Our carbon footprint is the effect we may be having on the environment with our actions.
It's called carbon footprint because it's about how much carbon dioxide we produce by the things we use every day - like burning coal and using too much electricity.
Schools and hospitals can have a carbon footprint as well as children and adults.
Press Packer Alex tells us how her school is reducing its carbon footprint.
Here's her report.
"At my school we are trying to cut our carbon footprint to help the environment.
We have new lights that don't use as much electricity as the old bulbs. They are mostly in the toilet and stairways.
They only come on using motion detectors- which can tell when someone is there. It's a great idea because lights aren't just left on.
We also recycle all the paper and plastic we use.
Another good thing is that many people are now walking to school and to set a good example some teachers have started walking too.
Around my school there are plenty of bins so there's no excuse for pupils littering.
I'm scared that many of our animals suffer because of the pollution we cause and we could make some become extinct.
I'm also worried that our oceans are becoming extremely polluted with oil.
Press Packer Alex
My top five tips for reducing your carbon footprint are
- Don't litter
- Use low energy light bulbs
- Recycle more products
- Don't just leave TVs and computers on standby- turn them off fully
- Walk to more places
I think more schools should do this in my area.
Even recycling one small can will produce enough energy to power a TV for three hours.
The world is sacred and we can't buy a new one."
Alex, 12, England
Why don't you write us a Press Pack report - and get it published on the site?!
It can be about anything that's happened in your local area - or your views on the news.