Cities need more trees, G20 housing crisis and who owns the oceans? – Your weekly city news update

Big cities are increasingly turning to trees to help protect them from heatwaves and floods

Some of those who escaped the flames only to find themselves homeless, are expected to be allowed to return to inspect their properties

In Louisiana, coastal cities have joined an oyster-shell recycling program to save the state’s shrinking shoreline

On-demand public buses already run in parts of New York and Chicago. A service in Helsinki was popular, but proved to be too costly for the city

From Toronto to Sydney, governments are increasingly under pressure to boost housing affordability and tackle a growing problem of urban homelessness

Green investments, targets and policies in cities will be crucial if countries are to meet their emissions reduction targets

‘Children should be a focus of urban planning, yet in many cities they are forgotten’

Some cafes in Britain are ditching avocados on ethical grounds, claiming that the water-intensive fruit is harming farmers and land