scholarly journals Global maps of cropland extent and change show accelerated cropland expansion in the twenty-first century

Nature Food ◽  
2021 ◽  
Author(s):  
Peter Potapov ◽  
Svetlana Turubanova ◽  
Matthew C. Hansen ◽  
Alexandra Tyukavina ◽  
Viviana Zalles ◽  
...  
Keyword(s):  
Time Series ◽  
Agricultural Land ◽  
Net Primary Production ◽  
Terrestrial Ecosystems ◽  
First Century ◽  
Tree Cover ◽  
Sustainable Food ◽  
Cropland Area ◽  
Per Capita ◽  
Twenty First Century

AbstractSpatiotemporally consistent data on global cropland extent is essential for tracking progress towards sustainable food production. In the present study, we present an analysis of global cropland area change for the first two decades of the twenty-first century derived from satellite data time-series. We estimate that, in 2019, the cropland area was 1,244 Mha with a corresponding total annual net primary production (NPP) of 5.5 Pg C year−1. From 2003 to 2019, cropland area increased by 9% and cropland NPP by 25%, primarily due to agricultural expansion in Africa and South America. Global cropland expansion accelerated over the past two decades, with a near doubling of the annual expansion rate, most notably in Africa. Half of the new cropland area (49%) replaced natural vegetation and tree cover, indicating a conflict with the sustainability goal of protecting terrestrial ecosystems. From 2003 to 2019, global per-capita cropland area decreased by 10% due to population growth. However, the per-capita annual cropland NPP increased by 3.5% as a result of intensified agricultural land use. The presented global, high-resolution, cropland map time-series supports monitoring of natural land appropriation at the local, national and international levels.

scholarly journals Accelerated global cropland expansion and primary production increase in the 21st century

2021 ◽  
Author(s):  
Peter Potapov ◽  
Svetlana Turubanova ◽  
Matthew Hansen ◽  
Alexandra Tyukavina ◽  
Viviana Zalles ◽  
...  
Keyword(s):  
Time Series ◽  
Primary Production ◽  
21St Century ◽  
Food Production ◽  
Agricultural Land ◽  
Net Primary Production ◽  
Sustainable Food ◽  
Cropland Area ◽  
Sustainable Food Production ◽  
Per Capita

Abstract Spatiotemporally consistent data on global cropland extent is a key to tracking progress toward hunger eradication and sustainable food production1,2. Here, we present an analysis of global cropland area and change for the first two decades of the 21st century derived from satellite data time-series. We estimate 2019 cropland area to be 1,244 Mha with a corresponding total annual net primary production (NPP) of 5.5 Pg C yr-1. From 2003 to 2019, cropland area increased by 9% and crop NPP by 25%, primarily due to agricultural expansion in Africa and South America. Global cropland expansion accelerated over the past two decades, with a near doubling of the annual expansion rate, most notably in Africa. Half of the new cropland area (49%) replaced natural vegetation and tree cover, indicating a conflict with the sustainability goal of protecting terrestrial ecosystems. From 2003 to 2019 global population growth outpaced cropland area expansion, and per capita cropland area decreased by 10%. However, the per capita annual crop NPP increased by 3.5% as a result of intensified agricultural land use. The presented global high-resolution cropland map time-series supports monitoring of sustainable food production at the local, national, and international levels.

scholarly journals Seasonal Responses of Terrestrial Carbon Cycle to Climate Variations in CMIP5 Models: Evaluation and Projection

2017 ◽  
Vol 30 (16) ◽  
pp. 6481-6503 ◽  
Author(s):  
Yongwen Liu ◽  
Shilong Piao ◽  
Xu Lian ◽  
Philippe Ciais ◽  
W. Kolby Smith
Keyword(s):  
Temperature Sensitivity ◽  
Boreal Forests ◽  
Net Primary Production ◽  
Coupled Model ◽  
First Century ◽  
Cmip5 Models ◽  
Temperature And Precipitation ◽  
Northern High Latitude ◽  
Twenty First Century ◽  
Subarctic Ecosystems

Seventeen Earth system models (ESMs) from phase 5 of the Coupled Model Intercomparison Project (CMIP5) were evaluated, focusing on the seasonal sensitivities of net biome production (NBP), net primary production (NPP), and heterotrophic respiration (Rh) to interannual variations in temperature and precipitation during 1982–2005 and their changes over the twenty-first century. Temperature sensitivity of NPP in ESMs was generally consistent across northern high-latitude biomes but significantly more negative for tropical and subtropical biomes relative to satellite-derived estimates. The temperature sensitivity of NBP in both inversion-based and ESM estimates was generally consistent in March–May (MAM) and September–November (SON) for tropical forests, semiarid ecosystems, and boreal forests. By contrast, for inversion-based NBP estimates, temperature sensitivity of NBP was nonsignificant for June–August (JJA) for all biomes except boreal forest; whereas, for ESM NBP estimates, the temperature sensitivity for JJA was significantly negative for all biomes except shrublands and subarctic ecosystems. Both satellite-derived NPP and inversion-based NBP are often decoupled from precipitation, whereas ESM NPP and NBP estimates are generally positively correlated with precipitation, suggesting that ESMs are oversensitive to precipitation. Over the twenty-first century, changes in temperature sensitivities of NPP, Rh, and NBP are consistent across all RCPs but stronger under more intensive scenarios. The temperature sensitivity of NBP was found to decrease in tropics and subtropics and increase in northern high latitudes in MAM due to an increased temperature sensitivity of NPP. Across all biomes, projected temperature sensitivity of NPP decreased in JJA and SON. Projected precipitation sensitivity of NBP did not change across biomes, except over grasslands in MAM.

The Twenty-First Century Agricultural Land Rush

2014 ◽  
Author(s):  
Gregory Thaler
Keyword(s):  
Global Economy ◽  
Large Scale ◽  
Structural Changes ◽  
Agricultural Land ◽  
First Century ◽  
Political Actors ◽  
Land Grab ◽  
Investment Capital ◽  
Twenty First Century ◽  
Political Economic

The 2007–2008 global food crisis has been followed by a rapid acceleration in large-scale agricultural land deals, which activists have labeled a “global land grab.” This chapter explores the origins of this twenty-first century agricultural land rush, its geography, and the responses it has engendered. The origins of the land rush are located in interlinked food, financial, and ecological crises that are indicative of fundamental shifts in the global political economy. In response to these crises, land grabbing represents an effort to reconstruct a stable political-economic order, both on the part of investment capital seeking to relaunch accumulation and on the part of political actors and companies seeking to secure stable supplies of food and energy. The geography of the land rush is analyzed through the interrelated variables of land availability, the structural position of a country in the global economy, and a country’s domestic institutional structure. Finally, the main theoretical positions in the debate over land deals are linked to distinct political responses. The real historical significance of the structural changes behind the agricultural land rush suggests that the implications of the land rush will be both durable and systemic.

scholarly journals Climate Change Induced Trends and Uncertainties in Phytoplankton Spring Bloom Dynamics

2021 ◽  
Vol 8 ◽  
Author(s):  
Lőrinc Mészáros ◽  
Frank van der Meulen ◽  
Geurt Jongbloed ◽  
Ghada El Serafy
Keyword(s):  
Time Series ◽  
Chlorophyll A ◽  
Spring Bloom ◽  
First Century ◽  
Fusion Model ◽  
Feature Extraction Method ◽  
Structural Time Series ◽  
Twenty First Century

Spring phytoplankton blooms in the southern North Sea substantially contribute to annual primary production and largely influence food web dynamics. Studying long-term changes in spring bloom dynamics is therefore crucial for understanding future climate responses and predicting implications on the marine ecosystem. This paper aims to study long term changes in spring bloom dynamics in the Dutch coastal waters, using historical coastal in-situ data and satellite observations as well as projected future solar radiation and air temperature trajectories from regional climate models as driving forces covering the twenty-first century. The main objective is to derive long-term trends and quantify climate induced uncertainties in future coastal phytoplankton phenology. The three main methodological steps to achieve this goal include (1) developing a data fusion model to interlace coastal in-situ measurements and satellite chlorophyll-a observations into a single multi-decadal signal; (2) applying a Bayesian structural time series model to produce long-term projections of chlorophyll-a concentrations over the twenty-first century; and (3) developing a feature extraction method to derive the cardinal dates (beginning, peak, end) of the spring bloom to track the historical and the projected changes in its dynamics. The data fusion model produced an enhanced chlorophyll-a time series with improved accuracy by correcting the satellite observed signal with in-situ observations. The applied structural time series model proved to have sufficient goodness-of-fit to produce long term chlorophyll-a projections, and the feature extraction method was found to be robust in detecting cardinal dates when spring blooms were present. The main research findings indicate that at the study site location the spring bloom characteristics are impacted by the changing climatic conditions. Our results suggest that toward the end of the twenty-first century spring blooms will steadily shift earlier, resulting in longer spring bloom duration. Spring bloom magnitudes are also projected to increase with a 0.4% year−1 trend. Based on the ensemble simulation the largest uncertainty lies in the timing of the spring bloom beginning and -end timing, while the peak timing has less variation. Further studies would be required to link the findings of this paper and ecosystem behavior to better understand possible consequences to the ecosystem.

scholarly journals Twenty-first century ocean warming, acidification, deoxygenation, and upper-ocean nutrient and primary production decline from CMIP6 model projections

2020 ◽  
Vol 17 (13) ◽  
pp. 3439-3470 ◽  
Author(s):  
Lester Kwiatkowski ◽  
Olivier Torres ◽  
Laurent Bopp ◽  
Olivier Aumont ◽  
Matthew Chamberlain ◽  
...  
Keyword(s):  
Primary Production ◽  
Radiative Forcing ◽  
Net Primary Production ◽  
Ocean Warming ◽  
First Century ◽  
Upper Ocean ◽  
Global Changes ◽  
Model Uncertainties ◽  
Near Surface ◽  
Twenty First Century

Abstract. Anthropogenic climate change is projected to lead to ocean warming, acidification, deoxygenation, reductions in near-surface nutrients, and changes to primary production, all of which are expected to affect marine ecosystems. Here we assess projections of these drivers of environmental change over the twenty-first century from Earth system models (ESMs) participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6) that were forced under the CMIP6 Shared Socioeconomic Pathways (SSPs). Projections are compared to those from the previous generation (CMIP5) forced under the Representative Concentration Pathways (RCPs). A total of 10 CMIP5 and 13 CMIP6 models are used in the two multi-model ensembles. Under the high-emission scenario SSP5-8.5, the multi-model global mean change (2080–2099 mean values relative to 1870–1899) ± the inter-model SD in sea surface temperature, surface pH, subsurface (100–600 m) oxygen concentration, euphotic (0–100 m) nitrate concentration, and depth-integrated primary production is +3.47±0.78 ∘C, -0.44±0.005, -13.27±5.28, -1.06±0.45 mmol m−3 and -2.99±9.11 %, respectively. Under the low-emission, high-mitigation scenario SSP1-2.6, the corresponding global changes are +1.42±0.32 ∘C, -0.16±0.002, -6.36±2.92, -0.52±0.23 mmol m−3, and -0.56±4.12 %. Projected exposure of the marine ecosystem to these drivers of ocean change depends largely on the extent of future emissions, consistent with previous studies. The ESMs in CMIP6 generally project greater warming, acidification, deoxygenation, and nitrate reductions but lesser primary production declines than those from CMIP5 under comparable radiative forcing. The increased projected ocean warming results from a general increase in the climate sensitivity of CMIP6 models relative to those of CMIP5. This enhanced warming increases upper-ocean stratification in CMIP6 projections, which contributes to greater reductions in upper-ocean nitrate and subsurface oxygen ventilation. The greater surface acidification in CMIP6 is primarily a consequence of the SSPs having higher associated atmospheric CO2 concentrations than their RCP analogues for the same radiative forcing. We find no consistent reduction in inter-model uncertainties, and even an increase in net primary production inter-model uncertainties in CMIP6, as compared to CMIP5.

scholarly journals The Rainfall Sensitivity of Tropical Net Primary Production in CMIP5 Twentieth- and Twenty-First-Century Simulations*

2015 ◽  
Vol 28 (23) ◽  
pp. 9313-9331 ◽  
Author(s):  
Robinson I. Negrón-Juárez ◽  
William J. Riley ◽  
Charles D. Koven ◽  
Ryan G. Knox ◽  
Philip G. Taylor ◽  
...  
Keyword(s):  
Primary Production ◽  
Net Primary Production ◽  
Coupled Model ◽  
First Century ◽  
Annual Rainfall ◽  
Cmip5 Models ◽  
Co2 Fertilization ◽  
Intercomparison Project ◽  
Twenty First Century ◽  
The Individual

Abstract In this study, the authors used the relationship between mean annual rainfall (MAR) and net primary production (NPP) (MAR–NPP) observed in tropical forests to evaluate the performance (twentieth century) and predictions (twenty-first century) of tropical NPP from 10 earth system models (ESMs) from phase 5 of the Coupled Model Intercomparison Project (CMIP5). Over the tropical forest domain most of the CMIP5 models showed a positive correlation between NPP and MAR similar to observations. The GFDL, CESM1, CCSM4, and Beijing Normal University (BNU) models better represented the observed MAR–NPP relationship. Compared with observations, the models were able to reproduce the seasonality of rainfall over areas with long dry seasons, but NPP seasonality was difficult to evaluate given the limited observations. From 2006 to 2100, for representative concentration pathway 8.5 (RCP8.5) (and most RCP4.5 simulations) all models projected increases in NPP, but these increases occurred at different rates. By the end of the twenty-first century the models with better performance against observed NPP–MAR projected increases in NPP between ~2% (RCP4.5) and ~19% (RCP8.5) relative to contemporary observations, representing increases of ~9% and ~25% relative to their historical simulations. When climate and CO2 fertilization are considered as separate controls on plant physiology, the current climate yields maximum productivity. However, as future climate changes become detrimental to productivity, CO2 fertilization becomes the dominant response, resulting in an overall increase in NPP toward the end of the twenty-first century. Thus, the way in which models represent CO2 fertilization affects their performance. Further studies addressing the individual and simultaneous effect of other climate variables on NPP are needed.

scholarly journals The global nitrogen cycle in the twenty-first century

2013 ◽  
Vol 368 (1621) ◽  
pp. 20130164 ◽  
Author(s):  
David Fowler ◽  
Mhairi Coyle ◽  
Ute Skiba ◽  
Mark A. Sutton ◽  
J. Neil Cape ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Agricultural Land ◽  
Anthropogenic Activities ◽  
Terrestrial Ecosystems ◽  
Control Measures ◽  
First Century ◽  
Secondary Pollutants ◽  
Biological Nitrogen ◽  
Global Nitrogen Cycle

Global nitrogen fixation contributes 413 Tg of reactive nitrogen (N r ) to terrestrial and marine ecosystems annually of which anthropogenic activities are responsible for half, 210 Tg N. The majority of the transformations of anthropogenic N r are on land (240 Tg N yr −1 ) within soils and vegetation where reduced N r contributes most of the input through the use of fertilizer nitrogen in agriculture. Leakages from the use of fertilizer N r contribute to nitrate (NO 3 − ) in drainage waters from agricultural land and emissions of trace N r compounds to the atmosphere. Emissions, mainly of ammonia (NH 3 ) from land together with combustion related emissions of nitrogen oxides (NO x ), contribute 100 Tg N yr −1 to the atmosphere, which are transported between countries and processed within the atmosphere, generating secondary pollutants, including ozone and other photochemical oxidants and aerosols, especially ammonium nitrate (NH 4 NO 3 ) and ammonium sulfate (NH 4 ) 2 SO 4 . Leaching and riverine transport of NO 3 contribute 40–70 Tg N yr −1 to coastal waters and the open ocean, which together with the 30 Tg input to oceans from atmospheric deposition combine with marine biological nitrogen fixation (140 Tg N yr −1 ) to double the ocean processing of N r . Some of the marine N r is buried in sediments, the remainder being denitrified back to the atmosphere as N 2 or N 2 O. The marine processing is of a similar magnitude to that in terrestrial soils and vegetation, but has a larger fraction of natural origin. The lifetime of N r in the atmosphere, with the exception of N 2 O, is only a few weeks, while in terrestrial ecosystems, with the exception of peatlands (where it can be 10 2 –10 3 years), the lifetime is a few decades. In the ocean, the lifetime of N r is less well known but seems to be longer than in terrestrial ecosystems and may represent an important long-term source of N 2 O that will respond very slowly to control measures on the sources of N r from which it is produced.

New Challenge of Legal Studies in Twenty-First-Century Asia: Towards a Sustainable Society

2019 ◽  
Vol 6 (2) ◽  
pp. 395-412
Author(s):  
Yoshiki KURUMISAWA
Keyword(s):  
Economic Growth ◽  
Agricultural Land ◽  
Environmental Law ◽  
Market Competition ◽  
First Century ◽  
Industrial Society ◽  
Sustainable Society ◽  
Legal Studies ◽  
Twenty First Century ◽  
The Government

AbstractSince the 1990s, the Japanese social structure has been changing mainly due to economic globalization. The gap between rich and poor has been widened. The economic policy of the government that tries to introduce the market-competition principle into all sectors in order to revive economic growth is promoting such social change. It seems illusionary that either activating market competition or the reconstruction of the welfare state could revive economic growth. Instead, we should consider a transformation from an industrial to a sustainable society as an inevitable course of social development in the twenty-first century. In 2015, the Japanese Association of the Sociology of Law (JASL) held a symposium entitled “Law and Legal Science in the Transformation to Sustainable Society” during its annual meeting. The main issue was which role legal studies can/must play in such a transformation. I think there are two different approaches. One is to establish the “sustainable principle” as a legal principle like the “precautionary principle” in environmental law. The other approach is to reconsider and reconstruct fundamental legal categories of modern law, which have supported industrial society as its legal infrastructure. This approach will be the subject of the paper. I will deal with the case of property rights to agricultural land.

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