Carboon footprint
When you walk across a floor with wet feet, you can see a line of 'feet' behind you.
Those are you footprints.
In the same way, people leave behind a carbom footprint that showa hoe much carbon dioxide thay make in their lives.
If you travel by car and buy lots of a new things,you have a bigger carbon footprint.
If you walk and buy second-hand things you have a smaller carbon footprint.
These are some of the things that make a carbon footprint smaller or bigger.