grgrn leafy plplants absorb b cn dioxide anand produce oxoxygen. and trees and other vegetation help regulate the urban temperature. they provide shade and cooling through evaporation. plants and unpaved soil absorb water when it rains heavily or rivers overflow. and parks are places for us to rest and relax. but we're not alone. lots of animals have adapted to city life. urban-dwelling animals o often have it better than their country cousins. but only if they have access to plenty of green areas and trees. many wild plants have also adjusted well to the urban jungle -- but they require unpaved areas in order to grow. so green spaces in a city are good for the quality of life of all its inhabitants. >> in 2010, there were already more than 1 billion cars on our planet -- and by 2040 there could be as many as 2 billion! and that even though congestion , is already a huge problem. in fact, in some cities, drivers spend more than 200 hours a year stuck in traffic jams. many chinese cities have major problems. but alternatives are making a comeback. >