With his announcement to pull the US out of the Paris Agreement US President Donald Trump has snubbed the international climate policy community. Key remaining parties to the Agreement such as Europe and China might call for carbon tariffs on US imports as sanctioning instrument to coerce US...

The Nationally Determined Contributions (NDCs) under the Paris Agreement fall short of the abatement needed to reach the 2°C target. Emissions trading could be a "costless" means to reduce the ambition gap if countries used their gains from trade for additional abatement. However, this requires...