The climatic regimes of the land areas adjacent to the North Sea are controlled by the influx of Atlantic water north of the British Isles and into the North Sea. A high-resolution record from the Norwegian Channel off western Norway covering the past 15 ka (14C) shows that prior to the Younger Dryas, there were three periods of sea-surface conditions there similar to those of the present, interspersed with arctic conditions. These changes, corresponding to an increase of (Approx.)5 °C in summer sea-surface temperatures, took place on the scale of <10 yr. Both the timing (based on atomic mass spectroscopy dates and ash layers) and the rate of change fit in detail the isotope record of the Greenland Ice Core Project core from Summit, Greenland. This correlation is taken as evidence that reordering of atmospheric circulation at the end of glaciation is controlled by the inflow of warm Atlantic waters into the Norwegian-Greenland Sea. These findings suggest that the Greenland ice-core data reflect northwest European climate in great detail.