How Humans Make the Earth Their Home

Beginning in 2012, and for many summers ever since, my team and I have been helicoptering onto the Greenland ice sheet, in this fantastical melt zone. We use helicopters to string cableways over the top of rushing super glacial rivers so that we can hang this river discharge measurement technology called Acoustic Doppler Current Profiler (ADCP). We operate around the clock to collect measurements of river discharge every hour, for up to a week in duration. We have collected the world's first meltwater runoff measurements on top of the ice sheet. What we then do is simultaneously use drones and satellites to map out the upstream contributing watershed area flowing to that point where we are collecting the discharge measurements. When we know the contributing watershed area and we have the flow measurements at the bottom of the watershed, we then have a completely independent field dataset from which we can test the ability of climate models to simulate meltwater runoff from the Greenland ice sheet. And it's those models that are being used to predict the future. It's those models that are being used to estimate projected ranges of sea level rise in IPCC reports and so forth.

LAURENCE C. SMITH is the John Atwater and Diana Nelson University Professor of Environmental Studies and Professor of Earth, Environmental and Planetary Sciences at Brown University. He is the author, most recently, of Rivers of PowerLaurence C. Smith's Edge Bio Page