If Genghis Khan's killings reduced carbon emissions, it was surely because it was reducing the existing number of living people contributing to them. So why would there be a similar effect if you create the people, then kill them?

@komodosp The OP isn't asking if there's a similar condition. He/she is merely letting us know what inspired the question, which is what affects would be seen due to the circumstances described.

If all that biomass is created off-earth, and then transported to earth to be killed, the amount of carbon in the biosphere would increase by a huge amount. The worldwide effect would be disastrous.

@komodosp Genghis Khan decimated enough cities and villages that tree regrowth was responsible for the dip in carbon emissions. People weren't driving many SUVs or sailing ships with bunker oil at the time.

@Wastrel: a human body has about 13 kg of carbon in them, and so this process would add roughly 6 billion tonnes of carbon to the biosphere. Existing global biomass is more like 550 billion tonnes of carbon, so the total amount of carbon in biosphere wouldn't increase that much. However, this would represent a significant fraction of annual anthropogenic carbon emissions (around 10 Gt/year.)

Upvote/Downvote to keep this question at +4 upvotes. Obviously 4 is the magic number here.

@JohnO - my point is that he took people (and cities) out of the population, but if you create the people just to kill them you wouldn't see a similar pattern since they didn't live in cities that would now be replaced by trees - having said that, JBH answered my question.

Isn't getting sued by the Church of Suitology physical impact enough?

The first major problem: world population

Would the isotopic composition of the folks teleported to earth from their manufacturing location be the same as current period humans. I'd hazard that those relative abundances would be detectable and obvious.

@Therac, more to the point the Church of Suitology has that many lawyers on retainer just wait until their vigorous efforts begin and their scuttling about commences with a flurry of demand letters the volume and weight and consequences of which is just as incomprehensible.

With so much human remains and fluids mixing with -everything- I wonder what kind of new and exotic diseases and human flesh eating bacteria will develop.

I thought this question was nearly unanswerable. Boy was I wrong!

Traditional tangential xkcd reference: what-if.xkcd.com/8

How would they "descend" to Earth of they're chthonic?

This feels like more of a "How would..." question than a "Would..." question.

You say that the humans are created "in the nation's subterranea", but later say that "this creation process doesn't happen on Earth". To me, this sounds like a contradiction. Can you clarify whether the humans are created on (or in) Earth and whether they're created using resources from Earth?

@Vaelus I edited it for better clarity

@MichaelSeifert - It is not carbon, the atom, that creates the greenhouse effect, but rather the molecule carbon dioxide in gaseous form. In fact, having more carbon atoms can actually reduce carbon dioxide levels, if, for instance, that carbon is in plant cells. A bunch of decaying animal flesh definitely would produce carbon dioxide and methane (another greenhouse gas), but it would also produce solid carbonaceous compounds, so it's not as simple as just adding the mass of carbon to carbon dioxide emissions. Also, carbon dioxide has more than 3 times the mass of carbon.

tl;dr. Confusing, and 444,444,444,444 is 55.56x the current world population.