amount of detail on where and when the Arctic Ocean froze over.

Our ability to understand the ice changed dramatically with the launch of the Nimbus-7 satellite in late 1978. The NASA and NOAA polar-orbiting satellite was fitted with an instrument that provided a way to observe the extent of the sea ice all year round, no matter the weather conditions, by studying the microwave energy bounced back from the surface. Continuous records have been taken since 1979, and the analysis has been deeply troubling. The extent of Arctic sea ice has been decreasing across those four decades, with each of the last 16 years the lowest on record.

Video: Changes in Arctic sea ice

Video credit: NASA’s Scientific Visualization Studio

For decades, scientists have tried to pinpoint when the total extent of Arctic sea ice will drop below 1 million square kilometers (or about 386,000 square miles) — the marker denoting a «sea ice-free» summer. In 2009, for instance, one study used climate models to determine that this mark would be hit by 2037. Other research has shown that the timing is unpredictable, with analyses suggesting we might still be decades away.

In June, a study in the journal Nature Communications analyzed 41 years of satellite data, from 1979 to 2019, reiterating that human greenhouse gas emissions are the dominant force in reduction of Arctic sea ice. It also generated a flurry of worrying headlines focused on the first ice-free summer, citing the near end of a range that it said had shifted to as early as the 2030s to 2050s. But those headlines gloss over a critical point: The current losses of summer sea ice are already having devastating effects.

«Although the first ice-free Arctic summer has constantly been a point of interest for understanding and communicating climate change, it’s more a symbolic threshold in some sense,» says Zachary Labe, a climate scientist at Princeton University and the National Oceanic and Atmospheric Administration. «Arctic climate change is already happening now and in all months of the year.»

An Antarctic paradox

From the beginning of the satellite era until 2010, Antarctic sea ice experienced a slight increase, with an acceleration in winter sea ice extent between 2012 and 2014. This was unexpected. Global temperatures have unequivocally risen in this time, largely due to human-induced climate change, raising ocean temperatures. Sea ice should’ve been melting. It didn’t.

The phenomenon was dubbed the Antarctic paradox.

Many climate models haven’t been able to reproduce these effects, though at least one high-resolution model has had success. Though explaining the paradox has been difficult, scientists have several hypotheses.

A visit to Antarctica

Natalie Robinson, a marine physicist at New Zealand’s National Institute of Water and Atmospheric Research, points out that changing wind patterns, release of freshwater from Antarctica, and ocean stratification could all have played a role over the last four decades, but she says that pointing to one variable as a driver of the increase is virtually impossible. «In reality, all of these processes act simultaneously and influence each other,» she notes.

About seven years ago, the story began to change. Antarctic sea ice extent plummeted in 2016 and hasn’t totally recovered since. In 2023, winter sea ice extent is dramatically lower than we’ve ever seen in the satellite era.

«Antarctic sea-ice extent has now adopted a downward trajectory as expected under warming and is congruent with observations of surface warming in the Southern Ocean,» says Petra Heil, a polar ice scientist with the Australian Antarctic Division. Graphs generated by Labe show the stark decline.

A line graph of Antarctic sea ice extent in 2023 generated by Zachary Labe

The record low extent has scientists concerned. Understanding the paradoxical increase over the past four decades could help unlock the reasons behind this sudden change. Does it represent a shift to a worrying new normal? Or is it merely a blip that can be attributed to the normal range of variability?

«There is certainly a fair bit of concern in the scientific community that it’s the former,» says Robinson.

«And we are racing to find out.»

When the ice ends

The great white sheets at either end of the Earth are particularly good at reflecting sunlight. Sea ice covers about 15% of the world’s oceans across the year, and up to 70% of the heating energy is reflected back into space. Cover that ice with a dusting of snow and up to 90% can be reflected.

When the sea ice disappears, the energy is absorbed by the ocean, raising its temperature. «In a positive feedback loop this ocean warming leads to even more ice loss and global warming,» says Heil. She suggests conceptualizing the impact of sea-ice loss by thinking about sea ice as the air conditioning unit of the Earth.

When the sea ice disappears, our planetary AC unit is being switched off. It becomes harder to reflect that heat into space and we lose the ability to «self-regulate» the Earth’s climate.

The change doesn’t affect just the ocean surface and the Earth’s air temperatures, though. Sea ice also plays one of the most critical roles on the planet in the ocean’s depths. As seawater freezes into ice, salt is expelled, making the surrounding water denser. This heavier, colder water sinks and gets whisked around the planet. Warmer waters are predominantly pushed by wind into the polar regions, then freeze up into ice. The cycle is known as thermohaline circulation.

«This process can be regarded as the starting point/engine of the global oceans’ overturning circulation,» says Jan Lieser, a sea ice scientist with the Australian Bureau of Meteorology and University of Tasmania.

image of the global conveyor belt with red arrows signifiying warmer water pushing around into the poles and blue arrows signifying colder deep currents

As the oceans continue to warm at both poles and sea ice extent decreases, this deep ocean current is likely to be disturbed. The knock-on effects could disrupt the polar ecosystems as nutrients and ocean biogeochemistry are altered, particularly in the Southern Ocean, where circulation is also heavily influenced by Antarctic meltwater and the currents already show signs of slowdown.

The atmosphere and ocean systems are incredibly complex and intertwined. Though the focus has long been on the extent of the sea ice, thickness also plays a role. So does snow cover. These measurements are harder to include in models because they’ve traditionally been difficult to gather. There are also differences at either pole. The Arctic typically has had thicker sea ice lasting for years, whereas Antarctic sea ice freezes new each year.

It now seems highly unlikely that the current declines can be stopped but Heil, and her colleague Melinda Webster from the University of Washington, say «it’s possible to slow and mitigate further detrimental effects of a warming climate by reducing greenhouse gas emissions and implementing ways to reduce existing atmospheric greenhouse-gas concentrations to levels that can sustain a habitable climate.»

On June 16, Heil and Webster, and more than 60 other polar scientists responded to the changes to the poles by calling for «urgent intensification of national and international research and observational capabilities in view of rapid Arctic and Antarctic change.»

«Action is required now,» she says, «to give future generations a fighting chance to mitigate the negative consequences of a warming climate.»

The anomaly in Antarctica’s sea ice this year, as if sounding its own alarm and affirming Heil’s calls, has only continued its downward trajectory.

Technologies

How Team USA’s Olympic Skiers and Snowboarders Got an Edge From Google AI

Google engineers hit the slopes with Team USA’s skiers and snowboarders to build a custom AI training tool.

Team USA’s skiers and snowboarders are going home with some new hardware, including a few gold medals, from the 2026 Olympics. Along with the years of hard work that go into being an Olympic athlete, this year’s crew had an extra edge in their training thanks to a custom AI tool from Google Cloud.

US Ski and Snowboard, the governing body for the US national teams, oversees the training of the best skiers and snowboarders in the country to prepare them for big events, such as national championships and the Olympics. The organization partnered with Google Cloud to build an AI tool to offer more insight into how athletes are training and performing on the slopes.

Video review is a big part of winter sports training. A coach will literally stand on the sidelines recording an athlete’s run, then review the footage with them afterward to spot errors. But this process is somewhat dated, Anouk Patty, chief of sport at US Ski and Snowboard, told me. That’s where Google came in, bringing new AI-powered data insights to the training process.

Google Cloud engineers hit the slopes with the skiers and snowboarders to understand how to build an actually useful AI model for athletic training. They used video footage as the base of the currently unnamed AI tool. Gemini did a frame-by-frame analysis of the video, which was then fed into spatial intelligence models from Google DeepMind. Those models were able to take the 2D rendering of the athlete from the video and transform it into a 3D skeleton of an athlete as they contort and twist on runs.

Final touches from Gemini help the AI tool analyze the physics in the pixels, according to Ravi Rajamani, global head of Google’s AI Blackbelt team. which worked on the project. Coaches and athletes told the engineers the specific metrics they wanted to track — speed, rotation, trajectory — and the Google engineers coded the model to make it easy to monitor them and compare between different videos. There’s also a chat interface to ask Gemini questions about performance.

«From just a video, we are actually able to recreate it in 3D, so you don’t need expensive equipment, [like] sensors, that get in the way of an athlete performing,» Rajamani said.

Coaches are undeniably the experts on the mountain, but the AI can act as a kind of gut check. The data can help confirm or deny what coaches are seeing and give them extra insight into the specifics of each athlete’s performance. It can catch things that humans would struggle to see with the naked eye or in poor video quality, like where an athlete was looking while doing a trick and the exact speed and angle of a rotation.

«It’s data that they wouldn’t otherwise have,» Patty said. The 3D skeleton is especially helpful because it makes it easier to see movement obscured by the puffy jackets and pants athletes wear, she said.

For elite athletes in skiing and snowboarding, making small adjustments can mean the difference between a gold medal and no medal at all. Technological advances in training are meant to help athletes get every available tool for improvement.

«You’re always trying to find that 1% that can make the difference for an athlete to get them on the podium or to win,» Patty said. It can also democratize coaching. «It’s a way for every coach who’s out there in a club working with young athletes to have that level of understanding of what an athlete should do that the national team athletes have.»

For Google, this purpose-built AI tool is «the tip of the iceberg,» Rajamani said. There are a lot of potential future use cases, including expanding the base model to be customized to other sports. It also lays the foundation for work in sports medicine, physical therapy, robotics and ergonomics — disciplines where understanding body positioning is important. But for now, there’s satisfaction in knowing the AI was built to actually help real athletes.

«This was not a case of tech engineers building something in the lab and handing it over,» Rajamani said. «This is a real-world problem that we are solving. For us, the motivation was building a tool that provides a true competitive advantage for our athletes.»

Technologies

Virtual Boy Review: Nintendo’s Oddest Switch Accessory Yet Is an Immersive ’90s Museum

No one needs a Virtual Boy. But I always wanted one. And now it’s living with me at last.

On my desk is a Nintendo device that looks like equipment stolen from a cyberpunk optical shop. It’s big, it’s red and black, it sits on a tripod, it has an eyepiece, and it has a Nintendo Switch 2 nestled inside. Hello, Virtual Boy, you’re back.

Nintendo has made a lot of weird consoles over the years, but the Virtual Boy was the weirdest. And the shortest lived. Released in 1995 and discontinued a year later, it lived for a blink of an eye during my final year in college. I never really had time to consider buying one.

It would have been perfect for me, a Game Boy fan who was in love with the idea of VR even back then. Nintendo has been flirting with virtual reality in various forms for decades, and the Virtual Boy was the biggest swing. But it wasn’t VR at all, really. It was a 3D game console in red and black monochrome, a 3D Game Boy in tripod form.

I’m setting the stage because right now you can order a $100 Virtual Boy recreation that’s a big, strange Switch accessory. It’s staring at me now, taking up a lot of space. It’s too big to fit in a bag. It’s a tabletop console, really, and Nintendo has created this Virtual Boy viewer as a way to play a set of free-with-subscription games on the Switch and Switch 2.

Is it worth your money? I’d call it a museum-piece collectible, not a serious piece of gaming hardware. Still, my kid stuck his head in, played 3D Wario Land, and came out declaring it was really cool. He loves old retro games. But I don’t know how often he’ll pop his head back in.

Nintendo’s first stab at 3D now feels like a museum piece

For comparison, I pulled my old Nintendo 3DS XL out of the drawer where it had been tucked away and booted it up, marveling again that Nintendo actually made a glasses-free 3D game handheld once upon a time. The 3DS is a far more capable and advanced game system, but consider the Virtual Boy an ancient attempt to get there first.

The Virtual Boy was a monochrome red-and-black LED display system, a tabletop-only device that was neither handheld nor TV-connected. The Nintendo Switch’s tabletop-style game modes feel like a bit of an evolutionary link to the Virtual Boy, so it’s poetic that the Switch pops into the new Virtual Boy to power the games and provide the display.

The plastic Virtual Boy is just an odd set of VR goggles for the Switch, but with a red filter on the lenses. Also, you can’t wear it. You keep your head stuck in it.

Awkward and easy to use

All the trappings on this recreation look like the old Virtual Boy but don’t work: You can see a simulated headphone jack, controller port, a sort of knob on top. I just unsnap the plastic case and slide the Switch in, carefully, and then snap it back over. That’s all it is.

To control it, you use the Switch controllers detached or another Switch-compatible controller. Launching the Virtual Boy app — free on the eShop, but you need a Switch Online Plus Expansion Pack account, which costs $50 a year, or $80 for a family membership — splits the Switch display into two smaller, distorted screens. In the Virtual Boy, it looks properly 3D. When I’m done playing, I pop the Switch back out.

As I said in my first hands-on, the big foam-covered eyepiece is more than wide enough for big glasses, and was fine to dip my face into. Getting a comfortable angle to stay playing for a while is another challenge. The Virtual Boy’s included tripod-like stand can adjust the angle, but not as wide as I’d like. I’m sort of hunched over while playing, which gives me a bit of pain. Leaning on the table with my controllers in hand helps.

The red-lensed front eyepiece can be removed, and a later software update will allow Virtual Boy games to be played in several color mixes beyond red and black. Also, you can unscrew an inner bracket to hold the Switch 2 and swap in an included Switch-sized bracket instead. The Switch Lite doesn’t work with the Virtual Boy, however.

The weirdness is my type of indie

All you get right now are seven of the 16 games Nintendo has promised to release for the Virtual Boy. Believe it or not, there were only 22 games ever released for this system. The 16 will include two that were never released before, which is a fun collector’s novelty.

But what’s amazing to me now is that, sinking into these oddball retro games with their pixelated NES-slash-Game Boy aesthetics in red and black, they feel weirdly timely. The janky, oddball, almost-parallel-universe Nintendo vibe feels like the indie retro aesthetic that’s been big for a while now. After all these years, is the Virtual Boy now finally awesome?

Games like UFO 50 (a compilation of new indie games made to feel like an archive of ’80s games for a console that never was) and indie consoles like Panic Playdate (still my favorite black and white mini handheld, a home for all sorts of homebrew retro games) match my feeling diving into these Virtual Boy games and figuring them out.

Wario Land is probably the best: A side-scrolling Wario game with multiple depth levels, it gives me Game Boy Mario game vibes. Golf has multiple holes and an aiming system, and it’s relaxed and basic (and hard to perfect). 3D Tetris has you dropping blocks down a well to fill in layers, with a Tron-like puzzle feel. Red Alert’s wireframe 3D shooter design is like Star Fox, but boiled all the way down to simple vector lines. Galactic Pinball has several tables, and it’s some lovely, very old-school 3D Nintendo pinball fun. Teleroboxer is Punch-Out with robots, with a style that also reminds me of the early Switch game Arms. And The Mansion of Innsmouth is a creepy 3D dungeon-crawling game (in Japanese) where you try to get to exits before time runs out… or monsters get you.

The remaining games coming this year include Mario Tennis, another Tetris game, a wireframe 3D racer, a 3D reinvention of the original Mario Bros. game called Mario Clash and a 3D Space Invaders. By the end of Nintendo’s release schedule, a good chunk of Virtual Boy’s catalog will be there.

A novelty that’s niche as hell

Worth it? Again, if you love weird and retro, and are intrigued by lost Nintendo 3D games, then yes. But if you’re looking for cutting-edge, then no.

Keep in mind: You can buy a cheaper $25 cardboard set of goggles for the Switch that lets you play the Virtual Boy games, too (or use the old Labo VR goggles Nintendo made in 2019, if you have them). That’s a more sensible path. There are even unofficial emulators for Virtual Boy games on the Meta Quest and Apple Vision Pro. But who said the Virtual Boy was sensible?

A Nintendo game system that’s a big set of red goggles on a tripod is inherently absurd. And I welcome its weird footprint in my home, because that’s exactly who I am. But it’s also a testament to Nintendo’s perpetual interest in the bleeding edge of gaming. VR, glasses-free 3D, AR, modular consoles… Nintendo’s poking around the edges.

Is the Virtual Boy a sign that Nintendo could make its own VR or AR game system again someday soon, or as an extension of the Switch 2? Who knows? Shigeru Miyamoto, Nintendo’s legendary video game designer, sounded intrigued and elusive about it when I asked him last year. But there’s never any real way to guess where Nintendo’s heading. The Virtual Boy is a museum-piece reminder of that.

Technologies

Today’s NYT Mini Crossword Answers for Friday, Feb. 20

Here are the answers for The New York Times Mini Crossword for Feb. 20.

Looking for the most recent Mini Crossword answer? Click here for today’s Mini Crossword hints, as well as our daily answers and hints for The New York Times Wordle, Strands, Connections and Connections: Sports Edition puzzles.

Today’s Mini Crossword expects you to know a little bit about everything — from old political parties to architecture to video games. Read on for all the answers. And if you could use some hints and guidance for daily solving, check out our Mini Crossword tips.

If you’re looking for today’s Wordle, Connections, Connections: Sports Edition and Strands answers, you can visit CNET’s NYT puzzle hints page.

Read more: Tips and Tricks for Solving The New York Times Mini Crossword

Let’s get to those Mini Crossword clues and answers.