I think that stating C02 is not a posionous gas is a little misleading if not flat out incorrect. Not to step on any toes but in high enough concentrations CO2 is toxic or fatal. It doesn't however exist in our atmosphere at anywhere near toxic levels and even the increases you mentioned wouldn't even come close, however before anyone goes out and starts inhaling concentrated CO2 and dies this needs to be said.
Government spending large amounts of money on anything should be heavily scrutinized and I agree there are better ways of spending this money.