Historical Population Estimates Research Articles

Analyzing urban scaling laws in the United States over 115 years

The scaling relations between city attributes and population are emergent and ubiquitous aspects of urban growth. Quantifying these relations and understanding their theoretical foundation, however, is difficult due to the challenge of defining city boundaries and a lack of historical data to study city dynamics over time and space. To address this issue, we analyze scaling between city infrastructure and population across 857 metropolitan areas in the conterminous United States over an unprecedented 115 years (1900–2015) using dasymetrically refined historical population estimates, historical urban road network models, and multi-temporal settlement data to define dynamic city boundaries. We demonstrate that urban scaling exponents closely match theoretical models over a century. Despite some close quantitative agreement with theory, the empirical scaling relations unexpectedly vary across regions. Our analysis of scaling coefficients, meanwhile, reveals that contemporary cities use more developed land and kilometers of road than cities of similar population in 1900, which has serious implications for urban development and impacts on the local environment. Overall, our results provide a new way to study urban systems based on novel, geohistorical data.

How many people lived in the world’s earliest villages? Reconsidering community size and population pressure at Neolithic Çatalhöyük

Adopting a building and village biography approach combining archaeology and ethnography, we critically reevaluate the historical argument that Neolithic villages were occupied by many thousands of people. Focusing on the settlement at Çatalhöyük, Turkey, where it has been argued that 3,500 and 10,000 people lived in the village, we argue that this is a significant overestimate of the number of people that occupied this settlement. Drawing upon revised distribution of residential buildings across the mound, and employing archaeological and ethnographic data exploring building life-history, we estimate that between 600 and 800 people would have lived at Çatalhöyük East during an average year during the Middle (6700–6500 cal BC) phase. This research highlights the need to critically revaluate historical population estimates for Neolithic villages, the importance of developing explicit population modeling methods in archaeology, and to reconsider population-driven evolutionary models linking the Near Eastern Neolithic to urbanism.

Phenology-based adjustments improve population estimates of Antarctic breeding seabirds: the case of Cape petrels in East Antarctica.

To monitor and conserve a species, it is crucial to understand the size and distribution of populations. For seabirds, population surveys are usually conducted at peak breeding attendance. One of the largest populations of Cape petrels in East Antarctica is at the Vestfold Islands, where environmental and logistical constraints often prevent access to breeding sites at the optimal time for population surveys. In this study, we aim to quantify the contemporary and historical breeding population size of these Cape petrels by adjusting nest counts for variation in breeding phenology using photographs from remote cameras. We also compare spatial distribution between 1970s and 2017/2018. Our results show ground counts occurred outside peak breeding attendance, and adjusting for phenology changed the contemporary and historical population estimates. The Cape petrels showed local intra-island or adjacent-island changes in their distribution between the 1970s and 2017/2018 with no evidence of expanding or restricting their distribution or a significant change in their breeding population size. The results emphasize the importance of accounting for phenology in population counts, where populations are inaccessible at an optimal survey time. We discuss the applications of our research methodology for populations breeding in remote areas and as a baseline for assessing population change.

A review of bottom-up vs. top-down control of sponges on Caribbean fore-reefs: what's old, what's new, and future directions.

Interest in the ecology of sponges on coral reefs has grown in recent years with mounting evidence that sponges are becoming dominant members of reef communities, particularly in the Caribbean. New estimates of water column processing by sponge pumping activities combined with discoveries related to carbon and nutrient cycling have led to novel hypotheses about the role of sponges in reef ecosystem function. Among these developments, a debate has emerged about the relative effects of bottom-up (food availability) and top-down (predation) control on the community of sponges on Caribbean fore-reefs. In this review, we evaluate the impact of the latest findings on the debate, as well as provide new insights based on older citations. Recent studies that employed different research methods have demonstrated that dissolved organic carbon (DOC) and detritus are the principal sources of food for a growing list of sponge species, challenging the idea that the relative availability of living picoplankton is the sole proxy for sponge growth or abundance. New reports have confirmed earlier findings that reef macroalgae release labile DOC available for sponge nutrition. Evidence for top-down control of sponge community structure by fish predation is further supported by gut content studies and historical population estimates of hawksbill turtles, which likely had a much greater impact on relative sponge abundances on Caribbean reefs of the past. Implicit to investigations designed to address the bottom-up vs. top-down debate are appropriate studies of Caribbean fore-reef environments, where benthic communities are relatively homogeneous and terrestrial influences and abiotic effects are minimized. One recent study designed to test both aspects of the debate did so using experiments conducted entirely in shallow lagoonal habitats dominated by mangroves and seagrass beds. The top-down results from this study are reinterpreted as supporting past research demonstrating predator preferences for sponge species that are abundant in these lagoonal habitats, but grazed away in fore-reef habitats. We conclude that sponge communities on Caribbean fore-reefs of the past and present are largely structured by predation, and offer new directions for research, such as determining the environmental conditions under which sponges may be food-limited (e.g., deep sea, lagoonal habitats) and monitoring changes in sponge community structure as populations of hawksbill turtles rebound.

Anthropogenic land use estimates for the Holocene – HYDE 3.2

Abstract. This paper presents an update and extension of HYDE, the History Database of the Global Environment (HYDE version 3.2). HYDE is an internally consistent combination of historical population estimates and allocation algorithms with time-dependent weighting maps for land use. Categories include cropland, with new distinctions for irrigated and rain-fed crops (other than rice) and irrigated and rain-fed rice. Grazing lands are also provided, divided into more intensively used pasture and less intensively used rangeland, and further specified with respect to conversion of natural vegetation to facilitate global change modellers. Population is represented by maps of total, urban, rural population, population density and built-up area. The period covered is 10 000 before Common Era (BCE) to 2015 Common Era (CE). All data can be downloaded from https://doi.org/10.17026/dans-25g-gez3. We estimate that global population increased from 4.4 million people (we also estimate a lower range < 0.01 and an upper range of 8.9 million) in 10 000 BCE to 7.257 billion in 2015 CE, resulting in a global population density increase from 0.03 persons (or capita, in short cap) km−2 (range 0–0.07) to almost 56 cap km−2 respectively. The urban built-up area evolved from almost zero to roughly 58 Mha in 2015 CE, still only less than 0.5 % of the total land surface of the globe. Cropland occupied approximately less than 1 % of the global land area (13 037 Mha, excluding Antarctica) for a long time period until 1 CE, quite similar to the grazing land area. In the following centuries the share of global cropland slowly grew to 2.2 % in 1700 CE (ca. 293 Mha, uncertainty range 220–367 Mha), 4.4 % in 1850 CE (578 Mha, range 522–637 Mha) and 12.2 % in 2015 CE (ca. 1591 Mha, range 1572–1604 Mha). Cropland can be further divided into rain-fed and irrigated land, and these categories can be further separated into rice and non-rice. Rain-fed croplands were much more common, with 2.2 % in 1700 CE (289 Mha, range 217–361 Mha), 4.2 % (549 Mha, range 496–606 Mha) in 1850 CE and 10.1 % (1316 Mha, range 1298–1325 Mha) in 2015 CE, while irrigated croplands used less than 0.05 % (4.3 Mha, range 3.1–5.5 Mha), 0.2 % (28 Mha, range 25–31 Mha) and 2.1 % (277 Mha, range 273–278 Mha) in 1700, 1850 and 2015 CE, respectively. We estimate the irrigated rice area (paddy) to be 0.1 % (13 Mha, range 9–16 Mha) in 1700 CE, 0.2 % (28 Mha, range 26–31 Mha) in 1850 CE and 0.9 % (118 Mha, range 117–120 Mha) in 2015 CE. The estimates for land used for grazing are much more uncertain. We estimate that the share of grazing land grew from 5.1 % in 1700 CE (667 Mha, range 507–820 Mha) to 9.6 % in 1850 CE (1192 Mha, range 1068–1304 Mha) and 24.9 % in 2015 CE (3241 Mha, range 3211–3270 Mha). To aid the modelling community we have divided land used for grazing into more intensively used pasture, less intensively used converted rangeland and less or unmanaged natural unconverted rangeland. Pasture occupied 1.1 % in 1700 CE (145 Mha, range 79–175 Mha), 1.9 % in 1850 CE (253 Mha, range 218–287 Mha) and 6.0 % (787 Mha, range 779–795 Mha) in 2015 CE, while rangelands usually occupied more space due to their occurrence in more arid regions and thus lower yields to sustain livestock. We estimate converted rangeland at 0.6 % in 1700 CE (82 Mha range 66–93 Mha), 1 % in 1850 CE (129 Mha range 118–136 Mha) and 2.4 % in 2015 CE (310 Mha range 306–312 Mha), while the unconverted natural rangelands occupied approximately 3.4 % in 1700 CE (437 Mha, range 334–533 Mha), 6.2 % in 1850 CE (810 Mha, range 733–881 Mha) and 16.5 % in 2015 CE (2145 Mha, range 2126–2164 Mha).

Modeling the pre-industrial roots of modern super-exponential population growth.

To Malthus, rapid human population growth—so evident in 18th Century Europe—was obviously unsustainable. In his Essay on the Principle of Population, Malthus cogently argued that environmental and socioeconomic constraints on population rise were inevitable. Yet, he penned his essay on the eve of the global census size reaching one billion, as nearly two centuries of super-exponential increase were taking off. Introducing a novel extension of J. E. Cohen's hallmark coupled difference equation model of human population dynamics and carrying capacity, this article examines just how elastic population growth limits may be in response to demographic change. The revised model involves a simple formalization of how consumption costs influence carrying capacity elasticity over time. Recognizing that complex social resource-extraction networks support ongoing consumption-based investment in family formation and intergenerational resource transfers, it is important to consider how consumption has impacted the human environment and demography—especially as global population has become very large. Sensitivity analysis of the consumption-cost model's fit to historical population estimates, modern census data, and 21st Century demographic projections supports a critical conclusion. The recent population explosion was systemically determined by long-term, distinctly pre-industrial cultural evolution. It is suggested that modern globalizing transitions in technology, susceptibility to infectious disease, information flows and accumulation, and economic complexity were endogenous products of much earlier biocultural evolution of family formation's embeddedness in larger, hierarchically self-organizing cultural systems, which could potentially support high population elasticity of carrying capacity. Modern super-exponential population growth cannot be considered separately from long-term change in the multi-scalar political economy that connects family formation and intergenerational resource transfers to wider institutions and social networks.

Impact of human population density on fire frequency at the global scale

Abstract. Human impact on wildfires, a major earth system component, remains poorly understood. While local studies have found more fires close to settlements and roads, assimilated charcoal records and analyses of regional fire patterns from remote-sensing observations point to a decline in fire frequency with increasing human population. Here, we present a global analysis using three multi-year satellite-based burned-area products combined with a parameter estimation and uncertainty analysis with a non-linear model. We show that at the global scale, the impact of increasing population density is mainly to reduce fire frequency. Only for areas with up to 0.1 people per km2, we find that fire frequency increases by 10 to 20% relative to its value at no population. The results are robust against choice of burned-area data set, and indicate that at only very few places on earth, fire frequency is limited by human ignitions. Applying the results to historical population estimates results in a moderate but accelerating decline of global burned area by around 14% since 1800, with most of the decline since 1950.

Historical declines of goliath grouper populations in South Florida, USA

Historical data are important in fisheries management and conservation, particularly for species which suffered significant population declines prior to the collection of ecological data. The globally endangered goliath grouper Epinephelus itajara was fished intensively long before data on population size were first collected. Historical population estimates have significant management implications, as the estimated time to full recovery depends on the size of the baseline population before depletion. Evidence used previously suggests that goliath grouper populations in Florida were reduced by as much as 95% relative to estimated baseline levels at the time of protection in 1990 and have since recovered to more than 30% of these values. However, actual historic abundances are not well known because few early data exist. I present 2 new data sets: (1) historical photographs of ‘trophy fish’ and (2) newspaper articles from the Florida Keys. I analyzed goliath grouper in photos taken of fish caught on Key West charter boats from 1956 to 1985 to assess changes in abundance before the fishery was closed in 1990. The average number of individuals displayed per trip decreased before 1960 and was reduced by 86% before 1979. Further evidence of declines is found in newspaper accounts of landings (1923 to 1977), which show decreases in the maximum individual fish size caught and the proportion of large grouper caught from land vs. offshore before 1950. These results demonstrate population declines over longer time scales than are currently considered and suggest that recent increases do not represent significant recovery compared to population abundances before depletion.

BOOK REVIEWS

Books reviewed in this article: Angus Maddison, The World Economy: A Millennial Perspective Anna Treves, Le nascite e la política neu'Italia del Navecento Carol Blum, Strength in Numbers: Population, Reproduction, and Power in Eighteenth‐Century France James Q. Wilson, The Marriage Problem: How Our Culture Has Weakened Families Sylvia Ann Hewlett, Creating a Life: Professional Women and the Quest for Children Rose E. Frisch, Female Fertility and the Body Fat Connection

People, skills, and resources: An interaction model for world population growth

A model is set up that yields the equation followed by world population ( P), past and present: P = A/( D - t) M , where t is time and A, D, and M are constants. Cumulated historical population estimates confirm this hyperbolical pattern first noticed by Cailleux, Meyer, and Foerster. Technological indices should grow according to the same pattern; partial confirmation of this part of the model is presented. The growth acceleration crisis that we are now facing may have had a counterpart around 4500 B.C., during the neolithic agricultural revolution. World-population projections up to 2000 A.D. are discussed in the light of the interaction model, with and without resource limitations.