Penelope Cruz talks about Global Green's "Greenest City Challenge". A competition to see what city is the Greenest of them all. They're hoping to incite everyone to participate, as a prize, the winner city will be awarded 10 environmental friendly cabs. "Global warming is threatening us all" said Oscar nominee and Global Green supporter Penelope Cruz. "Fortunately, there are many simple things we can all do such as driving greener cars or changing to compact fluorescent light bulbs, which can dramatically save energy and reduce global warming pollution."