Why does the world not run short of food and oxygen?

Answer 1

It's a cycle. Plants use energy from the sun with carbon dioxide (what we exhale) and water to produce sugar and oxygen (what we inhale). Plants basically give us oxygen to breathe and fruits and vegetables to eat. We and all other animals eat the food and breath the oxygen, giving off carbon dioxide for the plants. The large amount of water on the planet plays an important role also. Water in the sky, the oceans, the rivers, and the mountains run the water cycle. Although, the future for human civilization isn't so great. Global warming may kill many of the plants, ending the cycle. Surprisingly, of all the forests being destroyed and the growing population, we are still able to survive. I mentioned only plants and animals, but bacteria, fungi, and protists help too.