The first meeting of the AGU took place on April 23, 1920. In attendance were 25 members. Up to 1930, the number of members was restricted and members were elected. In 1932 the first annual dues of US$2 were imposed. The membership grew to 4600 in 1950; 13,000 in 1980; and 26,000 in 1990. As of 2018, it had 62,000 members from 137 countries.
AGU co-published (along with the AMS and the AAG) its first electronic journal, Earth Interactions, in 1997. It started its own electronic journal, Geochemistry, Geophysics, Geosystems, in December 1999. It made a full transition to electronic publishing in 2001. For all its journals, the electronic version became the publication of record. This was accompanied by a new identification scheme for articles that entirely did away with sequential page numbers. Instead, each article had a digital object identifier (DOI). As an example, 10.1029/2001GL014304 consists of the publisher identifier (10.1029), the year (2001), the journal code (GL), and an article number (014304). This new system was met with complaints from libraries and scientists. The article numbers provided no clue for libraries to find an article in printed versions, and even scientific databases were not set up to handle DOIs. AGU officials claimed that the problems were a temporary cost of being a frontrunner, but did retroactively assign each article a four-digit article number.
In 2012 the journals and books, including over one and a half million pages of legacy content, were transferred to the Wiley Online Library. John Wiley & Sons were recognized for this work with the IT Project Team of the Year Award at the UK IT Industry Awards for 2013.
Five AGU journals are open access only: AGU Advances, Earth’s Future, Earth and Space Science, GeoHealth, JAMES, and Space Weather. The remainder are delayed open access journals, having free access after a two-year rolling period.
The AGU hosts a number of blogs, collectively known as the AGU Blogosphere, informally publishing frequent updates on the Earth and space sciences.
AGU publications are copyrighted, but in the United States many exceptions to the exclusive rights of copyright are allowed under the fair use provision, part of the Copyright Act of 1976. Making copies of publications are allowed for such uses as teaching and research as long as a set of four criteria are met. However, when Texaco's corporate library made systematic copies of journal articles for its collection, AGU and five other publishers took Texaco to court. The judges found for AGU. Texaco was fined and agreed to retroactively purchase a license from the Copyright Clearance Center.
While more than 40 presidents have provided scientific leadership for the AGU since 1919, operational leadership has been provided by just four individuals. The first was John Adam Fleming, who was elected Secretary in 1925 and changed the name of his position to General Secretary. He served as a volunteer while working at the Department of Terrestrial Magnetism at the Carnegie Institution. By 1943, with the membership nearing 2,000, AGU recognized the need for a full-time professional administrator. The post was renamed Executive Secretary and Waldo E. Smith was hired. He served until 1970 and then Athelstan Spilhaus, Jr. was hired as executive director. Christine McEntee replaced him in 2010. Medals have been named after Fleming and Smith.
The AGU offers several awards, medals and fellowships.
The Africa Award for Research Excellence in Earth or Ocean Sciences (established 2015), awarded annually to an early career scientist from the continent of Africa, "for completing significant work that shows the focus and promise of making outstanding contributions to research in Earth or ocean sciences."
The Africa Award for Research Excellence in Space Science (established 2015), awarded annually to an early career scientist from the continent of Africa, "for completing significant work that shows the focus and promise of making outstanding contributions to research in space science."
The Ambassador Award (established 2013), awarded annually to up to five honorees in recognition "for outstanding contributions to one or more of the following area(s): societal impact, service to the Earth and space community, scientific leadership, and promotion of talent/career pool." This is the only AGU award whose recipients are conferred AGU Fellows.
The Charles S. Falkenberg Award (established in 2002), named after Falkenberg, who applied data visualization and information technology to earth sciences, to an individual "scientist under 45 years of age who has contributed to the quality of life, economic opportunities, and stewardship of the planet through the use of Earth science information and to the public awareness of the importance of understanding our planet."
The Climate Communication Award (established 2011 and funded by Nature's Own, a purveyor of fossils and minerals) "for the communication of climate science."
The David Perlman Award (established 2000), named after the science editor of the San Francisco Chronicle, "for excellence in researching and reporting a news story that meets one or more of the following criteria: brings new information or concepts about AGU sciences to the public's attention, identifies and corrects misconceptions about AGU sciences, or makes AGU sciences accessible and interesting to general audiences, without sacrificing accuracy."
The Edward A. Flinn III Award (established 1990), named after a leader of the NASA Geodynamics Program who directed efforts to detect motion of the Earth's crust using laser ranging, to an "individual who personifies the Union's motto 'unselfish cooperation in research' through their facilitating, coordinating, and implementing activities."
The Excellence in Geophysical Education Award (established in 1995) "to acknowledge a sustained commitment to excellence in geophysical education by a team, individual, or group. To educators who have had a major impact on geophysical education at any level (kindergarten through postgraduate), who have been outstanding teachers and trainers for a number of years, or who have made a long-lasting, positive impact on geophysical education through professional service."
The International Award (established 2007) "to recognize an individual scientist or a small team for making an outstanding contribution to furthering the Earth and space sciences and using science for the benefit of society in less favored nations."
The Outstanding Student Presentation Award (OSPA), "are awarded to promote, recognize and reward undergraduate, Master’s and PhD students for quality research in the geophysical sciences. Each year, Sections recruit judges to assess and score student oral and poster presentations at meetings. Typically the top 2–5% of presenters in each Section are awarded an OSPA."
The Robert C. Cowen Award (established 1991), named after a long-time editor of The Christian Science Monitor, "for a journalist or a group that has made significant, lasting, and consistent contributions to accurate reporting or writing on the geophysical sciences for the general public."
The Science for Solutions Award (established 2012) "for significant contributions in the application and use of Earth and space sciences to solve societal problems."
The Walter Sullivan Award for Excellence in Science Journalism (established 2000), named after the renowned science writer of The New York Times, awarded annually for science feature writing.
The William Kaula Award (established 2003), named after geophysicist and physical geodesist William M. Kaula, for "extraordinary dedication to, and exceptional efforts on behalf of, the Union's publications program." (Awarded on even-numbered years.)
AGU nominates members for fellowship in the society. According to the AGU website "To be elected a Fellow of AGU is a special tribute for those who have made exceptional scientific contributions to Earth and space sciences as valued by their peers and vetted by section and focus group committees." A maximum of 0.1% of the membership can be elected each year.
The Charles A. Whitten Medal (established 1984), named after Charles A. Whitten, a former AGU General Secretary and geodesist, "for outstanding achievement in research on the form and dynamics of the Earth and planets."
The Devendra Lal Memorial Medal (established 2016) was named after Devendra Lal. Lal had a founding role in developing the field in which cosmic rays produced isotopes on Earth and are used as tracers to investigate a wide range of Earth Science problems. The Medal is awarded "for outstanding Earth and/or space sciences research by a scientist belonging to and working in a developing country."
The James B. Macelwane Medal (established 1961), named after James B. Macelwane, a former AGU president who was deeply interested in teaching young scientists, "to be awarded annually for significant contributions by outstanding young scientists." Recipients must be no more than 10 years past their highest degree.
The Joanne Simpson Medal (established in 2017), named after Joanne Simpson, the first woman in the United States to receive a PhD in meteorology, "for significant contributions to the earth and space sciences by an outstanding mid-career scientist."
The John Adam Fleming Medal (established 1960), named after John Adam Fleming, a major contributor to magnetic standards and measurements, "for original research and technical leadership in geomagnetism, atmospheric electricity, aeronomy, space physics, and related sciences."
The Maurice Ewing Medal (established 1974 and co-sponsored by the United States Navy), named after Maurice Ewing, a major contributor to oceanography, "for significant original contributions to the scientific understanding of the processes in the ocean; for the advancement of oceanographic engineering, technology, and instrumentation; and for outstanding service to the marine sciences."
The Harry H. Hess Medal (established 1984), named after Harry Hammond Hess, who made major contributions to the study of the oceanic lithosphere, "for outstanding achievements in research of the constitution and evolution of Earth and other planets."
The Inge Lehmann Medal (established 1995), named after Inge Lehmann, the discoverer of the Earth's inner core, "for outstanding contributions to the understanding of the structure, composition, and dynamics of the Earth's mantle and core."
The Roger Revelle Medal (established 1991), named after Roger Revelle, an oceanographer notable for his contribution to the understanding of global change, "for outstanding contributions in atmospheric sciences, atmosphere-ocean coupling, atmosphere-land coupling, biogeochemical cycles, climate, or related aspects of the Earth system."
The Waldo E. Smith Medal (established 1982), named after Waldo E. Smith, the first Executive Secretary of AGU, to recognize "individuals who have played unique leadership roles in such diverse areas as scientific associations, education, legislation, research, public understanding of science, management, and philanthropy, and whose accomplishments have greatly strengthened and helped advance the geophysical sciences."
The Walter H. Bucher Medal (established 1966), named after Walter Hermann Bucher, a former AGU president and major contributor to crustal problems, "for original contributions to the basic knowledge of the crust and lithosphere."
The William Bowie Medal is the highest AGU honor and is awarded at most annually for "outstanding contributions to fundamental geophysics and for unselfish cooperation in research"; its namesake was the first recipient in 1939.
Plenary session at an American Geophysical Union policy conference in Washington, DC in May 2012.
AGU holds an annual meeting every December (known as the Fall Meeting). Until 2017, the meeting was held yearly in San Francisco. Because of renovations at the San Francisco venue, the 2017 meeting took place in New Orleans and the 2018 meeting in Washington, DC. It returned to San Francisco in 2019 and its location will rotate among San Francisco, New Orleans, Chicago, and Washington, DC. Previously, a second meeting was held every Spring (April through May) in locations around the world. The latter grew out of AGU's annual Spring meeting, which had been held for many years in Baltimore, until declining interest caused AGU to move the meeting to different locations, starting with Boston in 1998. With the 2003 meeting in Nice, France, it became known as the Joint Assembly because AGU co-sponsors it with other societies such as the Geochemical Society, the Mineralogical Society of America (MSA), the Canadian Geophysical Union (CGU), and the European Geosciences Union (EGU). The Fall Meeting had more than 25,000 attendees in 2018.
In addition to the Fall meeting that covers all areas of the geophysical sciences, AGU sponsors many specialized meetings that are intended to serve the needs of particular scientific disciplines or geographical areas, including the Ocean Sciences Meeting, which is held in even numbered years. Small, highly focused meetings are offered through the Chapman Conferences.
The large numbers and international participation in the Fall Meeting results in a large contribution to greenhouse gases. The 9500 participants in the 2002 meeting traveled an average of 8,000 kilometres (5,000 mi) to attend, producing 1.3 metric tons of carbon dioxide, or one-sixteenth of the average yearly emissions for Americans. The AGU has made some adjustments such as asking shuttle bus drivers to turn off their engines when they are not moving, but 95% of the emissions come from jet fuel. In an unpublished study, David Scott and Lawrence Plug of Dalhousie University estimated that the AGU could reduce emissions by 7.7% if it moved the Fall Meeting to Denver, Colorado.
In 2017, the first joint JpGU-AGU meeting was held in Chiba, Japan. The meeting was a joint effort between AGU and the Japan Geoscience Union.
Atmospheric concentrations of carbon dioxide and other greenhouse gases have substantially increased as a consequence of fossil fuel combustion and other human activities. These elevated concentrations of greenhouse gases are predicted to persist in the atmosphere for times ranging to thousands of years. Increasing concentrations of carbon dioxide and other greenhouse gases affect the Earth-atmosphere energy balance, enhancing the natural greenhouse effect and thereby exerting a warming influence at the Earth's surface.
The statement continued,
Present understanding of the Earth climate system provides a compelling basis for legitimate public concern over future global and regional-scale changes resulting from increased concentrations of greenhouse gases.
After a discussion of scientific uncertainties the statement concluded
AGU believes that the present level of scientific uncertainty does not justify inaction in the mitigation of human induced climate change and/or the adaptation to it.
The adopted position statement was backed up by a detailed supporting document. The AGU position statement has undergone several revisions, most recently revised and reaffirmed in 2012.
In 2014, AGU developed the Sharing Science program to provide scientists with the skills and tools that they need to communicate science with any audience. The program offers resources, workshops, hands-on support, and opportunities to help scientists more effectively communicate with broader audiences about Earth and space science. Audiences range from journalists, educators and students, policy makers, and the broader public.
Members of the AGU who work in politically-controversial fields have come under legal attack. For example, Michael Mann, a Fellow of the AGU and lead author of the original "hockey stick graph" study, faced a legal demand to turn over his private emails from Kenneth Cuccinelli II, at the time the attorney general of the state of Virginia, a conservative Republican who argues that there is no persuasive evidence that human activity is warming the planet. The court rejected Cuccinelli's demand. However, such legal challenges continue, so in 2012 AGU entered in a partnership with the Climate Science Legal Defense Fund to offer legal counseling at the Fall Meeting.
In 2011, AGU created a Task Force on Scientific Ethics, "to review and update existing policies and procedures for dealing with scientific misconduct." This effort received a setback when its chairman, Peter Gleick, announced that he had lied to obtain internal documents from the Heartland Institute and then leaked them to the public. Gleick, a climate scientist and recipient of the MacArthur Fellowship, said he was motivated by frustration with the efforts of groups such as the Heartland Institute to attack climate science and scientists, but admitted that it was a serious lapse of judgement. He resigned from the task force on February 16, 2012, and was replaced by Linda Gundersen, director of the Office of Science Quality and Integrity at the United States Geological Survey (USGS).
In July 2019, the AGU was awarded a three-year grant from the Alfred P. Sloan Foundation to launch the AGU Ethics and Equity Initiative, a collaboration among the AGU and the National Center for Professional and Research Ethics at the University of Illinois at Urbana–Champaign. The initiative will tackle issues around sexual harassment and gender-based discrimination by developing new educational resources and tracking tools to measure impact.
In 2014, the AGU accepted 5469 gifts, grants and pledges from individuals and corporations. Of these, the 1919 Society (gifts of over $100,000) included ExxonMobil, Integrated Ocean Drilling Program Management International, and Nature's Own.: 19 AGU also was found to have many annual events sponsored by corporations, including an annual Student Breakfast (supported by ExxonMobil) and Amazon Web Services supported research grants and that offer access to its cloud computing resources.: 26–27 In 2015, the AGU Board approved a new Organizational Support Policy. The policy covers subjects such as advertorials and member surveys. It requires that partnerships contribute to AGU's mission, vision and goals and that the AGU "apply vetting to ascertain that partners are not engaged in false misinterpretations of science."
The sponsorship of AGU by ExxonMobil became a source of concern for many members after evidence surfaced that ExxonMobil had known about climate change for decades but had actively worked to undermine climate science. On February 22, 2016, a letter signed by 100 scientists was delivered to the AGU, requesting that they cut all ties with ExxonMobil and other companies that foster climate misinformation. The AGU Board of Directors met on 22 April 2016 and voted to continue accepting sponsorship from ExxonMobil, arguing that there was not unequivocal evidence that ExxonMobil continues to participate in climate misinformation. Instead of making a short-term political statement, the Board wished to engage with the energy industry over the long term. In response, Senator Sheldon Whitehouse and Representative Ted Lieu sent a critical letter saying that ExxonMobil continues to fund climate denial and is misleading the AGU. The Union of Concerned Scientists also sent a letter urging them to reconsider. However, in a meeting on 23 September 2016, the Board upheld its previous decision.