United in Science 2021 delivers on its mission, to present the very latest scientific data and findings related to climate change, to inform policy and decision-makers. This work depends on a global network of scientists and institutions, and on the critical underpinning observation, modelling and research infrastructure, which we must be supported to meet the demands of today’s challenges. It provides a holistic assessment of the most recent climate science. The result is an alarming appraisal of just how far off course we are. We need a breakthrough on protecting people and their livelihoods, with at least half of all public climate finance committed to building resilience and helping people adapt. And we need much greater solidarity, including full delivery of the longstanding climate finance pledge to help developing countries take climate action.