Last Time it Was This Warm, Sea Levels were 20 Feet Higher, Study Says

When past temperatures were similar to or slightly higher than the present global average, sea levels rose at least 20 feet, suggesting a similar outcome could be in store century unless there is a substantial reduction in greenhouse gas emissions… "Present climate is warming to a level associated with significant polar ice-sheet loss in the past," said Rutgers oceanographer Benjamin Horton, one of study’s authors… In the new study, researchers assessed evidence of higher sea levels the past 3 million years to understand how polar ice sheets respond to warming. Using observations from the geologic record, supported by computer modeling, they found that during past periods with average temperatures 1 to 3 C (1.8 to 5.4 F) warmer than preindustrial levels, sea level peaked at least 20 feet higher than today… "We are beginning to understand the magnitude that sea level rose in the past and which ice sheets may be responsible," said Horton, a professor of marine and coastal sciences in the School of Environmental and Biological Sciences.