A study by the National Aeronautics and Space Administration's (NASA) Langley Research Center in Hampton, Virginia, found that the Earth's northern hemisphere is reflecting less sunlight than in previous decades.
An unexpected asymmetry
The study, published in the Proceedings of the National Academy of Sciences (PNAS), indicated that while the Southern Hemisphere experiences a net gain of radiation in the upper atmosphere, the Northern Hemisphere experiences a loss.
According to satellite measurements collected between 2001 and 2024, this difference is surprising, because until now it was assumed that atmospheric and oceanic currents balanced these variations.
Causes of the decline in reflective ability (albedo)
The research team, led by Norman Loeb, linked the decrease in albedo to several factors:
- Loss of ice and snow, which reflect much of the sunlight.
- Changes in cloud formation and variations in water vapor.
- Aerosol variability: In the Northern Hemisphere, reduced pollution decreased the amount of particulate matter; in the Southern Hemisphere, forest fires and volcanic eruptions increased it.
Impact and relevance
Although the magnitude of the change is relatively small—a difference of 0.34 watts per square meter per decade—the results are statistically significant.
This finding could force adjustments to global climate models to more accurately reflect the dynamics of solar energy on the planet.
(With information from Al Mayadeen Spanish)
Taken from Cubadebate
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