So, with melting ice-caps in the news again, this is probably too late, but
find out you carbon footprint here
According to another site I found, the impact on cimate will be nothing if everyone on earth emits 2tonnes (2000kg) of Co2 per year. UK average is 6 tonnes per person per year.
(ours is 520 kg per month or 8.4 tonnes per year between us. not great seeing as the babes are tiny and it doesn't take food miles into account)