As reported by the Washington Post, the anti-nuke movement (including representatives from Beyond Nuclear, NIRS, and other groups) was "in the house" at the White House for a climate rally in D.C. marking the beginning of COP21 in Paris, France:
In the District, several hundred gathered by the White House and marched along the Mall, with signs that read, “Preserve our home,” “Don’t nuke the climate” and “Keep it in the ground,” the latter referring to fossil fuels.
(Of course, the letter could -- and should -- also refer to uranium, as well as thorium, for that matter!)
Beyond Nuclear also attended a climate rally, called by FOE, on 12/12/15, marking the end of the COP21, "Don't Nuke the Climate!" poster in hand, once again.