Protectionism in Waxman-Markey

Although I'm glad Waxman-Markey passed the House, it's scary to learn from Green Sheet and MR that potentially protectionist measures were smuggled in via the late-night Thursday night addition. According to the NYT:

The House bill contains a provision, inserted in the middle of the night before the vote Friday, that requires the president, starting in 2020, to impose a “border adjustment” — or tariff — on certain goods from countries that do not act to limit their global warming emissions. The president can waive the tariffs only if he receives explicit permission from Congress.

The provision was added to secure the votes of Rust Belt lawmakers who were wavering on the bill because of fears of job losses in heavy industry.

Carbon tariffs could conceivably spark a disastrous trade war. One good sign is that Obama promptly stated his opposition to the potential sanctions.

Update: Tyler Cowen reemphasizes his skepticism.