Airline travel is notoriously carbon-intensive, and it probably accounts for a sizable chunk of your annual carbon footprint. Flying out to spend time with family this year? Consider buying some carbon credits to offset all of those emissions. For less than the cost of a sad airport salad, you can invest in carbon sequestration initiatives like reforestation or solar farms through organizations such as The Gold Standard and Cool Effect. And if you can get away with swapping your plane for a train or automobile this year, do that instead!