Can we refreeze the Arctic?

It's not news that we're losing Arctic ice fast: since the 1970s, Arctic summer sea ice volume has shrunk by at least 75%. What you may not know is how much our climate depends on it. Arctic ice reserves are the “refrigerator of the earth”, as Christian Haas puts it. He's a professor in geophysics at the University of Bremen and the head of the sea ice physics section at the Alfred Wegener Institute, and has studied sea ice for some 30 years. “When I started with my research, the ice was thicker than the size of a person.” Today, he said, that is no longer the case. A wider frozen surface is key to alleviating the effects of global heating. Ice reflects up to 85% of the sun’s heat back into space, while the open ocean reflects just 7%. Melting ice risks becoming a catastrophic feedback loop. Summer sea ice could vanish as early as the 2030s, potentially pushing the climate past irreversible tipping points: losing ice exposes a darker ocean that absorbs more heat, accelerating further melting and drastically disrupting global weather patterns. To slow the melt, so-called geoengineering technologies are being developed to artificially add more ice to the ocean's surface. Pumping ice back to life Theoretically, melted sea ice could recover if global heating slowed or reversed. But Fonger Ypma believes that, at this point, more needs to be done. “We need to tackle the symptoms, too.” Ypma founded Arctic Reflections, a Dutch enterprise researching ice thickening as a targeted restoration of Arctic sea ice. Arctic Reflections has conducted multiple field experiments since 2021. Earlier this year, they thickened almost 17 hectares in Nunavut, Canada. Their method uses pumps to bring water from underneath the ice onto the surface, where it freezes. That leaves more ice that survives the summer and reflects a lot of sunlight, Ypma explained. The technique isn’t new. “People have been using this technology for decades already, for instance to create ice roads.” Even if it doesn’t work at scale, he said, “it could still be very valuable, for instance, for Inuit communities as a local climate adaptation measure.” Despite their field trials, Arctic Reflections is still in the research phase. They’re also managing ecological impacts by avoiding sites with marine mammals. Startup Real Ice uses a similar method and other projects are exploring different approaches, from underwater drones to amphibious vehicles fitted with larger pumps. Science fiction? Not everyone is happy with these experiments. Last September, more than 40 scientists criticised different forms of “dangerous geoengineering” in the Arctic, including this method. The criticism mainly concerns financing and scale, but also environmental damage, governance, and ethics. A 2019 study by the Alfred Wegener Institute found the best-case outcome of ice restoration technology – maintaining current summer ice levels for the next 60 years – would have only a negligible effect on global heating. Martin Siegert, glaciologist and one of the 40 critical scientists, calls the approach “science fiction”. He explained that the cold surface layer acts as a lid on warmer water beneath. Pump and mix enough, and you risk bringing that warmth up, accelerating the very melt you're trying to stop. Geophysics professor Haas agrees. “You’re bringing a lot of heat and moisture also to the bottom of the atmosphere... You will warm the atmosphere big time.” Geoengineering trials also pull attention from emissions reduction, he warned. “What we need to do is reduce our emissions as soon as we can. All these ideas offer a cure to the symptoms, but not the cause.” Besides, Haas said, “It’s not only the thickness of the ice that matters, but also the quality of the ice.” Flooding ice with pumped seawater makes the ice saltier, which may cause it to rot or melt from the inside. “I think physics and maybe philosophy [are] against it,” he concluded. “We should rather spend our efforts in limiting the problem than fighting the symptoms.” Ypma agrees tackling CO₂ emission reductions is the most important, but believes it may not be enough to avoid an ice-free Arctic summer in the near future. For him, a best-case scenario is proof that this method is effective and scalable, so they can meaningfully preserve Arctic ice. And if it doesn’t work? He believes even that has value: “It’s less fulfilling, of course, but it’s still scientific progress.”