Of course, I went to the Begreen site. It has a calculator that you can use to figure out how many metric tons of CO2 you put in the air. This might be an enlightening thing for EVERYONE TO DO!!
My family residence is below national average, but the national average is much higher than it needs to be....and I did not add our big truck...so...I cheated. I planted about 15 trees this year and we cut our mowing area by over 75% and we do not mow but maybe once a month.
This site has all kinds of tips to lessen your carbon footprint. Wish we could choose Green Mountain Energy!!