Space launches account for negligible amount of the CO2 emissions at present time compared to the total that our society emits.
There is obviously the very strong likelyhood that number of launches will continue to grow, to a point where this will become a major issue.
There is however a financial incentive to lower the fuel consumption as much as possible in these rockets, which I believe will push these companies to do so. But only to a degree.
Hopefully human kind will be able to use something akin to mass drivers or a space based gravity hook to launch loads without exhaust in the future.
But in the meantime we will need to emit something.
