Credit: THALIA THEATER VERLAG, PROVIDED BY MUSIKANTIQUARIAT RAAB, MUNICH

Impact factors are the opiate of the scientific people. They can be deceptive. It is easy to lose large amounts of time obsessing over them. But being on a high is quite intoxicating. To mark the occasion of the release of the first journal impact factor for Nature Geoscience, we indulge in some statistical contemplations.

With a value of 8.1 we are pleased to announce that we rank at the top of the combination of subject categories that overlap significantly with our scope (in the classification of Thomson Reuters). The list comprises the fields of environmental science, geochemistry and geophysics, geology, limnology, meteorology and atmospheric sciences, mineralogy, multidisciplinary geosciences, oceanography, physical geography, soil science and water resources, and contains 607 journals.

Nature Geoscience papers published so far have been cited in as many as 408 other journals, most often in Geophysical Research Letters, Earth and Planetary Science Letters, Atmospheric Chemistry and Physics, Nature, Quaternary Science Reviews and Science. Those six journals span the range of the geosciences. Nevertheless, they generated only about one fifth of the citations, suggesting that our papers are read by scientists from a broad variety of disciplines.

Our journal impact factor may look low compared with other monthly research journals published by Nature Publishing Group. But in different fields of science, average citations per paper can vary by factors of five or six — and the geosciences are at the low end. Nature Geoscience will never be able to compete with multidisciplinary journals such as Nature or Science, whose impact factors are largely determined by the papers they publish in highly cited research areas outside our scope, such as genetics and stem-cell research.

Furthermore, our 2009 impact factor stands on only one leg, as it were. Essentially defined as the number of citations in 2009 to papers published in 2007 and 2008, divided by the number of citable papers in the earlier two years, the calculation for Nature Geoscience is skewed by the fact that we only launched in January 2008. We did not publish any papers in 2007, so the number is based only on the year 2008. But geoscience papers tend to receive more citations in the second year after publication than the first. For example, the papers published in 2007 in Geology, Geophysical Research Letters and Earth and Planetary Science Letters collectively received almost 1.6 times as many citations in 2009 than in 2008. As a consequence, an impact factor based only on the previous year is bound to be lower than one based on the preceding two years. We will have to wait until 2012 before we are assigned an impact factor that allows a direct comparison with more established journals.

All in all, we are pleased with our debut in Thomson Reuters's journal citation report. And we are fully aware that the success of any journal is a community effort. We would therefore like to take this opportunity to thank all of our authors for submitting their best papers to us, all of our referees for their invaluable help in developing those papers, and all of our readers for their interest in Nature Geoscience.

We discussed the use of impact factors as a research metric in an earlier Editorial (Nature Geosci. 1, 563; 2008), and concluded that they are just one way of judging the success of a journal. As far as this measure goes, we seem to have won the trust and support of the community of Earth and planetary scientists. We at Nature Geoscience are extremely grateful for that.