Jonathan A. Foley's research while affiliated with California Academy of Sciences and other places

Publications (154)

Article
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The climate crisis threatens to exacerbate numerous climate-sensitive health risks, including heatwave mortality, malnutrition from reduced crop yields, water- and vector-borne infectious diseases, and respiratory illness from smog, ozone, allergenic pollen, and wildfires. Recent reports from the Intergovernmental Panel on Climate Change stress the...
Chapter
The VINCERA (Vulnerability and Impacts of North American Forests to Climate Change: Ecosystem Response and Adaptation) project was a collaborative effort between vegetation modeling teams from the UK, Canada, and the US to investigate possible impacts of climate change and increasing atmospheric CO2 concentration on the key attributes of forests an...
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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...
Conference Paper
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Background/Question/Methods The Amazon is a key frontier where agricultural expansion to meet growing global demand for agricultural commodities competes with the preservation of natural systems that provide globally important ecosystem services. Thus, identifying land-use strategies that accommodate increasing agricultural production while also...
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Feeding a growing and increasingly affluent world will require expanded agricultural production, which may require converting grasslands and forests into cropland. Such conversions can reduce carbon storage, habitat provision, and other ecosystem services, presenting difficult societal trade-offs. In this paper, we use spatially explicit data on ag...
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Nitrogen fertilizer use across the world's croplands enables high-yielding agricultural production, but does so at considerable environmental cost. Imbalances between nitrogen applied and nitrogen used by crops contributes to excess nitrogen in the environment, with negative consequences for water quality, air quality, and climate change. Here we u...
Conference Paper
Increasing population, rising affluence, changing diets, and increasing consumption are placing unprecedented demands on the world's agriculture and natural resources. Today, approximately a billion people are chronically malnourished while our agricultural systems are concurrently degrading land, water, biodiversity and climate across regional and...
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Expansion of agricultural lands and inherent variability of climate can influence the water cycle in the Amazon basin, impacting numerous ecosystem services. However, these two influences do not work independently of each other. With two once-in-a-century-level droughts occurring in the Amazon in the past decade, it is vital to understand the feedb...
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The world's agricultural systems face the challenge of meeting the rising demands from population growth, changing dietary preferences, and expanding biofuel use. Previous studies have put forward strategies for meeting this growing demand by increasing global crop production, either expanding the area under cultivation or intensifying the crop yie...
Article
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Worldwide demand for crops is increasing rapidly due to global population growth, increased biofuel production, and changing dietary preferences. Meeting these growing demands will be a substantial challenge that will tax the capability of our food system and prompt calls to dramatically boost global crop production. However, to increase food avail...
Conference Paper
Background/Question/Methods Growth in agricultural trade has important implications for management of global land and water resources. Exports of agricultural commodities embody the characteristics of the production systems they are derived from among different regions. If countries import specific commodities rather than producing them domestical...
Conference Paper
Background/Question/Methods Global agricultural demand is expected to roughly double by 2050 due to population growth, diet shifts and biofuel use. However, already 24%-39% of our most important croplands are no longer witnessing yield improvement raising the important question of whether we can continue to feed the world and increase food securi...
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Global maps of the coefficient of variation (r2) for maize, rice, wheat, and soybean when fitted to 20 years of yield information at each political unit analyzed. (TIFF)
Data
Diagnostic plots for a linear fit (r2 = 0.49, p<0.01) to maize yield data in Angola. Subplots show a) model fit and standard 95% confidence interval, b) QQ plot, c) residuals versus fitted values, and d) residuals versus lagged residuals. Durbin-Watson test for autocorrelation: p<0.05. Lilliefors test for normality of yield data: p>0.5. (TIFF)
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Parsimoniously fitted yields at each of the political units and using them to project global crop yields to the year 2025. (TIFF)
Article
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Several studies have shown that global crop production needs to double by 2050 to meet the projected demands from rising population, diet shifts, and increasing biofuels consumption. Boosting crop yields to meet these rising demands, rather than clearing more land for agriculture has been highlighted as a preferred solution to meet this goal. Howev...
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Similar to Figure 1 in the main text but only for the Brazilian Legal Amazon. (TIFF)
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Country data source, number of political units analyzed per country, time frame and number of official statistics collected per crop for the period 1989 to 2008. (DOCX)
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Comparison with the future U. S. crop yields reported by the USDA-ERS [91] (maize, wheat, and soybean were reported in bushels per acre, rice in pounds per acres from USDA-ERS and converted to ton/ha), and global wheat yields reported by the FAO-OECD [90]. (DOCX)
Data
Diagnostic plots for a linear fit (r2 = 0.49, p<0.01) to soybean yield data in the United States. Subplots show a) model fit and standard 95% confidence interval, b) QQ plot, c) residuals versus fitted values, and d) residuals versus lagged residuals. Durbin-Watson test for autocorrelation: p = 0.66. Lilliefors test for normality of yield data: p>0...
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Additional Data, Model Fitting, Rates, and Inter-comparison information. (DOC)
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Consequences of extrapolating linear and quadratic maize yield models for Angola to 2050. (TIFF)
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Global maize, rice, wheat, and soybean yield fitted to 15 and 25 years of data and using it to project yields to the year 2025. Dashed lines correspond to analysis using 15 years of data (1994–2008), dotted lines correspond to using 25 years of data (1984–2008), and solid lines correspond to using 20 years of data (1989–2008). Due to the similarity...
Data
Global maps of autocorrelation of the data for maize, rice, wheat, and soybean at each political unit analyzed from the Durbin-Watson test (green colors show where the autocorrelation assumptions are violated at p>0.05 and red colors where they hold at p≤0.05). (TIFF)
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Current yields, projections and production for the Brazilian Legal Amazon. (DOCX)
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Global maps of normality of the data for maize, rice, wheat, and soybean at each political unit analyzed from the Lilliefors test (green colors show where the normality assumptions are not violated at p>0.05 and red colors where they are violated at p≤0.05). (TIFF)
Article
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Irrigation consumes more water than any other human activity, and thus the challenges of water sustainability and food security are closely linked. To evaluate how water resources are used for food production, we examined global patterns of water productivity—food produced (kcal) per unit of water (l) consumed. We document considerable variability...
Conference Paper
Many educational institutions are moving to address the educational and research needs of sustainability science. However, it is less clear how academic centers can meanigfully engage outside stakeholders, especially from business, government, NGOs, media and beyond. What new institutional structures and processes are needed to make this happen? Wh...
Conference Paper
Land is a vital but limited resource, while population growth, changing diets, and rising biofuel demand already threaten the long-term viability of the biosphere. How can we meet future demands for food, fiber, and fuel on a stressed global land base, without further degrading the environment or affecting human well-being? This talk will discuss n...
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In the coming decades, continued population growth, rising meat and dairy consumption and expanding biofuel use will dramatically increase the pressure on global agriculture. Even as we face these future burdens, there have been scattered reports of yield stagnation in the world's major cereal crops, including maize, rice and wheat. Here we study d...
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We evaluate the comparative productivity of maize and sugarcane biofuel feedstocks as a function of latitude. Solar radiation for photosynthesis varies by latitude and contributes to differential productivity of tropical and temperate zones. We calculate comparative productivity in two ways—the amount of net sugar energy produced per unit area, and...
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In the coming decades, a crucial challenge for humanity will be meeting future food demands without undermining further the integrity of the Earth's environmental systems. Agricultural systems are already major forces of global environmental degradation, but population growth and increasing consumption of calorie- and meat-intensive diets are expec...
Conference Paper
Background/Question/Methods Agricultural expansion (both in the form of cropland and pastureland) is a persistent pressure on Amazonia’s tropical forest resources, with that land-use change having associated environmental impacts on one of the world’s most biodiverse and carbon-rich tracts of tropical forest. As population size and incomes increa...
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Fires in agricultural ecosystems emit greenhouse gases and aerosols that influence climate on multiple spatial and temporal scales. Annex 1 countries of the United Nations Framework Convention on Climate Change (UNFCCC), many of which ratified the Kyoto Protocol, are required to report emissions of CH4 and N2O from these fires annually. In this stu...
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Numerous reports have emphasized the need for major changes in the global food system: agriculture must meet the twin challenge of feeding a growing population, with rising demand for meat and high-calorie diets, while simultaneously minimizing its global environmental impacts. Organic farming—a system aimed at producing food with minimal harm to e...
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The majority of the world's food production capability is inextricably tied to global precipitation patterns. Changes in moisture availability—whether from changes in climate from anthropogenic greenhouse gas emissions or those induced by land cover change (LCC)—can have profound impacts on food production. In this study, we examined the patterns o...
Conference Paper
Can the world feed 9 billion people? That’s a question many scientists, business leaders and policy makers are asking today. But in a world that can’t even feed 7 billion today, and completely fails to produce food in an environmentally sustainable manner, we’ll have to ask even tougher questions. In this presentation, I will review the state of...
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A five-step plan would raise yield and reduce carbon emissions, water use and water pollution
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Increasing population and consumption are placing unprecedented demands on agriculture and natural resources. Today, approximately a billion people are chronically malnourished while our agricultural systems are concurrently degrading land, water, biodiversity and climate on a global scale. To meet the world's future food security and sustainabilit...
Article
Full-text available
The impacts of changing land cover on the soil-vegetationatmosphere system are numerous. With the fraction of land used for farming and grazing expected to increase, extensive alterations to land cover such as replacing forests with cropland will continue. Therefore, quantifying the impact of global land-cover scenarios on the biosphere is critical...
Conference Paper
Background/Question/Methods Agriculture consumes on average 70% of the almost 4,000 cubic kilometers of water extracted worldwide from surface and groundwater for human use. Irrigation is instrumental to worldwide food production, allowing agriculture in arid areas and mitigating the effects of drought. Water diversion also has environmental impa...
Article
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We find that irrigation significantly affects Asian summer climate, according to model simulations using the Community Atmosphere Model (CAM3.0) coupled to the Community Land Model (CLM3.5). Irrigation over the major river basins in the Middle East and central Asia causes a decrease in sensible heat fluxes and an increase in latent heat fluxes in b...
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Ecosystems provide multiple benefits to people, including climate regulation. Previous efforts to quantify this ecosystem service have been either largely conceptual or based on complex atmospheric models. Here, we review previous research on this topic and propose a new and simple analytical approach for estimating the physical regulation of clima...
Conference Paper
As the international community focuses on climate change as the great challenge of our era, we have been largely ignoring another looming problem — the global crisis in agriculture, food security and the environment. Our use of land, particularly for agriculture, is absolutely essential to the success of the human race: we depend on agriculture to...
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Expanding croplands to meet the needs of a growing population, changing diets, and biofuel production comes at the cost of reduced carbon stocks in natural vegetation and soils. Here, we present a spatially explicit global analysis of tradeoffs between carbon stocks and current crop yields. The difference among regions is striking. For example, for...
Article
Aim As the demands for food, feed and fuel increase in coming decades, society will be pressed to increase agricultural production – whether by increasing yields on already cultivated lands or by cultivating currently natural areas – or to change current crop consumption patterns. In this analysis, we consider where yields might be increased on exi...
Article
Aim As the demands for food, feed and fuel increase in coming decades, society will be pressed to increase agricultural production - whether by increasing yields on already cultivated lands or by cultivating currently natural areas - or to change current crop consumption patterns. In this analysis, we consider where yields might be increased on exi...
Article
Aim  To assemble a data set of global crop planting and harvesting dates for 19 major crops, explore spatial relationships between planting date and climate for two of them, and compare our analysis with a review of the literature on factors that drive decisions on planting dates.Location  Global.Methods  We digitized and georeferenced existing dat...
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and Introduction In order to quantify the impact of shifts in land use patterns on the climate, a complementary approach to global climate models (GCMs) has been developed. The model presented here is specifically designed to investigate the impacts of changing land use on the earth's surface and lower atmosphere. It is capable of testing the impac...
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Anthropogenic pressures on the Earth System have reached a scale where abrupt global environmental change can no longer be excluded. We propose a new approach to global sustainability in which we define planetary boundaries within which we expect that humanity can operate safely. Transgressing one or more planetary boundaries may be deleterious or...
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We investigated carbon cycling and ecosystem characteristics among two prairie restoration treatments established in 1987 and adjacent cropland, all part of the Conservation Reserve Program in southwestern Wisconsin, USA. We hypothesized that different plant functional groups (cool-season C3 vs. warm-season C4 grasses) between the two prairie resto...
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Identifying and quantifying planetary boundaries that must not be transgressed could help prevent human activities from causing unacceptable environmental change, argue Johan Rockström and colleagues.
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1] As humanity develops strategies to manage and adapt to climate change, potential changes to carbon cycles are of increasing interest. The potential sensitivity of carbon sources and sinks in lakes may be of global importance, yet the direction and magnitude of possible changes are poorly understood across entire lake-rich regions. We used a spat...
Article
Recent analyses of the energy and greenhouse-gas performance of alternative biofuels have ignited a controversy that may be best resolved by applying two simple principles. In a world seeking solutions to its energy, environmental, and food challenges, society cannot afford to miss out on the global greenhouse-gas emission reductions and the local...
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Climate changes are altering patterns of temperature and precipitation, potentially affecting regions of malaria transmission. We show that areas of the Amazon Basin with few wetlands show a variable relationship between precipitation and malaria, while areas with extensive wetlands show a negative relationship with malaria incidence.
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The developing country comparison bars in figure 3 on page 6 of the original article have been revised as shown in the PDF.
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Aggressive renewable energy policies have helped the biofuels industry grow at a rate few could have predicted. However, while discourse on the energy balance and environmental impacts of agricultural biofuel feedstocks are common, the potential they hold for additional production has received considerably less attention. Here we present a new biof...
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Ecosystem processes are strongly affected by the magnitude, timing, and variability of water flows. As such, our understanding of biogeochemical and ecological processes can be enhanced when our ability to track water flow and storage within ecosystems is improved. We assess how climatic variability and land cover change affect water flow and stora...
Article
We calculated carbon budgets for a chronosequence of harvested jack pine (Pinus banksiana Lamb.) stands (0-, 5-, 10-, and∼29-year-old) and a∼79-year-old stand that originated after wildfire. We measured total ecosystem C content (TEC), above-, and belowground net primary productivity (NPP) for each stand. All values are reported in order for the 0-...
Conference Paper
Background/Question/Methods Agricultural activities have dramatically altered the face of our planet, covering a third of our planet's land surface today. Nonetheless, few descriptions are available of the nature and extent of these changes. We have therefore developed new global data sets of agricultural land cover and land use for ca. 2000. The d...