This document provides an overview of reasons to be hopeful about addressing humanity's impact on the planet despite various challenges. It notes that while evolutionary forces have rewarded both aggression towards the planet and cooperation, the challenge is to reach a threshold of global cooperation before resource depletion leads to a "fortress world." It highlights pioneers working on ecological economics and planetary health as reasons for optimism. The document argues that increasing global cooperation, technology, lifestyle changes and shifts in consciousness can help solve environmental problems.