Question

then why is increase i co2 percentage becoming a serious global issue

Answer 1

Heya......!!!

Carbon dioxide becomes a poisonous gas when there is too much of it in the air you breathe. Carbon dioxide poisoning can lead to central nervous system damage and respiratory deterioration in humans and other breathing creatures

increase in CO2 plays havoc with the Earth's climates by causing changes in weather patterns.
The major threat from increased CO2 is the greenhouse effect. As a greenhouse gas, excessive CO2 creates a cover that traps the sun's heat energy in the atmospheric bubble, warming the planet and the oceans.

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