Greenhouses are having a moment—or rather, a few decades. According to a new analysis of satellite data published in Nature Food, greenhouses now cover more than 13,000 square kilometers (5,000 square miles) of land worldwide—an area nearly the size of Connecticut. Four decades ago, they covered just 300 square kilometers.
The most expansion occurred in China, now home to 60 percent of the world's greenhouses. The structures can be found on farmland in several Chinese provinces and across a range of climates, but they are most concentrated in the North China Plain—a large alluvial plain west of the Yellow and Bohai seas. The largest cluster of greenhouses in China, and the world, spreads across more than 820 square kilometers of this plain in Weifang, a prefecture-level city in Shandong Province in northeastern China.
The pair of Landsat images above highlights the rapid expansion of greenhouses in Weifang. The image on the left, acquired by the TM (Thematic Mapper) on Landsat 5, shows Weifang in 1987; the image on the right, from the OLI (Operational Land Imager) on Landsat 8, shows the same area in 2024. Large expanses of once-open farmland are now covered by a sea of plastic. Many of the greenhouses have opaque or translucent plastics that appear white from a distance, while open farmland is generally brown or green. Towns appear slightly blue or pink due to the colors of roofs.
In this part of China, fruits and vegetables are generally grown in the greenhouses. "Cucumbers, eggplants, and tomatoes provide off-season vegetables to the whole country," said Xiaoye Tong, a postdoctoral researcher at the University of Copenhagen and an author of the study. "Increasingly, farmers in Weifang are also planting high-value fruits, such as strawberries, grapes, kiwi, and dragon fruit."
Read more at: earthobservatory.nasa.gov