There are many studies which show that livestock is a major contributor to greenhouse gas emissions (from CO2 and Methane to Nitrous Oxide) and that our diet impacts emissions.
According to ABC News, Gidon Eshel and Pamela Martin concluded that the average "American diet is responsible for an additional ton-and-a-half of greenhouse gas emissions a year from each of us".
I mention this because I'm a little overweight (a bit of a porker is the polite term) and that additional mass I carry is a consequence of unnecessary carbon emissions (i.e. food I didn't need to eat). My additions however are nothing compared to the Greenpeace wearing Kraken I witnessed hauling himself out of a Land Rover in Tonbridge today. I couldn't work out which caused more damage: the SUV, the extraneous mass or a combination of both. Was the t-shirt ironic?
Anyway for reasons of vanity I've decided to do something about my additional mass. Having caused environmental damage gaining it, I'd rather minimise the environmental cost of removing it. Whilst one obvious option is to spend time down the gym, I was wondering whether anyone has done a study of how much additional co2 such pointless exercise causes. I say pointless because there are usually no additional benefits to gym exercise other than the exercise itself.
What I'm looking for is exercise with some form of point, such as an allotment or forestry work or volunteer gardening. However, I'd still be interested to know what each kilo of my additional mass means in unnecessary and unsociable environmental damage caused.