Excluding Antarctica, which continent has the largest percentage of desert land?

Often pictured for its lush coastlines, the island continent is in fact the driest inhabited one on Earth. A massive portion of its interior, famously known as the Outback, is exceptionally arid. While definitions can vary slightly, about 18% of the Australian mainland is officially classified as desert. When you expand this to include all arid and semi-arid lands, the figure jumps to a staggering 70% of the continent, a higher proportion than any other besides the polar desert of Antarctica.

This extreme dryness is primarily caused by its location. Much of the continent lies under a subtropical high-pressure belt, a global band of sinking, dry air that prevents cloud formation and leads to very little rainfall. Additionally, the Great (Review) Dividing Range, a mountain chain running down the eastern coast, creates a powerful rain shadow effect. Moisture-rich winds from the Pacific Ocean are forced upward by the mountains, releasing their rain along the coast and leaving the vast interior dry.

This combination of factors has created an immense arid heartland composed of ten major deserts, including the Great Victoria Desert and the Great Sandy Desert. While other continents like Africa and Asia contain larger individual deserts, no other has such a high percentage of its total landmass classified as desert, making Australia uniquely defined by its dry, red center.