More money is needed to protect the Earth's biodiversity, but there are obstacles in the way of a trading system that could raise the necessary funds. Biodiversity credits could be the key to funding the protection of Earth's ecosystems, but creating a functioning market to buy and sell these payment tokens will not be easy.  Protecting the world's plant and animal diversity has a direct impact on economies and societies: According to research by the World Economic Forum about half of the world's output — about $44 trillion — depends on nature. According to the Paulson Institute think tank, to stop and repair the damage caused to the natural world by global industry and agriculture, approximately 600 to 800 billion dollars a year. One potential source of funding is emerging biodiversity credit markets. The credits act as tokens that can be purchased by companies and investors to fund restoration and conservation projects that theoretically demonstrate positive outcomes for biodiversity. (Joshua Kirby)