One of the most important, yet underappreciated, features of the Arctic sea ice is the ability of its blindingly white surfaces to reflect sunlight. For at least as long as our species has existed, the frozen seas at the top of our world have acted as a massive parasol that helps keep the planet cool and its climate stable.
Yet now, much of that ice is rapidly vanishing. Rising temperatures have locked the Arctic in a self-destructive feedback loop: the warmer it gets, the reflective white ice dissolves into darker, blue water, which absorbs more of the Sun’s warmth rather than reflecting it back into space. Warmer water accelerates melting, which means yet more absorption of heat, which drives further melting – and so on in a vicious cycle that is part of the reason why the Arctic is warming around twice as fast as the rest of the planet. This July, ice cover was as low as it had ever been at that time of the year.
As planet-warming greenhouse gas emissions continue to rise, some have been driven to explore desperate measures. One proposal put forward by the California-based non-profit Arctic Ice Project appears as daring as it is bizarre: to scatter a thin layer of reflective glass powder over parts of the Arctic, in an effort to protect it from the Sun’s rays and help ice grow back. “We’re trying to break [that] feedback loop and start rebuilding,” says engineer Leslie Field, an adjunct lecturer at Stanford University and chief technical officer of the organisation.