A first-order approximation of how much pollution a man-made event or object contributes is its actual cost.
Cost is a crude but very real measure of the resources required to make, use, and consume the subject.
At the lowest end of the cost scale, one breathes constantly. Obviously this causes little by way of pollution.
You then go to your faucet and drink 500 ml of tap water. Eat an apple or orange off the tree growing in
your own back yard. Zero impact. Zero.
At the other end, we have Barack Obama, shredding the Constitution at a cost of trillions of dollars; taking vacations
all the time, and flying Air Force One constantly to fund raisers, where he gladhands leftist fat cats for millions of dollars in campaign contributions, so far costing the United States Treasury about $1,400,000,000 - or $1.4 BILLION dollars.
Limousine liberals could care less. Their legs are still tingling. And that's what really matters to them.