First-time voters turned out in historic numbers. Campaigners, researchers and the voters themselves explain the shift.

One city mapped every street by temperature and found a nine-degree gap between rich and poor neighbourhoods. Then it had to decide what to fix first.

New lamp posts can count pedestrians, listen for accidents and dim themselves at will. Residents were rarely asked if they wanted any of it.

A melting passage, a stranded convoy and a scramble for the fastest route on Earth. We reconstructed the days that changed global trade.

Six parties, one conference room and a draft agreement that lasted exactly four hours. Here’s what really happened behind the closed doors.

Deep in a mountain vault, researchers are banking ice cores from vanishing glaciers — a library of the atmosphere for scientists who haven’t been born yet.