Does Libertarian Party presidential nominee Gary Johnson support a carbon tax, a specific levy on fossil fuels that produce greenhouse gases and contribute to climate change? As Ronald Bailey noted here a few days ago, the answer seemed to be yes. In a CNBC interview, Johnson

suggested that a carbon tax might be a "very libertarian proposal" to address the open access commons problem of climate change. Johnson is tentative, saying that he is "open" to considering a carbon tax. He specifically notes that a carbon tax would be a simple comprehensive way to replace all sorts of clunky expensive top-down centralized regulations and subsidies that aim to limit carbon dioxide emissions.

In a rally yesterday in Concord, New Hampshire, Johnson explicitly distances himself from a carbon tax. He also reiterates his position that vaccines (presumably for childhood diseases) are effective but should not be mandatory absent a large-scale pandemic or disease outbreak.

This footage is a trimmed YouTube video from a rally captured by WMUR (for footage of the entire event, go here).

If any of you heard me say I support a carbon tax…Look, I haven't raised a penny of taxes in my politicial career and neither has Bill [Weld]. We were looking at—I was looking at—what I heard was a carbon fee which from a free-market standpoint would actually address the issue and cost less. I have determined that, you know what, it's a great theory but I don't think it can work, and I've worked my way through that. And I support a person's right to choose, so when it comes to vaccinations we should be able to make the decision whether we want to vaccinate our kids or not. I choose to vaccinate my kid and you never say never. Look, in the case of a zombie apocalypse taking over the United States, and there is a vaccine for that, as president of the United States, you might find me mandating that vaccine.

In April 2014, Reason magazine hosted a libertarian debate on whether vaccines, including MMR and other child-related vaccines, should be mandatory. Read that here.

Hat tips: Erick Sturrock and Mark Bozeck

Updated: The Johnson campaign sends this "definitive statement" on vaccinations: