Should I buy a travel offset?

As I write this, I am about to set off on a trip to New Orleans. We will be driving. Come with me now as I navigate the somewhat guilty landscape of researching carbon offsets for my journey.

Googling "carbon offset travel," I immediately get a slew of results: dozens of different companies that will calculate the footprint of my trip and then sell me an appropriately-priced offset. I start with TerraPass, the company I’ve heard of the longest in connection with carbon offsets; its site tells me that the trip will produce approximately 1,450 pounds of CO2. (Yikes.) An offset for this sin will cost me $11.90, and that money will go toward any of three types of projects: capturing methane from cattle, capturing methane from landfills, or supporting wind farms.

I don’t know exactly what "supporting wind farms" means, and I’ve seen a little of the political and economic uncertainty that seems to accompany the proposal and installation of wind farms. So while I think wind energy is a fine idea, I can easily imagine my $11.90 getting swallowed in red tape.

To broaden my scope a bit, I try another site, Sustainable Travel International. Oddly, the calculator on this site gives me fairly different results for exactly the same data: 1,311 pounds of CO2 (expressed in tons, but I converted for comparison’s sake). On this site, I can feel less guilty, but I’ll pay more to assuage that guilt—$16.62. STI is slightly more vague in describing its offset projects, but they boil down to renewable energy and energy efficiency.

The amounts of money are certainly affordable. I’m starting to wonder something, though. Why exactly am I worried about offsetting carbon for a vacation, when I’ve never even considered doing so for my substantial daily commute? STI calculates that I produce 4.6 tons of carbon per year just getting to work. Now that really makes me wince. Would an offset for my vacation just be a silly kind of souvenir, doing more to offset my feelings about my commute than it does to actually slow down climate change? Should I plant a bunch of trees instead of sending my money to a company I ultimately have to just blindly trust? Should I walk to New Orleans?

Input appreciated!