For 50 years, millions of workers in northern China have used a method called "straw checkerboards" to stop deserts from spreading. They push sticks into the sand to make squares, then plant small trees in the center of each square. Water pipes help the young trees grow.

This effort is part of China's Three-North Protective Forest Program, a tree-planting project that started in 1978. Since 2000, desert land in China has shrunk by about 10%. Each year, the desert also gets more than 1,000 square kilometers (400 square miles) smaller.

One worker, Yin Yuzhen, 60, has planted trees near her home in northern China for over 40 years. Long ago, thick sand made it hard to see far. "But now we can see the sun. We can see the green in the distance," Yin said. Scientists warn these good results will need many more years of hard work to continue.