Now about reasons of our high emission of CO2: most of homes and apartments in Poland has "central heating" - there is company with big stove with big chimney, they're heating water and this water goes with pipes to heaters in our apartments.

We had problem because there wasn't this option in CO2 calculator.

So we made call to that company and they calculated how many kilograms of coal is used for one meter2.

With this data and area of apartments pupils were calculated how many kilograms of coals they are using per year and it was big numbers.