From the first trans-Atlantic flight to the first privately funded space exploration, a high profile cash prize has long been an effective motivator for advancing technology. Even if the prize money cannot possibly recoup the expense of preparing a competition entry, the publicity and increased funding it brings a technology sector is well-worth the expenditure. Nowhere is this more evident than in the buzz surrounding next year's Automotive X-Prize. The problem is, the ambitious competition may simply not be a far-enough reaching solution.

There's no question that the technical requirements of the competition will lead to significant automotive innovations. The competition's requirement that vehicles be capable of carrying four adults for ranges of 200 miles at a stretch while getting the equivalent of 100 miles per gallon is a difficult technical hurdle to clear. But because all teams must also complete a business plan to create 10,000 unit production runs of their vehicle, the transition of these technologies to the consumer market should be easier than the standard technology trickle-down.

The mission of the X Prize, which has received financial backing from sources as varied as software marker Adobe to the Union of Concerned Scientists, is solid, and its shortcomings are certainly not technical.

Perhaps the sentiment that best sums up my misgivings about the race comes from the X Prize's promotional material: "People love their cars. They are vital links to our jobs, our community, ourselves. For everything we love about them, cars are chained to the most severe global crises of our time: oil dependence and climate change."

While a consumer market of super-clean, super-efficient cars will make a tremendous dent in humanities' contribution to climate change, the fact remains that direct emissions and oil consumption are only part of the problem caused by a world ever-more reliant on the automobile. While many of the entries primarily rely on petroleum, even if future vehicles switch to get some or all of their energy from an emissions-free source—say, electricity— the massive energy demand that brings billions of people to work each day would, in the course of a few years, be transferred to an aging and frequently unstable power grid.

Further compounding the problem, many skeptics have raised concerns that existing renewable energy technologies may not be able to meet present power consumption levels. Adding some 590 million vehicles worldwide to that power demand may force municipalities to rely on the ease and relative inexpensiveness of coal power, effectively setting back many of the gains the X Prize will have made.

Even without considering the continued economic and environmental impacts of near-constant road construction and congestion, it's clear to see that the X Prize alone is not a cure-all solution to the transportation challenges currently facing the world. Efficient, carbon-friendly vehicles are an important step in the right direction, and will reap immediate, noticeable returns. But at the end of the day, fewer car trips and more reliance of alternate forms of transportation will need to be part of any effective climate solution.