New Study Suggests Global Warming Has Reached 1.5°C Since Pre-1700

Research using Antarctic ice cores challenges existing baselines, indicating greater warming than previously estimated.

A new study published in Nature Geoscience indicates that human-induced global warming has reached 1.5°C when measured from a pre-1700 baseline.
The study, conducted by researchers at Lancaster University and the University of Leeds, uses CO2 data from Antarctic ice cores to establish a more accurate pre-industrial baseline.
Current global warming estimates using the 1850–1900 baseline show 1.31°C of warming, with significant uncertainty, but the new method reduces this uncertainty by more than half.
The findings suggest that nearly 0.2°C of warming occurred before the 1850–1900 period typically used by the IPCC, highlighting the need for more ambitious climate action.
The study aims to provide a clearer measure for policymakers, though it cautions against using the method to predict future warming due to potential climate tipping points.