Here’s a possible assessment of the level of certainty for each prediction:

1. The Earth gets warmer - **Certain with evidence (CE)**
2. No more house chores - **Less certain (L)**
3. Sea level gets higher - **Certain with evidence (CE)**
4. Renewable energy becomes popular - **Certain without evidence (C)**
5. Some cities disappear - **Less certain (L)**
6. Fewer families of multiple generations - **Less certain (L)**

This classification is based on scientific evidence, social trends, and speculation.