Recently, a leaked agenda laid bare a strategy session among a virtual Who’s Who of left-leaning big-government activist groups, hosted by a generally conservative policy group, the American Enterprise Institute. By the agenda’s title, this fifth in a series was part of a “Lame Duck Initiative” to strategize enactment of a “carbon” tax, or federal energy tax on oil, coal and gas, in the post-election session of Congress that began this week.

AEI thereby joined former Republican politicians and advisers seeking to rebrand, as a conservative idea, the latest incarnation of what the political Left has long pined for, only to be told it was a dead letter given the political debacle of the Clinton administration’s 1993 “BTU tax.”

The headings and justifications for the new effort were equally as incongruent as conservatives falling for this call to bail out opponents of abundant, affordable reliable energy. These reflected diametrically opposed sales pitches apparently foretelling different audiences what they want to hear.

Specifically, AEI and the other groups are preparing to sell the carbon tax both as “revenue neutral” and as a “deficit hawk” measure. But this new energy tax can’t actually be both.

Revenue neutrality means it would be offset by reducing other taxes – this is the sales pitch for conservatives and swing voters. One rumored target is the 18.4 cents-per-gallon federal gasoline tax. This strategy would further illuminate the campaign’s confusion, given that the purpose of a carbon tax, as a “sin” tax, is to make activities deemed undesirable (energy use) more expensive.

Alternately, the new energy tax is supposedly targeted for deficit reduction – which in Washington means directed to new spending.

However absurd on its face, this is politics, and saying both just might work. The key thing is simply to get the new energy tax enacted, by whatever means necessary.

This is only the beginning of the muddled sales pitch. The new tax would be sold as a response to man-made climate change. The biggest problem here, outside of the political baggage of myriad climate-science scandals, is that it is universally agreed that such a tax would be a meaningless gesture.

Specifically, under no scenario, even accepting every assumption proffered by global warming activists, would any strategy ever proposed actually detectably impact climate. This includes the “global” Kyoto Protocol treaty, which within days of being agreed upon in 1997 was footnoted by proponents as actually being just the first of 30 such treaties needed to impact climate.

So much for a “climate” rationale for a U.S.-only carbon tax, which seeks unilateral, marginal reductions in carbon dioxide. CO2 is a marginal greenhouse gas, all of which gases, together, still amount to a marginal climate “forcing” (major forcings being the sun, oceans, clouds). A fraction of a fraction does not climatic impact bring.

The temperature after imposition of cap-and-trade, the Kyoto Protocol or a carbon tax will be whatever it would have been without any of them. So, while a new energy tax may be chicken soup for the wealthy world’s environmental guilt, as a substantive matter, it is a futile gesture.

There are few opportune times for such things, but now certainly is not one of them.

So let’s have an open, honest debate, which requires first acknowledging that a “carbon” tax is less likely being proposed for things it would not do, like impact climate, than for what it would do.

A proposed carbon tax is actually about finding a new, massive and ultimately expanding revenue source, an ATM machine, a European-style revenue gusher to fund a European-style government.

When the carbon tax’s proponents can acknowledge these things, or demonstrate that they are not true, we can have a useful debate over their new energy tax.

Christopher C. Horner is a Senior Fellow at the Competitive Enterprise Institute in Washington, D.C., and author of “The Liberal War on Transparency: Confessions of a Freedom of Information ‘Criminal'” (Threshold Editions).