Life on Earth has existed for over 3 billion years. By studying ancient climate, called paleoclimate, researchers can learn about how the Earth changes over time and how life is impacted. The USGS uses rock and fossil records to understand ancient climate, giving us insights into how modern climate change may alter our world.
What is paleoclimate research?
The Earth has been around for a long time – 4.6 billion years! In that time, there have been warm periods, where inland seas covered much of what is now North America. And there have been cold ice ages, where glaciers stretched across whole continents. Whether it is thousands or millions of years ago, scientists can study ancient climate conditions, or paleoclimates, to learn about how the Earth changes and how ancient life dealt with it.
Today, we study climate by using instruments to measure temperature, humidity, and rainfall. Since we can’t travel back in time, scientists use paleoclimate archives, geologic and biologic materials (like rocks and tree rings) that preserve evidence of past changes in climate, to reconstruct what the Earth was like a long time ago.
Rocks are ancient time capsules. Geologists can look at the texture, layers, grains, and minerals in a rock and find out what the past environment was like. Rocks from millions of years ago still hold the stories of past oceans, rivers, lakes, floods, dunes, and deserts.
Paleoclimate scientists also look for clues in the remains of ancient life. Fossilized animals, plants, and their traces (tracks, burrows, scat) reveal what was alive during different time periods. Fossils of cold-loving species, like wooly mammoths, tell scientists that those areas probably had cooler climates. Whale fossils found high in coastal cliffs indicate a past elevated sea level.
Long-lived organisms, like corals and trees, change how they grow during cooler or warmer years. Analyzing ancient growth patterns, for example by measuring tree rings, can reveal shifts in climate over their lifespan. Some ancient species even collected records for us! Ten-thousand-year-old packrat dens contain the remains of plants, bones, and dung hoarded long-ago and preserved by packrat pee. These are a treasure trove to paleoclimate scientists!
How does ancient climate change compare to today?
Our planet has experienced both colder and hotter periods than the climate we live in today. So, why would anyone be concerned about the rapid warming trend today? Changes that occurred over millions of years in the past are happening within a human lifespan.
Paleoclimate studies indicate that most ancient changes in climate happened over very long periods of time. The scale was on the order of tens of thousands to millions of years, not 100 or 200 years. Plants and animals had countless generations to adapt or migrate to the slow change of conditions.
Rapid climate change in the past was usually associated with a major disruptive event, like a meteor impact or massive volcanic eruption, which caused abrupt, long-lasting changes in climate. A good example is an asteroid that struck the Earth around 65 million years ago. The impact, and rapid climate change that resulted, contributed to the extinction of around 75 percent of all species alive at the time, including the dinosaurs.
USGS Uses Paleoclimatology to Shed Light on Modern Climate Change
By collecting data on past climates and their impacts on ecosystems, USGS scientists can better predict what the future could look like. This provides valuable insights to help resource managers better respond to present and future ecosystem changes.
Within the last 65 million years, there have been a few intervals of warmer climates that particularly interest USGS researchers. None of them are exactly like our modern climate, but we can learn useful information by comparing them to each other and to today’s conditions. One USGS research effort is exploring sudden and extreme global warming events that occurred during the Paleocene-Eocene eras about 56 million years ago. These researchers are learning that some global warming events had smaller effects and then stabilized, while others took tens of thousands of years to stabilize. Another USGS effort is exploring the climate about 3 million years ago during the Pliocene Epoch, when continents, ocean currents, and plant and animal life were similar to today’s. The global temperature during this period was around 5°F warmer than today, where many climate models predict it will be by the end of this century.
Researchers are applying paleoclimate insights to modern-day problems, including understanding how sea level rise might affect coastal fishing industries, assessing future vegetation patterns to inform agricultural practices, and predicting future El Niño events.
USGS paleoclimate efforts are aimed at:
-
Improving climate models for more accurate forecasts
-
Predicting how the water cycle may change around the world
-
Characterizing ancient climate conditions using data sources such as marine microfossils, soil cores, ice cores, tree rings, and packrat middens.
-
Understanding ancient ocean and marine conditions using data sources such as corals, microfossils in sediment cores, and geochemical techniques.
-
Understanding ancient human distribution and migration
-
Understanding drivers and consequences of ancient climate change
Explore some of the many USGS science projects on paleoclimate.
Paleoclimate Proxies
Paleoclimate Archives
Paleoclimate Research
Drivers and Impacts of North Pacific Climate Variability
Pacific Ocean Patterns, Processes, and Productivity (POP3): Impacts of ancient warming on marine ecosystems and western North America
Reconstructing Ocean Circulation & Hydroclimate in the Subtropical Atlantic
Natural Drought and Flood Histories from Lacustrine Archives
Holocene Synthesis Project
Pliocene Research, Interpretation and Synoptic Mapping (PRISM4)
Eocene Hyperthermals Project
Paleoclimate Reconstruction from Marine and Lake Sediments
Climate and Environmental Change in the Gulf of Mexico and Caribbean
How long can we expect the present Interglacial period to last?
No one knows for sure. In the Devils Hole, Nevada paleoclimate record, the last four interglacials lasted over ~20,000 years with the warmest portion being a relatively stable period of 10,000 to 15,000 years duration. This is consistent with what is seen in the Vostok ice core from Antarctica and several records of sea level high stands. These data suggest that an equally long duration should be...
- Overview
What is paleoclimate research?
Sources/Usage: Public Domain.Today, we study climate by using instruments to measure temperature, humidity, and rainfall. Since we can’t travel back in time, scientists use rocks and fossils to reconstruct what the Earth was like a long time ago. The Earth has been around for a long time – 4.6 billion years! In that time, there have been warm periods, where inland seas covered much of what is now North America. And there have been cold ice ages, where glaciers stretched across whole continents. Whether it is thousands or millions of years ago, scientists can study ancient climate conditions, or paleoclimates, to learn about how the Earth changes and how ancient life dealt with it.
Today, we study climate by using instruments to measure temperature, humidity, and rainfall. Since we can’t travel back in time, scientists use paleoclimate archives, geologic and biologic materials (like rocks and tree rings) that preserve evidence of past changes in climate, to reconstruct what the Earth was like a long time ago.
Rocks are ancient time capsules. Geologists can look at the texture, layers, grains, and minerals in a rock and find out what the past environment was like. Rocks from millions of years ago still hold the stories of past oceans, rivers, lakes, floods, dunes, and deserts.
Paleoclimate scientists also look for clues in the remains of ancient life. Fossilized animals, plants, and their traces (tracks, burrows, scat) reveal what was alive during different time periods. Fossils of cold-loving species, like wooly mammoths, tell scientists that those areas probably had cooler climates. Whale fossils found high in coastal cliffs indicate a past elevated sea level.
Long-lived organisms, like corals and trees, change how they grow during cooler or warmer years. Analyzing ancient growth patterns, for example by measuring tree rings, can reveal shifts in climate over their lifespan. Some ancient species even collected records for us! Ten-thousand-year-old packrat dens contain the remains of plants, bones, and dung hoarded long-ago and preserved by packrat pee. These are a treasure trove to paleoclimate scientists!
How does ancient climate change compare to today?
Our planet has experienced both colder and hotter periods than the climate we live in today. So, why would anyone be concerned about the rapid warming trend today? Changes that occurred over millions of years in the past are happening within a human lifespan.
Paleoclimate studies indicate that most ancient changes in climate happened over very long periods of time. The scale was on the order of tens of thousands to millions of years, not 100 or 200 years. Plants and animals had countless generations to adapt or migrate to the slow change of conditions.
Rapid climate change in the past was usually associated with a major disruptive event, like a meteor impact or massive volcanic eruption, which caused abrupt, long-lasting changes in climate. A good example is an asteroid that struck the Earth around 65 million years ago. The impact, and rapid climate change that resulted, contributed to the extinction of around 75 percent of all species alive at the time, including the dinosaurs.
USGS Uses Paleoclimatology to Shed Light on Modern Climate Change
The USGS Florence Bascom Geoscience Center (FBGC) is at the leading edge of scientific research addressing critical societal issues and providing unbiased data and information to decision makers and the public. Listen to the audio-described version. By collecting data on past climates and their impacts on ecosystems, USGS scientists can better predict what the future could look like. This provides valuable insights to help resource managers better respond to present and future ecosystem changes.
Within the last 65 million years, there have been a few intervals of warmer climates that particularly interest USGS researchers. None of them are exactly like our modern climate, but we can learn useful information by comparing them to each other and to today’s conditions. One USGS research effort is exploring sudden and extreme global warming events that occurred during the Paleocene-Eocene eras about 56 million years ago. These researchers are learning that some global warming events had smaller effects and then stabilized, while others took tens of thousands of years to stabilize. Another USGS effort is exploring the climate about 3 million years ago during the Pliocene Epoch, when continents, ocean currents, and plant and animal life were similar to today’s. The global temperature during this period was around 5°F warmer than today, where many climate models predict it will be by the end of this century.
Researchers are applying paleoclimate insights to modern-day problems, including understanding how sea level rise might affect coastal fishing industries, assessing future vegetation patterns to inform agricultural practices, and predicting future El Niño events.
USGS paleoclimate efforts are aimed at:
-
Improving climate models for more accurate forecasts
-
Predicting how the water cycle may change around the world
-
Characterizing ancient climate conditions using data sources such as marine microfossils, soil cores, ice cores, tree rings, and packrat middens.
-
Understanding ancient ocean and marine conditions using data sources such as corals, microfossils in sediment cores, and geochemical techniques.
-
Understanding ancient human distribution and migration
-
Understanding drivers and consequences of ancient climate change
Sources/Usage: Public Domain.Summer Praetorius from the Geology, Minerals, Energy, & Geophysics (GMEG) Science Center collects samples from an ocean sediment core in the Pacific Ocean Paleoclimatology Lab at Menlo Park, CA.
Sources/Usage: Public Domain. Visit Media to see details.Alaska Science Center scientist Louis Sass uses ice cores to learn about ancient climate and ice formation.
Sources/Usage: Public Domain.Tom Sheehan, a lab technician at the Florence Bascom Geoscience Center, separates fossilized pollen from heavier mineral material. -
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Explore some of the many USGS science projects on paleoclimate.
Filter Total Items: 14Paleoclimate Proxies
Paleoclimate proxies are physical, chemical and biological materials preserved within the geologic record (in paleoclimate archives) that can be analyzed and correlated with climate or environmental parameters in the modern world. Scientists combine proxy-based paleoclimate reconstructions with instrumental records (such as thermometer and rain gauge readings) to expand our understanding of...Paleoclimate Archives
Paleoclimate archives consist of geologic (e.g., sediment cores) and biologic (e.g., tree rings) materials that preserve evidence of past changes in climate. They contain substances or features (climate proxies) that can be sampled and analyzed using a variety of physical and chemical methods. Using results from the analyses of proxies in archives, scientists reconstruct changes through time and...Paleoclimate Research
Lessons from the Past, Roadmap for the Future The present-day climate of the Earth is influenced by a combination of natural climate variability, increased concentrations of greenhouse gases in the atmosphere since the Industrial Revolution, and changes in land cover (such as conversion from forest to agriculture and back again).Drivers and Impacts of North Pacific Climate Variability
Climate model forecasts indicate an increase in extreme hydrologic events, including floods and droughts, for California and the western U.S. in the future. To better understand what the consequences of this future change in climate may be, USGS scientists are studying the frequency, magnitude, and impacts of past hydroclimate variability and extremes in the region. This project produces well...Pacific Ocean Patterns, Processes, and Productivity (POP3): Impacts of ancient warming on marine ecosystems and western North America
Projections for AD 2100 suggest warming of +1-4°C in the North Pacific Ocean, which will result in widespread transformations throughout the marine environment and western North America. Many of these changes are beyond the predictive capabilities of current climate models. To better address this future uncertainty, our team is developing a geological framework using past warm intervals as...Reconstructing Ocean Circulation & Hydroclimate in the Subtropical Atlantic
Changes in rainfall patterns as a result of anthropogenic climate change are already having large ecological and socioeconomic impacts across the globe. Increases in flood damage, wildfire damage, and agricultural losses can all be attributed to anomalous rainfall events and prolonged droughts across the United States in recent years. Additionally, Atlantic Ocean circulation, which has a large...Natural Drought and Flood Histories from Lacustrine Archives
Previous work performed as part of the USGS Holocene Synthesis project illuminated complex centennial-scale patterns of drought and wetter-than-average conditions across the North American continent interior during the past two millennia, where paleorecord data coverage is sparse. In order to explain the patterns of naturally-occurring drought, floods, and storms for the past, identified by the...Holocene Synthesis Project
The Holocene Synthesis Project integrates a variety of information about past climate variability across the North American continent for the past ~12,000 years to characterize the spatial patterns of previous climate states, advance our understanding about mechanisms that drive natural climate variability, and improve the quality of climate models that are used to predict future climate patterns...Pliocene Research, Interpretation and Synoptic Mapping (PRISM4)
PRISM will help distinguish the USGS as a world leader in paleoclimate research, data generation and delivery for use in addressing the modern world's climate-related needs. We will be recognized for the passion of our researchers and partners in providing quality, innovative paleoclimate interpretation and data analysis to the science (climate change) community and to the public we serve.Eocene Hyperthermals Project
Sudden and extreme global warming events of the past are known as hyperthermals. The most intensely studied of these is the Paleocene-Eocene Thermal Maximum (PETM) that occurred about 56 million years ago. During the PETM, global temperatures rose by ~5°C, ocean acidification was widespread, floral and faunal communities were severely disrupted, and changing oceanic circulation and a disrupted...Paleoclimate Reconstruction from Marine and Lake Sediments
Instrumental measurements of climate variables (e.g., precipitation, temperature, ocean circulation, etc.) are only available over the past century or less. In order to quantify the rate and magnitude of natural climate variability going back in time beyond the 20th century, scientists rely on paleoclimate reconstructions.Climate and Environmental Change in the Gulf of Mexico and Caribbean
This project documents paleoceanographic, climatic, and environmental changes in the Gulf of Mexico and adjacent land areas over the last 10,000 years. The paleoenvironmental data is used to determine rates of change in the past, and to better understand both the natural and anthropogenic factors that contribute to climate variability on inter-annual to millennial timescales. - Multimedia
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How long can we expect the present Interglacial period to last?
No one knows for sure. In the Devils Hole, Nevada paleoclimate record, the last four interglacials lasted over ~20,000 years with the warmest portion being a relatively stable period of 10,000 to 15,000 years duration. This is consistent with what is seen in the Vostok ice core from Antarctica and several records of sea level high stands. These data suggest that an equally long duration should be...