As governments worldwide increase their commitments to tackling climate change, the number of low-carbon jobs is expected to grow rapidly. Here we provide evidence on the characteristics of low-carbon jobs in the US using comprehensive online job postings data between 2010-2019. By accurately identifying low-carbon jobs and comparing them to similar jobs in the same occupational group, we show that low-carbon jobs differ from high-carbon or generic jobs in a number of important ways. Low-carbon jobs have higher skill requirements across a broad range of skills, especially technical ones. However, the wage premium for low-carbon jobs has declined over time and the geographic overlap between low- and high-carbon jobs is limited. Overall, our findings suggest there will be labour reallocation costs as workers transition into low-carbon activities. This suggests a role for targeted public investments in re-skilling to minimise transitional costs and ensure a workforce fit to deliver a rapid transition.