Well, they can try, and legally and constitutionally speaking, they'd be completely within their rights to do so.
But they won't have the power:
A Senate committee is threatening to block any global warming agreements signed by the Obama administration at a world summit in Paris — including a pledge of more than $3 billion to a U.N. climate fund.
The challenge comes in a forty-page white paper published by the Senate Environmental and Public Works Committee, which provides oversight on climate issues.
Oklahoma Republican Senator Jim Inhofe, who chairs the committee, calls the panel's document a look at Barack Obama's "radical climate agenda," the Washington Free Beacon reports.
"As the president urges action to fulfill his personal climate legacy in Paris, the American people and their representatives in Congress have strongly voiced opposition to any deal that is reached and will not tolerate American tax dollars being used for an economically disastrous policy."
"This potluck approach to international policy will not accomplish anything substantial," he adds.
The committee document declares "the United States will not be a party to any agreement that sets targets or timetables for [green house gas] reductions, nor will the United States provide taxpayer dollars to a [United Nations] slush fund for foreign bureaucrats without congressional approval."
"Without approval from Congress, the president's commitments will be little more than a press release."
How I wish that were so. And, to be fair, unlike with O's Iran nuclear "deal," congressional Republicans haven't made themselves preemptively complicit to it by forfeiting the Senate's Article II, Section 2 treaty ratification power, at least as specifically pertains to Greenapolooza, although that general precedent has been set, as you can count on Barack Obama arguing when it comes down to it.
But it really doesn't matter all that much. The One does not recognize any limits on his power, does not heed the Constitution and its limitations, sees Congress as an irrelevant ceremonial rump entity, and is going to impose whatever "deal" emerges from Paris this week on the U.S. regardless of what Senator Inhofe says or does. Which is what "declaring portions of the global warming deal being hammered out in Paris should be legally binding on the countries that sign on" means.
Don't forget that he imposed cap & trade by executive decree back in his first term, folks. "De-carbonization" isn't going to be any different.
But kudos to congressional GOPers for giving it "the old college try," anyway.