Will your grandkids have enough oxygen to breathe in 2100?

I am guilty of not listening to the podcast, but I am immensely skeptical of the claim that Earth's oxygen is seriously threatened, simply because there's nearly a thousand times more oxygen in the atmosphere than carbon.

Googling for how much methane is on the seafloor yields the blurb "ten times more carbon than in the atmosphere". If that quantity of methane were burned, it would increase the CO2 in the atmosphere to about half a percent (ignoring absorption by the oceans, etc) and reduce the oxygen by about 1%. Going from 21% oxygen to 20% oxygen (which don't get me wrong, is impressive) would be significantly less of a change than between sea level and Denver, so I can't imagine mammals being threatened.

Does anyone else have more information on whether there's a plausible threat there? My take is that we'd all be dead from increased temperatures and the accompanying ecosystem disruptions long before the oxygen dropped below what we need to survive.

Yes,

Inverted Betteridge's law of Headlines

> "Any headline that ends in a question mark can be answered by the word no."

I looked but other than this podcast there is very little material from Dr Wanless available online.

EDIT: Also consider the source website, it doesn't alter Dr Wanless's assertions directly but the previous post was "Lumber Liquidators in trouble over this chemical found in flooring, but CDC wants to inject your children with it" make of that what you will.

Will the grandkids need oxygen to breathe in 2100?