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The Earth's climate is shifting, and it's our fault.
Not Seeker, specifically, I mean humans in general.
We're digging up and burning sources of carbon that otherwise would have been locked
away within the Earth, adding it to our atmosphere and driving average global temperatures up.
So why don't we take the carbon from the air, and push it somewhere else?
That's the idea behind Negative Emission Technologies, or NETs.
They're one possible tool to stop climate change, but they aren't the silver bullet.
It's tempting to think that if we develop a way to scrub the air of CO2 we won't have to cut down our emissions so much.
No lifestyle change, no big shift in energy infrastructure, just some quick fix that keeps this climate change thing from getting out of hand.
Unfortunately while that's theoretically possible it's very far from practical.
At the start of 2018 the European Academies Science Advisory Council released a report
on how feasible NETs are for slowing or reversing the effects of atmospheric carbon dioxide and their conclusion is… not good.
First it helps to understand why plucking CO2 from thin air isn't as easy as it sounds.
As of 2013 we were adding an estimated 40 billion tons of CO2 to the air annually.
While that's a lot of CO2, it's not very concentrated; there are only about 400 CO2 molecules per million molecules that make up our air.
So if you want to just neutralize the stuff we're putting out each year, you're going to have to churn through a lot of air.
Jennifer Wilcox, an assistant professor at Stanford University, imagines what she calls a synthetic forest.
Sounds like cool funky neon trees but really it's more a 200 meter wall of fans pushing air through liquid with chemicals that capture carbon dioxide.
The chemical is then separated from the CO2 using high heat, allowing it to go back and capture more carbon.
What's left behind is high-purity CO2 that's easier to liquify or repurpose.
Now you may have noticed this process isn't passive, you need to put energy into it.
Wilcox estimates that to remove a million tons of CO2 a year,
you'd need a dedicated power plant putting out anywhere from 300 to 500 megawatts.
So to balance out that 40 billion tons we're emitting annually, that works out to 40,000 additional power plants.
And that's assuming you use carbon neutral power.
If you use a coal plant, you emit more than you extract.
A synthetic forest isn't the only possible negative emission technology.
We could go au naturale and plant more forests.
Let the trees do the work.
Except planting new forests is hard and we're already deforesting what currently exists.
Really it'd be better to get that under control first.
Another alternative is sprinkling iron into the ocean, stimulating photosynthetic plankton to absorb more CO2.
But that process is kind of like unleashing a tiger and hoping it takes care of your gorilla problem.
We could try making a carbon capturing mineral like magnesite in a lab.
The mineral forms when magnesium is introduced to carbonic acid, a molecule that results when CO2 and water react.
In August of 2018 scientists discovered how to make it artificially in just 72 days,
as opposed to the hundreds of thousands of years it takes to form naturally.
Now we just need to make 80 billion tons of the stuff every year and we're set.
All of these issues led the European Academies Science Advisory Council to conclude that betting on NETs alone is not the answer.
We can't keep emitting at the rate we are now and hope some future carbon capture wonder tech will turn the tide.
The goal is still to cut current emissions as drastically as possible.
In the meantime we can still develop negative emission technologies.
Just because they can't stop climate change alone doesn't mean they can't help.
But humans need to scale back our carbon emission so NETs don't have to counter 40 billion tons of CO2 every year.
While you're here subscribe for more videos, and check out Marens video about new solar technology powered by bacteria.
While CO2 levels are at 400 parts per million today, until 1950 CO2 hadn't risen above 300 parts per million for over 400 thousand years.
Thanks for watching and I'll see you next time on Seeker!
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Why It's So Hard to Capture CO2 From the Air

243 Folder Collection
Jerry Liu published on May 4, 2019    Jerry Liu translated    Evangeline reviewed
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