How can a desert burn? Australia’s vast deserts aren’t just sand dunes—they’re often dotted with flammable spinifex grass hummocks. When heavy rains fall, grass grows quickly before drying out. That’s how a desert can burn. How can a desert burn? Australia’s vast deserts aren’t just sand dunes—they’re often dotted with flammable spinifex grass hummocks. When heavy rains fall, grass grows quickly before drying out. That’s how a desert can burn. Environment Phys.org – latest science and technology news stories