The European Union faces a large climate investment gap. To fill it, we propose the joint issuance of EU climate bonds. These bonds would be funded by the sale of emission allowances, traded on the EU Emissions Trading System and extended to cover all sectors. Access to the resulting funds would be conditional on countries’ performance on the implementation of climate investments. EU climate bonds would meet global demand for a safe and liquid asset, while increasing the speed and efficiency of EU climate investing, its resilience to sovereign crises, and the greening of investors’ portfolios and monetary policy.