this continent to do things right at this particular moment can africa rise to that challenge christian benny mana and others are trying to make it happen. urban planning is a huge challenge how many cities can the climate cope with and what about human health according to the u.n. and pollution now contributes to the deaths of four million people a year so how can we keep the air in major population centers clean. cities have always had a strong appeal they offer medical care educational and job opportunities infrastructure and cultural institutions and other attractions is anything lacking at all yes nature but why do we need green spaces in cities. for food for example with so many people in cities it makes sense to produce food there urban gardening is popular lettuce herbs and other easy to grow greens are being cultivated on rooftops or in small plots. but not every part of the city is suitable play. ants that grow alongside busy streets are exposed to pollution. urban green spaces can impact the climate cities account for seventy percent of global c o two emissions bad for the planet a