Hot deserts

• Less than 250 mm of rain a year
• Xerophytes are plants that can survive in very dry conditions
• Tap roots go deep underground
• Horizontal roots are wide and shallow
• Average temperature in Thar Desert is 27.3 °C but can get to 40 °C
• Roads can melt at 50 °C
• 30 million people living in Sahel in 1950, now there is half a billion.
• In Sahel temperatures are rising 15x faster than the rest of the world