High up in the stratosphere, naturally occurring ozone reflects solar radiation back into space, protecting people and the planet from harmful ultraviolet rays. But closer to Earth’s surface, rising ozone levels – formed when pollutants from a wide range of sources react ...

India is ground zero for extreme heat. More than 6,100 people have died from heat events since 2010. Half of the country reeled under severe heat waves this summer, when temperatures reached over 48 degrees Celsius (118 degrees Fahrenheit) in many places. The urban ...

The narrative about global inequality and poverty often focuses on rural areas in the global south, with a heavy emphasis on sub-Saharan Africa and South Asia. But the reality is that poverty is becoming more concentrated in cities across the ...

With a population of 12.2 million – eighth largest in the world – São Paulo faces a daunting task in making its streets safe for all. But in April 2019, the city pledged to do just that, becoming the first ...

In 2003, London followed the example of Singapore and launched a congestion charge, requiring drivers to pay £11.50 ($15.90) to enter the city center and becoming a global example of how this innovative but sometimes fraught policy can work. Sixteen ...

Cities in the global south today face a complex challenge: like all cities, they need to reduce carbon emissions, but they also need to expand access to energy. Around the world, 1.1 billion people currently lack access to electric cooling ...