I have been meaning to follow up on my earlier note about the Minamata Convention, but too many things going on, which I will post separately about.
First, here's an interesting early comment on the US acceptance of the Minamata Convention, http://opiniojuris.org/2013/11/12/doesnt-u-s-senate-care-mercury/. The blog post raises the possibility of the US joining the Convention as a Congressional-Executive or as a sole executive agreement. Based on my understanding and also some conversations with folks in EPA and at State, the intention is to go at this as a sole executive agreement. As far as I know, this thinking is not being advertised anywhere. But given that there were consultations with Congress (at least the Senate, presumably), as I was told, such thinking must have been communicated (since that would be the first question any lawyer would ask), and the Senate (or some key senators) appears to be OK with this.
This is of course highly unusual. While the use of the sole executive power itself is not at all uncommon with respect to participation in international treaties, it is arguably unprecedented with respect to a major multilateral environmental agreement (though the US has used this device with respect to a subsidiary protocol to a major MEA). With MEAs, Congress has virtually always been involved, which would make especially great sense since these treaties oftentimes overlap and complement domestic environmental legislation.
On the other hand, most, if not all, of the treaty can already be implemented by EPA's authority under the Clean Air Act (guess where all of the concepts/provisions about BAT came from . . . ) and TSCA, as well as the authority of other agencies. So, if one sees Congress' role just as providing implementing tools, as opposed to giving its "approval" for US participation in the Minamata Convention, the Administration's approach makes sense.
What's curious is that there has not been more coverage of this. But I suppose that this is sufficiently technical that it would escape most journalists.