datoid

Atmospheric CO₂ at Mauna Loa reached 431.12 ppm on April 15, 2026—2.0 standard deviations above the recent mean of 424.35 ppm (σ=3.30). This represents a statistical outlier in the measurement series. The reading coincides with global temperature anomalies rising 9.3% over three months to 1.18°C above baseline. The CO₂ pattern shows typical seasonal variation with spring peaks, but this measurement exceeds expected ranges. Whether this reflects measurement error, local conditions, or broader atmospheric trends warrants examination.