[JabavuAdams]

I agree with the sentiment, but there are some practical problems.

Barring a machine intelligence explosion in the next half-century, we'll probably be getting to orbit on rockets.

Nitrous oxide and methane are two big greenhouse gasses. So to get to space, we're going to have to dump a whole lot more of this stuff into the atmosphere.

Note, I haven't run the numbers, so I may well sound like an idiot by noon.

[jerf]

Not all rocket fuels are the same. Falcon 9 appears to run on kerosene and LOX, which combusts into H2O and CO2. H20 is all but a noop (technically a greenhouse gas but cycles very quickly and you're not going to affect the net balance with a rocket), and while the CO2 may be a concern, bear in mind that as big as a rocket may be visually it isn't necessarily a big contributor relative to the rest of the industrialized planet as a whole.

Also, remember that one of the things a practical commercial space program will do is start mining the asteroid belt for rare earth metals, many of which are needed for green technologies. For instance, one problem with fuel cells is that there isn't enough platinum on Earth to make them for everybody. It is not hard to spin the math such that private spaceflight could be one of the greenest things to ever happen to industry. (And I felt I should be honest about the word "spin", but there is a truth there too. One must make full accountings to decide whether something is good, not count up the costs, ignore the benefits, and make grand pronouncements.)