Those who want to place government-mandated limits on carbon dioxide (often erroneously and sometimes maliciously referred to as just “carbon”) emissions claim that their goal is to keep the planet from overheating — that is, to prevent global warming. CO2 reduction is not an end in and of itself. So if carbon dioxide taxes, cap-and-trade regulations, subsidies to the wind and solar power industries, or renewable portfolio standards — each of which is a strategy designed to reduce CO2 emissions — won’t make a significant difference when it comes to future temperatures, then they are nothing but feel-good measures with all costs and no benefits.

Now the Cato Institute has produced a handy-dandy calculator to help measure those costs and benefits. This calculator allows its user to plug in a certain percentage of CO2 reduction. Then, using the Intergovernmental Panel for Climate Change’s own estimates for climate sensitivity, it spits out the amount of “cooling” the earth would get by 2050 and by 2100.

And here you have it. If the United States were somehow magically able to eliminate all of its carbon dioxide emissions, by 2100 temperatures would be 0.137 degrees Celsius (0.246 degrees Fahrenheit) cooler than they would be if we had no CO2 reductions at all. In other words, temperatures would cool by an undetectable amount. This is an amount so small that if one walked from one side of a street to another and the temperature fell by this amount, it wouldn’t be noticed.

What if we included all industrialized nations in our calculations? In other words, what if, in addition to the United States completely eliminating its CO2 emissions, all of the European Union, Japan, Australia, and other industrial powers did the same. That surely would cool things off, right? Well, the number is 0.278 degrees Celsius (0.5 degrees Fahrenheit) lower than business as usual in 100 years.

Of course, the idea of eliminating CO2 emissions completely is absurd, and no one is even coming close to proposing this. So here’s the truth of the matter: Reducing CO2 emissions in reality, as we can see, has nothing to do with reducing temperatures. First, it is about promoting an environmentalist ethic of reducing energy consumption for its own sake.

As former U.S. Sen. Tim Wirth of Colorado states it:

“What we’ve got to do in energy conservation is try to ride the global warming issue. Even if the theory of global warming is wrong, to have approached global warming as if it is real means energy conservation, so we will be doing the right thing anyway in terms of … environmental policy.”

For many on the political left, the energy-reduction goal goes even further. It is about destroying capitalism, which by definition means the destruction of liberty. As one progressive group is pointing out, “The really inconvenient truth is that it’s not about carbon [carbon dioxide] — it’s about capitalism.”

They are so right. And the more quickly we who are in the business of advancing liberty understand this, the more effective we will be in defending it.

Dr. Roy Cordato (@RoyCordato) is Vice President for Research and Resident Scholar at the John Locke Foundation.