Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia;
Department of Agricultural Economics and Rural Development, University of Goettingen, D-37073 Goettingen, Germany.
Proc Natl Acad Sci U S A. 2018 Sep 18;115(38):9533-9538. doi: 10.1073/pnas.1807026115. Epub 2018 Sep 5.
Scientists understand how global ecological degradation is occurring but not why it seems to be so difficult to reverse. We used national-level data and a mathematical model to provide an empirical test of the hypothesis that national economies display two distinct economic regimes that are maintained by self-reinforcing feedbacks between natural resources and society. Our results not only support previous findings that two distinct groups exist, but also show that countries move toward one of these two different equilibrium points because of their different patterns of natural resource use and responses to population growth. At the less economically developed equilibrium point maintained by "green-loop" feedbacks, human populations depend more directly on ecosystems for income. At the more economically developed equilibrium point maintained by "red-loop" feedbacks, nonecosystem services (e.g., technology, manufacturing, services) generate the majority of national gross domestic product (GDP), but increasing consumption of natural resources means that environmental impacts are higher and are often exported (via cross-scale feedbacks) to other countries. Feedbacks between income and population growth are pushing countries farther from sustainability. Our analysis shows that economic growth alone cannot lead to environmental sustainability and that current trajectories of resource use cannot be sustained without breaking feedback loops in national and international economies.
科学家们了解全球生态退化是如何发生的,但不明白为什么似乎很难扭转这种局面。我们利用国家级数据和一个数学模型,对以下假设进行了实证检验:各国经济呈现出两种截然不同的经济状态,这两种状态是通过自然资源和社会之间的自我强化反馈来维持的。我们的研究结果不仅支持了先前存在两种截然不同的群体的发现,还表明,由于各国自然资源利用模式和人口增长应对方式的不同,它们会朝着这两种不同的均衡点之一移动。在“绿环”反馈维持的欠发达经济均衡点,人类人口更直接地依赖生态系统获取收入。在“红环”反馈维持的更发达经济均衡点,非生态系统服务(如技术、制造、服务)产生了大部分国家国内生产总值(GDP),但对自然资源的消费不断增加意味着环境影响更高,而且往往通过跨尺度反馈输出到其他国家。收入和人口增长之间的反馈正在使各国远离可持续性。我们的分析表明,经济增长本身并不能带来环境可持续性,如果不打破国家和国际经济中的反馈循环,目前的资源利用轨迹是不可持续的。