"Earth is getting dimmer, researchers have found, and climate change is likely to blame. As the oceans get hotter, they appear to be generating fewer bright clouds, which means less sunlight is reflected back into space – and that warms up the planet even more.

Researchers measured the reflectance or albedo of Earth by observing the earthshine that illuminates the Moon. Nearly 20 years of data, from 1998 to 2017, was collected to inform the results of the study.

The measurements showed that Earth is now reflecting about half a watt less light per square meter compared to 1998, the equivalent of a 0.5 percent decrease in Earth's reflectance. In total, our planet reflects about 30 percent of the sunlight that reaches it."

The Research Paper: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021GL094888