Ecological wisdom is one of the original Four Pillars of the Green Party? and is retained in the Global Greens Charter. It is usually considered the most basic of these, although nonviolence is considered by some to be equal, as the Green Party was the political expression of both the ecology movement? and peace movement? especially as they emerged after the Cold War which threatened "nuclear winter" that would completely destroy almost all life on this Earth. More recently the archaeology of Easter Island? and Angkor Wat showed that failures of ecological wisdom played a major role in the decline and fall of both of those civilizations. What did these societies, modern and ancient, fail to realize? Nature's services? are the basis of all human wealth. There is simply no argument about this: our ability to live as we would like is absolutely dependent on clean air, water, and the ability to grow or catch good local food and not be forced into dependence on outsiders simply to survive. Respect for the natural capital which generates these services and an ecological yield? of goods that humans can use to feed themselves, house themselves (wood), or use for energy?, is ultimately respect for what feeds us - this is stated in more economic terms as the idea of sustainability. In 1995, Robert Costanza and a group at the University of Maryland compiled over 100 studies which showed that the overall contribution of just seventeen of nature's services (primary agricultural services like pollination, erosion prevention, etc.) actually exceeded that of human exchanges: US$33 trillion as compared to the US$25 trillion in that year of measurable human trades/exchanges. Obviously, a society that has no access to nature's services or which is entirely engaged in trying to prop them up by artificial means (irrigation, fertilizers, major earthworks or flood controls) has no excess energy or attention to devote to respect social justice, participatory democracy, or respect for diversity. It may even find it impossible to respect nonviolence as competition for scarce resources escalates and people grow more desperate, perhaps seize what they need to live. However, even mild ecological scarcity? can lead to conflict, as has been seen sometimes in Nova Scotia with respect to fishery? disputes. Today, most biologists recognize biodiversity? and ecological health? as relatively objective ideas that can be used to predict stability of ecosystems and their impact on well-being?.