What happened
A study published in Geophysical Research Letters reports evidence that global warming has accelerated, with a reported change in warming rate beginning around 2015. The study reports high confidence that the faster warming is not a short-lived random fluctuation.
Background and earlier position
Year-to-year global temperature records are noisy because natural influences can temporarily push temperatures up or down. Natural influences mentioned in the study include volcanic eruptions and changes in solar activity. Because these influences affect annual temperatures, earlier work struggled to prove acceleration from raw data alone.
What changed now
The Geophysical Research Letters study analyses multiple major global temperature datasets and uses statistical approaches to remove the estimated contribution of natural factors such as volcanic effects and solar variability. After these adjustments, the study reports an increased warming rate with a reported change beginning around 2015.