Green Options

Failure to read the field on Chicago’s Olympic bid begs the question: who is counting votes for President Obama? The White House will need a much better ground game if the US is going to lead the world on climate change.

The Rio state government will build concrete walls around some of the city’s biggest slums (pictured on the hillside above) in an attempt to halt deforestation of the surrounding jungle, officials said.

Seven miles of walls, reaching a height of three metres (10ft) will be built around sections of at least 11 slums this year, Icaro Moreno, the president of the state’s public works department, said.