A new Dartmouth-led study shows that degrading satellite sensors, not soot or dust,
are responsible for the apparent decline in reflectivity of inland ice across northern Greenland.
The study's results suggest the ice sheet hasn't lost as much reflectivity as previously thought,
and that black carbon and dust concentrations haven't increased significantly and are thus not responsible for darkening on the upper ice sheet.

Further reading - http://www.sciencedaily.com/releases...1030220525.htm
Journal reference - http://onlinelibrary.wiley.com/doi/1...65912/abstract