AUSTIN (KXAN) – The ground is getting darker; The planet itself, when viewed from space, appears darker than it did in the past. It appears that the top half actually becomes darker than the bottom half.
new Research published this fall in PNAS We used two decades of observations from NASA’s Clouds satellite and the Earth’s Radiant Energy System (CERES) satellite to learn more about what’s happening.
“(The records) show that there is an increase in the amount of energy that we are putting into the Earth system compared to the amount of energy that is leaving the Earth system,” Øyvind Hodnebrugge, a senior researcher at the Norwegian Center for International Climate Research, told the Associated Press.
Basically, the Earth absorbs more energy than it releases. As a result, the Earth’s temperature is also increasing.
“It’s a bit like wearing a black shirt on a summer day. You get warmer because you absorb more sunlight because it’s a dark shirt. If you have a white shirt, more sunlight reflects away, so it becomes lighter and less dark. It’s kind of the same thing,” Hodnebrug said.
What is the cause of darkening?
There are a few factors that are believed to play a role, according to the report.
One factor is that Earth’s air is cleaner than it was in the 1950s, when we first started observing Earth from space. Aerosol pollution has decreased. Aerosols, made of small particles, are used to return more sunlight back into space.
Melting sea ice also plays a role. White ice is very good at reflecting light back into space. As the planet warmed, the glaciers in the Arctic melted. According to the study, the melting of sea ice is more concentrated in the northern hemisphere, which explains the difference in opacity between the north and the south.
Finally, cloud cover has declined over the past few decades. Aerosols can act as cloud seeds. Less aerosol means less clouds.
“When you have aerosol pollution, it makes the clouds brighter, which leads to cooling. And again, when you clean up the aerosols, the clouds also get darker, and that’s a big effect,” Hodenborg said.
A 2024 study by the National Oceanic and Atmospheric Administration (NOAA) Cleaning up our shipping industry and reducing emissions from boats has led to fewer clouds in the sky, she revealed.
“While reducing sulfur emissions is critical to improving air quality and public health, it also eliminates the cooling effect that would otherwise offset some of the warming caused by greenhouse gases,” according to the National Oceanic and Atmospheric Administration (NOAA).