This is today’s edition of The Download , our weekday newsletter that provides a daily dose of what’s going on in the world of technology. Inside the quest to combat Arctic fires and save the planet’s frozen carbon
—James Temple
In July 2021, a wildfire burned through a forest on the University of Alaska, Fairbanks campus, stripping away the moss and organic-rich soil insulating the permafrost below. Five years later, I followed researchers into the forest to investigate how fighting fires could help keep that carbon locked in the ground. A simple metal probe revealed how much deeper the ground had thawed. This rudimentary tool offered a glimpse of an escalating problem: As climate change fuels more frequent and severe fires, they’re accelerating permafrost thaw and releasing greenhouse gases. Now, researchers are exploring how to break that cycle. But how much should we spend, and what risks are worth taking? Read the full story on how scientists are rethinking the fight against wildfires . AI researchers stranded Claude on a virtual desert island. It started to “play.” What do AI agents do if you don’t tell them to do anything? The answer looks a lot like play. Researchers repeatedly stranded them alone on a virtual desert island for 30 hours in an experiment reminiscent of the movies Cast Away or Home Alone. The agents started behaving in surprising ways. They set about exploring the limits of the world, and came up with their own goals—attempting to scale the highest point on the map, or seeing how high they could throw a block. A lot of what they were doing met the bar for play. But is it truly playful behavior, or simply role-playing? Read our full story to learn more. —Amit Katwala
10 Climate Tech Companies to Watch: X-energy and its helium-cooled nuclear reactors
X-energy is one of MIT Technology Review’s 10 Climate Tech Companies to Watch 2026 , available exclusively to subscribers . Making concrete, steel, and chemicals takes huge amounts of heat, much of it generated by burning fossil fuels. X-energy hopes to offer an alternative with a nuclear reactor that uses helium gas instead of water as a coolant, allowing it to operate at higher temperatures. The proposed Xe-100 reactor could supply superheated steam directly to industrial facilities, generate 80 megawatts of electricity—or do both. See how X-energy hopes to bring high-temperature nuclear power to heavy industry . —Mark Ellis Harris
Subscribers can now access the full 10 Climate Tech Companies to Watch , spanning everything from cleaner cement to streamlined geothermal power . Catch up on our conversation with a creator of AI-designed viruses
Can AI design new life forms? In 2025, Stanford University PhD student Samuel King came up with a preliminary answer when he used a generative AI model to propose genetic blueprints for microscopic viruses. It isn’t yet an example of AI-generated life, but that could be next. He spoke about his work with our senior AI reporter James O’Donnell on Friday. If you missed it, you can watch their chat now , and subscribe to get invites to our Roundtables events in future. The must-reads
I’ve combed the internet to find you today’s most fun/important/scary/fascinating stories about technology. 1 Tech stocks shed over $1 trillion on Friday
It’s unclear if AI companies can turn sustainable profits, and investors are getting jittery. ( NBC )
+ Musk and Anthropic are pledging big financial giveaways. ( BBC )
+ Microsoft just pulled out of a giant AI cloud deal in the UK. ( Gizmodo )
+ What’s at stake in AI’s trillion-dollar gamble…
