Define the term carbon tax.

a) i) A carbon tax is a tax imposed on the emission of carbon dioxide and other greenhouse gases, typically by companies, to discourage activities that contribute to climate change. It aims to make polluters pay for the environmental damage they cause. a) ii) The information explaining a positive externality is: "If one is cured of an infectious disease, not only the cured is going to benefit, but also others, since they are not going to be infected." Reason: This is a positive externality because the benefit of one individual being cured of an infectious disease extends to other members of society (who avoid infection) without them directly paying for that benefit.