Two UConn Researchers Among Authors of Fifth National Climate Assessment Report

Guiling Wang and Zhe Zhu explain how the gold standard of national climate reports gets put together - and why climate change isn't all doom and gloom

Dawn over a canal in spring with wind turbines in the background.

(Adobe Stock)

Since 2000, the United States Global Change Research Program has produced a series of National Climate Assessment Reports detailing research on the impacts, risks, and vulnerabilities resulting from climate change. Two UConn faculty members served as co-authors on the most recent version, the Fifth National Climate Assessment Report (NCA5) which was released this week. Professor in the Department of Civil and Environmental Engineering in the College of Engineering Guiling Wang, and Associate Professor in the Department of Natural Resources and the Environment in the College of Agriculture, Health and Natural Resources Zhe Zhu both helped to write the sixth chapter of the report which focuses on land cover and land-use change.

In brief remarks during the opening announcement, President Joseph R. Biden spoke about how these detailed, congressionally mandated reports have served as the most comprehensive source for policymakers for information on the climate crisis and for developing solutions.

The fifth report was written over a period of four years with the help of hundreds of scientists, and it shows in clear terms that the climate crisis is impacting all areas of the United States. As the most pressing existential threat to humanity, President Biden asserted that the climate crisis presents an opportunity to unite and focus on implementing adaptation and mitigation measures, saying the stakes are high, but solutions are within reach.

Professors Wang and Zhu recently met with UConn Today to discuss the assessment and their experiences and insights from working on this instrumental report.


Can you talk about some of the findings and advances since the previous assessment report?

Zhu: The land chapter in the fourth report relied heavily on the two U.S. Geological Survey (USGS) land cover and land-use products, which are the National Land Cover Database (NLCD) and Land Cover Trends blocks that are updated every two or three years, and most of that analysis ended in 2010. The key message from the fourth assessment report mostly focuses on land-cover change influences and the impacts of climate on land and ecosystems. However, for the fifth assessment, the annual land cover and land-use data from the Land Change Monitoring, Assessment, and Projection (LCMAP) products are used as the core inputs for this analysis, and we can see the annual trends and changes in land cover and land-use areas and the most recent change patterns (from 1985 to 2020). The focus of this assessment has shifted to threats to services, land-system resilience, and mitigation and adaptation, which is more proactive and focused on solutions.

Wang: A couple of findings in our chapter stand out to me. First, through the increasingly more frequent and intense extreme events — such as flood, drought, heat, and fire — climate change is threatening the goods and services provided by our land system. Second, it has become increasingly evident that land cover and land use changes — such as urbanization and agricultural intensification — have influenced regional climate and land ecosystem resilience.

More broadly, for NCA5 in general, climate actions in terms of both mitigation and adaptation, climate resilience, and environmental justice are important aspects for all chapters of the assessment, not just for the chapters so titled. Of note, NCA5 has a chapter on adaptation and a chapter on mitigation and for the first time, NCA5 includes two new chapters, one on economics that highlights the impacts and opportunities related to climate actions, and one on social systems and justice that highlights how different communities experience and respond to climate change differently and that climate change overburdens underserved communities.


The key message for the chapter you both co-authored was that the future of land use depends on how the climate changes, decisions made about how to mitigate climate change, and how agricultural and energy technologies evolve and are adapted. Can you talk about land use change and potential mitigation and adaptation strategies?

Zhu: The report includes different mitigation and adaption strategies for different areas. For example: reforestation/afforestation, bioenergy with carbon capture and storage, enhanced weathering, coastal wetland restoration, agroecological practices, biochar, riparian buffers, urban trees, coastal infrastructure planning, and prescribed fire. There are many choices and good solutions out there for us to adopt (See figure 6.8, which shows the different mitigation and adaptation strategies).

Wang: I will just provide one example: urbanization. Urbanization increases both flood and heat risk and exacerbates thermal inequality. Urban green spaces such as urban forests can be an effective natural solution to alleviate the climate risks.


What was the process like working on and creating this report?

Zhu: It is a lot of work. Many meetings, writing, figure making, and thinking. However, it is very satisfying to see the final, clean version of it, and the entire process is fun.

Wang: I am impressed with two aspects of the process; one is that NCA5 was written to inform a broad audience of decision makers around the country who are not climate scientists. Every sentence went through multiple revisions to make the writing accessible – “de-jargoning.” The second is that NCA5 went through a stringent review process, including comments from the public, reviews by every one of the 14 federal agencies involved, and reviews by the National Academies of Science, Engineering, and Medicine. The writing therefore went through many rounds of revisions, and in each round, we had to clearly explain how we responded to every comment. What made this process particularly hard was that each chapter had a stringent word limit. If responding to a comment leads to an increased word count, which happens all too often, it necessitates other revisions to keep the word count within the limit.

As Zhe already pointed out, it is a lot of work, but it is also fun. Speaking of fun, I would like to share my experience during the only in-person all-authors meeting, which took place in the first week of April in Washington D.C. On the first day of the meeting – the day when UConn was to play San Diego in the NCAA Final – I met a Husky, David Hoover ’03 (CLAS) MSc ‘08, a former student of mine who I hadn’t seen for 15 years, and who is an author for Chapter 11: Agriculture, Food Systems, and Rural Community. Through our conversation, we gained quite a few fans for our Huskies among the NCA5 authors! After a long day working on the NCA5 writing, the National Museum of Natural History held a private viewing for all authors in the evening. Afterward, I rushed back to the hotel in time to enjoy the game. It was quite a remarkable day for me!


What is the biggest takeaway or impression for you from this report?

Zhu: Climate is changing, and we are also changing the earth substantially. However, by adopting enough “good land-use choices,” we can make a big difference in making our planet better.

Wang: Think globally, act locally. There have been increasingly more success stories for climate action nationwide. UConn has many campus initiatives, too. Climate change is not all doom and gloom. With climate action comes hope, optimism, and opportunities.