Maureen E. Raymo (born 1959) is an American paleoclimatologist and marine

geologist A geologist is a scientist who studies the structure, composition, and History of Earth, history of Earth. Geologists incorporate techniques from physics, chemistry, biology, mathematics, and geography to perform research in the Field research, ...

. She is the Co-Founding Dean Emerita of the Columbia Climate School and the G. Unger Vetlesen Professor of Earth & Environmental Sciences at Columbia University. From 2011 to 2022, she was also Director of Lamont-Doherty Earth Observatory's (LDEO) Core Repository and, until 2024, was the Founding Director of the LDEO Hudson River Field Station. From 2020 to 2023, she was first Interim Director then Director of Lamont-Doherty Earth Observatory, the first

climate scientist Climatology (from Greek , ''klima'', "slope"; and , ''-logia'') or climate science is the scientific study of Earth's climate, typically defined as weather conditions averaged over a period of at least 30 years. Climate concerns the atmospheric ...

and first female scientist to head the institution. Raymo has done pioneering work on the origin of the

ice ages An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages, and Gre ...

, the geologic temperature record of the Earth, and past sea level change, publishing over 100 peer-reviewed scientific articles. Her work underlies fundamental ideas in

paleoceanography Paleoceanography is the study of the history of the oceans in the geologic past with regard to circulation, chemistry, biology, geology and patterns of sedimentation and biological productivity. Paleoceanographic studies using environment model ...

including the uplift weathering hypothesis, the "41,000-year problem," the Pliocene sea-level paradox, and the Lisiecki-Raymo

δ18O In geochemistry, paleoclimatology and paleoceanography ''δ''18O or delta-O-18 is a measure of the deviation in ratio of stable isotopes oxygen-18 (18O) and oxygen-16 (16O). It is commonly used as a measure of the temperature of precipitation ...

stack. In 2014, Raymo became the first woman to win the

Wollaston Medal The Wollaston Medal is a scientific award for geology and the highest award granted by the Geological Society of London, the oldest geological society in the world. The medal is named after William Hyde Wollaston, and was first awarded in 1831. I ...

for geology, which had been awarded for 183 years at the time. She was described in her nomination as "one of the foremost and influential figures in the last 30 years."

Early life and education

Raymo was born in

Los Angeles Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, ...

, and at the age of eight she sailed with her family to Europe on the ocean liner S.S. United States and resolved to dedicate her life to studying the ocean. The books and films of

Jacques Cousteau Jacques-Yves Cousteau, (, also , ; 11 June 191025 June 1997) was a French naval officer, oceanographer, filmmaker and author. He co-invented the first successful open-circuit self-contained underwater breathing apparatus (SCUBA), called the ...

were also important early influences. Raymo attended Oliver Ames High School in

Easton, Massachusetts Easton is a New England town, town in Bristol County, Massachusetts, United States. The population was 25,058 at the 2020 census. It is part of the Greater Boston area. Easton is governed by an elected Select Board. Town meeting, Open Town Meeti ...

, where she graduated with the Bausch and Lomb Honorary Science Award, and then attended

Brown University Brown University is a Private university, private Ivy League research university in Providence, Rhode Island, United States. It is the List of colonial colleges, seventh-oldest institution of higher education in the US, founded in 1764 as the ' ...

, receiving her Sc.B. Geology in 1982. After a brief stint working in a lab, she then attended

Columbia University Columbia University in the City of New York, commonly referred to as Columbia University, is a Private university, private Ivy League research university in New York City. Established in 1754 as King's College on the grounds of Trinity Churc ...

, where she earned her M.A. in geological sciences in 1985, her M.Phil. in geology in 1988, and her Ph.D. in geology in 1989.

Career

Early climate research

Raymo is known for developing (along with William Ruddiman and Philip Froelich) the ''Uplift-Weathering Hypothesis.'' According to this hypothesis,

tectonic uplift Tectonic uplift is the orogeny, geologic uplift of Earth#Surface, Earth's surface that is attributed to plate tectonics. While Isostasy, isostatic response is important, an increase in the mean elevation of a region can only occur in response to ...

of areas such as the Himalayas and

Tibetan plateau The Tibetan Plateau, also known as the Qinghai–Tibet Plateau or Qingzang Plateau, is a vast elevated plateau located at the intersection of Central Asia, Central, South Asia, South, and East Asia. Geographically, it is located to the north of H ...

over the last 40 million years contributed to surface cooling and thus the Ice Ages. Mountain uplift enhances the chemical weathering of minerals, a process that removes

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

from the atmosphere. The resulting cooling led to the growth of large ice sheets at both poles. Raymo and her colleagues initially suggested that measuring the proportions of

isotopes Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), but ...

strontium Strontium is a chemical element; it has symbol Sr and atomic number 38. An alkaline earth metal, it is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is exposed to ...

(Sr) in deep ocean sediments could substantiate the Uplift-Weathering Hypothesis but soon recognized that ambiguities in the sources of strontium to the ocean existed. Over 35 years later, the hypothesis continues to be debated and studied with many new lines of evidence proposed. Their proposed mechanism of removal, the chemical weathering of mechanically crushed rock, is also the scientific basis behind projects which aim to remove anthropogenic from the atmosphere via artificially enhanced chemical weathering. Five Myr Climate Change

Raymo is known for her research using sedimentological and geochemical data from deep sea cores to better understand how the ocean's

thermohaline circulation Thermohaline circulation (THC) is a part of the large-scale Ocean current, ocean circulation driven by global density gradients formed by surface heat and freshwater fluxes. The name ''thermohaline'' is derived from ''wikt:thermo-, thermo-'', r ...

changed in the past, as well as how Earth's

Milankovitch cycles Milankovitch cycles describe the collective effects of changes in the Earth's movements on its climate over thousands of years. The term was coined and named after the Serbian geophysicist and astronomer Milutin Milanković. In the 1920s, he pr ...

have influenced the pacing of ice ages over the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

and

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58 Raymo's ''Anti-phase Hypothesis'' explains the 41,000 year pacing of Earth's climate cycles from 3 to 1 million years ago as due to the out-of-phase response of the northern and southern polar ice sheets to orbital precession at this time. Raymo has also made contributions to the

stratigraphy Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithost ...

and dating of the past by means of oxygen isotope analysis of

foraminifera Foraminifera ( ; Latin for "hole bearers"; informally called "forams") are unicellular organism, single-celled organisms, members of a phylum or class (biology), class of Rhizarian protists characterized by streaming granular Ectoplasm (cell bio ...

from deep ocean sediments. This included publishing the first continuous oxygen isotope stratigraphy and time scale of the northern hemisphere Ice Ages from DSDP Site 607. In 2005, with her post-doc Lorraine Lisiecki who led the project, Raymo published the widely adopted 5-million-year LR04 benthic isotope stack which defines

Marine isotope stages Marine isotope stages (MIS), marine oxygen-isotope stages, or oxygen isotope stages (OIS), are alternating warm and cool periods in the Earth's paleoclimate, deduced from oxygen isotope data derived from deep sea core samples. Working backward ...

and continues to be the chronological benchmark against which most studies of the last 5.5 Ma are measured. In 1996, Raymo published the first paleo- estimate for the Middle Pliocene Warm Period using carbon isotopes of marine organic matter. This was a time three million years ago when global temperatures were about 2-3 °C above preindustrial levels and their estimate, between 350 and 400 ppm, later became the inspiration for the name of the activist organization 350.org which advocates for a return to 350 ppm as a safe level of carbon dioxide in the atmosphere.

Sea level research

In an analysis of collapsed polar ice sheets during the stage 11 Marine Isotope Interglacial (MIS), Raymo and Jerry X. Mitrovica computed global sea-level variations over the past 500 kyr. In their analysis, they assumed that the melting of the East Antarctic Ice Sheet (EAIS) and the Greenland Ice Sheet (GIS) happened towards the end of this interglacial period. One of the methods they used in their examination involved using a “gravitationally self-consistent theory”. Additionally, the researchers performed a Monte Carlo parameter where they observed mantle viscosity, lithospheric thickness, and the duration of the break during MIS 11 (Raymo & Mitrovica, 2012). Raymo and Mitrovica have said that employing this method “yields a preferred bound on the peak

eustatic sea level The eustatic sea level (from Greek εὖ ''eû'', "good" and στάσις ''stásis'', "standing") is the distance from the center of the Earth to the sea surface. An increase of the eustatic sea level can be generated by decreasing glaciation, inc ...

(ESL) during MIS 11”. Understanding the durability of existing ice sheets amidst climate change remains a significant concern for societal safety. During the PLIOMAX project, Raymo formulated a method for correcting shorelines during the Pliocene period, for post-depositional isostatic changes (PLIOMAX, n.d.). One of the main hurdles the PLIOMAX project faced was the ability to adjust and verify the model performance under and climate conditions (PLIOMAX, n.d.). The accuracy of accessible paleoclimate data hindered these factors as mentioned earlier (PLIOMAX, n.d.). In another analysis, Raymo and her colleagues examined how polar ice sheets evolved during previous warm periods, specifically during the Pliocene period. For their research, the scientists examined existing evidence of previous sea levels and ice sheet constructions (Dutton et al., 2015). Despite many geological advances in the understanding of global mean sea level during previous warm periods, potential research hindrances still exist for future paleoclimate researchers. For instance, the peak heat temperatures during previous warm periods may have varied on the span of the respective interglacial period, which suggests that warm periods that lasted thousands of years may not represent “equilibrium conditions for the climate-cryosphere system” (Dutton et al., 2015). Additionally, it is currently not possible for researchers and scientists to make exact estimates of peak global mean sea level during the Pliocene period. In a research paper by Raymo and her colleagues, they explained that the majority of existing sea level projections focus on shorter timelines of less than 2000 years, however, longer timeline projections are critical for predicting potential future sea-level heights to effectively develop long-term sea level defense infrastructure (Kemp et al., 2015). The demand to present location-specific details regarding future sea level projections in the midst of climate change is a critical aspect of climatology research because of the growing concentration of socioeconomic and residential activity along global coastlines.

Awards and honors

In 2002, she was included by the illustrated magazine ''Discover'' in a list of the 50 most important women in science and in her nomination for the Wollaston Medal, Professor James Scourse described her as "one of the foremost and influential figures in the last 30 years...She's been an important role model to women scientists—you can get to the top. "^. Following this, in 2003 she became a fellow of John Simons. Raymo has won various prizes for her scientific work, including becoming in 2014 the first woman to be awarded the prestigious

- the highest award of the

Geological Society of London The Geological Society of London, known commonly as the Geological Society, is a learned society based in the United Kingdom. It is the oldest national geological society in the world and the largest in Europe, with more than 12,000 Fellows. Fe ...

. In 2014, she received the Milutin Milankovic Medal at the

European Geosciences Union The European Geosciences Union (EGU) is a non-profit international union in the fields of Earth, planetary, and space sciences whose vision is to "realise a sustainable and just future for humanity and for the planet". The organisation has headq ...

’s annual meeting for her use of geochemistry, geology and geophysics to solve

paleoclimatology Paleoclimatology ( British spelling, palaeoclimatology) is the scientific study of climates predating the invention of meteorological instruments, when no direct measurement data were available. As instrumental records only span a tiny part of ...

’s big problems. In 2016 she was elected a member of the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, NGO, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the ...

. As well, in 2017 Raymo became a fellow of the Explores Club and became and received the Honoris Causa from the

University of Lancaster Lancaster University (officially The University of Lancaster) is a collegiate public university, public research university in Lancaster, Lancashire, England. The university was established in 1964 by royal charter, as one of several new univer ...

, Great Britain. In 2019 she was awarded the Maurice Ewing Medal by the American Geophysical Union. Raymo is a fellow of the

American Geophysical Union The American Geophysical Union (AGU) is a 501(c)(3) nonprofit organization of Earth, Atmospheric science, atmospheric, Oceanography, ocean, Hydrology, hydrologic, Astronomy, space, and Planetary science, planetary scientists and enthusiasts that ...

and the

American Association for the Advancement of Science The American Association for the Advancement of Science (AAAS) is a United States–based international nonprofit with the stated mission of promoting cooperation among scientists, defending scientific freedom, encouraging scientific responsib ...

. In 2022 she was elected as a Member of the

Royal Swedish Academy of Sciences The Royal Swedish Academy of Sciences () is one of the Swedish Royal Academies, royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special responsibility for promoting nat ...

, Class for Geosciences.

References

External links

*
Personal Website
for Maureen Raymo
Current projects
of Maureen Raymo {{DEFAULTSORT:Raymo, Maureen Marine geologists Paleoclimatologists Date of birth missing (living people) Living people 1959 births American women geologists Columbia University faculty Lamont–Doherty Earth Observatory people Fellows of the American Geophysical Union Fellows of the American Association for the Advancement of Science Members of the United States National Academy of Sciences Wollaston Medal winners 21st-century American geologists 21st-century American women scientists Brown University alumni Columbia University alumni American women academics