Slow reception and under-citedness in climate change research: A case study of Charles David Keeling, discoverer of the risk of global warming
Scientometrics
Werner Marx 0 1 2
Lutz Bornmann 0 1 2
Robin Haunschild 0 1 2
Bernie French 0 1 2
Werner Marx 0 1 2
0 Division for Science and Innovation Studies, Administrative Headquarters of the Max Planck Society , Hofgartenstr. 8, 80539 Munich , Germany
1 CAS Innovation LAB, CAS (Chemical Abstracts Service), a division of the American Chemical Society , 2540 Olentangy River Road, Columbus, OH 43202-1505 , USA
2 Max Planck Institute for Solid State Research , Heisenbergstraße 1, 70569 Stuttgart , Germany
The Keeling curve has become a chemical landmark, whereas the papers by Charles David Keeling about the underlying carbon dioxide measurements are not cited as often as can be expected against the backdrop of his final approval. In this bibliometric study, we analyze Keeling's papers as a case study for under-citedness of climate change publications. Three possible reasons for the under-citedness of Keeling's papers are discussed: (1) The discourse on global cooling at the starting time of Keeling's measurement program, (2) the underestimation of what is often seen as ''routine science'', and (3) the amount of implicit/informal citations at the expense of explicit/formal (reference-based) citations. Those reasons may have contributed more or less to the slow reception and the under-citedness of Keeling's seminal works.
Bibliometrics; Climate change; Keeling curve
-
RPYS
Introduction
Charles David Keeling (1928–2005) started his scientific career as chemist at the
Department of Geochemistry at Caltech, studying groundwater in the pristine Big Sur
wilderness. Around 1956, Roger Revelle, director of the Scipps Institution of
Oceanography near San Diego (California), invited Keeling to perform atmospheric carbon dioxide
(CO2) measurements for the International Geophysical Year (IGY). Keeling had proposed
that he could deploy a new analytical tool called infrared (IR) gas analyzer to perform
continuous measurements of CO2 in air samples. The first analyzer was sent to Antarctica
and a second one was prepared for installation aboard a research ship. In March 1958, an
analyzer was installed on the top of Mauna Loa (Hawaii) with the intention to measure
pristine air over the Pacific Ocean. Keeling soon detected strong seasonal variations in CO2
levels, oscillating from peak levels in the northern hemisphere spring (before the beginning
of the growing season) and minimum levels in autumn. Since 1960, Keeling’s data
revealed that CO2 levels were rising steadily in what became known as the ‘‘Keeling
curve’’. The data collection of Keeling’s measurement program is the longest continuous
record of atmospheric CO2 in the world and shows that its concentration has grown from
315 ppm (parts per million) in 1958 to 408 ppm in May 2015 and is correlated to usage of
fossil fuel as energy source.
Keeling is seen as the discoverer of the risk of global warming
(Weart 1997)
. Keeling’s
contribution to climate change research has been acknowledged and appreciated in
numerous publications and press releases. A good example is a profound article presented
under the rubric ‘‘National Historic Chemical Landmarks’’ of the American Chemical
Society (ACS) entitled: ‘‘The Keeling curve: Carbon dioxide measurements at Mauna
Loa’’. The ACS states that ‘‘Keeling’s legacy includes a measurement program that
endures to this day, providing an authoritative record of atmospheric CO2 concentrations
that is a cornerstone of modern climate science’’. We further get to know that ‘‘Keeling
received numerous accolades during his career. He was elected a fellow of the American
Academy of Arts and Sciences in 1986 and a member of the National Academy of Sciences
in 1994. In 2002, Keeling was awarded the National Medal of Science, the nation’s highest
award for lifetime achievements in science. In 2005, he received the Tyler Prize for
Environmental Achievement for his data collection and interpretation’’
(ACS 2015)
.
Further examples, which demonstrate the acknowledgement of Keeling’s lifework, are
shown in the Appendix.
Keeling was a specific type of researcher, which can be seen as uncommon (e.g., he
absolutely preferred an outdoor job). He was stimulated by Callendar (reading his papers)
and by Plass (personal discussions). ‘‘He wants to measure CO2 in his belly … And he
wants to measure it with the greatest precision and the greatest accuracy he possibly can’’
(Weart 2008, p. 34, cites Roger Revelle)
. This called for new and expensive instruments.
Keeling ordered a gas analyzer from the only company, in which he ‘‘was able to get past a
salesman and talk directly with an engineer’’
(Harris 2010, p. 7867)
. Keeling arranged
many provisions to obtain representative data for pristine air.
One of his most important characteristics was his persistency and subject-specific
determination: (1) He refused a job offer (for an indoor job in a dark cellar lab) from the
Division of Meteorological Research in the Weather Bureau in Washingto (...truncated)