Hey please it's really urgent. Thanks so much

Explanation:

1. Humans should worry about atmospheric changes as they can affect their health in the sense of their lungs and other important body organs being damaged.

2. Positive effect of humans on ozone layer:

The fact that humas have stopped using CFCs has helped the ozone layer as these had a bad effect on this layer protecting us.

Negative effect:

One thing causing a bad effect on the ozone layer is carbon dioxide and the fact that humans are using it very often it causes the ozone layer to decrease in size meaning that the ozone layer won't be capable to protect us from harmful gases.

4. Scientists think that we should try stop the amount of carbon dioxide from rising because the increase in carbon dioxide leads to the earth becoming warmer and this can lead to a drastic change in the climate.

HOPE IT HELPED

answer: dna

because all cells have genes