Although Earth\u2019s two hemispheres lie on opposite sides of the planet and differ in many ways, they share a peculiar commonality\u2014or at least they used to. The Northern and Southern Hemispheres reflected nearly the same amount of sunlight back into space. This balance, though long considered odd, is now coming undone, as new data reveals that one side of Earth is darkening faster than the other.<\/p>\n
Using 24 years\u2019 worth of data from NASA\u2019s Clouds and the Earth\u2019s Radiant Energy System (CERES) mission, a team of scientists discovered that the Northern Hemisphere is absorbing more sunlight than the Southern Hemisphere. This shift in Earth\u2019s energy balance could have lasting impacts on weather patterns, rainfall, and the overall climate in the coming decades, a new study<\/a> published in the Proceedings of the National Academy of Sciences suggests.<\/p>\n A delicate balance <\/p>\n Earth receives energy from the Sun and reflects part of it back to space. This reflectivity is known as albedo, a measure of the percentage of sunlight reflected by a surface. Throughout the year, the Southern and Northern hemispheres receive the same amount of energy from the Sun, with each one receiving more sunlight at different times of the year.<\/p>\n The Southern Hemisphere is dominated by oceans, which absorb more sunlight, while the Northern Hemisphere has more land and less sea ice, which absorbs heat faster and reflects less sunlight. In the early 2000s, satellite data revealed that the two hemispheres reflect the same amount of solar energy back into space. Scientists had expected the hemispheres to differ, but data showed that clouds in the Southern Hemisphere were slightly thicker and more reflective, therefore balancing out the darker land surfaces in the Northern Hemisphere.<\/p>\n The new study, however, suggests this once-balanced system is coming to an end. NASA\u2019s CERES, launched in 1997, measures the amount of sunlight absorbed by Earth and the amount of infrared energy emitted to space. The team behind the study analyzed CERES data from 2001 to 2024 and found that the Northern Hemisphere is absorbing around 0.34 watt more solar energy per square meter per decade than the Southern Hemisphere.<\/p>\n The team\u2019s analysis pointed to three main driving factors behind the emerging imbalance: melting snow and ice, declining air pollution, and rising water vapor.<\/p>\n