From 2001 to 2024, Earth has been reflecting less solar radiation. According to NASA data, the key factors are a reduction in ice cover and changes in the atmosphere.
A team of researchers from NASA and international scientific centers has determined that over the past two decades, Earth has been reflecting less and less sunlight. The results of the work were published in the journal Proceedings of the National Academy of Sciences.
From 2001 to 2024, the planet’s reflectivity (albedo) significantly decreased, particularly in the Northern Hemisphere. Analysis of satellite data showed a net loss of energy is being recorded in this part of the Earth, while the Southern Hemisphere is receiving more. However, the circulation of the atmosphere and oceans can no longer fully compensate for the resulting imbalance.
According to the study’s authors, the main reasons for this include a decrease in snow cover and sea ice area, as well as changes in cloud cover and water vapor content. Ice and snow reflect much more solar radiation than water or land, so their reduction leads to the planet’s “dimming.”
Furthermore, aerosols have also played a role. Their quantity in the Northern Hemisphere has decreased due to environmental measures in the US, Europe, and China. At the same time, the situation in the Southern Hemisphere was the opposite, with contributions from large-scale fires in Australia and the Hunga Tonga volcanic eruption in 2021–2022.
Scientists emphasize that the identified differences between the hemispheres are critically important for climate change projections. They highlight the need to improve climate models and more accurately account for the influence of clouds and aerosols.
