Which regions are becoming deserts the fastest right now?

Northern China's desertification is worth highlighting because it's happening at a massive industrial scale - the Gobi and surrounding areas are expanding partly due to overgrazing and water extraction for agriculture, but also because of how fast the changes are accelerating. The previous answer touches on the usual suspects correctly, but what makes China's situation distinct is how it's caught between trying to expand farming and pasture while simultaneously running out of groundwater, creating this vicious loop that's hard to reverse even with government intervention like tree-planting campaigns.