Answer:
A carbon tax puts a price on carbon by increasing the private cost of polluting.
Step-by-step explanation:
Going by the argument of the economist of Booking institution, it can be concluded that a carbon tax put a price on carbon "by increasing the private cost of polluting."
As the private cost of polluting increases, this will discourage the private individuals or businesses in carrying out activities that emit greenhouse gases in the human environment which in turn threatens the climate.