They are understandably worried that the act, sponsored by Sens. Joe Lieberman, I-Conn., and John Warner, R-Va., and with support from both sides of the aisle, would force changes that would hit the extractive industries in the bottom line. And so it would, in some cases. And it's likely, at least initially, to raise the prices consumers pay for electricity, fuel and natural gas.

But the cost of maintaining the status quo is much more dear.

Evidence is mounting, most recently with a U.S. Department of Agriculture study, that the effects of human-caused global warming are apt to be worse than expected and occur sooner than predicted.

The USDA study found that agriculture, land resources, water, and plant and animal species are exhibiting the impacts of warming now. According to the report, the American West, Southwest and Alaska are experiencing more - and more dangerous - forest fires, reduced snowpack, insect outbreaks, invasive species and tree mortality.

Climate scientists predict more severe storm patterns, flooding and drought in the United States and around the globe. A new study by researchers at Tufts University for the Natural Resources Defense Council estimates the cost of doing nothing to curb greenhouse gases, and the resulting warming, at $3.8 trillion per year by the end of the century.

Clearly, we cannot sit idly by as disasters worsen and economic costs balloon. The Lieberman/Warner act is a reasonable first step.

The Climate Security Act is aimed at providing financial incentives for companies to cut greenhouse gas emissions and to limit the country's total volume of carbon emissions. The proposal, referred to as a cap-and-trade plan, would establish an emissions trading system that would let power plants, manufacturers and other companies that emit fewer greenhouse gases than their permits allow, to sell or trade the balance to companies that exceed their own permits. The size of those allowances would shrink each year until 2050, when the overall reduction in emissions would hit 70 percent.

The act would encourage development of non-polluting energy sources and energy conservation.

Inevitably, there will be winners and losers as the U.S. and the world shift from petroleum-based energy production to renewable energy sources including wind, solar, biofuels and geothermal power.

But the ultimate winners will be the Earth and all of us who live on it.