In 1984, the desert in Al Jowf, Saudi Arabia, was empty. Then engineers discovered hidden aquifers—as deep as a kilometer underground—and started turning the sand into tomato and alfalfa farms. A NASA time-lapse video, stitched together from high-res satellite images, shows the transformation.
Google used its Earth Engine platform to build similar time-lapse images of the entire globe, showing how dramatically most of the world has changed in the last 32 years. On the Timelapse site, you can type in an address and watch megacities and mines sprawl as glaciers and lakes shrink.
Many of the changes are recent. In Brazil, the massive Jirau Dam, which displaced thousands of people as it spanned five miles across a river and flooded land, was completed in 2015. A lake in Bolivia that used to stretch 1,200 miles dried up by 2015.
Perhaps the biggest change happened in cities. The number of megacities (with more than 10 million citizens) more than doubled over the past two decades. The sprawl is staggering to watch: Shenzhen, a town of 200,000 people in 1985, now covers an area roughly 33 times larger than Manhattan.