The Copenhagen Summit sometimes gives observers the impression that elaborate formulas and systems are needed to reduce greenhouse gases.

And, to be sure, a cap-and-trade system (or an equivalent) at the national level, and then coordinated at the international level, will be needed to ensure that nations are reforming their climate changing ways.

However, the above does not mean substantive greenhouse gas reductions cannot occur outside of the Copenhagen framework. They can, and one obvious way is: reduce the weight of vehicles.

The Bush administration opposes a United Nations draft proposal calling on developed nations to make binding emissions cuts of 25%-40% by 2020, Bloomberg News reported Monday.

A U.N. draft document will call for industrialized nations to implement those cuts as part of a proposal to replace the Kyoto Protocol, Reuters reported Monday. Representatives from 187 nations are meeting in Bali for global climate talks.

Environmental and international group leaders hope to replace the Kyoto Protocol, which expires in 2012, with the new U.N. agreement, preferably by 2009. The United States is the only developed nation to reject the Kyoto Protocol. U.S. senior climate negotiator Harlan Watson said Monday that the U.S.'s "principal difficulty with having any numbers in the text to begin with is that it might prejudge outcomes,'' Bloomberg News reported.

Speaking at the Los Angeles Auto Show, Ford (NYSE: F) CEO Alan Mulally said the automaker is committed to improving miles per gallon efficiency and reducing emissions via implementing technological advances.

And the technological advances Ford's looking to incorporate to help stabilize its market share? Direct fuel injection, smaller-cylinder engines with turbo charges, lighter weight materials, hybrids, and diesels, among others. Moreover, Mulally said Ford's goal will be to increase fuel economy without sacrificing engine performance or auto safety. Ford's shares drifted three cents lower to $7.95 in Thursday afternoon trading.

In general, analysts were encouraged by Ford's presentation, despite the company's lack of a time-table for efficiency improvements or announcement of changes to specific vehicle models, other than a promise to apply diesel fuel and technology to improve the mpg of its popular but fuel-guzzling F-150 pickups.

In a move reminiscent of the tobacco lawsuits against Philip Morris years ago, the State of California has sued General Motors Corporation (NYSE: GM), Ford Motor Company (NYSE: F), Toyota Motor Corporation (ADR) (NYSE: TM), Daimler Chrysler AG (NYSE: DCX), Honda Motor Co. Ltd (ADR) (NYSE: HMC) and Nissan Motor Co. The theory is that the car companies created a "public nuisance" that will cost the state in infrastructure and health expenses. What the state will seek in damages is not clear.

At first blush, it would appear that these claims would eventually be no more successful than the smokers' suits were. The state had the power to set emissions standards or even to ban the sale of cars by manufacturers that built cars that did not fit criteria set by the state. Since the California legislature never took those steps, it will probably be difficult to claim monetary awards to offset the state's costs.

It is also likely that the issue of whether the cars accounted for all of the health and structural damage would be difficult to prove. Factories and other sources can also be tagged for producing toxic gas.

What the suit does do is open a Pandora's box of legal costs for the car companies, especially if other states follow California's lead. As Altria and other tobacco companies discovered, even winning cases can cost hundreds of millions of dollars. There was a time when Altria's legal costs were over $1 million a day.

Even if the car companies win against claims like those that have been brought by California, they could lose. The industry is not in any shape to shoulder that distraction or costs of litigation across a number of states.

Douglas McIntyre is a partner at 24/7 Wall St.