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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.
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!
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.
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:
Along reef-lined shores of the Pacific Islands, USGS Research Geologist and Oceanographer Ferdinand Oberle studies how warming surface waters, nutrient runoff, and increasingly powerful storms impact coral reefs.
Along reef-lined shores of the Pacific Islands, USGS Research Geologist and Oceanographer Ferdinand Oberle studies how warming surface waters, nutrient runoff, and increasingly powerful storms impact coral reefs.
Research Oceanographer Kira Mizell studies change in ocean chemistry by collecting marine minerals, looking for insights into past climate conditions and geologic history.
Research Oceanographer Kira Mizell studies change in ocean chemistry by collecting marine minerals, looking for insights into past climate conditions and geologic history.
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.
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.
This video introduces research that Florence Bascom Geoscience Center (FBGC) scientists are conducting on the 500,000 year history of Arctic sea ice to assess changes in weather, sea ice extent, temperature and ecosystems.
This video introduces research that Florence Bascom Geoscience Center (FBGC) scientists are conducting on the 500,000 year history of Arctic sea ice to assess changes in weather, sea ice extent, temperature and ecosystems.
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.
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.
Cores were collected from various areas of thawing permafrost-peatlands in Alaska. Permafrost thaw results in ground subsidence and inundation that kills black spruce and other understory plants living on the permafrost plateau.
Cores were collected from various areas of thawing permafrost-peatlands in Alaska. Permafrost thaw results in ground subsidence and inundation that kills black spruce and other understory plants living on the permafrost plateau.
These tree cores, taken from living trees with an increment borer, show the rings of the tree and allow scientists to learn about the tree's growth.
These tree cores, taken from living trees with an increment borer, show the rings of the tree and allow scientists to learn about the tree's growth.
Survey Analysis via Visual Exploration rock cores
Survey Analysis via Visual Exploration rock cores
Flyover of the southeast Ceti Mensa map. Distinct groups of rock layers, called geologic units, are shaded in different colors, with dark browns representing the oldest rocks and green representing the youngest rocks. All of these rocks formed as wind-blown sand that became trapped in shallow, ephemeral lakes, similar to the wet playas of the desert southwest US.
Flyover of the southeast Ceti Mensa map. Distinct groups of rock layers, called geologic units, are shaded in different colors, with dark browns representing the oldest rocks and green representing the youngest rocks. All of these rocks formed as wind-blown sand that became trapped in shallow, ephemeral lakes, similar to the wet playas of the desert southwest US.
Explore some of the many USGS science projects on paleoclimate.
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.
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!
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.
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:
Along reef-lined shores of the Pacific Islands, USGS Research Geologist and Oceanographer Ferdinand Oberle studies how warming surface waters, nutrient runoff, and increasingly powerful storms impact coral reefs.
Along reef-lined shores of the Pacific Islands, USGS Research Geologist and Oceanographer Ferdinand Oberle studies how warming surface waters, nutrient runoff, and increasingly powerful storms impact coral reefs.
Research Oceanographer Kira Mizell studies change in ocean chemistry by collecting marine minerals, looking for insights into past climate conditions and geologic history.
Research Oceanographer Kira Mizell studies change in ocean chemistry by collecting marine minerals, looking for insights into past climate conditions and geologic history.
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.
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.
This video introduces research that Florence Bascom Geoscience Center (FBGC) scientists are conducting on the 500,000 year history of Arctic sea ice to assess changes in weather, sea ice extent, temperature and ecosystems.
This video introduces research that Florence Bascom Geoscience Center (FBGC) scientists are conducting on the 500,000 year history of Arctic sea ice to assess changes in weather, sea ice extent, temperature and ecosystems.
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.
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.
Cores were collected from various areas of thawing permafrost-peatlands in Alaska. Permafrost thaw results in ground subsidence and inundation that kills black spruce and other understory plants living on the permafrost plateau.
Cores were collected from various areas of thawing permafrost-peatlands in Alaska. Permafrost thaw results in ground subsidence and inundation that kills black spruce and other understory plants living on the permafrost plateau.
These tree cores, taken from living trees with an increment borer, show the rings of the tree and allow scientists to learn about the tree's growth.
These tree cores, taken from living trees with an increment borer, show the rings of the tree and allow scientists to learn about the tree's growth.
Survey Analysis via Visual Exploration rock cores
Survey Analysis via Visual Exploration rock cores
Flyover of the southeast Ceti Mensa map. Distinct groups of rock layers, called geologic units, are shaded in different colors, with dark browns representing the oldest rocks and green representing the youngest rocks. All of these rocks formed as wind-blown sand that became trapped in shallow, ephemeral lakes, similar to the wet playas of the desert southwest US.
Flyover of the southeast Ceti Mensa map. Distinct groups of rock layers, called geologic units, are shaded in different colors, with dark browns representing the oldest rocks and green representing the youngest rocks. All of these rocks formed as wind-blown sand that became trapped in shallow, ephemeral lakes, similar to the wet playas of the desert southwest US.
Explore some of the many USGS science projects on paleoclimate.