Artificial intelligence shows rapid decarbonization won’t prevent warming beyond 1.5 degrees Celsius. The hottest years of this century are likely to shatter recent records. Many regions–South Asia, the Mediterranean, Central Europe, and parts of sub-Saharan Africa—will surpass 3 degrees Celsius of warming by 2060 if emissions continue to increase—sooner than anticipated. If emissions decline too slowly to reach net-zero by 2100, a nine-in-ten chance is likely that the hottest year will be 3 degrees Celsius hotter globally than the pre-industrial baseline with many regions experiencing temperature anomalies at least triple what occurred in 2023.