Recently being the past 1000 years. This question popped into my head this morning and I’ve been unable to find an answer. I know that there are many more humans than there were before, but there are many less of many other megafauna (e.g. wildebeeste, buffalo). Equally, we’ve cut down very many trees, but has that been balanced by cultivated areas?
And what about the aquatic biomass?
I think the question you want to ask is “Has the biomass of the earth increased?” As I understand it, every part of the earth that involves life is part of the biosphere whether or not it is alive. That would include the CO[sub]2[/sub] in the atmosphere.
As to the biomass of the planet, my intuitive answer is that it has decreased. I don’t think that the mass of human population and agriculture is significant next to the amount of forests that have been cut and land that has been paved and such.