You’ve heard of tiny homes, but what about tiny forests? More Australians are planting out dense, diverse forests on plots of land as small as a tennis court. These tiny forests, scientists say, not only boost biodiversity, they help reduce urban heat, run-off and localised flooding.

Bison are released in Romania, with results that surprise even zoologists, as plant biomass in the area increases by 30%.

The Spanish city of Seville is experimenting with underground aqueduct networks to beat the heat, building upon an ancient Middle Eastern urban cooling system.

Some cities are reconsidering how much they dedicate to parking. Austria's capital, Vienna, is streets ahead.