Overview

• The finding appears in PNAS and draws on 24 years of observations from NASA’s CERES satellite program.
• Researchers quantify the hemispheric divergence at roughly 0.34 W/m^2 per decade, with a stronger imbalance in recent years.
• Air-quality gains in Europe, the United States and China cut reflective aerosols in the north, while retreating Arctic snow and sea ice lowered surface reflectivity.
• Clouds have not compensated for the shift, and Southern Hemisphere boosts from the 2019–2020 Australian fires and the 2022 Hunga Tonga eruption were temporary.
• Scientists flag risks for rainfall patterns, heat extremes and ice melt, as NASA continues CERES monitoring and applies more advanced climate models.