For over two decades, NASA has been monitoring Earth’s energy balance—the difference between how much sunlight enters the planet and how much heat escapes back into space. The concern? More energy is being trapped than released, contributing to global warming.

While greenhouse gases are a major cause, scientists have struggled to explain why the imbalance is growing. A new study, reported by Science.org, suggests that Earth's cloud cover is shrinking, allowing more sunlight to reach the surface. Using data from NASA’s Terra satellite, researchers have confirmed that fewer clouds could be playing a bigger role in rising global temperatures than previously thought.

Cloud cover is shrinking in two major areas—the thick cloud zones near the equator and the stormy regions in mid-latitude areas.

Near the equator, clouds usually form when warm, moist air rises and cools, creating a dense cloud belt. But this band is getting narrower, meaning fewer clouds are forming to reflect sunlight. At the same time, storm systems in temperate regions are shifting closer to the poles, reducing cloud cover in areas that used to have more frequent storms.

With fewer clouds overall, more heat is being trapped on Earth’s surface. While scientists had suspected this for years, data from NASA’s Terra satellite has now provided the clearest confirmation of the scale of these changes.

Even though cloud cover has only decreased by about 1.5% per decade, the impact is huge. Clouds help cool the planet by reflecting sunlight back into space, but as they vanish, more heat gets absorbed, pushing temperatures higher.

The study also found that these changes are mostly caused by shifts in wind and weather patterns, not pollution levels. This means cloud cover could keep changing as atmospheric circulation patterns continue to evolve.

A major concern is whether shrinking cloud cover will create a feedback loop, trapping more heat and further disrupting cloud formation. This could lead to more extreme weather, rising temperatures, and unpredictable climate shifts.

While climate models have long predicted cloud changes, real-world data now confirms the trend. However, uncertainties remain—some models suggest the decline will continue, while others show mixed results. Scientists are racing to understand whether this trend will persist or if natural climate shifts might slow or reverse it.