It may be time to put American workers on the endangered-species list. For nearly 40 years, the environmental movement has all but declared war on high-wage, blue-collar jobs, with considerable success. Now, a proposed global-warming bill called the America's Climate Security Act would finish off many of the remaining ones. Green activists and regulators have sent many such working men and women to the unemployment line, or to lower-wage service-sector jobs.

Shutting down mines kills mining jobs, opposing logging decreases logging jobs, and, naturally, closing factories reduces factory jobs.

Since 1969, more than a dozen environmental statutes, each spawning volumes of unnecessarily costly regulations and litigation, have targeted all manner of industrial activity. Some of these jobs have been destroyed outright, while others have been outsourced to nations with less expensive restrictions or none at all.

But the Climate Security Act, currently debated in the Senate, may do more economic harm than all these past laws put together.

Beginning in 2012, the bill cracks down on emissions of carbon dioxide from burning fossil fuels, which is blamed for global warming. This would raise energy prices significantly. Particularly hard-hit would be energy-intensive industries that rely on coal-fired electricity, such as steel, cement and paper. Also losing out are segments of the chemical industry that depend on natural gas as an energy source and chemical feedstock. Domestic oil production and refining would be hurt as well.

According to a Heritage Foundation study, the bill would cost a half-million manufacturing jobs by 2018, 1 million by 2022, and more than 2 million by 2027. Of course, most of these displaced workers will eventually find something else to do, but often at lower wages.

Some proponents claim new "green collar" jobs would make up the difference. For example, there will be more work at solar-panel manufacturers and other industries helped by the bill.

But these jobs will be swamped by the number of those lost. The Heritage figures are net of any manufacturing jobs gained, and also exclude blue-collar jobs likely to be lost for reasons unrelated to the global-warming bill. The bottom line: This bill is a major job killer.

The impact will disproportionately hurt the working class - both those who have blue-collar jobs already and those who will seek them in the future. For many people, these are the best jobs, and they offer the highest standards of living available. But if this bill passes, their numbers would dwindle considerably.

To add insult to injury, as many households struggle with layoffs and shifts to lower-paying jobs, they also will have to endure higher prices for electricity, natural gas and gasoline thanks to this bill - a costly double whammy. The cost of gasoline alone is expected to rise 29 percent by 2030.

Is there an upside that makes this sacrifice worthwhile? Even if one assumes the worst, environmentally speaking, of global warming, this bill is expected to reduce the Earth's future temperature by a small fraction of 1 degree - too small to even verify. And even less so if manufacturing jobs killed here are shipped to developing nations such as China, which is less energy efficient and has far more emissions.

Overall, the America's Climate Security Act promises all economic pain for little or no environmental gain.

The federal government recently listed the polar bear under the Endangered Species Act, claiming that global warming is causing it harm. In reality, the number of polar bears has more than doubled in recent decades. Too bad there are no protections for something that is truly at risk of disappearing - the American blue-collar worker.

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