Our atmosphere consists of 20% of Oxygen, 70% Nitrogen and others being at 10%. In our daily life, 90% of energy comes with the Oxygen intake and remaining 10% with food consumption. By increasing the Oxygen to double its quantity, there are lot of complications, as below
The increased amount of Oxygen in our body can lead to a lungs damage. poor eyesight and cells not being reproduced because of increased chances of oxygen toxicity in humans. And also having too much amount of Oxygen creates free radicals (atoms) that look for other electrons to pair up, which leads to a damage of human body and DNA also.
The easy noticing factor would be the giant bugs! In general, insects take Oxygen with their trachea (similar to human nose). By increase in the Oxygen in atmosphere, their trachea also get expanded and thereby, the insect's body also get increased in size, to become giant bugs.
The increased amount of Oxygen in our body can lead to a lungs damage. poor eyesight and cells not being reproduced because of increased chances of oxygen toxicity in humans. And also having too much amount of Oxygen creates free radicals (atoms) that look for other electrons to pair up, which leads to a damage of human body and DNA also.
The easy noticing factor would be the giant bugs! In general, insects take Oxygen with their trachea (similar to human nose). By increase in the Oxygen in atmosphere, their trachea also get expanded and thereby, the insect's body also get increased in size, to become giant bugs.
Then comes the fire into play. We know that oxygen is key ingredient for fires to spread & expand. Because of increased quantity of Oxygen in atmosphere, there will be a massive fire explosions everywhere causing a lot of damage to both property and life forms.
The earth's crust (the lithosphere that we are living upon) gets more heavier than the atmosphere, because of the increased amount of Oxygen. This would lead to oxidization of the huge water bodies, so the water turns into hydrogen peroxide, which will make the water to evaporate quickly.
However, there are few advantages also because of the Oxygen increase in atmosphere. With the higher oxygen levels, we would be a lot more energetic than normal and get more active because of the improved blood circulation in body. We would see less diseases and would not be sick because of the increased number of infection-fighting immune cells, known as Neutrophylls.
Surprisingly, we would not become Hulks (as in Avengers movie).