Vinay Kini sent me this nice link
Basically, it asks you a series of questions, and in the end tells you that if the whole world lived like you, it would need 'x' number of earths ( which means 'x' times the exhaustible materials on the surface of the earth). Staying in a developed country, I expected myself to clock 4.3 earths, which is above normal, but then I found that many people whom I knew accounted for 10 or more ....which is sad :)
In general , if you read the questions, they tell you about potential mistakes you might be making, and how you never realised that they could be detrimental to the system .
Test yourself, and let me know how many earths did you need?
And yes, if you liked the article, try to go vegan....if not fully, upto some extent...it's good for everyone!