It is a sign of just how desperate things have become that several of those who know the most about global warming should be parties to a contest offering $25 million to someone who can invent a way to remove existing carbon dioxide from the air. Famed British entrepreneur Richard Branson announced the contest earlier this month with Al Gore at his side.

Other luminaries who will act as judges for the contest include the ultra-pessimistic James Lovelock, a world famous scientist and author of The Revenge of Gaia; NASA scientist James Hanson who is perhaps the most knowledgeable and respected climate researcher in the world; scientist Tim Flannery, author of the best-selling account of global warming, The Weather Makers; and Sir Crispin Tickell, one of the first scientists to write a major account of the consequences of climate change back in 1977.

No longer are drastic reductions in greenhouse gas emissions enough, this contest seems to say. We must also endeavor to undo the damage already done to the climate. To Branson’s credit, he says that a practical method for removing CO2 from the air may never be found and that even if it is, we will still need to push ahead with emission reductions.

Now, for the really hard part. It’s difficult to imagine how such a technology would not be extremely energy intensive. The current method for extracting useful gases such as oxygen, nitrogen and argon from the air involve what is called cryogenic fractional distillation. As one might glean from the name, the process starts with liquifying atmospheric gases at extremely low temperatures and then–since each gas has a different boiling point–boiling them off in succession.

Obviously, this method is not cost-effective for the large-scale extraction of CO2; otherwise, it would already have been proposed. But that just highlights my point. No one has been able to think of a non-energy intensive way to pull gases out of the air. Perhaps some better, more efficient technology will be found. But given the quantities which we seek to extract from the atmosphere–we added more than 24 billion tons of carbon dioxide in 2002 alone–that technology would probably have to be many orders of magnitude more efficient than current methods.

The second problem will be powering the newfound technology. More than 85 percent of the world’s energy comes from burning fossil fuels. Of course, we could try to run such carbon dioxide extracting plants on wind and solar power. But, shouldn’t we really be trying to run everything on non-carbon sources of energy? If we keep powering most of the economy using fossil fuels, then building such extraction plants would probably do little good.

Beyond this, the eventual (if not imminent) peaking of world oil production to be followed by the peaking of world natural gas production means that society will be relying more and more on alternative energy sources. Those sources may not be able to supply anything approaching our projected needs, let alone support an energy-intensive project to remove carbon dioxide from the air.

Of course, global warming solutions might come in another form. The seeding of the ocean with iron has already been tried. The idea is that some areas of the ocean are so poor in iron that they don’t support algae very well. Add iron and the algae thrive. After they die, they fall to the bottom of the ocean. If enough of them are buried before they decay, then the carbon in them gets sequestered. But there are serious questions about how much iron would be required, whether trying to engineer a system as large as the ocean would work or even be safe, and whether the algae would, in fact, fall to the bottom.

One possible problem with offering a highly visible prize to encourage such research is that it will provide false hope that technology alone can solve the global warming problem. Certainly, that is not Branson’s aim, but it might be the result.

Perhaps those who are giving their good names to Branson’s contest believe that we need a miracle technology to save us from the worst of global warming. But the kind of miracle we need most is one that will change the attitude of people worldwide about what each of them needs to do to prevent global warming from destroying the very civilization that has given us so much faith in technology.