The acidification of oceans is increasing. Why is this phenomenon a cause of concern?<br/>1. The growth and survival of calcareous phytoplankton will be adversely affected.<br/>2. The growth and survival of coral reefs will be adversely affected.<br/>3. The survival of some animals that have phytoplanktonic larvae will be adversely affected.<br/>4. The cloud seeding and formation of clouds will be adversely affected.<br/><br/>Which of the statements given above is/are correct?

1. Correct. Ocean acidification reduces carbonate ions, which harms calcifying organisms such as calcareous phytoplankton (for example, coccolithophores).

2. Correct. Coral reefs depend on calcium carbonate deposition; lower pH reduces calcification and weakens reef growth and survival.

3. Correct. Many marine animals with planktonic larval stages are sensitive to lower pH, especially where larval shell/skeleton formation is involved.

4. Correct. Oceans are a major natural source of dimethyl sulfide (DMS), produced largely by phytoplankton. Acidification can reduce such biogenic sulfur emissions, which may affect cloud condensation nuclei and hence cloud formation processes.

Therefore, all four statements are correct.