Human activities are threatening to push the Earth system beyond its planetary boundaries, risking catastrophic and irreversible global environmental change. Action is urgently needed, yet well-intentioned policies designed to reduce pressure on a single boundary can lead, through economic linkages, to aggravation of other pressures. In particular, the potential policy spillovers from an increase in the global carbon price onto other critical Earth system processes has received little attention to date. To this end, we explore the global environmental effects of pricing carbon, beyond its effect on carbon emissions. We find that the case for carbon pricing globally becomes even stronger in a multi-boundary world, since it can ameliorate many other planetary pressures. It does however exacerbate certain planetary pressures, largely by stimulating additional biofuel production. When carbon pricing is allied with a biofuel policy, however, it can alleviate all planetary pressures.

人类活动正威胁着将地球系统推到其行星边界之外，冒着灾难性和不可逆转的全球环境变化的风险。迫切需要采取行动，但旨在减少单一边界压力的善意政策可能会通过经济联系导致其他压力的加剧。特别是，全球碳价格上涨对地球系统其他关键过程的潜在政策溢出效应迄今很少受到关注。为此，我们探索了碳定价对全球环境的影响，而不仅仅是对碳排放的影响。我们发现，在一个多边界的世界中，全球碳定价的理由变得更加充分，因为它可以减轻许多其他的行星压力。然而，它确实加剧了某些行星压力，主要是通过刺激额外的生物燃料生产。然而，当碳定价与生物燃料政策相结合时，它可以减轻所有地球压力。