Fossil fuel subsidies undermine international efforts to avert dangerous climate change and represent a drain on national budgets. They also fail in one of their core objectives: to benefit the poorest. Phasing out fossil fuel subsidies would create a win-win scenario. It would eliminate the perverse incentives that drive up carbon emissions, create price signals for investment in a low-carbon transition and reduce pressure on public finances. This report documents the scale of fossil fuel subsidies and sets out a practical agenda for their elimination in the context of the global goal of tackling climate change. It spells out the real costs of fossil fuel subsidies within the top developed-country emitters (the E11), the G20, and more broadly across developing countries, and outlines ways to achieve their global phase-out by 2025.