Three University of Arizona professors have been selected to contribute to a significant report by the Intergovernmental Panel on Climate Change.

Diana Liverman, Regents' Professor in the School of Geography and Development; Carolyn Enquist, assistant professor in the School of Natural Resources and the Environment and a U.S. Geological Survey scientist; and Jessica Tierney, associate professor of geosciences, have been tapped as review editor and lead authors for three separate chapters in the report.

"The IPCC assessments are not only instrumental in shaping policy for governments around the world, but they are also used to inform and provide guidance for researchers working in climate and related fields," Liverman says. "It's a testament to the UA's strong research focus that we have a long history of involvement."

Founded in 1988 by the World Meteorological Organization and United Nations Environment Programme, the IPCC provides regular assessments of the latest climate science, impacts and risks due to variability and vulnerability, and options for adaptation and mitigation.

The work of producing the report is divided into three groups. Working Group I assesses the latest discoveries in the physical sciences of climate systems and change. Working Group II addresses impacts, adaptation, and vulnerability of people and natural systems, and options for adaptation. Working Group III is focused on options for mitigating greenhouse gas emissions and reviews measures and technologies that can reduce their concentration in the atmosphere.

Sixth Report Scheduled for 2021

Being selected as an author out of thousands of nominations from across the globe is an honor, but the job is a big one. Each lead author is responsible for reviewing all the peer-reviewed scientific literature published in their assigned chapter area since the last report, in this case the Fifth Assessment Report, or AR5, of 2014, then synthesizing the research and writing their section of the chapter. The sixth report, AR6, is scheduled for completion in 2021.

Liverman, who has served as a lead author for previous assessments, has been selected as a review editor for Chapter 18 of the Working Group II report, on climate resilient development paths. Also for Working Group II, Enquist, an ecologist and conservation biologist by training, is a lead author for Chapter 14, which focuses on North America. Tierney, a molecular paleoclimatologist, is a lead author addressing the water cycle in Chapter 8 for Working Group I.

The daunting amount of work is offset by tremendous opportunity.  

"I think this will be an interesting experience because I'll get to interact with an international community which I've never really done before," Tierney says. "And I like the format of AR6, which is actually doing something interesting with paleoclimate." 

AR6, unlike the previous reports that had a single chapter on paleoclimate, will include a section in many chapters on paleoclimate, or past climates. "It's expected that you look at past, present and future for each topic area which makes paleoclimate a much bigger part of the conversation, so I'm excited about that," Tierney says.

For the first time, the upcoming report also will include Mexico in the chapter on North America, along with the U.S. and Canada. For Enquist and her chapter co-authors, that means the volume of literature to review just got a lot bigger. Enquist is the only IPCC author from the U.S. Geological Survey.

"Our coordinating lead author is from Mexico City and there's an ecologist from the University of Idaho studying bark beetle outbreaks," Enquist says. "We'll be looking at vulnerability and adaptation across the whole spectrum."

In addition to being UA scientists and leaders in their fields, there is something else these three researchers have in common: All are women, and that is a reflection of changes in the IPCC world.

Overall, the percentage of AR6 authors who are women is only about 33 percent. The IPCC relies on governments for nominations, and in the U.S. all nominated names are forwarded for consideration. However, according to Liverman, many countries work within existing scientific hierarchies.

"The heads of institutes are nominated even though they may not be the best person for a particular chapter," she says. "There are several brilliant women addressing topics covered by Working Group I who were not nominated by their governments because of these hierarchies."

Female Representation and Voice

Even though more women are sitting at the table, Liverman says, they may not necessarily be heard.

"Representation matters, but voice matters, too," she says. "A seat at the table isn't enough if others don't listen to what you have to say."

Along with Miriam Gay-Antaki, who recently received her Ph.D. from the UA School of Geography and Development, Liverman authored "Climate for Women in Climate Science: Women Scientists and the Intergovernmental Panel on Climate Change" (PNAS, Vol. 115, No. 14), in which they interviewed women who have been IPCC authors since the first report in 1990 (which had only a few women authors). They find that gender, race and ethnicity, nationality, family responsibilities and English language ability are barriers to fully contributing to IPCC reports — and to succeeding in climate science more generally.

Given the global importance and implications of climate change, Liverman, Tierney and Enquist agree that it is critical for the voices of women scientists from many varied disciplines and from all corners of the world to be included in the IPCC.

Women, especially in the developing world, are some of those most affected by the impact of climate change.

"Vulnerability to climate change and the ability to adapt is affected by all these characteristics," Enquist says. "That's why we need to hear from scientists who represent and are attuned to those voices."

Being a scientist who also is a woman means not only excelling in one's chosen field, but also learning how to navigate institutional bias long embedded in organizations and governments — as well as unconscious bias from colleagues.

"It's gotten so much better since I started my career," Liverman says. "But younger scientists like Jessica and Carolyn still face challenges."