Here are the suggested words to fill in the blanks:

1. Planting trees helps reduce our **carbon footprint** and fight climate change.
2. We decided to build **a campfire** to keep warm during our outdoor trip to the mountains.
3. We shouldn't cut down **trees** as they provide vital oxygen and habitat for wildlife.
4. It's important to pick up **rubbish** to keep our environment clean and beautiful.
5. Efforts to protect **endangered species** are important to maintaining biodiversity.
6. To save **electricity**, remember to turn off lights when leaving a room.
7. Let's help the environment by recycling **paper products** like newspapers and cardboard.
8. Using **single-use products** increases waste, so it's better to choose reusable ones.