What If Oxygen Doubled in Earth’s Atmosphere? | The Shocking Effects on Life and the Planet!

Take a deep breath. We take 23,000 breaths a day trying to get oxygen to our brain and cells. Oxygen is essential to our survival. But it's only a small percentage of what's in the air we breathe. So what if there was more of it? What would happen?

Would it cause giant insects to roam the streets? Would everything catch fire? Would it make you superhuman?