The world’s cities are heating up at twice the global average due to the urban heat island effect. At this rate, by 2100 many cities across the world could warm as much as 4 degrees Celsius.

Hotter cities could be catastrophic for public health. If the current trends in urbanization and increasing heat continue, it is expected that the urban population exposed to high temperatures – that is, average summertime highs above 35 ̊C – will increase 800 per cent to reach 1.6 billion by mid-century.

To tackle this issue, UNEP and RMI have prepared a new guide "Beating the Heat: A Sustainable Cooling Handbook for Cities" which offers planners an encyclopedia of proven options to help cool cities.

In your experience, what are the best approaches to make cities cooler and more liveable?