These data are outputs from climate simulations carried out using HadGEM3-GC3.1. The simulations are labelled ay187, az575, az576 and bb819, corresponding to experiments FW, FWShelf, FWBerg and FWCO2 respectivey, which are described in detail in the two associated journal articles. Some data stored here are from the southern hemisphere only, and some separate data files have global coverage. These data were produced by University of Otago, New Zealand, in collaboration with the UK Met Office for a project funded by the New Zealand Deep South National Science Challenge using the Monsoon system, a collaborative facility supplied under the Joint Weather and Climate Research Programme, a strategic partnership between the Met Office and the Natural Environment Research Council.