You can see the growth of roads and human settlement from the central urban areas into the surrounding rural areas in just 12 years. Your students can investigate human settlement patterns in a single city or compare several cities around the world. The expansion of such deforested areas can be measured by comparing images of the same region over a period of several years, as in these two images. Students might measure the areas affected by deforestation, such as shown in the Rondonia images. Lakes and Rivers, and Ice Shelves.
Water is the a great agent of change in our Earth system.
But it also suffers dramatic changes in relatively short periods of time. Lake Aral, Lake Chad, and the Great Salt Lake are dramatic examples of such changes. A look at the polar regions will reveal changes in the shape and quantity of sea ice and ice shelves. Your students might compare the conditions under which these enormous bodies of water underwent radical change. An article about Antarctica's Filchner Ice Shelf may be a good starting point for thinking about the effects of climate change.