2. Experts say climate change is a problem that affects us all. (tenses do not change)
3. Edward said that nobody cares about global warming. (tenses do not change)
4. He told me that if he had known there was a recycling bin nearby, he wouldn't have thrown his newspapers in the rubbish. (tenses do change)
5. That scientist said the Earth is more polluted than it was in the past. (tenses do not change)
