One way to achieve a more sustainable society would be to impose progressive taxes on goods that are particularly detrimental to the environment when consumed. Marginal tax rates would increase with an individual's consumption of those goods — for example, a person's annual flight history could be used to compute the fee for his or her next ticket.

Fixed-rate consumption taxes present equity issues, which hinder their applicability and effectiveness by placing much of the burden on those with low incomes (see, for example, C. A. Grainger and C. D. Kolstad Environ. Resour. Econ. 46, 359–376; 2010). Implementing progressive consumption taxes on specific goods is now possible because of the widespread use of smartphones, credit cards and the Internet, which mean that we can keep track of individual consumption patterns.

Although such taxes may be perceived as a limitation on our freedom, in my view they would be a credible implementation of the 'polluter pays' principle.