Earlier quoted context omitted.
It's actually possible. If taxes due get assigned and tracked to particular bitcoin fractions, and since taxes incur interest, we could be in a situation one day where you would get paid to accept ownership of btc. It would be surreal, but if the IRS is given hope that it's a way to get people scared of btc, and that the KYC data all these exchanges have allow accurate enough accounting and tracking, they would do it…
Hm.. if BTC is negative, then you’d be paying negative taxes on it (IRS paying you, or equivalently you paying less tax on e.g. income). A lot of people want that, so they’d want BTC, bringing it back into positive.
Nouriel Roubini implies that carbon tax could mean a negative value. Contrary to income tax, a carbon tax wouldn't be a "negative" tax.