New fossil fuel developments are inconsistent with keeping global warming below 1.5 °C, and while most climate policies focus on reducing demand for fossil fuels, an emerging transversal consensus promotes efforts to simultaneously reduce supply. In this article, we discuss the obstacles to effective supply-side climate policies posed by international investment treaties that protect corporations against state interventions through investor-state dispute settlement (ISDS). We focus on two recently concluded ISDS cases (Rockhopper v Italy and Lone Pine v Canada) that concern prohibitions on fossil fuel development in ecologically sensitive areas. Italy was ordered to pay a British firm approximately € 250 million in compensation for a ban on offshore oil developments along the coastline, whereas Canada successfully defended Québec’s ban on gas development in the St. Lawrence River. Arbitrators in both cases reasoned that investors should be compensated when oil and gas exploration permits are revoked (even if such a remedy is not available under domestic law) and expressed antipathy towards civic engagement in the policy process. As companies can seek lost future profits through ISDS, these cases show that the system can engender material costs for states enacting supply-side policies. The threat of ISDS can generate a chilling effect, limiting the potential for supply-side initiatives, particularly in the Global South. Initiators of global efforts to limit further fossil fuel developments must consider the obstacles posed by international investment treaties, support efforts to abolish ISDS, and as an interim measure, promote the interpretation of treaty protections in line with climate objectives.

新化石燃料的发展与将全球变暖控制在 1.5°C 以下是不一致的，虽然大多数气候政策的重点是减少对化石燃料的需求，但新兴的横向共识促进了同时减少供应的努力。在本文中，我们讨论了国际投资条约对有效供应方气候政策构成的障碍，这些条约通过投资者与国家争端解决（ISDS）保护企业免受国家干预。我们重点关注最近审结的两起 ISDS 案件（Rockhopper 诉意大利和Lone Pine 诉加拿大），涉及禁止在生态敏感地区开发化石燃料。意大利因禁止沿海岸线进行海上石油开发而被责令向一家英国公司支付约2.5亿欧元的赔偿金，而加拿大则成功捍卫了魁北克省对圣劳伦斯河天然气开发的禁令。这两起案件的仲裁员都认为，当石油和天然气勘探许可证被吊销时，投资者应该得到赔偿（即使国内法没有这种补救措施），并对公民参与政策过程表示反感。由于公司可以通过 ISDS 寻求损失的未来利润，这些案例表明，该系统可能会给制定供应方政策的国家带来物质成本。ISDS 的威胁可能会产生寒蝉效应，限制供应方举措的潜力，特别是在南半球国家。全球努力限制化石燃料进一步发展的发起者必须考虑国际投资条约带来的障碍，支持废除 ISDS 的努力，并作为临时措施，促进根据气候目标解释条约保护。