Overview
A number of USGCRP agencies such as NSF, DOE, NOAA, NASA, USGS, and SI are investing in understanding the history of Earth’s climate, known as “paleoclimate.” Paleoclimate data extend records of climate and the environment beyond the time period for which we have instrumental measurements. Studying paleoclimate not only answers questions about what Earth was like in the past, but also provides critical context for the climate changes that we are experiencing today, and informs our understanding of how climate is likely to change in the future. A few examples of USGCRP agencies’ investments in paleoclimate research and education are described below.

Research and Societally Relevant Outcomes
NSF and international partners from 12 countries support the North Greenland Eemian Ice Drilling (NEEM) project, which focuses on the Eemian interglacial period. The Eemian climate was similar to that of the Holocene (which includes the present day), but temperatures were approximately 3–5°C warmer than they are currently, making the Eemian a useful analog for expected future temperature increases of 2–4°C by 2100. The NEEM project drilled a core 2.5 kilometers deep into the Northwest Greenland ice sheet, capturing ice from the Eemian through the present day. Analyses of this ice core have resulted in 25 publications since 2012 alone, ranging from topics such as the isotopic record of carbon monoxide to likely patterns of future ice melt and resultant sea-level rise.

The Paleoclimate Modelling Intercomparison Project (PMIP) is an international effort that involves NOAA, DOE, NSF, and NASA. PMIP uses state-of-the-art climate models to simulate paleoclimate, and evaluates the capabilities of those models to reproduce climate conditions that are radically different from those of today. Such modeling efforts depend on archives of paleoclimate data derived from sources like tree rings, ice cores, corals, and ocean and lake sediments. NOAA’s National Climate Data Center archives extensive paleoclimate data that are contributed and used by scientists all over the world. Paleoclimate data are also used in Earth and environmental science education: SI has developed lesson plans for students at a range of grade levels that demonstrate how researchers use sources of information about the past— like leaf fossils, ancient coral reefs, and even archeological artifacts—to reconstruct past climate conditions.