ArticlePublisher preview available

Changing risks of simultaneous global breadbasket failure

DOI:10.1038/s41558-019-0600-z
Authors:
Franziska Gaupp at International Institute for Applied Systems Analysis
Franziska Gaupp
Jim Hall at University of Oxford
Jim Hall
Stefan Hochrainer-Stigler at International Institute for Applied Systems Analysis
Stefan Hochrainer-Stigler
Simon James Dadson at University of Oxford
Simon James Dadson
Read publisher preview
Download citation
To read the full-text of this research, you can request a copy directly from the authors.

Abstract and Figures

The risk of extreme climatic conditions leading to unusually low global agricultural production is exacerbated if more than one global ‘breadbasket’ is exposed at the same time. Such shocks can pose a risk to the global food system, amplifying threats to food security, and could potentially trigger other systemic risks1,2. While the possibility of climatic extremes hitting more than one breadbasket has been postulated3,4, little is known about the actual risk. Here we combine region-specific data on agricultural production with spatial statistics of climatic extremes to quantify the changing risk of low production for the major food-producing regions (breadbaskets) over time. We show an increasing risk of simultaneous failure of wheat, maize and soybean crops across the breadbaskets analysed. For rice, risks of simultaneous adverse climate conditions have decreased in the recent past, mostly owing to solar radiation changes favouring rice growth. Depending on the correlation structure between the breadbaskets, spatial dependence between climatic extremes globally can mitigate or aggravate the risks for the global food production. Our analysis can provide the basis for more efficient allocation of resources to contingency plans and/or strategic crop reserves that would enhance the resilience of the global food system. The risk of concurrent climate extremes affecting breadbasket regions is increasing with climate change, with wheat, maize and soybean crops at risk of simultaneous failure. Correlation between the regions and climate extremes should be considered to ensure food security in the future.
Figures - available from: Nature Climate Change
This content is subject to copyright. Terms and conditions apply.
  • A preview of this full-text is provided by Springer Nature.
  • Learn more
Preview content only
Content available from Nature Climate Change
This content is subject to copyright. Terms and conditions apply.
Letters
https://doi.org/10.1038/s41558-019-0600-z
1Environmental Change Institute, University of Oxford, Oxford, UK. 2International Institute for Applied Systems Analysis, Laxenburg, Austria.
3School of Geography and the Environment, University of Oxford, Oxford, UK. *e-mail: gaupp@iiasa.ac.at
The risk of extreme climatic conditions leading to unusually
low global agricultural production is exacerbated if more than
one global ‘breadbasket’ is exposed at the same time. Such
shocks can pose a risk to the global food system, amplifying
threats to food security, and could potentially trigger other
systemic risks1,2. While the possibility of climatic extremes
hitting more than one breadbasket has been postulated3,4,
little is known about the actual risk. Here we combine region-
specific data on agricultural production with spatial statistics
of climatic extremes to quantify the changing risk of low pro-
duction for the major food-producing regions (breadbaskets)
over time. We show an increasing risk of simultaneous failure
of wheat, maize and soybean crops across the breadbaskets
analysed. For rice, risks of simultaneous adverse climate con-
ditions have decreased in the recent past, mostly owing to
solar radiation changes favouring rice growth. Depending on
the correlation structure between the breadbaskets, spatial
dependence between climatic extremes globally can mitigate
or aggravate the risks for the global food production. Our
analysis can provide the basis for more efficient allocation of
resources to contingency plans and/or strategic crop reserves
that would enhance the resilience of the global food system.
Climate variability explains at least 30% of year-to-year fluctua-
tions in agricultural yield5. Under ‘normal’ climatic circumstances,
the global food system can compensate local crop losses through
grain storage and trade6. However, it is doubtful whether the global
food system is resilient to more extreme climatic conditions7, when
export restrictions8 and diminished grain stocks may undermine
liquidity in agricultural commodity markets, resulting in higher
price volatility. The food price crisis in 2007–2008 showed that
climatic shocks to agricultural production contribute to food price
spikes9 and famine10, with the potential to trigger other systemic
risks, including political unrest1 and migration2. Climatic telecon-
nections between global phenomena such as El Niño/Southern
Oscillation and regional climate extremes such as Indian heatwaves11
or flood risks around the globe12 could lead to simultaneous crop
failure in different regions13, therefore posing a risk to the global
food system6,8 and amplifying threats to global food security. While
the possibility of a climatic extreme hitting more than one breadbas-
ket has been a growing cause for concern3,4, few studies have inves-
tigated the probability of simultaneous production shocks14–16 or
estimated the joint likelihoods of adverse climate conditions17. Here
we present quantitative risk estimates of simultaneous breadbasket
failures due to climatic extremes by explicitly accounting for spatial
dependence structures between the regions and show how risk has
changed over time.
We analysed climatic and crop yield data (Methods) for the main
agricultural regions within the highest crop-producing countries
(the United States, Argentina, Europe, Russia/Ukraine, China, India,
Australia, Indonesia and Brazil) by mass in both 1961 and 2012,
according to Food and Agriculture Organization data. The global
breadbaskets for each crop and corresponding states and provinces
are shown in Supplementary Fig. 1. For wheat, maize, soybean and
rice, the selected breadbaskets account for 74%, 74%, 81% and 74%
of the total production in the breadbasket countries and 56%, 56%,
73% and 38% of the total global production in 2012, respectively.
We developed region-dependent relationships between climatic
variables (temperature, precipitation and solar radiation indicators;
Supplementary Table 1) and logistically detrended crop yields using
data for the period 1967–2012, and we analysed the dependence
structure at regional and global scales using a vine copula approach
(Methods). We report results (1) for each breadbasket and the states/
provinces within that breadbasket and (2) aggregating across mul-
tiple breadbaskets at a global scale. We look at changes over time by
comparing the period 1967–1990 with 1991–2012. For the individ-
ual breadbaskets, increases of climate risk (defined as exceedance
of a region-specific climate threshold that corresponds to the lower
25th yield deviation percentile; Supplementary Fig. 3) and simul-
taneous crop failures of states/provinces within one breadbasket
were found for 18 out of 32 climate indicators across all regions and
crops. For example, for soybean in China, the critical climate indi-
cator is the number of days above 30 °C during the growing season
(Supplementary Table 1). While only 1.2% of extreme hot months
occurred simultaneously in all provinces of the Chinese soybean
breadbasket in any given year in the period 1967–1990 (defined
as the exceedance of the ‘days-above-30 °C’ temperature indica-
tor threshold), this increased to 18.4% for the period 1991–2012
(Fig. 1). This accords with other analyses18,19 that report a significant
increase in temperature extremes in China in recent decades.
On a global scale, there has been a substantial increase in the
probability of multiple global breadbasket failures for all crops
except rice (Fig. 2). The number of breadbaskets suffering from
an unfavourable climate for plant growth increased significantly
on average between the two periods for wheat, maize and soybean
and decreased for rice. Looking at the extremes, the annual prob-
ability of all breadbaskets experiencing climate risks simultaneously
increased from 0.3% to 1.2% for wheat, from 0.8% to 1.1% for maize
and from 1.7% to 2% for soybean. For rice, it decreased from 21.2%
to 11.8% between the two periods. Wheat has experienced the larg-
est increases in simultaneous climate risks (16.8% from an average
3.42 to 4 breadbaskets experiencing risks simultaneously). Risks
from temperature effects have increased in all temperature-sensi-
tive wheat breadbaskets, whereas precipitation risks have increased
only in India and Australia and decreased in China, Europe, Russia/
Ukraine and the United States (Supplementary Figs. 4 and 5). For
the summer crops soybean and maize, simultaneous risks have on
Changing risks of simultaneous global
breadbasket failure
Franziska Gaupp 1,2*, Jim Hall1, Stefan Hochrainer-Stigler2 and Simon Dadson3
NATURE CLIMATE CHANGE | VOL 10 | JANUARY 2020 | 54–57 | www.nature.com/natureclimatechange
54
Content courtesy of Springer Nature, terms of use apply. Rights reserved
... But reliance on global food trade does present the unique risk that production shocks in remote countries can lead to reduced availability of food, which can contribute to price spikes that make food unaffordable (Bren d 'Amour et al., 2016, Heslin et al., 2020, Marchand et al., 2016, Puma et al., 2015. In this context, the possibility of multiple simultaneous breadbasket yield shocks presents a potential risk to food security by limiting options for import diversification and raising the risk of export restrictions (Gaupp et al., 2020;Gaupp et al., 2019;Janetos et al., 2017, Mehrabi and Ramankutty, 2019, Tigchelaar et al., 2018. ...
... While the potential for these climate modes to affect crop yields in multiple breadbaskets at once has been established using a few case studies (Anderson et al., 2019;Singh et al., 2018), the importance of this mechanism to multiple breadbasket yield shocks as compared to those forced by random weather or non-climate factors is still poorly understood. A primary reason is that to date, research on multiple climate-forced breadbasket yield shocks has been limited by short statistical records of 38-47 years (Gaupp et al., 2020;Kornhuber et al., 2020;Mehrabi and Ramankutty, 2019;Tigchelaar et al., 2018) as noted in a recent review on multiple breadbasket failures (Hasegawa et al., 2022). Modes of climate variability such as ENSO, however, are complex phenomenon (Timmerman et al., 2018) that vary on interdecadal timescales in terms of amplitude and return-period (Wittenberg, 2009). ...
... For results using the historical dataset rather than static breadbaskets, which may be of interest with respect to the observed frequency of breadbasket yield shocks, see SI Figure 1. Breadbasket failures have been defined either as the lower quartile of observed yield anomalies (Gaupp et al., 2020;Raymond et al., 2022) or as a 10% deviation from expected yields (Caparas et al., 2021;Tigchelaar et al., 2018). The lower quartile of yield anomalies in our breadbaskets generally corresponds to yield deficits of between ~5% and 10%. ...
Climate variability and simultaneous breadbasket yield shocks as observed in long-term yield records
Article
Full-text available
That climate variability and change can potentially force multiple simultaneous breadbasket crop yield shocks has been established. But research quantifying the mechanisms behind such simultaneous shocks has been constrained by short records of crop yields. Here we compile a dataset of subnational crop yields in 25 countries dating back to 1900 to study the frequency and trends in multiple breadbasket yield shocks and how large-scale climate anomalies on interannual timescales have affected multiple breadbasket yield shocks over the last century. We find that major simultaneous breadbasket yield shocks have occurred in at least three, four, or five of nine breadbaskets 10.3%, 2.3% and 1.1% of the time for maize and 18.4%, 4.6% and 2.3% of the time for wheat. Furthermore, we find that multiple breadbasket yield shocks decreased in frequency even as those breadbaskets experience increasingly frequent climate-related shocks. For both maize and wheat breadbaskets, there were fewer simultaneous yield shocks during the 1975-2017 time period as compared to 1931-1975. Finally, we find that interannual modes of climate variability-such as the El Niño Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD), and the North Atlantic Oscillation (NAO)-have all affected the relative probability of simultaneous yield shocks in pairs of breadbaskets by up to 20-40% in both maize and wheat breadbaskets. While past literature has focused on the effects of ENSO, we find that at the global scale the NAO affects the overall number of wheat yield shocks most strongly despite only affecting northern hemisphere breadbaskets.
View
... It is also challenging to deal with concurrent heavy precipitation and floods in large river basins in multiple regions/countries, which lead to widespread infrastructure damage, loss of lives, and other substantial socioeconomic impacts (15,18,19). Spatially concurrent climate extremes may also impose a great risk to the global food supply chain and amplify threats to global food security (12,13,(20)(21)(22)(23). As supply chains are increasingly interconnected, climate-induced production failures in one region may trigger societal impacts in other regions through the trade networks, and simultaneous climate extremes in several agricultural regions may threaten global food security and affect the international financial market (21,23). ...
... Spatially concurrent climate extremes may also impose a great risk to the global food supply chain and amplify threats to global food security (12,13,(20)(21)(22)(23). As supply chains are increasingly interconnected, climate-induced production failures in one region may trigger societal impacts in other regions through the trade networks, and simultaneous climate extremes in several agricultural regions may threaten global food security and affect the international financial market (21,23). Beyond these impacts on our society, co-occurring climate extremes also pose serious threats to terrestrial ecosystems, for example, simultaneous large wildfires associated with hot and dry weather can overwhelm the suppression capacity, leading to greater fire damages and widespread forest mortality and environmental impacts (24). ...
Global concurrent climate extremes exacerbated by anthropogenic climate change
Article
Full-text available
  • Mar 2023
Increases in concurrent climate extremes in different parts of the world threaten the ecosystem and our society. However, spatial patterns of these extremes and their past and future changes remain unclear. Here, we develop a statistical framework to test for spatial dependence and show widespread dependence of temperature and precipitation extremes in observations and model simulations, with more frequent than expected concurrence of extremes around the world. Historical anthropogenic forcing has strengthened the concurrence of temperature extremes over 56% of 946 global paired regions, particularly in the tropics, but has not yet significantly affected concurrent precipitation extremes during 1901-2020. The future high-emissions pathway of SSP585 will substantially amplify the concurrence strength, intensity, and spatial extent for both temperature and precipitation extremes, especially over tropical and boreal regions, while the mitigation pathway of SSP126 can ameliorate the increase in concurrent climate extremes for these high-risk regions. Our findings will inform adaptation strategies to alleviate the impact of future climate extremes.
View
... This tendency of high-degree nodes (here, drought hubs) to connect with high-degree nodes is called homophily 56 (the tendency of a location to link with other areas of similar degree of connectivity, see Methods). For global drought, such affinity among drought hubs renders synchronous occurrences of regional droughts over several continents, possibly leading to simultaneous bread-basket failures 6 . A notable example is the 1982-1983 El Niño induced spatially compounding drought over multiple continents 17,36,57 . ...
Global droughts connected by linkages between drought hubs
Article
Full-text available
  • Jan 2023
Quantifying the spatial and interconnected structure of regional to continental scale droughts is one of the unsolved global hydrology problems, which is important for understanding the looming risk of mega-scale droughts and the resulting water and food scarcity and their cascading impact on the worldwide economy. Using a Complex Network analysis, this study explores the topological characteristics of global drought events based on the self-calibrated Palmer Drought Severity Index. Event Synchronization is used to measure the strength of association between the onset of droughts at different spatial locations within the time lag of 1-3 months. The network coefficients derived from the synchronization network indicate a highly heterogeneous connectivity structure underlying global drought events. Drought hotspot regions such as Southern Europe, Northeast Brazil, Australia, and Northwest USA behave as drought hubs that synchronize regionally and with other hubs at inter-continental or even inter-hemispheric scale. This observed affinity among drought hubs is equivalent to the ‘rich-club phenomenon’ in Network Theory, where ‘rich’ nodes (here, drought hubs) are tightly interconnected to form a club, implicating the possibility of simultaneous large-scale droughts over multiple continents.
View
... With increasing warming, the frequency, intensity and duration of heatwaves, droughts and extreme rainfall events are projected to increase in most world regions, increasingly threatening the stability of food supplies (IPCC 2019). For example, Gaupp et al. (2020) found an estimated 86% probability of losses across the world's maize breadbaskets with warming of 4°C, compared to 7% probability for 2°C warming under business-as-usual conditions and without considering crop adaptation to climate change. Likewise, in a business-as-usual scenario, Alae-Carew et al.'s (2020) review of predicted changes in environmental exposures has reported likely reductions in yields of non-staple vegetables and legumes. ...
Ensuring Access to Safe and Nutritious Food for All Through the Transformation of Food Systems
Chapter
Full-text available
  • Jan 2023
Action Track 1 of the Food Systems Summit offers an opportunity to bring together the crucial elements of food safety, nutrition, poverty and inequalities in the framework of food systems within the context of climate and environmental change to ensure that all people have access to a safe and nutritious diet. Achieving Action Track 1’s goal is essential to achieving the goals of the other Action Tracks. With less than a decade left to achieve the Sustainable Development Goals (SDGs), most countries are not on a course to hit either the World Health Organisation’s nutrition targets or the SDG 2 targets. The COVID-19 pandemic has exacerbated malnutrition and highlighted the need for food safety. The pandemic has also exposed the deep inequalities in both food systems and societies as a whole. Nonetheless, future food systems can address many of these failings and ensure safe and nutritious food for all. However, structural change is necessary to address the socio-economic drivers behind malnutrition, inequalities and the climate and environmental impacts of food. Adopting a whole-system approach in policy, research and monitoring and evaluation is crucial for managing trade-off and externalities from farm-level to national scales and across multiple sectors and agencies. Supply chain failures will need to be overcome and technology solutions adopted and adapted to specific contexts. A transformation of food systems requires coordinating changes in supply and demand in differentiated ways across world regions: bridging yield gaps and improving livestock feed conversion, largely through agro-ecological practices, deploying soil carbon sequestration and greenhouse gas mitigation at scale, and reducing food loss and waste, as well as addressing over-nourishment and shifting the diets of wealthy populations. The sustainability of global food systems also requires halting the expansion of agriculture into fragile ecosystems, while restoring degraded forests, fisheries, rangelands, peatlands and wetlands. Shifting to more sustainable consumption and production patterns within planetary boundaries will require efforts to influence food demand and diets, diversify food systems, and develop careful land-use planning and management. Integrative policies need to ensure that food prices reflect real costs (including major externalities caused by climate change, land degradation and biodiversity loss, and the public health impacts of malnutrition), reduce food waste and, at the same time, ensure the affordability of safe and healthy food and decent incomes and wages for farmers and food system workers. The harnessing of science and technology solutions and the sharing of actionable knowledge with all players in the food system offer many opportunities. Greater coordination of food system stakeholders is crucial for greater inclusion, greater transparency and more accountability. Sharing lessons and experiences will foster adaptive learning and responsive actions. Careful consideration of the trade-offs, externalities and costs of not acting is needed to ensure that the changes we make benefit all, and especially the most vulnerable in society.
View
Achieving Food Security Through a Food Systems Lens
Chapter
Full-text available
  • Mar 2023
Achieving food security for the global population of 8 billion will be a challenge without functional, equitable, and resilient food systems. This chapter examines the history of how food security has been framed and addressed in international development, and the importance of a food systems approach and mindset in tackling food security. While this new food systems framing is important in bringing together the myriad of actors and components that food touches upon, food security has become more complex in the modern, challenged world, and functional food systems do not necessarily equate to improved food security. As international goals and commitments are made, policymakers must consider how food systems engage with other systems, and the failures and successes that history has taught us in efforts to achieve food security for all.
View
The extreme 2016 wheat yield failure in France
Article
Full-text available
France suffered, in 2016, the most extreme wheat yield decline in recent history, with some districts losing 55% yield. To attribute causes, we combined the largest coherent detailed wheat field experimental dataset with statistical and crop model techniques, climate information, and yield physiology. The 2016 yield was composed of up to 40% fewer grains that were up to 30% lighter than expected across eight research stations in France. The flowering stage was affected by prolonged cloud cover and heavy rainfall when 31% of the loss in grain yield was incurred from reduced solar radiation and 19% from floret damage. Grain filling was also affected as 26% of grain yield loss was caused by soil anoxia, 11% by fungal foliar diseases, and 10% by ear blight. Compounding climate effects caused the extreme yield decline. The likelihood of these compound factors recurring under future climate change is estimated to change with a higher frequency of extremely low wheat yields.
View
Bias correcting climate model simulations using unpaired image-to-image translation networks
Article
  • Feb 2023
We assess the suitability of unpaired image-to-image translation networks for bias correcting data simulated by global atmospheric circulation models. We use the UNIT neural network architecture to map between data from the HadGEM3-A-N216 model and ERA5 reanalysis data in a geographical area centred on the South Asian monsoon, which has well-documented serious biases in this model. The UNIT network corrects cross-variable correlations and spatial structures but creates bias corrections with less extreme values than the target distribution. By combining the UNIT neural network with the classical technique of quantile mapping, we can produce bias corrections that are better than either alone. The UNIT+QM scheme is shown to correct cross-variable correlations, spatial patterns, and all marginal distributions of single variables. The careful correction of such joint distributions is of high importance for compound extremes research.
View
Genome-wide transcriptional response of Escherichia coli O157:H7 to light-emitting diodes with various wavelengths
Article
Full-text available
  • Feb 2023
We investigated the physiological and transcriptomic response of Escherichia coli at the early stationary phase to light-emitting diodes with different wavelengths. The growth and metabolic changes of E. coli O157:H7 were examined under the influence of 465, 520, and 625 nm illuminated light. Under 465 nm illumination, the growth of E. coli O157:H7 was significantly retarded compared to 520 nm and 625 nm illumination and non-illuminated control. Metabolic changes were examined under these illumination and non-illuminated conditions based on transcriptomic reads. Transcriptomic response under 520 nm and 625 nm remained almost similar to control except few up-and down-regulated genes. Carbohydrates metabolic transcriptomic reads were greatly down-regulated under 465 nm illumination compared to 520 nm and 625 nm illumination and non-illuminated control showing depletion of glucose as a sole energy source during the exponential phase. Fatty acid degradation such as fad regulon-related genes was up-regulated in cells under 465 nm illumination revealing the shifting of cells to use fatty acid as a new carbon energy source during the early stationary phase. Exposure of E. coli O157:H7 cells to 465 nm illuminated light down-regulated virulence factor genes such as hlyA, hlyB, hlyC, stx1A, stx2B, paa, and bdm. Under the stress of 465 nm illumination, expression of stress and flagellar motility-related genes were up-regulated causing consumption of energy and reduction in cell growth. Also, oxidative phosphorylated transcriptomic reads were up-regulated under 465 nm illumination probably due to the production of ROS that might involve in the reduction of cell growth during the early stationary phase. These results indicate that pathogenic E. coli O157:H7 respond differentially to a different wavelength of the light-emitting diodes used in this study.
View
Combined Organic Fertilizer and Straw Return Enhanced Summer Maize Productivity and Optimized Soil Nitrate–N distribution in Rainfed Summer Maize–Winter Wheat Rotation on the Southeast Loess Plateau
Article
  • Dec 2022
Organic fertilizer and straw return are sustainable measures for increasing crop yield and improving the soil environment. The present study investigated the effects of combined organic fertilizer and straw return on soil nutrient status, soil nitrate–N distribution, and crop productivity in rainfed maize–wheat rotation on the southeast Loess Plateau. Based on a long-term field fertilization experiment, we reported the effects of four fertilizer management strategies (i.e., chemical NP fertilizers [NP, conventional practice]; chemical NPK fertilizers [NPK]; chemical NP fertilizers combined with organic fertilizer [NPOF]; and chemical NP fertilizers combined with organic fertilizer and straw return [NPOFS]) on productivity in summer maize and winter wheat from 2015 to 2020 season and the soil properties in the 0–60-cm soil layer and the soil nitrate–N distribution in the 0–380-cm soil layer at maturity of winter wheat in 2020. The results averaged from 2015 to 2020 showed that NPOFS increased the grain yield of summer maize by 10.34–11.25%, and water use efficiency by 21.44–32.54%, compared with NP, NPK, and NPOF; however, it had no significant effect on winter wheat yield. All four treatments benefited topsoil (0–20 cm) properties, and NPOFS was superior to NP, NPK, and NPOF in increasing the content of soil organic matter, total nitrogen, available phosphorus, and available potassium, in the 0–60-cm soil layer. Meanwhile, compared with NP and NPK, NPOFS significantly increased soil nitrate–N accumulation by 63.22% and 49.87%, respectively, in the 0–100-cm soil layer and decreased by 24.78% and 10.19%, respectively, in the 200–380-cm soil layer. These results suggest that the combination of organic fertilizer and straw return could improve soil fertility and summer maize productivity and significantly reduce nitrate–N accumulation in the 200–380-cm soil layer. Their use should be recommended for coordinated crop productivity and the soil environment in rainfed summer maize–winter wheat rotation on the southeast Loess Plateau.
View
Genome-wide transcriptional response of Escherichia coli O157:H7 to light- emitting diodes with various wavelengths
Preprint
Full-text available
  • Nov 2022
We investigated the physiological and transcriptomic response of Escherichia coli at the early stationary phase to light-emitting diodes with different wavelengths. The objective of this study was to investigate the effects of 465, 520, and 625 nm illuminated light on the growth and metabolic changes of E. coli O157:H7. Under 465 nm illumination, the growth of E. coli O157:H7 was significantly retarded compared to 520 nm and 625 nm illumination and non-illuminated control. Metabolic changes were examined under these illumination and non-illuminated conditions based on transcriptomic reads. Transcriptomic response under 520 nm and 625 nm remained almost similar to control except few up-and down-regulated genes. Carbohydrates metabolic transcriptomic reads were greatly down-regulated under 465 nm illumination compared to 520 nm and 625 nm illumination and non-illuminated control showing depletion of glucose as a sole energy source during the exponential phase. Fatty acid degradation such as fad regulon-related genes was up-regulated in cells under 465 nm illumination revealing the shifting of cells to use fatty acid as a new carbon energy source during the early stationary phase. Exposure of E. coli O157:H7 cells to 465 nm illuminated light down-regulated virulence factor genes such as hlyA , hlyB , hlyC , stx1A , stx2B , paa , and bdm . Under the stress of 465 nm illumination, expression of stress and flagellar motility-related genes were up-regulated causing consumption of energy and reduction in cell growth. Also, oxidative phosphorylated transcriptomic reads were up-regulated under 465 nm illumination probably due to the production of ROS that might involve in the reduction of cell growth during the early stationary phase. These results indicate that pathogenic E. coli O157:H7 respond differentially to a different wavelength of the light-emitting diodes used in this study.
View
Synchronous crop failures and climate-forced production variability
Article
Full-text available
  • Jul 2019
Large-scale modes of climate variability can force widespread crop yield anomalies and are therefore often presented as a risk to food security. We quantify how modes of climate variability contribute to crop production variance. We find that the El Niño Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD), tropical Atlantic variability (TAV), and the North Atlantic Oscillation (NAO) together account for 18, 7, and 6% of globally aggregated maize, soybean, and wheat production variability, respectively. The lower fractions of global-scale soybean and wheat production variability result from substantial but offsetting climate-forced production anomalies. All climate modes are important in at least one region studied. In 1983, ENSO, the only mode capable of forcing globally synchronous crop failures, was responsible for the largest synchronous crop failure in the modern historical record. Our results provide the basis for monitoring, and potentially predicting, simultaneous crop failures.
View
Synchronized failure of global crop production
Article
Full-text available
Multiple breadbasket failure is a risk to global food security. However, there are no global analyses that have quantitatively assessed if global crop production has actually tended towards synchronized failure historically. We show that synchronization in production within major commodities such as maize and soybean has declined in recent decades, leading to increased global stability in production of these crops. In contrast, synchrony between crops has peaked, making global calorie production more unstable. Under the hypothetical event of complete synchronized failure we estimate simultaneous global production losses for rice, wheat, soybean and maize to lie between −17% and −34%. We find that offsetting these losses by reducing variation in production across all growing locations, and raising production ceilings in breadbaskets, are far more effective than strategies focused on reducing variability in breadbaskets alone or closing production gaps in low productive locations. Our findings suggest that maintaining asynchrony in the food system requires a central place in discussions of future food demand under mean climate change, population growth and consumption trends.
View
Multidimensional risk in a nonstationary climate: Joint probability of increasingly severe warm and dry conditions
Article
Full-text available
  • Nov 2018
We present a framework for quantifying the spatial and temporal co-occurrence of climate stresses in a nonstationary climate. We find that, globally, anthropogenic climate forcing has doubled the joint probability of years that are both warm and dry in the same location (relative to the 1961-1990 baseline). In addition, the joint probability that key crop and pasture regions simultaneously experience severely warm conditions in conjunction with dry years has also increased, including high statistical confidence that human influence has increased the probability of previously unprecedented co-occurring combinations. Further, we find that ambitious emissions mitigation, such as that in the United Nations Paris Agreement, substantially curbs increases in the probability that extremely hot years co-occur with low precipitation simultaneously in multiple regions. Our methodology can be applied to other climate variables, providing critical insight for a number of sectors that are accustomed to deploying resources based on historical probabilities.
View
Future warming increases probability of globally synchronized maize production shocks
Article
Full-text available
  • Jun 2018
Significance Climate-induced shocks in grain production are a major contributor to global market volatility, which creates uncertainty for cereal farmers and agribusiness and reduces food access for poor consumers when production falls and prices spike. Our study, by combining empirical models of maize production with future warming scenarios, shows that in a warmer climate, maize yields will decrease and become more variable. Because just a few countries dominate global maize production and trade, simultaneous production shocks in these countries can have tremendous impacts on global markets. We show that such synchronous shocks are rare now but will become much more likely if the climate continues to warm. Our results underscore the need for continued investments in breeding for heat tolerance.
View
View
Comparing estimates of climate change impacts from process-based and statistical crop models
Article
Full-text available
The potential impacts of climate change on crop productivity are of widespread interest to those concerned with addressing climate change and improving global food security. Two common approaches to assess these impacts are process-based simulation models, which attempt to represent key dynamic processes affecting crop yields, and statistical models, which estimate functional relationships between historical observations of weather and yields. Examples of both approaches are increasingly found in the scientific literature, although often published in different disciplinary journals. Here we compare published sensitivities to changes in temperature, precipitation, carbon dioxide (CO2), and ozone from each approach for the subset of crops, locations, and climate scenarios for which both have been applied. Despite a common perception that statistical models are more pessimistic, we find no systematic differences between the predicted sensitivities to warming from process-based and statistical models up to +2 °C, with limited evidence at higher levels of warming. For precipitation, there are many reasons why estimates could be expected to differ, but few estimates exist to develop robust comparisons, and precipitation changes are rarely the dominant factor for predicting impacts given the prominent role of temperature, CO2, and ozone changes. A common difference between process-based and statistical studies is that the former tend to include the effects of CO2 increases that accompany warming, whereas statistical models typically do not. Major needs moving forward include incorporating CO2 effects into statistical studies, improving both approaches' treatment of ozone, and increasing the use of both methods within the same study. At the same time, those who fund or use crop model projections should understand that in the short-term, both approaches when done well are likely to provide similar estimates of warming impacts, with statistical models generally requiring fewer resources to produce robust estimates, especially when applied to crops beyond the major grains.
View
Anatomy of Indian heatwaves
Article
Full-text available
  • Apr 2016
India suffers from major heatwaves during March-June. The rising trend of number of intense heatwaves in recent decades has been vaguely attributed to global warming. Since the heat waves have a serious effect on human mortality, root causes of these heatwaves need to be clarified. Based on the observed patterns and statistical analyses of the maximum temperature variability, we identified two types of heatwaves. The first-type of heatwave over the north-central India is found to be associated with blocking over the North Atlantic. The blocking over North Atlantic results in a cyclonic anomaly west of North Africa at upper levels. The stretching of vorticity generates a Rossby wave source of anomalous Rossby waves near the entrance of the African Jet. The resulting quasi-stationary Rossby wave-train along the Jet has a positive phase over Indian subcontinent causing anomalous sinking motion and thereby heatwave conditions over India. On the other hand, the second-type of heatwave over the coastal eastern India is found to be due to the anomalous Matsuno-Gill response to the anomalous cooling in the Pacific. The Matsuno-Gill response is such that it generates northwesterly anomalies over the landmass reducing the land-sea breeze, resulting in heatwaves. http://www.nature.com/articles/srep24395
View
Global Relationships between Cropland Intensification and Summer Temperature Extremes over the Last 50 Years
Article
  • Jun 2017
Conversion of native ecosystems to cropland and the use of irrigation are considered dominant pathways through which agricultural land use change alters regional climate. Recent research proposes that increases in cropland productivity, or intensification, also influences climate through increasing evapotranspiration. Increases in evapotranspiration are expected to have the greatest temperature influence on extremely hot summer days with high vapor pressure deficits. Here we assess the generalizability and importance of such relationships by examining historical land use and climate trends in seven regions across the globe, each containing a major temperate or subtropical cropping area. Trends in summer high temperature extremes are sequentially compared against trends in cropland area, area equipped for irrigation, precipitation, and summer cropping intensity. Trends in temperature extremes are estimated using quantile regression of weather station observations, and land use data are from agricultural inventories and remote sensing. Intensification is the best predictor of trends in extreme temperatures amongst the factors that we consider, and is generally associated with trends that are 0.2–0.4°C per decade cooler than in adjacent regions. Neither cropland area nor precipitation trends are systematically associated with extreme temperature trends across regions, though high temperatures are suppressed over those portions of Central North America and East Asia experiencing growth in irrigation. Both the temperature trends associated with intensification and increased irrigation can be understood as a consequence of increased latent cooling. These results underscore that the weather experienced by crops is not entirely external, but also depends on agricultural practices.
View
Observing adaptive capacity in Indian rice production systems
Article
  • Apr 2017
Theoretically we understand the dimensions of both generic and specific adaptive capacity, however, there are few studies which document actual observed adaptive capacity. This study aims to address this gap by documenting the adaptive capacity of Indian rice production systems, an agro-socio-ecological system. We explore how Indian rice production systems have responded to historical climate shocks in order to assess their likely capacity to respond to current and future climate changes. Using a panel dataset of both Indian rice crop yield and extreme heat and drought shocks measured at the district level from 1980 to 2009, we sought to detect evidence of farmers: (i) adapting through reduced rice crop yield sensitivity to climate shocks over time, and (ii) responding to climate shocks by altering farming practices. We found that changes in average climate shock exposure over time was not linked to changes in average rice crop yields over time at a location. We also observed that rice crop yield sensitivity to year-to-year fluctuations in climate shocks has not decreased over time; this implies that over time the Indian rice production system has not increased its capacity to buffer inter-annual variation in shock exposure. We did not detect the presence of learning from exposure to climate shocks; in fact, greater exposure to extreme heat shocks eroded farmers’ capacity to respond to current heat events. There was no clear pattern of farmers in districts that experienced worsening average climate shock exposure responding with the uptake of plausible adaptive practices. In summary, there was not a clear signal of adaptive capacity being present in Indian rice production systems.
View
Dependency of Crop Production between Global Breadbaskets: A Copula Approach for the Assessment of Global and Regional Risk Pools: Dependency of Crop Production between Global Breadbaskets
Article
As recent events have shown, simultaneous crop losses in different parts of the world can cause serious risks to global food security. However, to date, little is known about the spatial dependency of lower than expected crop yields from global breadbaskets. This especially applies in the case of extreme events, i.e., where one or more breadbaskets are experiencing far below average yields. Without such information, risk management approaches cannot be applied and vulnerability to extremes may remain high or even increase in the future around the world. We tackle both issues from an empirical perspective focusing on wheat yield. Interdependencies between historically observed wheat yield deviations in five breadbaskets (United States, Argentina, India, China, and Australia) are estimated via copula approaches that can incorporate increasing tail dependencies. In doing so, we are able to attach probabilities to interregional as well as global yield losses. To address the robustness of our results, we apply three different methods for constructing multivariate copulas: vine copulas, ordered coupling using a minimax approach, and hierarchical structuring. We found interdependencies between states within breadbaskets that led us to the conclusion that risk pooling for extremes is less favorable on the regional level. However, notwithstanding evidence of global climatic teleconnections that may influence crop production, we also demonstrate empirically that wheat production losses are independent between global breadbaskets, which strengthens the case for interregional risk pooling strategies. We argue that through interregional risk pooling, postdisaster liabilities of governments and international donors could be decreased.
View