Question

Which of the following processes lead to an increase in the amount of CO2 in the atmosphere? Select all that apply.

ocean acidification

decreasing ocean temperatures

increasing sunlight

deforestation

increasing water vapor concentration

Answer 1

The ocean water is slightly basic due to presence of dissolved salts. Ocean water absorbs carbon dioxide from air which lowers the pH of ocean water. This is called ocean acidification. But the reverse is not true, ocean acidification doesn't increase CO₂ in air.

Decreasing ocean temperatures, increases solubility of CO₂ in water as solubility of CO₂ (or any gas) in water increases with decrease in the temperature. So this will decrease the amount of CO₂ in atmosphere.

Increasing sunlight-As sunlight increases, more of it is trapped by green house gases in air, leading to warming of earth, which in turn reduces solubility of CO₂ in ocean waters, eventually leading to an increase in the amount of CO₂ in atmosphere.

Deforestation- Cutting down of trees is called deforestation. Trees absorb CO₂ from air during the process of photosynthesis. So deforestation means less trees, means less absorption of CO₂. So deforestation increases amount of CO₂ in atmosphere.

Increasing water vapour concentration in air increases the greenhouse effect caused by CO₂ as water vapour is also a greenhouse gas. It will increase the warming effect caused by CO₂ which may increase the temperature of earth and oceans, thereby reducing solubility of CO₂ in oceans. So this may eventually increase the amount of CO₂ in atmosphere.