Hrm, okay so we're trying to answer this keeping aside things that relate to surival, that makes it a little harder :P will probably have to exclude some ecosystem services then. Well some studies show that peoples happiness is related to the amount of natural environment that is around. Maybe have a read of the "Recreational and cultural values" section of www.eve.ucdavis.edu/catoft/eve101/Protected/PDF/lit/Bolund_Hunhammer_1999.pdf if that link doesn't work use: http://www.sciencedirect.com/science/article/pii/S0921800999000130 (I'm not sure what access rights you would have). Another reason is money - life/processes are generally more expensive if we try to do things without ecosystems. http://www.mendeley.com/research/value-worlds-ecosystem-services-natural-capital-15/ (sorry took me awhile to find refs :P)
No wonder, I practically dozed off while waiting for you to finish!:P Thanks for your time and stuff! :) And, are we of any use to the Earth? (besides the Earth being "useful" to us).
Unfortunately I couldnt access either of the links on recreational values. :/
hmm have attahed the pdf and lol yes I did notice you run away to snooze in the corner :P Why are we useful to the earth? Arrr that is a really hard one! I suppose that depends on your spiritual beliefs. In a scientific sense I don't think humans are much "use" to the earth but then again, I'm not sure if the earth itself "needs" anything - after all it is also just another object. I suppose this all just jumps into the realms of philosophy.
oh. by Earth, I meant the biosphere with all its creatures and stuff, not the chunk of rock itself. just clarifying. :P i guess we just make good biomass (when were dead.) :P
Though keep in mind I probably have a very jaded, cynical view of humanity :P
This post deserves question of the group award!!!!!!!
Haha thanks! :) :D