There is a connection between the habits of thinking in science, economics and diplomacy that are hindering our response to climate change. Western science since the Enlightenment has built its success on reductionism. This has left us less good than we need to be at thinking holistically, and at understanding the potential for systemic change in our environment, economy, and international relations. New ways of thinking can take generations to spread through society and displace their predecessors. In our present crisis, we must accelerate this process deliberately – we cannot afford to wait.