I'm not sure what libertarianism has to do with believing or not believing climate scientists. Are climate scientists violating the nonaggression principle or something?
I'm not sure how familiar you are with economics, Time, so bear with me if this is all basic knowledge for you.
In economics, there is a concept known as an externality; an externality is a cost of production that isn't paid by the producer. As an example, imagine a widget maker who owns a widget factory. The costs of making widgets include the pieces of the widget, the electricity needed to run the factory, the wages of the workers on the floor, and
also the noise created when making the widgets. The factory owner pays for the first three, but he doesn't pay for that last one. The noise created is so loud, in fact, that the sandwich shop next door loses significant business, because everyone would rather go down a few blocks and buy a sandwich from a shop that's less noisy.
The noise is a consequence of the widget production, but the
cost of that noise is paid by the owner of the sandwich shop next door -- that's an externality. Libertarians tend to either downplay the significance of externalities, because they typically require government intervention of some sort to correct.
Now, with that concept in mind, climate change is the mother of all externalities; some factory in New York is polluting the air and costing
you something, even as you live thousands of miles away. The world gets ever so slightly warmer, and the ocean rises ever so slightly, with each puff of pollution they create, and yet they are not and never have paid you for that. It's a massive, complex problem that requires commensurate massive oversight to fix, and libertarians tend to reflexively downplay problems which require government oversight to resolve.