Our world is hugged by complex layers of gases that make up the atmosphere.
They protect and nurture all life as we know it. Now, we're shrinking an
entire one of those layers – the stratosphere – thanks to the profound impacts
we are having on our planet.
An alarming new study has found that the thickness of the stratosphere has
already shrunk by 400 meters (1,312 feet) since 1980. While local decreases
in the stratosphere's thickness have previously been reported, this is the
first examination of this phenomenon on a global scale.
"It is shocking," one of the research team, University of Vigo Earth
physicist Juan Añel told Damian Carrington at The Guardian. "This proves we
are messing with the atmosphere up to 60 kilometers."
Enveloping the sky around 20 to 60 kilometers (12 to 37 miles) above us, the
stratosphere blankets the atmospheric layer we're breathing (the
troposphere). Few clouds venture this high and only the occasional birds. It
holds the all-important ozone layer, which we've already wreaked havoc upon
through our emissions of CFCs.
While collective global efforts have managed to stem ozone depletion, which
caused a hole in the ozone layer above Antarctica, our emissions of
greenhouse gases have been altering the entire stratosphere.
Charl's University atmospheric physicist Petr Pisoft and colleagues used
satellite observations since the 1980s combined with climate models to
determine that the rise of CO2, rather than previously suspected ozone
depletion, is causing the stratosphere to contract.
"[We] demonstrate that the stratospheric contraction is not only a response
to cooling, as changes in both tropopause and stratopause pressure
contribute," the team wrote in their paper.
Greenhouse gas-induced warming in the troposphere is causing it to expand
and squash the stratosphere above it, they explain. On top of this, the
addition of CO2 into the stratosphere itself is causing its combination of
gasses to cool and huddle closer together (the opposite effect they have on
the troposphere) – shrinking the entire layer.
"In a plausible climate change scenario, our planet's stratosphere could
lose 4 percent of its vertical extension (1.3 km [0.8 mi]) from 1980 to
2080," Anel told the Anadolu Agency.
Ozone and molecular oxygen in the stratosphere absorb most of the ultraviolet
radiation from the sun, shielding us all from the most harmful sunlight –
wavelengths of less than ~300 nm. Here, the air temperature increases with
altitude (the opposite of the troposphere beneath), which keeps this layer of
gases stable. So aircraft can retreat here when the weather gets rough below,
but this stability also means any chemicals that reach the stratosphere tend
to linger.
If the predicted changes come to fruition, their scale becomes large enough
to potentially affect satellites, GPS, and radio communications, Pisoft and
team warned.
It may also change the altitude distributions of absorbing and emitting
molecules and therefore alter how the stratosphere absorbs radiation and its
overall dynamics, but there is still a lot to figure out before we can
understand if and how these impacts would occur.
This is just the latest discovery of the astonishing global-wide impacts the
climate crisis has on our world. Another recent find showed the
redistribution of weight due to melting glaciers has shifted the Earth's
axis.
'It is remarkable that we are still discovering new aspects of climate
change after decades of research," University of Reading's atmospheric
scientist Paul Williams, who was not involved in the study, told The
Guardian.
"It makes me wonder what other changes our emissions are inflicting on the
atmosphere that we haven't discovered yet."
Reference:
Stratospheric contraction caused by increasing greenhouse gases DOI:
https://doi.org/10.1088/1748-9326/abfe2b