Multiple Brown community members contributed to the Fifth National Climate Assessment, a quadrennial report released Nov. 14 that synthesizes interdisciplinary research on topics including energy and air quality, community and national responses to climate change and the wide-ranging impacts of global warming.
NCA5 presents a thorough examination of the social science aspect of climate change, a topic traditionally given less attention compared to the physical and environmental aspects of climate science.
Written by more than 500 co-authors and 250 contributors, the report is one of the most comprehensive in the U.S. and seeks to lay out the “scientific foundation to support informed decision-making across the United States,” according to its website.
“The National Climate Assessment is a really important piece of science communication, big picture,” said Kathryn McConnell, a postdoctoral research associate in Brown’s Population Studies and Training Center and a review editor for the Northwest chapter of NCA5.
“The crudest way of describing it is scientists sifting through all the most recent science on their different areas of climate change research, and figuring out what's new, what’s happened in the last five years that informs how we think about climate change and greenhouse gas reductions here in the United States,” she said.
Professor of Population Studies and Environment and Society Elizabeth Fussell contributed as a co-author for the Social Systems and Justice chapter, which is the first of its kind to appear in the NCA.
“More recently, we’ve been focused on, ‘What are the impacts of climate change on society?’” Fussell said. “In earlier iterations, climate scientists were speculating what those would be, but that wasn't their area of expertise. So they needed to turn to the social scientists and health scientists who have society and population health as their domain of expertise to understand how climate change related events would actually play out in terms of their societal impacts.”
The chapter employs a “human-centered” approach to addressing climate change that pays concentrated attention to “safeguarding the rights of the most vulnerable people” and equitable distribution of climate change’s burdens and benefits, Fussell added.
One of the report’s key findings is that climate change exacerbates social inequalities. One passage notes the inadequacy of “flood infrastructure, green spaces, safe housing and other resources that help protect people from climate impacts” in “low-income communities and communities of color.”
Low-income neighborhoods, for example, tend to skew hotter, which increases rates of illness and death. The report also noted the effects of rising water levels, which disproportionately affect neighborhoods with higher minority and low-income populations.
Fussell’s work in NCA5 focused on human migration as a vehicle of either climate justice or inequity.
“I found it really important to focus on what we've learned from weather-related disasters and their impact on housing and infrastructure, the built environment,” Fussell said. “That was really important to me because it helped us to identify which social systems were most important for translating the impacts of these damaging events to the human individual level.”
Fussell emphasized that human migration patterns and the recovery process from natural disasters are driven more by the social systems — such as housing markets, insurance markets and federal disaster assistance — than by disaster alone, indicating the relevance of the social science research included in NCA5.
“The report really frames climate action both as a necessity but also as an opportunity to create what the NCA5 calls a more resilient and just nation,” said McConnell. “So here, they're really interested not just in incremental changes, but also sort of transformative societal changes that could address underlying root causes of some of the climate-related inequities that we're now experiencing.”
NCA5 affirms that the US has made significant progress, with emissions falling since their peak in 2007, but that current conditions will only worsen at the current rate.
Reaching global net-zero emissions is expected to halt global warming from CO2, but only net-negative CO2 emissions will cool the planet. “Regardless of when or if further warming is avoided,” the report reads, “some long-term responses to the temperature changes that have already occurred will continue.”
But Director of the Institute at Brown for Environment and Society Kim Cobb said she feels “more hopeful than (she has) in past assessments.”
“While certainly we don’t have the kinds of policies that we would need, at any level, to really meet the science-based targets that the report supports,” Cobb said, “we certainly have done a huge amount in terms of national, state and local level policies as climate action (and) climate solutions across the country, both with respect to emissions mitigation, but also with respect to adaptation and resilience policy.”
Additional reporting by Julia Vaz.