You are here

Due to scheduled maintenance, some NCEI systems may be unavailable (01/20/2021 4PM - 01/22/2021 12PM MT). We apologize for any inconvenience. Please contact with concerns or questions. Thank you for your patience.

Paleoclimatic Data before 2,000 Years Ago

Paleoclimate data for times before 2,000 years ago are also useful because they reveal the full extent of natural climate variability. These older records show that Earth has experienced other warm times in the past, including the mid-Holocene (around 6,000 years ago), the penultimate interglacial period (around 125,000 years ago), and the Early Eocene Climatic Optimum (48–54 million years ago). These records also show that temperature has changed abruptly in the past, and they reveal a remarkable correspondence between carbon dioxide change and temperature change during Earth's glacial cycles.