EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

The story of Skeptical Science: How citizen science helped to turn a website into a go-to resource for climate science

Bärbel Winkler1 and John Cook1,2
Bärbel Winkler and John Cook
  • 1Skeptical Science, Fellbach, Germany (
  • 2Center for Climate Change Communication, George Mason University, Fairfax, Virginia, United States of America (

Skeptical Science (SkS) is a website with international reach founded by John Cook in 2007. The main purpose of SkS is to debunk misconceptions and misinformation about human-caused climate change and features a database that currently has more than 200 rebuttals based on peer-reviewed literature. Over the years, SkS has evolved from a one-person operation to a team project with science-minded volunteers from around the globe. The Skeptical Science team also actively contribute to published research, with a highlight being the often cited 97% consensus paper published in 2013 (Cook et al. 2013) for which team members content-analysed about 12,000 abstracts in a study whose publication fee was crowd-funded by readers of the website.

The SkS author community formed in 2010 in response to the proposal to expand existing rebuttals to three levels: basic, intermediate, and advanced. Since then, team members regularly collaborate to write and review rebuttal and blog articles for the website. Volunteer translators from many countries have translated selected content into more than 20 languages including booklets such as The Debunking Handbook, The Uncertainty Handbook or The Consensus Handbook. In addition to the already mentioned consensus study, team members have helped with other research projects initiated by John Cook such as the efforts to train a computer to detect and classify climate change misinformation. Another significant project is the Massive Open Online Course (or MOOC) “Denial101x: Making Sense of Climate Science Denial” in collaboration with the University of Queensland, for which the SkS team produced numerous video lectures and for which forum moderators were recruited. Outreach activities such as the “97 Hours of Consensus” were crowdsourced with team members collecting and organising content and providing technical support.

Challenges: Due to the volunteer nature of people’s involvement, there are some challenges involved as not everybody is available to help with tasks all the time. People help as much – or as little – as their time allows and there’s always some turn-over with new people joining while others leave.

Skeptical Science (SkS): (accessed November 29, 2019)

Cook, J., Nuccitelli, D., Green, S. A., Richardson, M., Winkler, B., Painting, R., Way, R., Jacobs, P., & Skuce, A. (2013). . Environmental Research Letters, 8(2), 024024+.

Cook, J., Schuennemann, K., Nuccitelli, D., Jacobs, P., Cowtan, K., Green, S., Way, R., Richardson, M., Cawley, G., Mandia, S., Skuce, A., & Bedford, D. (April 2015). Denial101x: Making Sense of Climate Science Denial. edX.

Cook, J., & Lewandowsky, S. (2011). . St. Lucia, Australia: University of Queensland. ISBN 978-0-646-56812-6.

How to cite: Winkler, B. and Cook, J.: The story of Skeptical Science: How citizen science helped to turn a website into a go-to resource for climate science, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-562,, 2019

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