Watch dating on earth
What began as a photographic assignment has become a mind-blowing odyssey into an unpredictable world, where entire landscapes teeter between solid and liquid states.
On the Greenland ice sheet, a crack opens and a mile-wide lake pours down a 3,000-foot chasm. It is volatile and constantly in flux, but what Balog is witnessing suggests something extraordinary is going on.
In the early 1980s, the Columbia started flowing faster and began calving far more ice into the ocean than was being replenished by snowfall upstream.
It is rapidly-calving glaciers, like these, that are the main contributors to rising sea levels.
Alaska's Columbia is one of the biggest ocean-feeding glaciers in North America.
Temperatures are climbing, and the ice is melting faster than ever.
I think that if we stay on the path we're on, we will change the amount of land ice and therefore we will change sea level. It is the speed of the melt that is most astonishing, and nowhere is it happening faster than in the glaciers along the west coast of Alaska. High in the mountains, snowfall builds up and is compacted over hundreds of years. Some glaciers flow all the way to the ocean, shearing off icebergs, in a process called calving.
He is deploying 26 time-lapse cameras on glaciers across the northern hemisphere and programming them to shoot a frame every daylight hour for three years.