Used planet: A global history

In the paper

“The strikingly different predictions of these two models (Figs. 1 and 2) are almost entirely the result of differences in the way they represent land-use intensification processes; their population datasets are nearly the same (Fig. 2).”

What the sources say

• Not checked yetcites Fig. 2

In the paper

“HYDE predicts that except for the developed regions of Europe, human use of land was insignificant in every biome and region before A.D. 1750 (Fig. 2 A and C).”

What the sources say

• Not checked yetcites Fig. 2 A and C

In the paper

“HYDE suggests that no region outside Europe reached these levels before A.D. 1900.”

What the sources say

• Not checked yetcites Fig. 2D

In the paper

“In KK10, land use emerges as a major global change far earlier in the Holocene, with more than 20% of Earth’s Temperate Woodlands already significantly used by 1000 B.C. and most other biomes by A.D. 1000 (Fig. 2B).”

What the sources say

• Not checked yetcites Fig. 2B

In the paper

“Regionally, KK10 predicts that 20% of Europe and Asia were already used significantly by 3000 B.C. and most other regions by A.D. 1000 (Fig. 2D)”

What the sources say

• Not checked yetcites Fig. 2D

In the paper

“Results from the first spatially explicit quantitative global land-use models over the course of the Holocene demonstrate that land-use intensification is a potentially pivotal process in both regulating the ecological impacts of human populations and in sustaining their global growth from the beginning of the Holocene to the present day.”

In the paper

“Boserup’s theory opposed the classic Malthusian claim that human populations were limited by agricultural productivity (36)”

What the sources say

• Not checked yetcites [36] Malthus TR. An Essay on the Principle of Population, as it Affects the Future Improvement of Society, with Remarks on the Speculations of Mr Godwin, M. Condorcet, and other writers. London: J. Johnson; 1798. pp. 3–143. [Google Scholar]

In the paper

“proposing instead that agriculturalists increased productivity only when population increases demanded this, because their objective was to invest the least amount of labor, technology, and other resources necessary to support their livelihoods, even when the technological capacity for greater productivity was available (34, 37).”

What the sources say

• Not checked yetcites [34] Boserup E. The Conditions of Agricultural Growth: The Economics of Agrarian Change under Population Pressure. London: Allen & Unwin; 1965. p. 124. [Google Scholar]
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In the paper

“Overall, these global model intercomparisons reveal two very different Earth histories, one in which land use has recently accelerated, and one in which land use began early and became strikingly more efficient over time, leading to recoveries in some regions.”

In the paper

“No single existing model of Holocene land use is able to make entirely accurate global predictions”

In the paper

“By this model, hunter-gatherer’s use of fire to enhance foraging success is a form of land-use intensification, as is land clearing for shifting cultivation, wet rice cultivation, the moldboard plow, and contemporary use of synthetic nitrogen fertilizer and mechanization (44, 45).”

What the sources say

• Not checked yetcites [44] Grigg DB. The Agricultural Systems of the World: An Evolutionary Approach. Cambridge, UK: Cambridge Univ Press; 1974. p. 358. [Google Scholar] source
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In the paper

“Even as human populations increase beyond seven billion and per capita demand for food is increasing, rates of growth in the global extent and per capita use of land for agriculture seem to be declining (22).”

What the sources say

• Not checked yetcites [22] Foley JA, et al. Solutions for a cultivated planet. Nature. 2011;478(7369):337–342. doi: 10.1038/nature10452. [DOI] [PubMed] [Google Scholar] source

In the paper

“As a result, a general trend toward increasing productivity with population density is attained not as a smooth and continuous process but through a complex succession of land system regime shifts, some of them regressive, with populations and their production systems subject to both surplus production and productivity crises, as depicted in Fig. 3.”

What the sources say

• Not checked yetcites Fig. 3

In the paper

“Boserup’s theory inspired a wide array of intensification theories across archaeology (14), anthropology (38), geography (39), development studies (40), economics, environmental history, and other disciplines and has been extended to include land tenure and other social institutions, market forces, and nonagricultural populations (39, 41, 42).”

What the sources say

• Not checked yetcites [14] Kirch PV. Archaeology and global change: The holocene record. Annu Rev Environ Resour. 2005;30(1):409. [Google Scholar] source
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In the paper

“with long-term impacts from forest clearing, increased fire frequencies, megafaunal extinctions, species invasions, soil erosion, and others (13, 14)”

What the sources say

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In the paper

“Studies have suggested that intentional burning could have had very large effects on vegetation cover in the mesic environments of New Zealand (49), the wet tropical forests of the pre-Columbian Amazon (50), and across the savannas and woodlands of Africa (51).”

What the sources say

• Not checked yetcites [49] McWethy DB, et al. Rapid landscape transformation in South Island, New Zealand, following initial Polynesian settlement. Proc Natl Acad Sci USA. 2010;107(50):21343–21348. doi: 10.1073/pnas.1011801107. [DOI] [PMC free article] [PubMed] [Google Scholar] source
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In the paper

“there are significant differences in the land-use definitions of different models, with HYDE focusing exclusively on cultivated, pasture, and urban areas, and KK10 on land use more generally, including shifting cultivation and forest harvest along with agricultural land use.”

What the sources say

• Not checked yetcites [31] Klein Goldewijk K, Beusen A, van Drecht G, de Vos M. The HYDE 3.1 spatially explicit database of human induced global land use change over the past 12,000 years. Glob Ecol Biogeogr. 2011;20(1):73–86. [Google Scholar] source
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In the paper

“Most continental to global reviews of the Holocene sedimentary charcoal record have concluded that fire activity is most strongly correlated with climate variability and suggest that anthropogenic burning had only local effects on land cover (52, 53).”

What the sources say

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In the paper

“In Southwest Asia (by 7000 B.C.) and Europe (by 5000 B.C.), the early presence of intensive land-use technologies has been confirmed by stable nitrogen isotope ratios in preserved crop grains, indicating that manures were used to sustain intensive cultivation near settlements (90, 91).”

What the sources say

• Not checked yetcites [90] Bogaard A, Heaton THE, Poulton P, Merbach I. The impact of manuring on nitrogen isotope ratios in cereals: Archaeological implications for reconstruction of diet and crop management practices. J Archaeol Sci. 2007;34(3):335–343. [Google Scholar] source
• Not checked yetcites [91] Bogaard A. ‘Garden Agriculture’ and the nature of early farming in Europe and the near East. World Archaeol. 2005;37(2):177–196. [Google Scholar] source

In the paper

“Although some pathways led from sedentary hunter-gatherers to early farmers, as in Southwest Asia or Yangtze China (68), others shifted from mobile hunting to the addition of herding first, for example in Africa (70), or from mobile hunting and gathering to mobile forms of agriculture like shifting cultivation, as in India (75), New Guinea (76), or South America (77).”

What the sources say

• Not checked yetcites [68] Fuller D, Qin L. Declining oaks, increasing artistry, and cultivating rice: The environmental and social context of the emergence of farming in the Lower Yangtze Region. Environ Archaeol. 2010;15(2):139–159. [Google Scholar] source
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In the paper

“As populations gradually increased, more intensive land-use practices were adopted to sustain them (intensification), or populations migrated to areas with lower levels of land use (extensification), including uninhabited wildlands.”

In the paper

“Once settled into new environments, human populations grew to levels unprecedented by earlier Hominins, putting pressure on plant and animal resources that ultimately led to expanding human procurement of increasingly smaller and harder to catch prey, in an adaptive transition that archaeologists have dubbed the “broad spectrum revolution” (57).”

What the sources say

• Not checked yetcites [57] Stiner MC. Thirty years on the “broad spectrum revolution” and paleolithic demography. Proc Natl Acad Sci USA. 2001;98(13):6993–6996. doi: 10.1073/pnas.121176198. [DOI] [PMC free article] [PubMed] [Google Scholar] source

In the paper

“Although existing archaeological and historical evidence seems to support this theory in general, data are not currently available at the levels necessary to quantify the status of agricultural land-use intensification in specific regions and time periods across the Holocene.”

In the paper

“Nevertheless, the evidence is clear that agricultural human populations had spread across most continents by the mid-Holocene, leading to the clearing of native vegetation and herbivores, their replacement with domesticates, and the increasingly intensive application of techniques and inputs to enhance the productivity of land as populations became denser (44, 61).”

What the sources say

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In the paper

“These techniques may have boosted the nutritional returns on foraging efforts for small seeds and tubers to levels that made them worth exploiting at high levels for the first time (59), thereby potentially setting them on course to later domestication (60).”

What the sources say

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In the paper

“Processing techniques such as grinding, boiling, fermenting, and roasting were gradually adopted to enhance nutrient bioavailability from plant and animal foods, further increasing the amount of food extractable from a given area of land (59).”

What the sources say

• Not checked yetcites [59] Wollstonecroft M. Investigating the role of food processing in human evolution: A niche construction approach. Archaeological and Anthropological Sciences. 2011;3(1):141–150. [Google Scholar] source

In the paper

“Similarly, as rice agriculture gradually spread southward and westward, reaching Thailand and northern India by 2000 B.C., less intensive rainfed and naturally inundated systems were first used (72), followed much later by more intensive systems (44).”

What the sources say

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In the paper

“By the early Holocene, hunter-gatherer populations had spread across the Earth and depended on early land-use intensification processes to survive and to grow and lived mostly within ecosystems reshaped by their ancestors to enhance their productivity.”

In the paper

“Some developed at the Pleistocene–Holocene transition, including Southwest Asia (60, 64), South America (65, 66), and North China (67), whereas others took place closer to 6,000–7,000 y ago, such as Yangtze China (68) and perhaps central America (cf. 69).”

What the sources say

• Not checked yetcites [60] Fuller DQ, Willcox G, Allaby RG. Cultivation and domestication had multiple origins: Arguments against the core area hypothesis for the origins of agriculture in the Near East. World Archaeol. 2011;43(4):628–652. [Google Scholar] source
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In the paper

“The rise and dispersal of agricultural populations across Earth’s land was likely driven by increasing rates of population growth sustained by early agricultural economies (93–95), which likely enabled them to dominate Earth’s most productive landscapes, where increasingly intensive agricultural systems became established in most regions of the world, despite the periodic collapse of individual”

What the sources say

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In the paper

“In China, historical evidence supports a long and gradual history of extensification and later intensification of rice production, even though advanced technologies were available early (92).”

What the sources say

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In the paper

“Widespread agricultural land use by mid-Holocene is further evidenced by altered fire regimes that may have transformed vegetation structure and species composition across many regions, with woodland ecosystems from the Mediterranean to the Tropics increasingly recognized as the bio-cultural legacies of long histories of prior human use (50, 74, 78–84).”

What the sources say

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In the paper

“Although preagricultural technologies for ecosystem engineering have far lower productivities than the agricultural technologies that came later, they still enabled human populations to grow beyond the capabilities of unaltered ecosystems to support them.”

In the paper

“Agricultural yields within the most densely populated and productive preindustrial land-use systems compared well with modern yields and were sustained in some regions for centuries to millennia, even though they also tended to require extreme inputs of labor and other socially unsustainable hardships (43–45, 92).”

What the sources say

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In the paper

“However, most simulation studies are based on a narrow set of land cover reconstructions over at most one millennium and do not incorporate the effects of land use and its intensification across the Holocene.”

In the paper

“Industrial technologies, especially mechanization, have also largely decoupled human labor from productivity increases, enabling an unprecedented proportion of human populations to live within cities, which even today occupy less than 1% of Earth’s ice-free land (19).”

What the sources say

• Not checked yetcites [19] Klein Goldewijk K, Beusen A, Janssen P. Long-term dynamic modeling of global population and built-up area in a spatially explicit way: HYDE 3.1. Holocene. 2010;20(4):565–573. [Google Scholar] source

In the paper

“Still, the scale and rate of urbanization over the past two centuries is unprecedented, with the percentage of human populations living in cities growing from approximately 7% in 1800, to 16% in 1900, to more than 50% today (19).”

What the sources say

• Not checked yetcites [19] Klein Goldewijk K, Beusen A, Janssen P. Long-term dynamic modeling of global population and built-up area in a spatially explicit way: HYDE 3.1. Holocene. 2010;20(4):565–573. [Google Scholar] source

In the paper

“Despite their unprecedented scale, sophistication, and productive capacity, the rise of intensive industrial land-use systems fits well within our general definition of land-use intensification (Fig. 3), with increasing human population densities, concentrated within urban settlements in this case, driving ever increasing productivity per unit area of land.”

What the sources say

• Not checked yetcites Fig. 3

In the paper

“The first urban populations dependent on trade for their sustenance emerged as early as 4000 B.C. in the Near East and became common across the Indus Valley, Egypt, and China by 1500 B.C. (97), with major cities (populations >100,000) developing by 2000 y ago in the Near East, Europe, and Asia (14).”

What the sources say

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In the paper

“Vegetation cover changes caused by land use can alter regional and global climate through both biogeochemical (emissions of greenhouse gases and aerosols) and biogeophysical (albedo, evapotranspiration, and surface roughness) feedbacks with the atmosphere, with reverse effects following land abandonment, reforestation, and other vegetation recoveries (107).”

What the sources say

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In the paper

“The massive food and resource demands of large, wealthy, and growing urban populations require high levels of agricultural surplus production and trade, which tend to be met by increasingly intensive and productive agricultural systems concentrated in Earth’s most productive agricultural lands, supported by ever larger scales of farming operations, trading systems, and technological institutions (”

What the sources say

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In the paper

“As agriculture continues to intensify and migration to cities depopulates rural landscapes, lands less suited to industrial-scale production are being abandoned in some regions, enabling large-scale forest recoveries, especially where governance systems support this (84, 105, 106).”

What the sources say

• Not checked yetcites [84] Foster DR, Motzkin G, Slater B. Land-use history as long-term broad-scale disturbance: Regional forest dynamics in central New England. Ecosystems (N Y) 1998;1(1):96–119. [Google Scholar] source
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In the paper

“Modeled regional and global climate responses to simulated (107, 110, 111) and reconstructed historical land cover changes over the past century (112) and millennium (113) generally agree that anthropogenic deforestation drives biogeophysical cooling at higher latitudes and warming in low latitudes and suggest that biogeochemical impacts tend to exceed biogeophysical effects (113).”

What the sources say

• Not checked yetcites [107] Bounoua L, DeFries R, Collatz GJ, Sellers P, Khan H. Effects of land cover conversion on surface climate. Clim Change. 2002;52(1-2):29–64. [Google Scholar] source
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In the paper

“To be effective in conserving ecosystems and biodiversity altered by millennia of human interaction, ecological science and conservation will need to go beyond the view of humans as a recent disturbance and incorporate a solid theoretical and historical understanding of the dynamics of human populations and land-use systems and their role in shaping ecosystems over the long term (83, 115, 118).”

What the sources say

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In the paper

“increased fire frequencies are associated with low human population densities and fire suppression with higher population densities (117)”

What the sources say

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In the paper

“Concentrating human populations within cities transforms the economies of scale in human interactions, producing higher average incomes and enabling a wide array of novel social benefits as urban systems advance (98, 99), which in turn enable further growth and help to drive rural–urban migration (100, 101).”

What the sources say

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In the paper

“Combustion processes often leave signs of land use and related human activities, including enhanced fire rates and forest clearing (122) and the preindustrial use of harvested biomass for fuel (53, 117).”

What the sources say

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In the paper

“Although projected increases in greenhouse gas concentrations caused by fossil fuel combustion are expected to dominate 21st century climate change, some studies suggest that anthropogenic land use may yet be at least as important and may remain so in the near future (8).”

What the sources say

• Not checked yetcites [8] Feddema JJ, et al. The importance of land-cover change in simulating future climates. Science. 2005;310(5754):1674–1678. doi: 10.1126/science.1118160. [DOI] [PubMed] [Google Scholar] source

In the paper

“Maps depicting first significant land use were produced by overlaying maps of cells with land-use areas >20% of land area within each cell at each time period (20% criteria for significant land use as per refs. 1 and 115), for all cells where A.D. 2000 land use was also >20% of land area in each cell (earliest at the top; Fig. 1).”

What the sources say

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In the paper

“If, as suggested by intensification theory and archaeological data, land-use intensification was gradual across the Holocene, the results of historical modeling reveal an Earth significantly transformed by land use by 1000 B.C., with significant areas on nearly every continent now in recovery from past historical peaks of land use (Fig. 1B).”

In the paper

“Although the scale of these efforts would require unprecedented levels of support, standardized global sets of local historical land use and population reconstructions might ultimately enable strong empirical testing of the global importance and historical dynamics of land use as a force transforming the terrestrial biosphere across the Holocene.”

In the paper

“Global market integration has increased connectivity between world regions, with regions having the highest demand for land resources often experiencing agricultural abandonment and reforestation while displacing their production needs to less developed regions (127), mirroring patterns from the colonial era.”

What the sources say

• Not checked yetcites [127] Meyfroidt P, Rudel TK, Lambin EF. Forest transitions, trade, and the global displacement of land use. Proc Natl Acad Sci USA. 2010;107(49):20917–20922. doi: 10.1073/pnas.1014773107. [DOI] [PMC free article] [PubMed] [Google Scholar] source

In the paper

“Alternatively, if land use per capita has been fairly constant across the Holocene, early land use was mostly localized and globally insignificant and accelerated greatly only in recent centuries (Fig. 1A).”

In the paper

“These maps were then overlaid on maps depicting recovery from peak land use in each cell, assessed as the difference between A.D. 2000 land use and the historical maximum percentage land use (Fig. 1).”

In the paper

“These data were analyzed using a Geographic Information System to estimate global areas and populations within a simplified set of terrestrial biomes (aggregated from the potential vegetation classes of ref. 28) and world regions (after ref. 1).”

What the sources say

• Not checked yetcites [28] Ramankutty N, Foley JA. Estimating historical changes in global land cover: Croplands from 1700 to 1992. Global Biogeochem Cycles. 1999;13(4):997–1027. [Google Scholar] source
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In the paper

“The paleohistory of anthropogenic change across much of the Americas is especially unclear and controversial (e.g., refs. 74, 82, and 125) and may be exceptional compared with other continents.”

What the sources say

• Not checked yetcites [74] Munoz SE, Gajewski K. Distinguishing prehistoric human influence on late-Holocene forests in southern Ontario, Canada. Holocene. 2010;20(6):967–981. [Google Scholar] source
• Not checked yetcites [82] Cronon W. Changes in the Land: Indians, Colonists, and the Ecology of New England. New York: Hill and Wang; 1983. p. 235. [Google Scholar]
• Not checked yetcites [125] Bush MB, Silman MR. Amazonian exploitation revisited: Ecological asymmetry and the policy pendulum. Front Ecol Environ. 2007;5(9):457–465. [Google Scholar] source

In the paper

“Although the evidence from archaeology and environmental history point toward the former view of land-use history, available data remain far from adequate to quantify the global significance of land use and intensification processes over the long term.”

In the paper

“there remain a wide array of societal challenges in adapting land systems to meet growing demands (104).”

What the sources say

• Not checked yetcites [104] Tilman D, Balzer C, Hill J, Befort BL. Global food demand and the sustainable intensification of agriculture. Proc Natl Acad Sci USA. 2011;108(50):20260–20264. doi: 10.1073/pnas.1116437108. [DOI] [PMC free article] [PubMed] [Google Scholar] source

In the paper

“Global land use and population datasets divided into five arc minute grid cells (spatial resolution ∼85 km2 at the equator) were obtained for the HYDE 3.1 (19, 31) and KK10 (4) global land-use models.”

What the sources say

• Not checked yetcites [19] Klein Goldewijk K, Beusen A, Janssen P. Long-term dynamic modeling of global population and built-up area in a spatially explicit way: HYDE 3.1. Holocene. 2010;20(4):565–573. [Google Scholar] source
• Not checked yetcites [31] Klein Goldewijk K, Beusen A, van Drecht G, de Vos M. The HYDE 3.1 spatially explicit database of human induced global land use change over the past 12,000 years. Glob Ecol Biogeogr. 2011;20(1):73–86. [Google Scholar] source
• Not checked yetcites [4] Kaplan JO, et al. Holocene carbon emissions as a result of anthropogenic land cover change. Holocene. 2011;21(5):775–791. [Google Scholar] source