The Real World's Earth returns to its peak amounts of oxygen & ozone (layer). What happens?

[Imaginym]

As the title says. All of it happens instantly. Are there any notable effects, from say, huge quantities of oxygen suddenly existing? Sudden fires/explosions? Metals rusting? How much larger might life become? How would all that ozone (layer) being back affect things? If there's a connection, would the temperature change quickly enough to have a significant effect?

What are the consequences?

 

[Randomlamdom]

Don't know what peak is compared to now but here's a video about what would happen if it doubled

https://youtube.com/watch?v=Wha6bs6Un00