The architects of the Paris agreement deliberately designed it to get the Congress of the U.S. to approve it because it does not bind the U.S. to set emissions targets or to do anything to reduce man-made global warming.  The authors were mindful of the Kyoto Protocol, which was roundly rejected by the United States Congress because, inter alia, it set binding emissions targets for wealthy countries while letting most developing nations, including China, off the hook.

But now, as forces within the Trump administration continue to debate whether to leave the Paris agreement, they face a far different calculus.  The accord is alleged to be nonbinding, imposing no serious legal restraints on the United States or any other nation.  But in fact, it binds the signatories to make periodic reports of what action they have been taking to reduce CO2 emissions.  That means that the signatories are expected to take some action to reduce man-made global warming and to report what actions they have been taking.  Whom are they supposed to be reporting to?  To all the other members through a super-government international agency set up by the treaty to receive periodic reports.

The evidence shows that the U.S. federal and state governments have already spent billions of dollars on alternative energy, subsidies to producers of alternative energy, subsidies to millionaire buyers of expensive electric autos, and subsidies to those who install insulation or heat panels.  Other nations, principally European, have spent additional billions they can ill afford.

Scientists are in general agreement that there has been global warming, but they are not in agreement as to how much is man-made and how much is due to natural forces.  Some scientists  estimate that fossil fuel emissions account for at most 15 to 20 percent of global warming.  The late Prof. Robert M. Carters of James Cook University in Australia wrote in 2009 that the "reality is that almost every aspect of climate science is the subject of vigorous debate" and doubts whether there has been any genuine evidence of global warming since 1950.  Prof. Judith Curry, a climate scientist at the Georgia Institute of Technology, in testimony before a congressional committee, agreed in all respects with Prof. Cook and pointed out:

The biggest problem, however, is that the call for proposals from the federal funding agencies (notably NASA and NOAA) make an implicit assumption of the dominance of human caused global warming in the topics for which they are requesting research proposals. Something is clearly wrong with the current contract between climate scientists and society that is biasing the science and breeding scientists who are advocates, partisans and alarmist. And the taxpayer foots the bill. How can we press the 'reset button' on all this? First, we need to recognize that the politically driven push to manufacture a premature consensus on human caused climate change is biasing climate research, and in particular is resulting in the relative neglect of research on natural climate variability. Until we have a better understanding and predictive capability of natural climate variability, we don't have a strong basis for predicting the climate in the decades or century to come.

At least 60 scientists around the world have expressed themselves as questioning the accuracy of the U.N.'s IPCC climate projections, or arguing that nature is the principal cause of global warming, or believing that we don't know enough about global warming.

There is no general agreement as to what measures our country and the world should take to reduce man-made global warming.  There is no evidence that the billions spent by the U.S. and other nations have had any effect at all on slowing global warming.

Why continue to waste billions in taxpayer money in a vain attempt to reduce global warming?  The Paris accord is designed to force us to do so.  The appearance of a nonbinding treaty has given ammunition to those urging the Trump administration to sign the Paris agreement, a group that is reported to include Ivanka Trump and diplomats like Secretary of State Rex W. Tillerson, and of course the multi-nationals who can no longer be called American.  They are American in name only because they are incorporated in the U.S.

As we noted, the cost of cutting greenhouse gas emissions to date far exceeds its benefits.  Within the White House, Trump advisers like the chief strategist, Stephen K. Bannon, have urged the president to follow through on his promise to exit the deal.  They argue that staying in the Paris accord could entangle the United States in a series of legal obligations, much as Kyoto did.  That is obviously true.  Signing the agreement binds us to spend additional billions on reducing man-made global warming and to give billions to countries totally unaffected by past or present global warming.  The Czech president, who said the movement to reduce man-made global warming is a hoax, was absolutely right, as the huge international waste of billions of dollars since then has shown.

Global warming has become a political issue.  The Paris accords continues to maintain, contrary to fact, that all scientists acknowledge that emissions from burning fossil fuels cause man-made global warming.  And they fail to state what measures tried to date have been cost-effective in reducing man-made emissions.

The billions we've spent have enriched government cronies and created a vested interest in the hundreds of thousands engaged in projects that end up contributing nothing to the problem of global warming.  The U.S. should not give its approval to the Paris agreement.

The author has a Ph.D. in economics from the University of Chicago and is professor emeritus of public and international affairs at the University of Pittsburgh.  Email: richmanpitt@aol.com.