A shorty, pithy interview with Kolbert is available online. Her article for the print edition is not online, which is a pity because it is well worth reading from start to finish. Here's a taste of the clarity of her writing:
An ideal white surface, which reflected all the light that shone on it, would have an albedo of one, and an ideal black surface, which absorbed all the light, would have an albedo of zero. The albedo of the earth, in aggregate, is 0.3, meaning a little leasss than a third of sunlight that hits it gets reflected back out. Anything that changes the earth's abledo changes how much energy the planet absorbs, with potentially dramatic consequences...
Imagine [the scientist Donald Perovich tells Kolbert] that we were looking down at the earth from a spaceship above the North Pole. "It's spring time and the ice is covered with snow, and it's really bright and white. The albedo's around 0.8, 0.9. Now let's suppose that we melt that ice away and we're left with the ocean. The albedo of the ocean is less than 0.1; it's like 0.07."
"Not only is the albedo of the snow covered ice high; it's the highest we find on earth [Perovich goes on] and not only is the albedo of water low; it's pretty much as low as anything you can find on earth. So what you're doing [if the ice melts] is replacing the best reflector with the worst reflect". The more open water that's exposed, the more solar energy goes into heating the ocean. The result is a positive feedback...
"As we melt that ice back, we can put more into the system, which means we can melt the ice back even more, which means we can put more heat into it, and you see, it just kind of builds on itself", Perovich said. "It takes a small nudge to the climate system and amplifies into a big change".
[by the way, Perovich seems to have a pretty good track record destroying monsters, if the photo on his home page is anything to go by]