The role of climate and population change in global flood exposure and vulnerability

Nature Portfolio (Springer Nature) | February 3rd, 2025

Flooding is a pervasive natural hazard with wide-ranging impacts on society. Using a high-resolution global flood model considering coastal, fluvial, and pluvial hazards,

Flooding is a pervasive natural hazard with wide-ranging impacts on society. Using a high-resolution global flood model considering coastal, fluvial, and pluvial hazards, we clarify the role of climate effects versus population growth effects in changing flood exposure. Between 2020 and 2100, the population likely exposed to 1% annual risk (100-year) flood hazard will increase from 1.6 to 1.9 billion people. Of this change from the 2020 exposure, we attribute 21.1% to climate change, 76.8% to population change, and 2.1% to both climate and population change. The largest driver of uncertainty in exposure is population change, while climate change remains a smaller but still important driver. The global increase in exposure between 2020 and 2100 is primarily driven by low-GDP regions, and by 2100 the lowest GDP areas will make up 63% of the exposure both overall and in urban areas. Urban areas are especially vulnerable in nearly all global regions, and urban areas sensitive to extreme events are expected to see a 33% increase in population exposure. This study highlights the vast inequities in flood exposure, and future work should direct resources and strategies toward sustainable risk mitigation in these areas.

The Science Charade in Species Conservation

Supreme Court Economic Review | September 2nd, 2017

The Endangered Species Act (ESA) is among the nation’s most important and powerful environmental laws. It is also a source of great conflict and controversy.  The list

The Endangered Species Act (ESA) is among the nation’s most important and powerful environmental laws. It is also a source of great conflict and controversy.  The listing of individual species, the designation of critical habitat and the implementation of conservation measures often prompt fierce legal and political battles. In these conflicts, activists on all sides claim that “sound science” supports their respective positions, and scoff at the “junk science” relied upon by the other side. The U.S. Fish & Wildlife Service fails to rely upon the best science, critics claim.  If it did, they charge, it would adopt policies more to their liking.  The debate over the use of science under the ESA is part of the “science charade” that clouds substantive policy debate about species conservation.3 What typically divides competing interest groups is not a devotion to science, but sharply divergent policy preferences dressed up in scientific garb. The political debate over the use of science under the ESA tends to obscure the dividing line between science and policy and undermines the development of more effective and equitable conservation strategies. Further, efforts to reform the ESA by mandating additional scientific procedures or increasing judicial scrutiny of the use of science by federal agencies will do little to address the ESA’s underlying problems or make species conservation efforts more effective.  Scientific research is necessary to inform species conservation decisions. But species conservation is not – and cannot be – a wholly scientific exercise. Judgments about what constitutes a distinct species or how to evaluate incomplete scientific data necessarily draw upon normative premises. More significantly, policy decisions about what sorts of conservation measures should be adopted are not scientific at all. Whether habitat loss will reduce the likelihood that a given species or population will survive in the wild may be a scientific question, but what measures should be adopted to conserve such habitat, and at what cost, is a normative policy judgment. Science can – indeed, must – inform such inquiries, but science cannot tell us what to do. Engaging in the “science charade,” either by pretending that ESA implementation may be guided by scientific judgment alone or by claiming that reforms of how science is used is unlikely to improve species conservation. To the contrary, efforts to constrain or control the use of science in ESA listing decisions or enhance judicial review of agency scientific determinations will undermine the quality and reliability of ESA science and lead to less effective conservation policy.  Whatever ails the ESA, a failure to incorporate adequate science is not the cause of the disease. As this Article explains, efforts to augment the amount or type of science used in ESA decision-making, whether through additional procedural mandates or altered standards of judicial review, will not address the conflicts that afflict species conservation policy. In some cases, such measures could further undermine the ESA’s ability to conserve species.  Part I of the Article gives a brief overview of the ESA, its operation, and the scientific requirements written into the Act. Part II describes the “science charade,” through which policymakers and others pretend that policy judgments are purely scientific questions, and the legal and political incentives that ensure this artifice persists. Part III details how the ESA’s structure generates political pressure on the use of science and encourages the science charade in species conservation. Part IV explains why various “sound science” reforms will not address these problems, and Part V outlines alternative policy reforms. 

U.S. Department of the Interior Environmental Justice Annual Implementation Report 2016

U.S. Department of the Interior (DOI) | June 1st, 2017

In 1994, Executive Order 12898, Federal Actions to Address Environmental Justice in Minority Populations and Low-income Populations, set forth the responsibility

In 1994, Executive Order 12898, Federal Actions to Address Environmental Justice in Minority Populations and Low-income Populations, set forth the responsibility of Federal agencies to “make achieving environmental justice part of their missions by identifying and addressing, as appropriate, disproportionately high and adverse human health or environmental effects of their programs, policies, and activities on minority populations and low-income populations in the United States and its territories and possessions, the District of Columbia, the Commonwealth of Puerto Rico, and the Commonwealth of the Mariana Islands.” In addition, the Executive Order called for the creation of the Federal Interagency Working Group on Environmental Justice (EJIWG). The EJIWG is comprised of the DOI and 16 other Federal agencies plus White House staff to fact find, receive public comments, and conduct inquiries concerning environmental justice. The roles of the EJIWG are to guide, support and enhance federal environmental justice and community-based activities. The Environmental Protection Agency (EPA) is the convener of the EJIWG. The EJIWG has established committees to develop guidance and support the following topic areas: goods movement, civil rights, strategic planning and implementation, rural communities, regional committees, the National Environmental Policy Act (NEPA), and Native American peoples, and public participation. During 2016, the DOI continued to work to incorporate the provisions of EO 12898 within the scope of its overall mission. The DOI also continued to be an active member in the EJ IWG and participates in its collaborative efforts to support healthy and economically viable minority, low- income, and tribal communities.

Water, environment, and socioeconomic justice in California: A multi-benefit cropland repurposing framework

Science of the Total Environment (Elsevier) | November 22nd, 2022

Western and Traditional Ecological Knowledge in ecocultural restoration

University of California, Davis (UC Davis) | October 1st, 2018

 The Delta Plan (DSC 2013) calls for “protecting and enhancing the unique cultural values” of California’s Sacramento–San Joaquin Delta, a 2,800-km2 (1,100 mi2)

 The Delta Plan (DSC 2013) calls for “protecting and enhancing the unique cultural values” of California’s Sacramento–San Joaquin Delta, a 2,800-km2 (1,100 mi2) region that was occupied by indigenous peoples for ~5,000 years. The legacies of Native Californians need to be included in the Delta Plan, especially Traditional Ecological Knowledge (TEK) of ways to gather, hunt, and fish for food; build shelters; prepare medicines; and perform ceremonies — along with ways to make tools, clothing, baskets, and shelters. Plants were not just collected but also tended, which involved planned burning, digging, planting, weeding, harvesting, and seed dispersal. Populations of plants that have cultural significance and unique values should be enhanced under the Delta Plan. While Western Ecological Knowledge (WEK) offers a strong foundation for restoration of species assemblages and ecosystems, TEK adds culturally-significant species to restoration targets and traditional management practices to achieve ecological resilience. We compare 11 attributes of WEK and TEK that aid ecological restoration; all are complementary or shared by these two ways of knowing. Both WEK and TEK emphasize adaptive approaches for managing natural resources, as mandated in the Delta Plan. We suggest that WEK–TEK restoration sites throughout the Delta can be linked (virtually) to honor cultural integrity and nurture a “Sense of Place” for Native Californians and others. At the same time, such a network could foster ways to achieve sustainability through the TEK ethic of reciprocity, which WEK lacks. A network of WEK–TEK sites could enhance unique cultural values while supporting passive recreation and attracting ecotourists. 

Your Delta, Your Voice

California Department of Water Resources (DWR) | May 28th, 2021

In Fall 2020, the California Department of Water Resources (DWR) launched an environmental justice community survey entitled Your Delta, Your Voice. The survey was live f

In Fall 2020, the California Department of Water Resources (DWR) launched an environmental justice community survey entitled Your Delta, Your Voice. The survey was live from September 30 through December 11, 2020. Survey development and outreach was led by Ag Innovations and supported by numerous partners and agency staff. The survey had the following goals: 1) to gather information from disadvantaged communities in the Delta region about how they work, live, recreate and experience the Delta, 2) to understand how the community values and uses its natural, economic, and social resources, and 3) increase awareness of the proposed project and interest in participating in public engagement among disadvantaged community members in the Delta region. These goals were pursued in order to inform the proposed Delta Conveyance Project environmental review and planning process, with a particular emphasis on the environmental justice chapter of the CEQA Environmental Impact Report. Ag Innovation’s intent was to faithfully reflect the input and perspectives gathered via the survey within this report. In January 2021, DWR began developing a Delta Conveyance Project Community Benefits Program. The information gathered from the survey will also be used to inform DWR’s efforts to work towards community benefits in the Delta region, although that was not part of the original intent of the survey as the program did not exist at that time.