Carbon offsets are a tricky problem. I happen to think they are more useful than not, but that's with the presumption that people move their energy use in fits and starts, and offsets are just for the in-bewteen time. Nonetheless, it's always important to keep front-and-center the idea that the energy savings and direct switchover to renewables need to come as they can.
In that vein, Charles Komanoff was quoted in the linked article as saying "There isn’t a single American household above the poverty line that couldn’t cut their CO2 at least 25 percent in six months through a straightforward series of fairly simple and terrifically cost-effective measures." Kindly, Komanoff has followed up at Grist with his back-of-the-envelope calculations backing up his off-the-cuff estimate.
So, if you're interested in fighting global warming, and you're looking at carbon offsets (or even planning on buying into CWLP's green power program when it's offered), go take a look.