Read the sentences again and say which of them:
- Describes a condition whose result is true at any time.
- Describes a condition whose result is very possible.
- Describes a condition whose result is impossible now.
a. Describes a condition whose result is true at any time.
3. If carbon dioxide (CO2) emissions in the atmosphere dissolve in the ocean, oceans become more acidic .
The condition part: Past simple, the result part: Present simple.
b. Describes a condition whose result is very possible.
1. If billions of annual emissions increase, greenhouse concentrations in the atmosphere will continue.
The condition part: Present simple, the result part: future simple.
d. Describes a condition whose result is impossible now.
2. If emissions stopped increasing, atmospheric greenhouse gas concentrations would continue to warm.
The condition part: Past simple, the result part: present conditional.