Sea-surface temperatures during the last interglaciation period were like those of today, a new study reports. The trend is worrisome, as sea levels during the last interglacial period were between six and nine meters above their present height.

• Interglaciation is the term used by geologists to refer to the alternating periods of warming and cooling in the earth’s past.
• The cooler times are called the “glacial period” during which ice shelves from the Arctic slowly creep southward and spread across the earth.
• Times when the earth is covered in these large ice sheets are known as glacial periods (or ice ages).
• When the ice sheets are not spread, it is called an interglacial period.
• The most recent glacial period occurred between about 120,000 and 11,500 years ago.
• Since then, the earth has been in an interglacial period called the Holocene.