A study published in Geophysical Research Letters shows that Earth is not as bright as it used to be, and that it has been darkening at a remarkable rate in recent years due to climate change.
Scientists at the New Jersey Institute of Technology in the US, the authors of the study published in late August, have been measuring the brightness of the Earth for 20 years, a phenomenon in which part of the light emitted by the Sun is reflected back by the planet. in the space. Over the past three years, they have observed that the Earth’s reflection has begun to decrease dramatically.
The study found that the planet reflects about half a watt of light per square meter than it did 20 years ago, equivalent to a 0.5% decrease in reflected brightness.
The problem is that although it reflects less light than the sun, the Earth receives more of this radiation.
“The Earth is getting warmer because of less reflected light, so there’s more sunlight coming in,” explains Philip Good, a researcher at the New Jersey Institute of Technology and lead author of the study.
A decrease in Earth’s brightness, according to the study, may be caused by a decrease in cloud cover, as sunlight is reflected back into space when it encounters a layer of clouds. Thus, when there is a decrease in cloud cover, more sunlight is allowed to enter the planet.
The largest decrease in cloud cover occurred off the western coasts of North and South America, the same region where sea surface temperatures have risen due to climate change, the study said.
As the ocean warms and cools in different places, changes occur in the path of the jet stream. The researchers say this change has a direct impact on long-term weather and climatic conditions, especially on the western coasts of North and South America, without specifying conditions.
Ocean warming is greater than thought
About 30% of the light that the Earth receives from the sun is reflected by clouds and returned to the universe, illuminating the visible surface of our planet’s moon.
The amount of light reflected from the sun varies from night to night and season to season. The spring months in the northern hemisphere, in the days close to the new moon, are the best time to observe this phenomenon.
