Twelve months at 1.5 °C signals earlier than expected breach of Paris Agreement threshold

Abstract June 2024 was the twelfth month in a row with global mean surface temperatures reaching 1.5 °C above pre-industrial conditions. Does this imply failure to meet the Paris Agreement goal of limiting long-term warming to 1.5 °C? Evidence from climate model simulations, conditional on reaching this threshold for 12 consecutive months, regardless of recent El Niño conditions, suggests that the Paris Agreement target may be crossed earlier than expected.