Following resolution of a long-standing debate over the timing of the initial settlement of New Zealand from Polynesia (late 13th century), a prevailing paradigm has developed that invokes rapid transformation of the landscape, principally by fire, within a few decades of the first arrivals. This model has been constructed from evidence mostly from southern and eastern regions of New Zealand, but a more complicated pattern may apply in the more humid western and northern regions where forests are more resilient to burning. We present a new pollen record from Lake Pupuke, Auckland, northern New Zealand, that charts the changing vegetation cover over the last 1000 years, before and after the arrival of people. Previous results from this site concurred with the rapid transformation model, although sampling resolution, chronology and sediment disturbance make that interpretation equivocal. Our new record is dated principally by tephrochronology together with radiocarbon dating and includes a cryptotephra deposit identified as Kaharoa tephra, a key marker for first settlement in northern New Zealand. Its discovery and stratigraphic position below two Rangitoto-derived tephras enables a clearer picture of environmental change to be drawn. The new pollen record shows an early phase (step 1) of minor, localised forest clearance around the time of Kaharoa tephra (c. 1314 AD) followed by a later, more extensive deforestation phase (step 2) commencing at around the time of deposition of the Rangitoto tephras (c. 1400–1450 AD). This pattern, which needs to be corroborated from other well-resolved records from northern New Zealand, concurs with an emerging hypothesis that the ‘Little Ice Age’ had a significant impact on pre-European Māori with the onset of harsher conditions causing a consolidation of populations and later environmental impact in northern New Zealand.

In this paper we present new proxy‐based sea‐level reconstructions for southern New Zealand spanning the last millennium. These palaeo sea‐level records usefully complement sparse Southern Hemisphere proxy and tide‐gauge sea‐level datasets and, in combination with instrumental observations, can test hypotheses about the drivers of 20th century global sea‐level change, including land‐based ice melt and regional sterodynamics. We develop sea‐level transfer functions from regional datasets of salt‐marsh foraminifera to establish a new proxy‐based sea‐level record at Mokomoko Inlet, at the southern tip of the South Island, and to improve the previously published sea‐level reconstruction at Pounawea, located about 110 km to the east. Chronologies are based on radiocarbon, radiocaesium, stable lead isotope and pollen analyses. Both records are in good agreement and show a rapid sea‐level rise in the first half of the 20th century that peaked in the 1940s. Previously reported discrepancies between proxy‐based sea‐level records and tide‐gauge records are partially reconciled by accounting for barystatic and sterodynamic components of regional sea‐level rise. We conclude that the rapid sea‐level rise during the mid‐20th century along the coast of southern New Zealand was primarily driven by regional thermal expansion and ocean dynamics.