The planet may have found its newest and perhaps greatest ally: the law. In the past three years, the number of climate-related lawsuits across the world has tripled. In 2017, there were 900 cases in 24 countries, two thirds of them in the United States. The number one target of these lawsuits is big businesses, particularly the fossil fuel industry. Saúl Luciano Lliuya, a Peruvian farmer, is suing Europe’s biggest polluter, German energy giant RWE, for causing a glacier to melt near his home. In the US, cities and counties are leading the battle. New York City is the latest to join the fight, suing the world’s five largest oil companies. The idea is to hold them responsible for present and future damage to the city from climate change, demanding financial compensation for their loss.

But it’s not just a question of money. A green revolution is underway. Citizens are suing their own leaders in order to get them to implement real climate policy. The Urgenda case in the Netherlands has become a symbol of a growing movement. In 2015, 900 Dutch citizens got their government sentenced by a District Court in The Hague. According to the verdict, the Dutch government isn't doing enough to protect its citizens from severe but avoidable harm and must cut its greenhouse gas emissions by at least 25% by 2020.