For several years, researcher Tom Painter has been examining what happens when dust gets on snow. At the same time, on a much larger scientific level, there research on European glaciers… and why they started melting in the mid 1800’s.
Tom Painter: “It’s funny on public television I heard somebody talking about the end of the little ice age in the Alps around 1850 and that’s when temperatures started going up. And I was yelling at the television ‘NO! That’s not when temperatures were going up!’ ”
Well, Painter’s research recently shed light on all of that and more.
Reporter: Tom Painter is one of those researchers who really likes to get out of the lab…partly because he loves to ski. So he’s been in the snow in Colorado and other parts of the Western US, getting an up close and personal look at the effects of dust on snow. Namely, that dust holds more sunlight, and therefore heat… and all that warming makes snow melt more quickly. A few years ago, Painter and other snow scientists were pondering a question that’s plagued researchers for more than a hundred years. Why did glaciers in Europe start disappearing in the mid 1800’s? Because according to precipitation and temperatures, the glaciers should have gotten bigger.
Tom Painter: “Being in the snowpack, looking at dust layers in the Colorado River Basin is what allowed me to make the connection that “Hey – I wonder if particulates can be that missing part that the glaciologists had been missing in the Alps.’ ”
Reporter: And when Painter and his colleagues looked at records showing what was on and in the glaciers, they saw that soot from factories and other modern inventions started showing up in the snow around 1850… the same time the glaciers started getting smaller. Painter has a much more technical name for soot, of course.
Tom Painter: “As soon as I saw the black carbon deposition in the ice core records, I was quite confident at that point that this was the case, and that we put together the hypothesis and then ran these simulations and even with our minimum case, it still affects the kind of retreat that we would expect. This is one of the beauties of science, that these nuggets to pick up and fill in the gaps of our knowledge.”
Reporter: In other words, there was enough soot on the glaciers to soak in sunlight…. warm them up… and make the glaciers start melting, or retreating. I asked Painter what a finding like this could mean for today… or if it’s only an update for the history books.
Tom Painter: “An important case is the Himalaya between India and Tibet, and the industrialization that’s going on in those regions, it’s dramatic, and the increases in black carbon are dramatic. This is dropping out into those snows of the high Himalaya, and so we really need to understand what impact that’s having. The water resource that comes out of those high mountains provides the fresh water for a billion and a half people. But there is a bit of a silver lining in that there’s a regional solution. If we can reduce the black carbon deposition, then we can allow those snowpacks to be cleaner, can last longer.”
Reporter: Just like the snow along Colorado’s Western Slope.