Is it a good thing that delegates from the United States and 191 other countries have convened a U.N. conference in Copenhagen to work on a new global-warming treaty? Well, it's good to the extent that warming is a real problem. But the "climategate" scandal -- the release of e-mails and other documents indicating gross misconduct among key scientists -- suggests otherwise.

Climategate offers one more reason why America should avoid a costly deal at Copenhagen.

The scandal implicates a number of scientists who helped draft the U.N.'s 2007 global warming report, which is often cited as near-proof of a global warming crisis. This report is the official U.N. scientific basis for the Copenhagen conference. Among other things, these scientists admit to manipulating the data to show recent warming as unusual.

One, Phil Jones (who has since resigned his post at the University of East Anglia pending an investigation), referred to a "trick" he and others have used to "hide the decline." Talk about an inconvenient truth. Worse, the computer programs these scientists used were designed to add more of a warming trend to the actual measurements.

In many other cases, this clique of scientists went to extreme (and probably illegal) lengths to withhold what should have been publicly available temperature data. Thus, we have only their admittedly-manipulated temperature trends. The underlying measurements, on which independent researchers could do their own analysis, have not been made available. Jones also threatened to delete some of this data rather than hand it over -- and in fact some of the older data already has been destroyed.

In their e-mails, these scientists also discuss keeping dissenting views from getting published, presumably to create a stronger façade of scientific certainty and unanimity.

Needless to say, scientists who had an open-and-shut case would hardly act this way. Indeed, this is hardly the conduct of persons who could call themselves scientists at all, as science is based on an honest, open debate, and on transparent results that can be reproduced.

Climategate is not the only reason for doubt. Another thing recently missing from the global warming debate is ... global warming. Temperatures have been flat for more than a decade. Ironically, the purpose of the Copenhagen conference is to replace the supposedly inadequate provisions in the 1997 Kyoto global warming treaty, but temperatures have barely budged since then.

Another scientist, Kevin Trenberth, admitted in one of the released e-mails that "we can't account for the lack of warming at the moment and it is a travesty that we can't." Actually the travesty is that such doubts were largely kept private while the opposite was said in public and in the 2007 U.N. report, even though the non-warming trend was well underway by then.

On one aspect of global warming there is little dispute: addressing global warming by reducing carbon dioxide emissions from fossil fuels will cost money and jobs. The Copenhagen proposals would amount to a massive new energy tax, the last thing our still-weak economy needs.

We wouldn't rush to execute a convicted killer just after learning that his main accusers committed perjury. We shouldn't do the same to the economy in order to combat the increasingly questionable threat of global warming. The U.S. should agree to nothing in Copenhagen until we get to the bottom of climategate. We need to find out for certain how much of the case for global warming we can still trust.

Ben Lieberman is a senior policy analyst in the Thomas A. Roe Institute for Economic Policy Studies at the Heritage Foundation.