Trees provide each megacity with over USD 500 million every year in services that make urban environments cleaner, more affordable and pleasant places to live, a study of 10 magacities, including Mumbai, has found. Megacities are home to nearly 10 per cent of the world’s 7.5 billion people. Researchers found that tree-based ecosystem benefits had a median annual value of USD 505 million, which is equivalent to USD 1.2 million per square kilometre of trees. The value of trees’ services was USD 35 per capita for the average megacity resident. It could easily be doubled by simply planting more of them, they said.