Surface albedo is important because it largely affects the Earth’s energy budget and it is used in a varietyof scientific fields. Satellites like MODIS measure the reflected radiation from the Earth, but daily nadiracquisitions are not enough to estimate the albedo, because of the surface anisotropy. Multi-dateobservations account for the multiple angles. The MODIS bi-directional reflectance products productcontains three-dimensional data sets with parameters to model the directional-hemispherical (black-sky)and bi-hemispherical (white-sky) albedo, which are combined to give the real (blue-sky) albedo. To estimatetrends for a 15-year time series of blue-sky albedo globally, we need to loop over 24 solar zenith angleswithin a day, times 3 billion pixels, times 45 products per year, times 15 years. The Google Earth Engineallows for this kind of Big Data analysis to derive snow-free land surface albedo trends at 500 m x 500 mscale, for any area of the globe.