Fact Check: Will Climate Change Wipe Out Ocean Oxygen?

Fact Check: Will Climate Change Wipe Out Ocean Oxygen?

We’ve heard plenty of claims recently about how wildfires in the Amazon rainforest threaten to kill us all because the rainforest produces half of Earth’s oxygen. It turns out that’s not true; the Amazon produces something like 7% of Earth’s oxygen, almost all of it is immediately soaked right back up by the rainforest itself, and as we already reported, most of the Amazon isn’t on fire anyway.

Don’t relax too quickly though, because Democrat presidential wannabe Pete Buttigieg says we’re still going to run out of oxygen. The reason, he says, is climate change — it’s going to catastrophically lower oxygen levels in the oceans, and that’s going to make atmospheric oxygen fall, too. Is this true? Will warmer oceans suffocate us all to death? Let’s dive deeper.


  • Last week, Pete Buttigieg, the South Bend mayor with ambitions of being the next president, told a CNN town hall event that unless the US takes radical — meaning expensive and government-mandated — action on climate change, changing ocean temperatures mean “we could lose half the world’s oxygen because of what’s going on in the oceans.”
  • According to Buttigieg, this loss of oxygen would be a problem for “the people who will be alive at the turn of the century,” although if he’s right about oxygen levels falling by half there isn’t going to be anyone alive.
  • When questioned about this claim, the Buttigieg campaign directed journalists to a story in the Smithsonian Insider, which in turn talks about a paper in the peer-reviewed journal Science. The paper says that around half of the oxygen in Earth’s atmosphere comes from the oceans — which is a fact.
  • However, the oxygen produced by the oceans doesn’t really have much of an impact on how much is in the atmosphere. Most everyone that’s taken a grade-school science class knows that plants release oxygen as a by-product of photosynthesis. What most people don’t know is that about half of Earth’s photosynthesis is carried out by plankton in the top layers of the oceans.
  • Something else most people don’t know is that photosynthesis has almost no effect on how much oxygen is in the atmosphere. Plants only photosynthesize — turning carbon dioxide and water into oxygen and sugars — when the sun is shining. As soon as it gets dark they absorb oxygen and burn those sugars, turning them both back into carbon dioxide and water.
  • An array of climate scientists and biologists quickly shot down Buttigieg’s claim. They say there are plenty of good reasons to avoid climate change, but falling oxygen levels definitely isn’t one of them.

Copyright 2019, RightWing.org