Robert Mcdonald

The Nature Conservancy · Science

Natural climate solutions (NCS) play a critical role in climate change mitigation. NCS can generate win–win co-benefits for biodiversity and human well-being, but they can also involve trade-offs (co-impacts). However, the massive evidence base on NCS co-benefits and possible trade-offs is poorly understood. We employ large language models to asses...

Recent advances in data science and urban environmental health research utilise large-scale databases (100s–1000s of cities) to explore the complex interplay of urban characteristics such as city form and size, climate, mobility, exposure, and environmental health impacts. Cities are still hotspots of air pollution and noise, suffer urban heat isla...

Forests play a crucial role in regulating the global climate. Yet, forests also influence the local climate conditions through biophysical processes that directly impact human wellbeing. With growing policy emphasis on these climate adaptation effects, we review the scale dependent impacts of forests on climate conditions and their implications for...

Nature-based solutions (NBS) can deliver many benefits to human wellbeing, including some crucial to climate adaptation. We quantitatively assess the global potential of NBS strategies of protection, restoration, and agroforestry by modeling global climate change mitigation and local ecosystem services (water availability, sediment retention, runof...

Background As the world becomes increasingly urbanised, there is recognition that public and planetary health relies upon a ubiquitous transition to sustainable cities. Disentanglement of the complex pathways of urban design, environmental exposures, and health, and the magnitude of these associations, remains a challenge. A state-of-the-art accoun...

Excessive heat is a major and growing risk for urban residents. Here, we estimate the inequality in summertime heat-related mortality, morbidity, and electricity consumption across 5723 US municipalities and other places, housing 180 million people during the 2020 census. On average, trees in majority non-Hispanic white neighborhoods cool the air b...

Nature-based solutions are increasingly used in domestic wastewater treatment, because of their potential to remove contaminants and pathogens from water (e.g., stormwater, river water, wastewater) as well as their provided co-benefits, such as mitigation of the heat island effect or enhanced biodiversity. The transition from traditional grey techn...

Cities are faced with multiple challenges in the twenty-first century, from rapid urban growth to climate change. This chapter discusses how to plan for and implement nature-based solutions in cities, presenting techniques to incorporate nature into urban landscapes, which we call “greenprinting.” Urban greenprinting refers to planning how natural...

Coastal ecosystems have the potential to contribute to disaster risk reduction and adaptation to climate change. While previous studies have estimated the value of current coastal ecosystems for reducing coastal risk, there have been relatively few studies that look at changes in ecosystem service provision, in the past and under climate change. We...

Coastal ecosystems have the potential to contribute to disaster risk reduction and adaptation to climate change. While previous studies have estimated the value of current coastal ecosystems for reducing coastal risk, there have been relatively few studies that look at changes in ecosystem service provision, in the past and under climate change. We...

Excessive heat is a major and growing risk for urban residents. Urban trees can significantly reduce summer peak temperatures, thus reducing heat-related mortality, morbidity, as well as cooling energy demand. However, urban tree canopy is inequitably distributed in US cities, which has been shown to contribute to higher summer temperatures in peop...

Green spaces in urban areas—like remnant habitat, parks, constructed wetlands, and street trees—supply multiple benefits. Many studies show green spaces in and near urban areas play important roles harbouring biodiversity and promoting human well‐being. On the other hand, evidence suggests that greater human population density enables compact, low‐...

A review of ecological, social, engineering, and integrative approaches to define and apply resilience thinking is presented and comparatively discussed in the context of watershed management. Knowledge gaps are identified through an assessment of this literature and compilation of a set of research questions through stakeholder engagement activiti...

Significance Understanding the impacts of urbanization and the associated urban land expansion on species is vital for informed urban planning that minimizes biodiversity loss. Predicting habitat that will be lost to urban land expansion for over 30,000 species under three different future scenarios, we find that up to 855 species are directly thre...

There is an emerging consensus that the health of the planet depends on the coexistence between rapidly growing cities and the natural world. One strategy for guiding cities towards sustainability is to facilitate a planning process based on positive visions for urban systems among actors and stakeholders. This paper presents the Urban Nature Futur...

Urban nature—such as greenness and parks—can alleviate distress and provide space for safe recreation during the COVID-19 pandemic. However, nature is often less available in low-income populations and communities of colour—the same communities hardest hit by COVID-19. In analyses of two datasets, we quantified inequity in greenness and park proxim...

Green stormwater infrastructure (GSI), which includes features like rain gardens, constructed wetlands, or urban tree canopy, is now widely recognized as a means to reduce urban runoff impacts and meet municipal water quality permit requirements. Many co-benefits of GSI are related to increased vegetative cover, which can be measured with satellite...

There are 2.4 billion people without improved sanitation and another 2.1 billion with inadequate sanitation (i.e. wastewater drains directly into surface waters), and despite improvements over the past decades, the unsafe management of fecal waste and wastewater continues to present a major risk to public health and the environment (UN, 2016). Ther...

Natural infrastructure such as parks, forests, street trees, green roofs, and coastal vegetation is central to sustainable urban management. Despite recent progress, it remains challenging for urban decision-makers to incorporate the benefits of natural infrastructure into urban design and planning. Here, we present an approach to support the green...

Urban tree cover provides benefits to human health and well-being, but previous studies suggest that tree cover is often inequitably distributed. Here, we use National Agriculture Imagery Program digital ortho photographs to survey the tree cover inequality for Census blocks in US large urbanized areas, home to 167 million people across 5,723 munic...

Urban nature can alleviate distress and provide space for safe recreation during the COVID-19 pandemic. However, nature is often less available in low-income and communities of color—the same communities hardest hit by COVID-19. We quantified nature inequality across all urbanized areas in the US and linked nature access to COVID-19 case rates for...

Non-technical summary: We summarize some of the past year's most important findings within climate change-related research. New research has improved our understanding of Earth's sensitivity to carbon dioxide, finds that permafrost thaw could release more carbon emissions than expected and that the uptake of carbon in tropical ecosystems is weakeni...

This chapter presents a case study of the Los Angeles River, from its ecological death through its partial rebirth. We live in a world filled with many places like the LA River. If we continue building cities like this, we risk condemning billions of people to suffer from the urban mental health penalty. But cities have a choice of taking another,...

This chapter provides an overview of the different ways that nature benefits people, sometimes called ecosystem services. We list the ecosystem services that are key in urban contexts, describing the servicesheds they operate within. We then focus on the evidence that nature exposure benefits health specifically, discussing a few key ecosystem serv...

This book argues that, paradoxically, at their moment of triumph and fastest growth, cities need nature more than ever. Only if our urban world is full of biophilic cities will the coming urban century truly succeed. Cities are quintessentially human, the perfect forum for interaction, and we are entering what could justly be called the urban centu...

Biophilic cities pursue the goal of abundant nature at multiple scales. This chapter examines in detail the best practices and design ideas that have been applied at the scales of building, neighborhood, and city-region. It is argued here that nature can be designed in at each scale, but ideally a biophilic city aspires to the interconnection of th...

Cities are our greatest invention, an arrangement of homes and businesses that drastically increases the speed of interaction. This interaction then leads to numerous benefits, which is the primary subject of this chapter. We discuss first agglomeration economics—the benefits to firms and people productivity of being in clusters (agglomerations). O...

This chapter presents one way to plan for using nature as a solution: biophilic design and planning. Biophilic cities represent a new vision of global urbanization that puts nature at the center of design and planning. It calls for a shift from seeing cities as places where there are discrete elements of nature to a more integrative and holistic se...

This century could rightly be called the urban century, with 2.4 billion more people expected in cities by 2050. This chapter presents the major choice facing planners: whether we want nature to play a central role in our urban future. We briefly present the central argument of this book that, paradoxically, cities need nature more than ever. Citie...

In this chapter, we explore ways in which urban environments and urban lifestyles are bad for human health. We discuss the urban health penalty historically, presenting a case study of how London solved its urban health penalty over the centuries. We then move on to discuss the aspects of the urban health penalty that remain in today’s cities, with...

Green infrastructure (GI), which mimics natural hydrological systems, is a promising solution for flood management at the intersection of urban built infrastructure and natural systems. However, it has not yet achieved widespread uptake, due in part to insufficient understanding of human dimensions of the broader socio-ecological-technical system....

High air temperatures are a public health threat, causing 1300 deaths annually in the United States (US) along with heat-related morbidity and increased electricity consumption for air-conditioning (AC). Increasing tree canopy cover has been proposed as one way to reduce urban air temperatures. Here, we assemble tree cover and developed land-cover...

By 2030, an additional 1.2 billion people are forecast in urban areas globally. We review the scientific literature (n = 922 studies) to assess direct and indirect impacts of urban growth on habitat and biodiversity. Direct impacts are cumulatively substantial, with 290,000 km2 of natural habitat forecast to be converted to urban land uses between...

Background: The increase in frequency and intensity of urban flooding is a global challenge. Flooding directly impacts residents of industrialized cities with aging combined sewer systems, as well as cities with less centralized infrastructure to manage stormwater, fecal sludge, and wastewater. Green infrastructure is growing in popularity as a su...

Although health, development, and environment challenges are interconnected, evidence remains fractured across sectors due to methodological and conceptual differences in research and practice. Aligned methods are needed to support Sustainable Development Goal advances and similar agendas. The Bridge Collaborative, an emergent research-practice col...

Urban nature has the potential to improve air and water quality, mitigate flooding, enhance physical and mental health, and promote social and cultural well-being. However, the value of urban ecosystem services remains highly uncertain, especially across the diverse social, ecological and technological contexts represented in cities around the worl...

Governments, development banks, corporations, and nonprofits are increasingly considering the potential contribution of watershed conservation activities to secure clean water for cities and to reduce flood risk. These organizations, however, often lack decision-relevant, initial screening information across multiple cities to identify which specif...

This century will be remembered as the urban century. Our generation will witness the most signi cant urban growth in human history. By 2050, there will be 2.4 billion more people in cities, a rate of urban growth that is equivalent to building a city with the population of London every seven weeks. Humanity will urbanize an area of 1.2 million km2...

Limiting climate warming to <2°C requires increased mitigation efforts, including land stewardship, whose potential in the United States is poorly understood. We quantified the potential of natural climate solutions (NCS)—21 conservation, restoration, and improved land management interventions on natural and agricultural lands—to increase carbon st...

By 2050, there are forecast to be 2.4 billion more people in cities, and this century could rightly be called the urban century. This paper argues that, paradoxically, without the use of nature the urban century will fail. We review three literatures to assess the scientific support for this proposition. First, studies from economics show that it i...

Investments in watershed services (IWS) programs, in which downstream water users pay upstream watershed service suppliers for actions that protect drinking water, are increasing in number and scope. IWS programs represent over $170 million of investment in over 4.3 million ha of watersheds, providing water to over 230 million people. It is not yet...

A hopeful vision of the future is a world in which both people and nature thrive, but there is little evidence to support the feasibility of such a vision. We used a global, spatially explicit, systems modeling approach to explore the possibility of meeting the demands of increased populations and economic growth in 2050 while simultaneously advanc...

Global assessment, at the request of the Convention on Biological Diversity, of where urban growth affects biodiversity

Earth is undergoing unprecedented urban growth, with urban areas forecasted to increase by 120 million ha from 2000 to 2030, impacting natural habitat. However, to date it is unclear where conservation investments can best mitigate biodiversity loss due to urban expansion into natural habitat. Here we combine spatially-explicit global forecasts of...

The economic development-environmental protection dichotomy is an out-dated construct. A 21st century approach to the world's water problems is progressively being developed by researchers and practitioners, who are combining traditional and ecosystem-based engineering systems to yield cost-effective solutions. Given the continuing and widespread l...

Urban trees reduce respirable particulate matter (PM 10) concentrations and maximum daytime summer temperatures. While most cities are losing tree cover, some are considering ambitious planting efforts. Maximizing PM 10 and heat mitigation for people from such efforts requires cost-effective targeting. We adapt published methods to estimate the imp...

Mitigating the effects of urban expansion on habitat with high conservation value depends largely on national and sub-national governance that can effectively shape urban growth. This paper is the first study to map urban-caused biodiversity decline and governance. The central goal of this paper is to identify where and how weak governance and futu...

Urban water demand will increase by 80% by 2050, while climate change will alter the timing and distribution of water. Here we quantify the magnitude of these twin challenges to urban water security, combining a dataset of urban water sources of 482 of the world’s largest cities with estimates of future water demand, based on the Intergovernmental...

Watersheds are under increasing pressure worldwide, as expanding human activities coupled with global climate change threaten the water security of people downstream. In response, some communities have initiated investments in watershed services (IWS), a general term for policy-finance mechanisms that mitigate diverse watershed threats and promote...

Energy production in the United States for domestic use and export is predicted to rise 27% by 2040. We quantify projected energy sprawl (new land required for energy production) in the United States through 2040. Over 200,000 km² of additional land area will be directly impacted by energy development. When spacing requirements are included, over 8...

Significance Urban water-treatment costs depend on the water quality at the city’s source, which in turn depends on the land use in the source watersheds. Here, we show that globally urban source watershed degradation is widespread, with 9 in 10 cities losing significant amounts of natural land cover in their source watersheds to agriculture and de...

Many water utilities and other large water users struggle with degrading raw water quality over time, such as increases in turbidity, nutrient and algal load, or other pollutants. Raw water quality matters, of course, because it affects the costs of operations and maintenance of a water supply system, and in extreme cases, poor raw water quality ca...

Businesses are increasingly concerned about water scarcity and its financial impacts, as well as competing needs of other stakeholders and ecosystems. Industrialized watersheds may be at more serious risk from water scarcity than previously understood because industrial and municipal users have inelastic demand and a high value for water. Previous...

Globally, urbanization is rapidly growing cities and towns at a historically unprecedented rate, and this rapid urban growth is influencing many facets of the environment. This paper reviews the effectiveness of conservation interventions that are designed to increase urban sustainability. It presents evidence for an apparent urban-environmental pa...

Using findings of the Cities and Biodiversity Outlook (CBO), we propose three specific solutions to mitigate the loss of ecosystem services and biodiversity in our urban and urbanizing landscapes. The CBO identified continued loss of criti-cal habitats for biodiversity conservation and degradation of many important ecosystem services due to urbaniz...

Water scarcity presents a major risk to businesses, but it can be hard to quantify. Ecosystem service valuation methods may help businesses better understand the financial impacts of water shortages and identify solutions. At The Dow Chemical Company’s facility in Freeport, TX, we used natural capital asset valuation to assess the risk from future...

With this book, Robert McDonald offers a comprehensive framework for maintaining and strengthening the supporting bonds between cities and nature through innovative infrastructure projects. It's time to think differently about cities and nature. More people than ever live in cities, and all of this urban growth, along with challenges of adapting to...

San Diego had a problem. It was a rapidly growing city, accumulating almost a million new residents in the 1990s and early 2000s (UNPD 2011). But the landscape was also home to lots of rare plants and animals, having one of the highest levels of biodiversity in the United States. Many of the rare species were listed as endangered and had protection...

Looking at the skyline, it is hard for me to imagine that just a few decades ago this was a sleepy town by the Fustian River. The skyscrapers of Shenzhen now stretch out to the horizon. Some of the newer towers have a glass façade and fashionable design, but many of the other buildings appear as more or less identical grey concrete blocks, lined up...

During summer 2007, a research team went all around Portland, Oregon, visiting more than 3,000 homes. At each house, they counted the number of trees in the front yard and along the sidewalk. They wrapped a tape around each tree to measure its circumference, and visually assessed its condition. Actually, calling it a team is a bit too generous a de...

An age-old conflict around a seemingly simple question has resurfaced: why do we conserve nature? Contention around this issue has come and gone many times, but in the past several years we believe that it has reappeared as an increasingly acrimonious debate between, in essence, those who argue that nature should be protected for its own sake (intr...

Background/Question/Methods Urban growth is increasing the demand for freshwater resources, yet surprisingly the water sources of the world’s large cities have never been globally assessed, hampering efforts to assess the distribution and causes of urban water stress. I led the first global survey of the water sources of large cities (population >...

Abstract Urban growth is increasing the demand for freshwater resources, yet surprisingly the water sources of the world's large cities have never been globally assessed, hampering efforts to assess the distribution and causes of urban water stress. We conducted the first global survey of the large cities’ water sources, and show that previous glob...