Here's a deceptively simple question, which will take you, and any (generally older) children you might be teaching, into some wonderful places. It requires some investigation, but everything you learn will be fascinating.
Why is there enough oxygen in the air for us to breathe?
Why is there enough oxygen in the air for us to breathe?
The immediate reason is photosynthesis. But, if systems are in balance, why is almost all the free oxygen not consumed (inc by heterotrophic species with lower requirements than ours)?
The answers will take you to The Boring Billion, the coal seams, lignotrophic fungi etc etc
The answers will take you to The Boring Billion, the coal seams, lignotrophic fungi etc etc
You can travel from the initial answers to this question in almost any direction you wish, tapping into almost any component of ecology and Earth systems.
This article provides part of the answer. But the rate was not constant. There was a huge burial of carbon (and therefore release of O2) when the Coal Measures were laid down.
So ... why did so much coal form in the Carboniferous, and so much less since?
theconversation.com/amazon-fires-a…
So ... why did so much coal form in the Carboniferous, and so much less since?
theconversation.com/amazon-fires-a…
A major reason is that, for a long time after woody plants first arose, nothing could break down their dead trunks. Fungi had not developed lignin-digesting enzymes.
You see? It gets weirder and more interesting with every step.
You see? It gets weirder and more interesting with every step.
