"It has recently become quite obvious that significant changes are also needed in the way our economic system is structured. Global warming is intimately related to the gargantuan quantities of energy that our industries devour to provide the levels of consumption that many of us have learned to expect. From a Buddhist perspective, a sane and sustainable economy would be governed by the principle of sufficiency: the key to happiness is contentment rather than an ever-increasing abundance of goods. The compulsion to consume more and more is an expression of craving, the very thing the Buddha pinpointed as the root cause of suffering."
See full declaration text here: The Time to Act is Now: A Buddhist Declaration on Climate Change