Oceanic forcing of penultimate deglacial and last interglacial sea-level rise.

Sea-level histories during the two most recent deglacial-interglacial intervals show substantial differences despite both periods undergoing similar changes in global mean temperature and forcing from greenhouse gases. Although the last interglaciation (LIG) experienced stronger boreal summer insolation forcing than the present interglaciation, understanding why LIG global mean sea level may have been six to nine metres higher than today has proven particularly challenging. Extensive areas of polar ice sheets were grounded below sea level during both glacial and interglacial periods, with grounding lines and fringing ice shelves extending onto continental shelves.