Deep breaths, everyone.
Don't
panic, but researchers have discovered that oxygen is (very) slowly draining
out of Earth's atmosphere, and right now, they're not sure why.
By
analysing air bubbles trapped inside ice cores from Greenland and Antarctica, a
team from Princeton University has found oxygen levels have dropped by 0.7
percent in the last 800,000 years, and figuring out why could be crucial to
predicting our planet's future.
Getting
the answer isn't going to be easy though – oxygen on our planet is constantly
being recycled by humans, animals, plants, and even silicate rock. Right now,
ice cores are among the best ways we have of getting fixed readings of how much
oxygen is present.
Since the rate is actually very very slow but still it is there and scientist are doing whatever they can to find the cause.
Researchers studied ice core samples from Greenland and Antarctica and discovered the oxygen levels of our planet have varied wildly since the dawn of time, according to a peer-reviewed Princeton University study published in Science
As far as
ecosystems on Earth are concerned, the drop is only a trivial one, but it can
still tell us more about the secrets of what makes a planet habitable – useful
information to have if we're ever going to live on Mars.
An
increase in erosion rates is one hypothesis behind the oxygen drop – more
erosion would expose and oxidise more fresh sediment, reducing atmospheric
oxygen levels.
Another
possible cause is long-term climate change – over the last few million years,
we've seen a slight overall drop in global temperatures, even though Earth has
been rapidly heating up over the past half a century.
But
before we started burning huge amounts of fossil fuels after the industrial
revolution, the ocean was very slowly cooling, and that could have set off an
ecological chain reaction where it started consuming more oxygen out of the
atmosphere.
For now,
though, these are only hypotheses that need further testing.
For the
first few billion years of its life, Earth's atmosphere didn't have any oxygen
in it at all. Scientists believe tiny algae called cyanobacteria evolved and
triggered a rapid rise in oxygen levels -and, subsequently, in the number of
animals who could breathe it in.
Today,
around 21 percent of the air we breathe is made up of oxygen – alongside
nitrogen, argon, and carbon dioxide.
While its
effects on the atmosphere aren't as severe as carbon dioxide, it does have an
impact on the amount of sunlight that reaches the ground, and there is evidence
that changing oxygen levels have affected Earth's climate in the past.
While the
rate of oxygen decline is nothing to worry about just yet, Stolper does have a
warning about the last 200 years since the industrial revolution started, data
which isn't included in the new report.
"We
are consuming O2 at a rate a factor of a thousand times faster than
before," he told Gizmodo. "Humankind has completely short-circuited
the cycle by burning tonnes of carbon... it's yet another indication of our
collective ability to do what happens [naturally] on the Earth, yet so much
faster."


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