I usually correct people when they tell me something like "but you believe in X, right?". Maybe it is just semantics, but for me it is significantly different:

- denying it: there is evidence, yet they do not accept it.

- do not believe in it: we cannot prove its existence factually and there are people who still think it exists and some who do not.

- skeptical: there is evidence, but not enough to convince me we should make policy changes such as taxing and regulation; rather we should allow the free market to develop solutions in the form of new technology.

Is this because you believe the free market will follow the most economically efficient path? What if the environmentally friendly options are always more expensive?

Without regulation or tax incentives, it's easy to ignore the externalities in your choices. As an example taken to the extreme: if there was no regulation against dumping your industrial waste in the river, the free market should use that option, as it's cheaper than properly disposing of the waste.

It's a complicated issue, to be sure. Speaking generally, you might be correct, though I think taxes and regulation should be the last resort. For carbon-free energy production, I think there are many free market possibilities on the horizon: safe nuclear fission, nuclear fusion, fuel cells, battery technology, wind power, solar power, or some combination of them.

But all that 'regulation' like carbon taxes do is internalize the cost of fossil fuels and adjust the different costs in the market. The 'free' market is changed like this all over the place - for example via import tariffs that change the market place to favor local production.

Regulation is really the first resort.

The last resort is things like out-right banning the use of fossil fuels or nationalizing the energy industry.

a.k.a. denying basic economic theory about externalities while pretending to believe in the free market