The Fellows of the Post carbon Institute make five key assumptions: 1. We have hit the limits to growth. 2. No issue can be addressed in isolation. 3. We must focus on responses, not just solutions. 4. We must prepare for uncertainty. 5. We CAN do something. These guys are experts in their various fields (climate, water, biodiversity, food, population, energy, economy, transportation, waste,health, education, and more) and they have put their experience and knowledge together to suggest some promising responses to the seemingly overwhelming interconnected threats to our global sustainability.