Ice ages are what climate changes

These ice ages are triggered and ended by slow changes in the Earth's orbit. But changing atmospheric concentrations of CO2 also plays a key role in driving both cooling during the onset of ice ages and warming at their end. The global average temperature was around 4C cooler during the last ice age than it is today.

Explanation:

20: 5

explanation:

about 20% of the world's population lives in   southwest asia, but on less than 5% of the world's   land area.