The title of our panel promises to explore whether investor-state dispute settlement (ISDS) is a barrier, a facilitator, or neither regarding the global fight against climate change. This is an issue of urgent concern because there is a growing consensus that the world economy needs to transition away from fossil fuels aggressively to avoid the worst case climate scenarios, which would require a massive flow of investment out of fossil fuel production and into the production of renewable energy sources (RES). Broadly speaking, state policymakers have two sets of tools at their disposal to encourage that transition: (1) tools to encourage investment in RES (carrots); and (2) tools to discourage investment and hasten divestment in hydrocarbon production (sticks). One way to frame the question is whether the ISDS system—designed as it is to protect foreign investment in a largely policy-neutral way—acts more as a facilitator of carrot-side policies, more as a barrier to stick-side policies, or neither? Put somewhat differently, does a strong ISDS system that would facilitate RES investment necessarily cause regulatory chill of stick-side policies aimed at divestment from fossil fuels, or is there a way to harmonize these seemingly divergent goals?