As debate continues in the Senate over a 500-page bill to address global warming through mandatory reductions in greenhouse gases, a coalition of Big Labor and environmental groups is trying to make the case that going green will create jobs.

Sponsored by several groups, including United Steelworkers, the Sierra Club and the Natural Resources Defense Council, a report released Tuesday looks how 12 states, including Pennsylvania, would benefit from building a clean-energy economy.

The report says that the following strategies will spur job growth: retrofitting buildings, mass transit, energy-efficient automobiles, wind power, solar power and cellulosic biofuels.

In Pennsylvania, there are more than 550,000 jobs in jobs categories such as carpenters, machinists, truck drivers and others that could see job growth or wage increases. Researchers from the University of Massachusetts, Amherst, define "green jobs" as occupations that contribute to building or products goods to achieve a "green" marketplace. And they take pains to say that many of these jobs are in the same fields people already work in now.

So are we just going to re-label the jobs people do as "green" jobs? Somebody in the replacement window business is now part of the green marketplace?

Called "Job Opportunities for the Green Economy," the report is more a laundry list of hourly wages of various occupations by state. Its authors admit that they "do not attempt here to estimate how much growth there is likely to be in any area of green investments or green jobs in the United States."

Pennsylvania has seen investments by wind energy and solar energy companies, but that's also because the state has been providing lots of incentives to those companies to do so. Is there demand for their products? Sure. But what happens when the subsidies go away?

Of the Senate bill being debated this week, the Bush administration has warned that the legislation would amount to a huge new tax and impose emissions cuts that would hurt the U.S. economy. U.S. Chamber of Commerce and other business groups have voiced their opposition.

Backers of the legislation dispute the claims of economic calamity, saying that action needs to be taken now to reduce the United States' greenhouse gas emissions. Hence the bill's name: America's Climate Security Act of 2007.

Still the Congressional Budget Office evaluated the bill and found that spending would exceed revenues. Plus, the private-sector mandate requiring certain companies to participate in "cap-and-trade" programs for greenhouse gas emissions would cost business more than $90 billion a year between 2012 and 2016. Ugh.