Determining future aflatoxin contamination risk scenarios for corn in Southern Georgia, USA using spatio-temporal modelling and future climate simulations

AbstractAflatoxins (AFs) are produced by fungi in crops and can cause liver cancer. Permitted levels are legislated and batches of grain are rejected based on average concentrations. Corn grown in Southern Georgia (GA), USA, which experiences drought during the mid-silk growth period in June, is particularly susceptible to infection by Aspergillus section Flavi species which produce AFs. Previous studies showed strong association between AFs and June weather. Risk factors were developed: June maximum temperatures > 33 °C and June rainfall < 50 mm, the 30-year normals for the region. Future climate data were estimated for each year (2000–2100) and county in southern GA using the RCP 4.5 and RCP 8.5 emissions scenarios. The number of counties with June maximum temperatures > 33 °C and rainfall < 50 mm increased and then plateaued for both emissions scenarios. The percentage of years thresholds were exceeded was greater for RCP 8.5 than RCP 4.5. The spatial distribution of high-risk counties changed over time. Results suggest corn growth distribution should be changed or adaptation strategies employed like planting resistant varieties, irrigating and planting earlier. There were significantly more counties exceeding thresholds in 2010–2040 compared to 2000–2030 suggesting that adaptation strategies should be employed as soon as possible.

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Determining Future Aflatoxin Contamination Risk Scenarios for Corn in Southern Georgia, USA using Spatio-temporal Modelling and Future Climate Simulations

10.21203/rs.3.rs-152995/v1 ◽

2021 ◽

Author(s):

Ruth Kerry ◽

Ben Ingram ◽

Esther Garcia-Cela ◽

Naresh Magan ◽

Brenda V. Ortiz ◽

...

Keyword(s):

Risk Factors ◽

Limited Range ◽

Aflatoxin Contamination ◽

Adaptation Strategies ◽

Future Climate ◽

Weather Data ◽

Climate Data ◽

Rcp 8.5 ◽

Maximum Temperatures ◽

Southern Georgia

Abstract Mycotoxins are toxins produced by fungi which are harmful to humans and animals and can contaminate staple crops. Aflatoxins are particularly toxic and can cause liver cancer so the permitted levels in foodstuffs are legislated. Batches of grain where average aflatoxin concentrations are higher than legislative thresholds are rejected or sold at a lesser price for a more limited range of use. High maximum temperatures and low rainfall have been shown to increase contamination. For corn grown in Southern Georgia, USA, June weather is particularly important as this coincides with the sensitive mid-silk growth stage. An AFs survey and weather data have been used to show the association between AFs and June weather [1]. The risk factors were June maximum temperatures >33˚C and June rainfall <50mm, the 30-year normals for the region. Future climate data were estimated for each year (2000-2100) and county in southern GA using the RCP 4.5 and RCP 8.5 emissions scenarios and weather risk factors were calculated. The number of counties with June maximum temperatures >33˚C and rainfall <50mm increased significantly between 30-year time periods. The percentage of years that counties exceeded thresholds was greater for the RCP 8.5 than the RCP 4.5 scenario. A change in the spatial distribution of high-risk counties was seen over time. The results suggest the need for changes in the where crops are grown or the employment of adaptation strategies such as planting more resistant varieties, improving irrigation and planting earlier to avoid increasingly frequent rejection of grain batches. There were significantly more counties with June maximum temperatures >33˚C and June rainfall <50mm in 2010-2040 compared to 2000-2030. This suggests that adaptation strategies should be employed as soon as possible.

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Localize the Impact of Global Greenhouse Gases Emissions under an Uncertain Future: A Case Study in Western Cape, South Africa

Earth ◽

10.3390/earth2010007 ◽

2021 ◽

Vol 2 (1) ◽

pp. 111-123

Author(s):

Bowen He ◽

Ke J. Ding

Keyword(s):

Climate Change ◽

South Africa ◽

Co2 Emissions ◽

Ghg Emissions ◽

Future Climate ◽

Emissions Reduction ◽

Western Cape ◽

Emissions Scenarios ◽

Rcp 8.5 ◽

The Impact

The growing impact of CO2 and other greenhouse-gas (GHG) emissions on the socio-climate system in the Western Cape, South Africa, urgently calls for the need for better climate adaptation and emissions-reduction strategies. While the consensus has been that there is a strong correlation between CO2 emissions and the global climate system, few studies on climate change in the Western Cape have quantified the impact of climate change on local climate metrics such as precipitation and evaporation under different future climate scenarios. The present study investigates three different CO2 emissions scenarios: Representative Concentration Pathway (RCP) 2.6, RCP 4.5, and RCP 8.5, from moderate to severe, respectively. Specifically, we used climate metrics including precipitation, daily mean and maximum near-surface air temperature, and evaporation to evaluate the future climate in Western Cape under each different RCP climate scenario. The projected simulation results reveal that temperature-related metrics are more sensitive to CO2 emissions than water-related metrics. Districts closer to the south coast are more resilient to severer GHG emissions scenarios compared to inland areas regarding temperature and rainfall; however, coastal regions are more likely to suffer from severe droughts such as the “Day-Zero” water crisis. As a result, a robust drying signal across the Western Cape region is likely to be seen in the second half of the 21st century, especially under the scenario of RCP 8.5 (business as usual) without efficient emissions reduction policies.

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Coupled application of R and WetSpa models for assessment of climate change impact on streamflow of Werie Catchment, Tigray, Ethiopia

Journal of Water and Climate Change ◽

10.2166/wcc.2020.238 ◽

2020 ◽

Author(s):

Selam Kidanemariam ◽

Haddush Goitom ◽

Yigzaw Desta

Keyword(s):

Climate Change ◽

Baseline Period ◽

Future Climate ◽

Calibration Data ◽

Climate Variables ◽

Emission Scenarios ◽

Climate Data ◽

Validation Data ◽

Data Set ◽

Rcp 8.5

Abstract This research assesses the streamflow response of Werie River to climate change. Baseline (1980–2009) climate data of precipitation, maximum and minimum temperature were analyzed using delta based statistical downscaling approach in R software packages to predict future 90 years (2010–2099) periods under two emission scenarios of Representative Concentration Pathways (RCP) 4.5 and RCP 8.5, indicating medium and extremely high emission scenarios respectively. Generated future climate variables indicate Werie will experience a significant increase in precipitation, and maximum and minimum air temperature for both RCPs. Further, Water and Energy Transfer between Soil, Plants, and Atmosphere (WetSpa) was applied to assess the water balance of Werie River. The WetSpa model reproduced the streamflow well with performance statistics values of R2 = 0.84 and 0.85, Nash–Sutcliffe efficiency = 0.72 and 0.72, and model bias = –0.14 and –0.15 for the calibration data set of 1999–2010 and validation data of 2011–2014 respectively. Finally, by taking the downscaled future climate variables as input, WetSpa future prediction shows that there will an increase in the Werie catchment mean annual streamflow up to 29.6% for RCP 4.5 and 35.6% for RCP 8.5 compared to the baseline period.

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Analysis of Climate Change and Extreme Climatic Events in the Lake Victoria Region of Tanzania

Frontiers in Climate ◽

10.3389/fclim.2020.559584 ◽

2020 ◽

Vol 2 ◽

Author(s):

Philbert Modest Luhunga ◽

Alexander Elias Songoro

Keyword(s):

Climate Change ◽

Lake Victoria ◽

Regional Climate ◽

Future Climate ◽

Emission Scenarios ◽

Climate Condition ◽

Lake Victoria Region ◽

Rcp 8.5 ◽

Maximum Temperatures ◽

Future Climate Condition

The understanding of climate change impacts and the associated climate extreme events at regional and local scales is of critical importance for planning and development of feasible adaptation strategies. In this paper, we present an analysis of climate change and extreme climate events in the Lake Victoria region of Tanzania, focusing on the Kagera and Geita regions. We use daily simulated climate variables (rainfall and minimum and maximum temperatures) from the Coordinated Regional Climate Downscaling Experiment Program Regional Climate Models (CORDEX_RCMs) for the analysis. Extreme climate event, rainfall, and minimum and maximum temperatures time series during historical (1971–2000) climate condition are compared to future climate projection (2011–2100) under two Representative Concentration Pathway (RCP): RCP 4.5 and RCP 8.5 emission scenarios. The existence, magnitude, and statistical significance of potential trends in climate data time series are estimated using the Mann–Kendall (MK) non-parametric test and Theil-SEN slope estimator methods. Results show that during historical (1971–2000) climate, the Lake Victoria region of Tanzania experienced a statistically significant increasing trend in temperature. The annual minimum and maximum temperatures in the Kagera and Geita regions have increased by 0.54–0.69°C, and 0.51–0.69°C, respectively. The numbers of warm days (TX90p) and warm nights (TN90p) during the historical climate have increased, while the numbers of cold days (TX10p) and cold nights (TN10p) have decreased significantly. However, in future climate condition (2011–2100) under both RCP 4.5 and RCP 8.5 emission scenarios, the Lake Victoria region is likely to experience increased temperatures and rainfall. The frequency of cold events (cold days and cold nights) is likely to decrease, while the frequency of warm events (warm days and warm nights) is likely to increase significantly. The number of consecutive wet days, the intensity of very wet days, and the number of extreme wet days are likely to increase. These results indicate that in future climate condition, socioeconomic livelihoods of people in the Kagera and Geita regions are likely to experience significant challenges from climate-related stresses. It is, therefore, recommended that appropriate planning and effective adaptation policies are in place for disaster risk prevention.

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Climate projections of chill hours and implications for olive cultivation in Minas Gerais, Brazil

Pesquisa Agropecuária Brasileira ◽

10.1590/s1678-3921.pab2020.v55.01852 ◽

2020 ◽

Vol 55 ◽

Author(s):

Fabrina Bolzan Martins ◽

Rodolfo Armando de Almeida Pereira ◽

Roger Rodrigues Torres ◽

Diego Felipe dos Santos

Keyword(s):

Radiative Forcing ◽

Minas Gerais ◽

The State ◽

Future Climate ◽

Climate Projections ◽

Present Climate ◽

Climate Data ◽

Olive Cultivars ◽

Rcp 8.5 ◽

Olive Cultivation

Abstract: The objective of this work was to determine the accumulation of chill hours and to define the areas with aptitude for olive (Olea europaea) cultivation in the state of Minas Gerais, Brazil, as well as to analyze the impacts of climate change projections on chilling-hour requirements and climatic zoning, in two radiative forcing scenarios. The trigonometric method was used to quantify the number of chill hours, considering base temperatures (Tb) of 7.0, 9.5, and 13°C (high, medium, and low chill, respectively), and was applied to present climate (1983-2012) and to two future climate (2041-2070 and 2071-2100) conditions. The present climate data were obtained from 47 conventional weather stations, and the future climate data were obtained from three Earth system models (IPSL-CM5A-LR, MRI-CGCM3, and MIROC5). Future projections point to a decrease in the suitable areas for olive crop cultivation, particularly under representative concentration pathway (RCP) 8.5 and for olive cultivars with a high-chilling requirement (Tb=7.0ºC). Of the olive cultivars requiring medium chill (Tb=9.5ºC), only 2.6% (RCP 4.5) and 1.6% (RCP 8.5) will be suitable in the extreme south and in higher altitude areas of Minas Gerais, while, of those requiring low chill (Tb=13ºC), 11.8% (RCP 4.5) and 6.7% (RCP 8.5) will be suitable. If the climate projections become true, the cultivation of olive crops will be viable in the southern region and in higher altitude areas of the state of Minas Gerais.

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Flood Risk and Adaptation Strategies for Soybean Production Systems on the Flood-Prone Pampas under Climate Change

Agronomy ◽

10.3390/agronomy11061187 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1187

Author(s):

Wouter Julius Smolenaars ◽

Spyridon Paparrizos ◽

Saskia Werners ◽

Fulco Ludwig

Keyword(s):

Climate Change ◽

Flood Risk ◽

Risk Perceptions ◽

Production Systems ◽

Adaptation Strategies ◽

Flood Events ◽

Climate Data ◽

Soybean Production ◽

Drying Trend ◽

Sowing Season

In recent decades, multiple flood events have had a devastating impact on soybean production in Argentina. Recent advances suggest that the frequency and intensity of destructive flood events on the Argentinian Pampas will increase under pressure from climate change. This paper provides bottom-up insight into the flood risk for soybean production systems under climate change and the suitability of adaptation strategies in two of the most flood-prone areas of the Pampas region. The flood risk perceptions of soybean producers were explored through interviews, translated into climatic indicators and then studied using a multi-model climate data analysis. Soybean producers perceived the present flood risk for rural accessibility to be of the highest concern, especially during the harvest and sowing seasons when heavy machinery needs to reach soybean lots. An analysis of climatic change projections found a rising trend in annual and harvest precipitation and a slight drying trend during the sowing season. This indicates that the flood risk for harvest accessibility may increase under climate change. Several adaptation strategies were identified that can systemically address flood risks, but these require collaborative action and cannot be undertaken by individual producers. The results suggest that if cooperative adaptation efforts are not made in the short term, the continued increase in flood risk may force soybean producers in the case study locations to shift away from soybean towards more robust land uses.

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