At CES this week, Michael Dell announced that Dell computers will launch a program called "Plant a Tree for Me" which will ask customers to donate $2 for every notebook and $6 for every desktop PC they purchase. The money would be given to Conservation Fund and Carbonfund, which will buy and plant the trees as a way to offset emissions from the production of electricity for the average three-year use of the computer.

While clearly a laudable idea, carbon offset schemes remain too vague for my comfort and – to the cynical – smell a lot like a "guilt tax" on those with an extra $400 a year to spend to offset their family's impact without having to change their behavior one bit. For example: a recent BBC News article cautioned "trees only really work to cool the planet if they are planted in the tropics."

Even more startling, the story quoted ecologist Govindasamy Bala of Lawrence Livermore National Laboratory as saying "What we have found is in the so-called mid-latitude region where the United States is located and majority of European countries are located, the climate benefits of planting will be nearly zero, [and in] the seasonally snow-covered regions [at even higher latitudes], planting new trees could be actually counter-productive."

Is it just me, or is there something seriously flawed with the whole idea of carbon offsets? Think about it: a tree absorbs CO2 over its entire decades-long lifespan, while an "offset" airplane trip or an SUV spews out that CO2 right now. And some of those "offset" trees might actually be doing more harm than good if they're not planted in the proper places, and we're just figuring some of those details out now.

The worst part about all of this is that carbon offsets allow people to carry on with their old ways of doing things rather than making real, tangible changes.

I'm all for supporting efforts to support renewable energy as well as education and outreach activities, but telling people they can offset their carbon by simply mailing in their hard-earned cash when we don't yet know enough to have the right checks and balances in place seems to teeter on the brink of snake oil salesmanship to me. Let's focus on real change – new technologies and good old-fashioned conservation – rather than just new ways to get people to part with their money.