NASA discovers dangerous phase shift between Earth's two hemispheres

New NASA research shows that the Northern Hemisphere is absorbing more sunlight than the Southern Hemisphere, a sign that our Earth is slowly drifting away from energy balance.

The Northern Hemisphere absorbs more energy and the Earth will have to readjust its entire climate system, from monsoons, rainfall to the distribution of heat between ocean regions - Photo: Francesco Ungaro via Pexels

For years, scientists have noticed a strange phenomenon: the two halves of the Earth reflect nearly the same amount of sunlight back into space.

This balance is surprising, because the Northern Hemisphere has more land, cities and industrial smog, which typically make the Earth’s surface more reflective, while the Southern Hemisphere is largely ocean, which is darker and absorbs more energy.

The Northern Hemisphere is getting more light

However, the latest satellite data from NASA shows that this symmetry is slowly disappearing. The Northern Hemisphere is getting "darker" and absorbing more solar energy than the rest of the planet.

In a study published in the journal Proceedings of the National Academy of Sciences (PNAS), Dr. Norman Loeb's team at NASA's Langley Research Center analyzed data collected over two decades from the CERES satellite mission, a system that measures the amount of radiation absorbed and reflected by the Earth.

The results show that the energy absorbed between the two hemispheres is no longer as balanced as before. The Northern Hemisphere is collecting more sunlight, while the Southern Hemisphere is holding steady. The difference is small but could have a big impact, changing ocean currents, rainfall patterns, and even the global climate system in the future.

As scientists explain, the Earth always tries to maintain balance by absorbing energy from the Sun and emitting it back into space as thermal radiation. When this process is out of whack, the planet adjusts itself through natural mechanisms such as changes in cloud cover, ice reflection, or surface temperature. But this time, it seems that those mechanisms are no longer strong enough to maintain balance.

Experts say there are three main reasons for this imbalance. First, the ice in the polar regions and the northern mountains is melting rapidly, exposing dark land and oceans, surfaces that absorb much more heat than white snow.

In addition, industrial smog and emissions in many developed regions have been significantly reduced over the past two decades thanks to environmental policies. This may sound positive, but in reality, the air has fewer light-reflecting particles, causing the Earth to absorb more energy.

Another factor is that warmer air can hold more water vapor, which absorbs sunlight rather than reflecting it. As the Northern Hemisphere warms faster, the amount of water vapor in the atmosphere increases, making the region appear darker to satellites.

Global climate impact warning

One surprising finding in the study was that global cloudiness had barely changed over the past two decades. If the climate system were self-balancing, scientists would expect the Northern Hemisphere to see more clouds to reflect the extra sunlight. But that hasn’t happened.

Dr. Norman Loeb said it was the cloud factor that puzzled him most. He questioned whether the Earth’s climate had always been symmetrical between the hemispheres, or whether current changes were breaking that pattern. Many climate models are still not detailed enough to fully account for the complex interactions between clouds, water vapor, and aerosols in the atmosphere.

Understanding how clouds and dust particles interact remains one of the biggest challenges in climate science, says Zhanqing Li, a climate scientist at the University of Maryland. Clouds play a key role in regulating the amount of energy the Earth receives and emits, and even small changes in this system can have profound effects on global climate.

While the energy gap between the two hemispheres is currently small, experts warn that it could grow rapidly in the coming decades. Once the imbalance becomes significant, the Earth will have to readjust its entire climate system, from monsoons and rainfall to the distribution of heat between the oceans.

According to Dr. Loeb, this research is just the beginning of a better understanding of how the Earth absorbs and reflects energy. He hopes that the next generation of climate models will help verify the results and make more accurate predictions about the changes to come.

“This imbalance is not just a number, it shows that our planet is changing faster than many people think,” he said.

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MINH HAI

Source: https://tuoitre.vn/nasa-phat-hien-su-lech-pha-nguy-hiem-giua-hai-ban-cau-cua-trai-dat-20251028094530675.htm