Researchers have confirmed a clear acceleration in the planet's warming trend beginning around 2015. Global warming is not proceeding at a constant rate — it is speeding up.
The distinction between linear warming and accelerating warming is not academic. Linear warming allows planning: if the planet warms 0.2°C per decade, you can project when thresholds will be crossed and prepare accordingly. Accelerating warming compresses the timeline. Thresholds arrive sooner than linear extrapolation predicts.
The acceleration is consistent with multiple reinforcing feedbacks: declining sea ice exposes dark ocean water that absorbs more solar radiation, thawing permafrost releases stored carbon, and warming oceans absorb less CO2. Each of these processes converts warming into more warming, producing a rate that increases with the level.
What makes acceleration difficult to detect is that the signal sits inside natural variability. El Niño, volcanic eruptions, and ocean circulation patterns create decade-scale fluctuations that can mask or amplify the underlying trend. The 2015 acceleration was partially obscured by the “hiatus” narrative of the early 2010s — a period when surface warming appeared to slow, which was later attributed to heat being absorbed by deep ocean layers.
The methodological lesson: a trend that appears to pause and then resumes faster was never actually pausing. It was redistributing energy within the system. The pause was a measurement artifact of tracking only one variable (surface temperature) in a system with many reservoirs (atmosphere, surface ocean, deep ocean, ice, land).
What looks like a pause at one resolution is acceleration at another.