Warmer ocean waters are causing Earth’s brightness to decrease, with fewer bright clouds reflecting sunlight back into space and even more energy being trapped in our planet’s climate system, according to a study published in AGU Geophysical Research Letters.
The team found that Earth now reflects about half a watt of light less per square meter than it did 20 years ago.
That equates to a 0.5% decrease in Earth’s reflectance, which reflects about 30% of the sunlight that illuminates it, and most of this reduction has occurred in the last three years of data on Earth’s light.
The researchers used decades of terrestrial light measurements — the light reflected from Earth that illuminates the moon’s surface — as well as satellite measurements.
data showed “Significant” decrease in albedo (the reflection of sunlight on the Earth) of the planet in the past two decades, indicated the Technological Institute of New Jersey (USA), which led the research.
Explained Philip Good, lead author of the study, which involved the participation of the Astrophysical Institute of the Spanish Canary Islands.
Net sunlight reaching the Earth is affected by two factors: the brightness of the Sun and the reflectivity of the planet.
The observed changes in albedo are not related to periodic changes in the brightness of the Sun, which means that changes in Earth’s reflection are caused by something on our planet.
The study indicates that in recent years, There was a dip in low, bright and reflective clouds over the eastern Pacific Ocean, Based on satellite measurements made for NASA’s Ceres project.
This is the same region, off the western coasts of North and South America, where increases in sea surface temperatures have been recorded due to the reversal of a climate condition called the Pacific Decadal Oscillation, with possible links with global climate change.
The fact that the Earth is dark also means that it exists Important additional solar energy present in the atmosphere and oceans, which could contribute to global warming.
University of California planetary scientist Edward Schwitterman considered it “extremely concerning” and noted that for some time, many experts had hoped that a warmer Earth would lead to more clouds and increased albedo.
Commenting on the study, in which he was not involved, Schwittermann said that increasing albedo would help mitigate global warming and balance the climate system, “but this shows the opposite.”