The wheels were already coming off the cart of the global-warming crisis before Climategate hit. But the recently released cache of e-mails and other documents showing that data were manipulated to hide a lack of warming, that other data were suppressed, and that contradictory research from "skeptics" (the pejorative term for those who dissent from climate-change dogma) was shut out of the debate just accelerates the process.

Those in the media and elsewhere straining to argue that Climategate is no big deal have had quite a bit of practice making far-fetched claims. For example, temperatures have been fairly flat since the late 1990s, but some have treated the complete lack of warming over this decade-plus stretch as a non-issue. The upcoming Copenhagen climate conference is tasked with replacing the supposedly inadequate provisions from the 1997 Kyoto Protocol, but, ironically, temperatures have barely budged since then.

If influential scientists' being caught manipulating and suppressing data is no big deal, and if the absence of any additional warming since the late 1990s is also no big deal, one wonders what if anything would be a big deal.

With Copenhagen coming up in two weeks, the revelations are very timely. As with cap-and-trade legislation currently stalled in the Senate, international efforts to ratchet down fossil-fuel use would be enormously expensive and likely ineffective even if global warming really were a serious threat. And now there is even more reason to believe that the costs will be for nothing.

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