A sourer sea
What extra CO₂ does to the oceans.
The sea soaks up CO₂
Oceans take in CO₂ from the air. With more CO₂ in the air, they take in more.
What might happen to sea water that takes in more CO₂?
What this lesson covers
The idea
Excess atmospheric CO2 increases ocean absorption, making sea water more acidic and threatening plankton and coral reefs; warmer ocean water absorbs less CO2, weakening the ocean as a carbon sink.
The sea soaks up CO₂
Oceans take in CO₂ from the air. With more CO₂ in the air, they take in more.
What might happen to sea water that takes in more CO₂?
- It becomes more acidic
- It becomes less acidic
- Nothing changes
More CO₂, more acid
Press Next step.
The sea as a sink
The ocean takes CO₂ out of the air, which is why it is called a carbon sink. But too much CO₂ makes the water more acidic. And a warmer sea can hold less CO₂, so it helps less.
Excess atmospheric CO₂ increases ocean absorption, making sea water more acidic and threatening plankton and coral reefs. Warmer ocean water absorbs less CO₂, weakening the ocean as a carbon sink.
Notes
Excess CO₂ makes sea water more acidic, threatening plankton and coral reefs. Warmer water absorbs less CO₂, weakening the ocean as a carbon sink.
Check yourself
What does excess atmospheric CO₂ do to sea water?
Which living things are threatened by more acidic sea water?
What happens to the CO₂ absorbed when the ocean water becomes warmer?
What happens to the ocean as a carbon sink when the water warms?
- Makes it less acidic. Excess CO₂ increases ocean absorption and makes sea water more acidic.
- Makes it more acidic — correct. Yes!
- Makes it colder. The chapter says excess CO₂ makes sea water more acidic.
- Forests on the mountains. The chapter names tiny plankton and coral reefs, which are in the sea.
- Birds in the desert. The chapter names tiny plankton and coral reefs.
- Tiny plankton and coral reefs — correct. Yes!
- Warmer water absorbs less CO₂ — correct. Yes!
- Warmer water absorbs more CO₂. Warmer ocean water reduces the ocean's capacity to absorb CO₂.
- Warm water does not absorb CO₂ at all. Warmer ocean water absorbs less CO₂, it does not stop absorbing completely.
- It becomes more effective. Warmer water absorbs less CO₂, so the sink is less effective.
- It becomes less effective — correct. Yes!
- It turns into a source of oxygen. Warmer ocean water reduces its capacity to absorb CO₂ as an effective carbon sink.