By Matt McGrath, BBC environment reporter

Tens of millions of people could be driven from their homes by encroaching deserts, particularly in sub-Saharan Africa and Central Asia, a report says.

The study by the United Nations University suggests climate change is making desertification “the greatest environmental challenge of our times”.

If action is not taken, the report warns that some 50 million people could be displaced within the next 10 years.

The study was produced by more than 200 experts from 25 countries.

Read the full story from the BBC