Project aims to transform LA billboards into aerial gardens

The modular 'Filtration Block' can be hung from a ceiling or wall to purify indoor air

Take a first look at the massive, 43,000 square-foot farm at the Brooklyn Navy Yard

Big surprise: Portland is number one

The indelible link between climate change and social unrest in the Arab world

And other report results that might surprise you

The seafood industry braces for the impact of the crisis in Japan.

As many as 1.5 million new jobs could be created by looming EPA regs, says report.

Company plants 'food oases' in a low-income Chicago communities, with a baked-in infrastructure to scale up fast.

Canadian environmentalist David Suzuki offers his take on the greenness of the games.