The study showed that climate change is already creating many challenges on the planet, but it will soon also affect the Earth's orbit.
Scientists at the Massachusetts Institute of Technology (MIT) have calculated that ongoing global warming caused by the burning of coal, oil and gas could reduce the available volume for low-Earth orbit satellites by between one-third and 82% by the end of the century, depending on the level of carbon emissions.
This is because space will become increasingly cluttered with debris, while climate change weakens natural mechanisms for cleaning it up.
The greenhouse effect that heats the air at the Earth's surface also cools the upper atmosphere, where space begins and where satellites in low orbit reside. This cooling makes the upper atmosphere less dense, which reduces the drag on millions of pieces of man-made debris and satellites.
This drag pulls space junk down toward Earth, burning up along the way. But a colder, less dense upper atmosphere means space is being cleaned less effectively. This suggests that space is becoming more crowded, according to a study published in the journal Nature Sustainability on Monday.
“We depend on the atmosphere to clean up our garbage. There's no other way to get rid of the garbage,” said lead author Will Parker, an astrodynamics researcher at MIT.
“It's trash. It's trash. And there are millions of them.”
There are millions of pieces of debris around three millimetres or larger circling the Earth, and they have the same energy as a bullet.
According to the Aerospace Corporation, which tracks orbital debris, there are tens of thousands of plum-sized pieces of space junk that fall with the same force as a bus. This debris includes old space crashes and rocket components, most of which are too small to track.
According to tracking website Orbiting Now, there are currently 11,905 satellites orbiting the Earth, of which 7,356 are in low orbit. Satellites play a key role in providing communications, navigation, weather forecasting, and monitoring environmental and national security issues.
“There used to be a common idea that space was limitless. So we might be good stewards of the environment because it is, in essence, limitless,” Mr Parker said.
However, in 2009, a collision between two satellites created thousands of pieces of space debris.
In addition, NASA measurements show a noticeable decrease in density, so scientists now realise that “the climate change factor is really important,” Mr Parker said.
Ingrid Cnossen, a space weather scientist at the British Antarctic Survey who was not involved in the study, noted that the density at 250 miles (400 km) above Earth is decreasing by about 2% per decade and is likely to continue to decline as greenhouse gas emissions into the atmosphere increase.
Ms Cnossen wrote in an email that the new study was “entirely valid” and that this is why scientists need to be aware of the orbital impacts of climate change “so that we can take the necessary steps to ensure its long-term sustainability.”
Sourse: breakingnews.ie
