The path to 1.5 °C requires ratcheting of climate pledges

Messages for policy Ratcheting near-term ambition to 2030 as called for by the Glasgow Climate Pact can help to reduce peak temperature change and bring us closer to the Paris Agreement's 1.5 degrees C temperature goal. Delaying ratcheting of ambition to beyond 2030 could still limit end-of-century temperature change to below 1.5 degrees C but would result in higher temperature overshoot over many decades. Ratcheting near-term ambition could also facilitate faster transitions to net-zero emissions systems, especially in major economies. Ratcheting near-term ambition could lay strong institutional infrastructures required to phase out fossil fuels and incentivize research and development, and to deploy more nascent technologies. Increasing climate ambition through 2030 will be crucial to limiting global peak temperature changes this century. Countries need to ratchet their 2030 pledges made in Glasgow to reduce temperature overshoot and consequently reduce the risks of irreversible and adverse consequences to natural and human systems.