Now that Sens. Barbara Boxer and John Kerry have introduced their climate change bill, the real debate about the best policy to address global warming can get started.

But the more I look at legislation for a cap-and-trade program, the more it looks like a Rube Goldberg device – one of those amusing contraptions that employ all manner of moving parts in a complicated, convoluted process that performs a simple task.

The task we're talking about – reducing carbon emissions by making fossil fuels more expensive than clean energy – is pretty straightforward. And yet to accomplish it, Boxer and Kerry have come up with an 840-page bill that gives "War and Peace" a run for its money.

To raise the cost of carbon-based energy and make clean energy technologies, such as wind and solar, more competitive, cap-and-trade creates a market in which thousands of companies are required to purchase permits to emit carbon dioxide. But wait – the Senate hasn't revealed how it will allocate permits, but if it follows the House, most of the permits will initially be given away rather than auctioned off. And there's also this messy contrivance called carbon offsets, which allows polluters to invest in projects that reduce carbon emissions. Good luck verifying the efficacy of those offsets.

Which brings us to even more moving parts, including a huge, mind-boggling bureaucracy that would be established to inspect industries and verify compliance. There's also a need to regulate the trillion-dollar market in carbon futures; Wall Street is already salivating over the speculative opportunities in subprime carbon.

And while the legislation includes a mechanism to help consumers afford higher energy costs, the choice of middleman for providing that assistance – utility companies – leaves me a bit skeptical.

I'm not a Nobel Prize-winning economist, but it seems to me we should look to someone other than Goldberg for inspiration in solving this problem. The trouble with such a complicated device is that, if any of the parts malfunction, the task is not completed. We need fewer moving parts.

And that's the beauty of the carbon tax and dividend, which would impose a steadily increasing fee on carbon at the source, whether it be a well, a mine or a port of entry. Most of the revenue from the tax would be returned to consumers, preferably in the form of a monthly payment.

In addition to being more efficient, the carbon tax and dividend approach is also more effective. An analysis by the Carbon Tax Center predicts that by 2020, a steadily increasing tax could reduce carbon dioxide emissions to 28 percent below 2005 levels. Even if it delivers as promised, the Boxer-Kerry bill would effect a reduction of only 20 percent by 2020.

One might be tempted to shrug off this difference, given that the cap-and-trade bill requires an 83 percent reduction by 2050. But the problem is that climate change is happening twice as quickly as previously believed, according to an exhaustive study released last spring by the Massachusetts Institute of Technology. Making matters worse are the "amplifying feedbacks" that climate scientist James Hansen has warned of. For example, as rising temperatures melt the tundra in the arctic regions, methane, a powerful greenhouse gas, is released into the air, trapping even more heat.

The policy we choose for climate change has to be a match for the science. Scientists like Hansen tell us that our atmosphere cannot sustain a carbon-dioxide concentration greater than 350 parts per million. To go higher for any length of time – we're at 389 ppm already – is to invite disaster. Why, then, are policy-makers operating under the assumption that 450 ppm of CO2 is an acceptable level?

Despite such warnings from the scientific community, the political will to address climate change appears to be flagging. At first count, the Boxer-Kerry bill has 45 votes in its corner.

Perhaps the best way to get climate-change legislation on track is to take a fresh approach – one with fewer moving parts. The carbon tax and dividend may not be as fun to watch as a Rube Goldberg machine, but I would gladly sacrifice the entertainment for something that works better.

Marshall Saunders is president of Citizens Climate Lobby, an organization based in Coronado that advocates for a sustainable climate. Contact him at ccl@citizensclimatelobby.org.