The possible mental health effects of city living affects a lot of people. The World Health Organization estimates that 54 percent of the world’s population lived in urban areas in 2014. The WHO adds that that amount will increase to 66 percent by 2050. People often move to cities for better jobs and more cultural activities. But are they putting themselves at risk? Maybe. Experts at the American Psychiatry Association say that natural environments or green spaces do much for good our mental health. Many studies have shown that nature can calm us and make us feel happy. Nature, experts say, can also help us learn better. And experiencing nature helps people recover from the mental tiredness that comes from day-to-day work.