I was a libertarian before the rise of Rand and the usurpation of the moniker. We used to be the crazy left, actually. I prefer to think of it as pragmatism.
If you want to put it on a bumper sticker, I basically want to ensure as much individual freedom as I can, while ensuring protections of the commons. As an avid hunter, fisherman, and gardener, I certainly consider the environment to be a part of the commons - and don't mind subsidizing things to improve it.
It's pragmatism and an awareness that humans are not rational actors who operate with complete information.
Note: I am not asserting that I am correct and you must change your views. I'm expanding to show why I believe as I do. I also don't mind taxes. I actually pay more than I use, but I am paying for the system that enabled that.
Well, if it were up to me? I'd stop it entirely. Pare Govt. back to 'core business': courts, embassies, Police, Defense (actual defense, not invading foreign countries on a whim), that sort of thing.
There's a grey area around public funding of defense-related technologies; it's hard for several reasons, especially the tendency towards such systems becoming incredibly corrupt.