Pres. Trump could present it to the Senate as a treaty, have them reject it, and the matter will be resolved instantaneously.

The vague language in the accord (with the "mights", "ifs", "could haves") does NOT make any signatory country do anything to effect any change whatsoever. The US could still do side deals with any country to exploit their respective resources and pay them for it to help them reduce their footprint.

Had Trump signed on to this accord, would any Liberal or Democrat give him any credit or leeway? I don't think so.