Is there any way to hook countries, such as the USA, who will only agree to take on voluntary emission reductions commitments in the new climate agreement currently being negotiated, to somehow commit to legally binding obligations in the future through something like a ‘dormant commitment clause’ or another provision/approach?

Advice:

If a country is adamant that it will not accept legally binding commitments, we don’t know of any way to force such commitments.  However, there are ways that might make it easier for a country to accept such future legally binding commitments.

The agreement could provide that all parties must make their commitments legally binding by a specified future date.  This might make it easier for countries to become parties now who would not become parties if their initial commitments were legally binding.  A variation on such a system might provide that the commitments will become legally binding provided that, for example, a sufficient number or proportion of participants had made legally binding commitments sufficient to meet global objectives.

The agreement could also create an incentive to make legally binding commitments by providing that countries failing to make legally binding commitments — or failing to meet their “voluntary” commitments – would be subject to punitive economic sanctions by parties that did make and honor their commitments.  This technique has been used in international commodity agreements such as the old International Coffee Agreements, where an exporter who did not join the Agreement, or who failed to honor its obligation to restrict exports of the product, was subject to harsher import controls by importing countries.  Something like a punitive carbon duty imposed on countries who did not meet their commitments would create an incentive to make and honor obligations.  While some kinds of such penalties might be inconsistent with current international trade rules, the same countries who agreed to such a regime in the Climate Agreement could also agree to modify or override existing international trade rules if necessary.  I note that the international trade rules of the GATT have long had an exception for international commodity agreements, so there would be precedent for providing some similar agreed exception to trading rules to permit enforcement of a climate change agreement.