Yesterday, while Donald Trump was calling for a ban on Muslims entering America, Bernie Sanders was calling for a carbon tax.

A carbon tax—a mechanism for putting a price on the carbon emissions that are causing global warming—is our best, easiest, and most realistic hope for slowing down carbon emissions in a meaningful way in a relatively short time frame. Makes carbon expensive, and you will see how amazingly fast polluters are able to curtail their pollution. The overwhelming logic of a carbon tax is agreed upon by lefty environmentalists and thoroughly mainstream economists and policymakers alike.

As part of Bernie Sanders’ full climate change plan, announced yesterday, explicitly advocates a carbon tax as a way to achieve its goal of cutting carbon emissions by 40% by 2030. This makes Bernie Sanders, by my reading, the only major presidential candidate of either party to call for a carbon tax.

Martin O’Malley and Hillary Clinton have both offered climate change plans that call for an aggressive push towards clean energy, but neither have explicitly included a carbon tax. And Republican candidates do not support a carbon tax, despite the fact that it is in many ways a conservative dream: a market-based solution to a problem that will generate revenue that could be used to lower other taxes.

It is easy to say we want to phase out dirty energy production. It is hard to actually do it unless there is a strong economic incentive to do so. A carbon tax is that incentive. We need it.

[Photo: AP]