The challenge for climate change detection and attribution research with regard to tropical cyclones is to determine whether an observed change in tropical cyclone activity exceeds the variability expected through natural causes, and to attribute significant changes to specific climate forcings, such as greenhouse gases or aerosols. For future projections of tropical cyclone activity, the challenge is to develop both a reliable projection of changes in the various factors influencing tropical cyclones, both local and remote, and a means of simulating the effect of these climate changes on tropical cyclone metrics, such as storm frequency, intensity and track distribution. This two-step process is required because the coupled atmosphere–ocean models used to project climate on a multidecadal to centennial timescale do not themselves simulate tropical cyclones adequately.