NASA discovers Earth is darkening: A warning sign

Data from NASA satellites have revealed that the Earth has been reflecting less and less sunlight over the past two decades.

This "darkening" trend is critical to understanding the impact of climate change on our planet, experts say.

24 YEARS OF OBSERVATION

The research was conducted as part of NASA's Clouds and the Earth's Radiant Energy System (CERES) project. CERES satellites measure how much sunlight Earth reflects back to space and how that amount changes over time.

With this data, scientists calculate Earth's "radiation budget." This is the difference between the sunlight the planet absorbs and the infrared energy it emits back into space.

According to data collected between 2001 and 2024, the Earth is reflecting less and less light. This darkening is particularly pronounced in the Northern Hemisphere compared to the Southern Hemisphere.

Melting Snow and Ice

According to BBC's Science Focus Magazine, one of the most important reasons for this change is the melting snow and ice cover in the polar regions.

Snow and ice help keep the planet cool by reflecting sunlight. But as temperatures rise, these white surfaces are melting and being replaced by darker land and sea surfaces.

These dark surfaces absorb more heat rather than reflect light, creating a feedback loop that further accelerates global warming.

Aerosol Change

The second important factor is the change in the amount of aerosols (air pollutant particles).

Aerosol pollution has decreased in the Northern Hemisphere in recent years due to tightened environmental regulations. While this has resulted in a cleaner atmosphere, aerosols historically kept the Earth cool by reflecting some of the Sun's light.

Ironically, the Northern Hemisphere therefore began absorbing more heat due to less pollution.

In the Southern Hemisphere, the situation is different: forest fires and volcanic eruptions increase aerosol levels, leading to greater reflection of sunlight.

CHANGE IN CLOUD STRUCTURE

The research reveals that changes in cloud formation and properties also play a role in Earth's darkening.

In some regions, the structure of clouds is changing, causing them to become less reflective and absorb more solar energy, especially in the Northern Hemisphere.

This leads to a disruption in the Earth's energy balance: the Northern Hemisphere is warming, while the Southern Hemisphere is changing more slowly.

The study's authors say that these differences are not fully reflected in current climate models and that the models need to be revised.

According to experts, understanding this change in Earth's reflectivity (albedo) is vital for predicting future climate trends and more accurately assessing the effects of global warming:

“If this trend continues, our planet will accumulate more heat and climate change will progress much faster.”