"With seven billion people now living on Earth, the ever growing demand is putting unprecedented pressure on global resources—especially forests, water, and food. How can Earth’s resources be managed best to support so many people? One key is tracking the sum of what is available, and perhaps nothing is better suited to that task than satellites."
...the top image shows where crops are grown throughout the world. Green areas are cropland, while tan areas are other types of land cover. In the last 40 years, cropland has increased by 70 percent to feed a growing population. Crops now cover about 40 percent of Earth’s land.
The lower image provides a landscape scale view of farming.
Measurements from the Landsat satellite also make it possible to tell how much water the crops consume in an arid environment. Such measurements are likely to become more important as demands on limited water resources increase. Currently, agriculture accounts for 85 percent of the world’s fresh water consumption.
Via Seth Dixon