Can we ever regain what has been lost? Thanks to climate change, the Arctic Ocean's ice cover has been shrinking with such speed that scientists expect that sometime in the next few decades, the ice will disappear completely during the summer months. That change could have catastrophic consequences, and not just for the polar bears, seals and other animals that depend upon the ice for survival. As retired Cambridge University professor and sea-ice expert Peter Wadhams details in this Yale Environment 360 article, for thousands of years the Arctic ice's whiteness has helped regulate the planet's temperature by reflecting solar energy back into space.
But as the increasingly blue summertime Arctic absorbs more and more energy, it's turning from a planetary air conditioner into a heater. Already, the decline in the ice "has profound global climatic effects, or feedbacks, that are already intensifying global warming and have the potential to destabilize the climate system," Wadhams writes.
Arctic ice is declining so rapidly, in fact, that some scientists argue we need to take drastic measures to keep the top of the world white, doing more than just trying to cut human-generated greenhouse gas emissions. In a recent article in the scientific journal Earth's Future, a group of Arizona State University researchers proposes what could be an ingenious, but also massive and costly, solution: They want to make more Arctic ice.
The ambitious plan would require building and deploying millions of wind-powered pumping installations in the Arctic, which during the wintertime would pull water from the warmer ocean depths to the colder surface, where it would freeze and add thickness to Arctic sea ice.
Lead author Steven Desch, a professor in ASU's School of Earth and Space Exploration, says via email that the key to make sea water freeze faster in the Arctic winter is to pump it from below the ice, where it's 28 degrees Fahrenheit (minus 2 degrees Celsius) up to the surface, where it's below minus 22 degrees F (minus 30 degrees C). Desch's team calculated there'd be enough wind power for one turbine to thicken the ice by 3.3 feet (1 meter) over 25 acres (0.1 square kilometers) over the Arctic winter.
Desch's background is in astrophysics and planetary science, and he got the inspiration for how to increase Arctic ice while attending scientific conferences on the climate of planets such as Mars and Venus. "Of course, Earth's climate was discussed, too," he says, "and I heard the perspectives of many heavy hitters in the field of climate science. I came away thinking that they had correctly identified the problem, but not the solution. The only thing they wanted to discuss was reductions in CO2 emissions, which of course is necessary and the purest solution. But I realized that this was not going to work in time to save the ice in the Arctic, the most sensitive part of the climate system. I thought, we can't wait for these guys to fix the problem. We need to save the Arctic now, through other means."
Other scientists have proposed massive geoengineering projects to fight global warming, such as simulating the effects of volcanic eruptions by spreading sulfuric acid droplets high into the stratosphere to block some of the incoming solar radiation. But some worry that tinkering with the atmosphere could disrupt weather patterns. Desch thought it made more sense to come up with a mechanical solution for making more Arctic ice. He says that he teamed up with two like-minded ASU colleagues — Hilairy Hartnett, a geochemist and oceanographer, and experimental astrophysicist Christopher Groppi — to teach a class on the subject, and those efforts eventually led to the pumping plan.
The scientists have calculated that it wouldn't be necessary to add ice over the entire Arctic Ocean. Instead, if wind-powered pumps were dispersed over about 10 percent of the Arctic for a decade, that would be enough at least to stave off catastrophic ice loss. Building the pumps would require about 10 million tons (9.1 million tonnes) of steel, and would cost an estimated $500 billion over a decade's time. Financing and building such a massive project probably would require an international effort.
"These numbers are big, [but] they are not impossible," Desch says. He and his colleagues plan to design and test a pump that disperses water over a wide area without freezing, and includes as few moving parts as possible — and is capable of surviving Arctic winters. "If we can develop a prototype in the next year, we'd like to then test it in the field, perhaps in the Canadian Arctic," Desch says.
Hartnett says she's confident all that can accomplished with existing technology. "Ideally, we have to try to implement something like our idea before the summertime Arctic ice is completely lost," she says.