I know in meteorology we generally average 30 years worth of data to determine what is 'normal'. I am assuming the geological community would do something similar; averaging over a multi-year period to obtain a normal emissions-rate for volcanism.
+1. I don't care if a product is branded eco-friendly or not; if it's better then I'll use it.
The only eco-friendly product I use is a Scott's Classic reel mover (although it's not branded as eco-friendly). I have been using one for the pass 6 years on a 1/4 acre lawn (no fumes, no noise and it starts every time.) My lawn has looked a lot better than my neighbor's for the pass 5 years and that's with zero fertilizing (the clippings disappears into the lawn) or watering (that's what rain is for). Good for the environment? Maybe. Good for my pocket book and lawn? Definitely.