However negligible the net effect may be, does increasing human population increase the mass of the Earth?

Question

Ignoring effects of added mass due meteorites or other extraterrestrial objects, does increasing human population increase the overall mass of the Earth? It would seem that it should not, given that humans and animals are comprised of Earthly stuff like water and minerals. If that's true, it would imply that increasing human and animal populations would require a commensurate reduction in the amount of plant mass on Earth, resulting in no net change to the Earth's mass.

True or not? Justify your answer!

Corollary: If increasing human and animal population requires an offsetting reduction of plant life, how long will it be before there is insufficient plant life to sustain animal life on Earth? Is there a "break even" point? Is it already here, and is resulting in the extinction of certain species, or would such extinction occur anyway?

Enjoy!

Answer 1

I don't really know what you mean by the first question, but as for your second, if there is a break point, it wont happen for thousands of years. Contrary to what many people would have you believe, THE EARTH IS EMPTY. I wish I could stress that more.

Answer 2

The mass remains constant - it's known as the law of the conservation of mass and applies within any closed system.  Because you're referring to the earth as a whole this is the closed system in the conservation equation.

In effect - whatever changes we undergo by growing, reproducing, dying and decaying etc - the material has to come from somewhere and has to go somewhere.  It can't be created or destroyed although it can change from one form to another (e.g. food components changing to bones).