Bias correction of extreme values of high resolution climate simulations for risk analysis.

Abstract Most climatic models show that climate change affects natural perils' frequency and severity. Quantifying the impact of future climate conditions on natural hazard is essential for mitigation and adaptation planning. One crucial factor to consider when using climate simulations projections is the inherent systematic differences (bias) of the modelled data compared with observations. This bias can originate from the modelling process, the techniques used for downscaling of results, and the ensembles' intrinsic variability. Analysis of climate simulations has shown that the biases associated with these data types can be significant. Hence, it is often necessary to correct the bias before the data can be reliably used for further analysis. Natural perils are often associated with extreme climatic conditions. Analysing trends in the tail end of distributions are already complicated because noise is much more prominent than that in the mean climate. The bias of the simulations can introduce significant errors in practical applications. In this paper, we present a methodology for bias correction of climate simulated data. The technique corrects the bias in both the body and the tail of the distribution (extreme values). As an illustration, maps of the 50 and 100-year Return Period of climate simulated Forest Fire Danger Index (FFDI) in Australia are presented and compared against the corresponding observation-based maps. The results show that the algorithm can substantially improve the calculation of simulation-based Return Periods. Forthcoming work will focus on the impact of climate change on these Return Periods considering future climate conditions.

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Expected Changes to Alpine Pastures in Extent and Composition under Future Climate Conditions

Agronomy ◽

10.3390/agronomy10070926 ◽

2020 ◽

Vol 10 (7) ◽

pp. 926

Author(s):

Camilla Dibari ◽

Sergi Costafreda-Aumedes ◽

Giovanni Argenti ◽

Marco Bindi ◽

Federico Carotenuto ◽

...

Keyword(s):

Climate Change ◽

Biodiversity Loss ◽

Future Climate ◽

Pastoral Systems ◽

Pastoral System ◽

Climate Conditions ◽

Nardus Stricta ◽

Livestock Feeding ◽

The Alps ◽

The Impact

As the basis of livestock feeding and related performances, pastures evolution and dynamics need to be carefully monitored and assessed, particularly in the Alps where the effects of land abandonment are further amplified by climate change. As such, increases in temperature associated with changes in precipitation patterns and quantity are leading to modifications of grassland extent and composition with consequences on the pastoral systems. This study applied a machine learning approach (Random Forest) and GIS techniques to map the suitability of seven pasture macro types most representative of the Italian Alps and simulated the impact of climate change on their dynamics according to two future scenarios (RCP4.5, 8.5), two time-slices (2011–2040, 2041–2070), and three RCMs (Aladin, CMCC, ICTP). Results indicated that (i) the methodology was robust to map the current suitability of pasture macro types (mean accuracy classification = 98.7%), so as to predict the expected alterations due to climate change; (ii) future climate will likely reduce current extend of suitable pasture (−30% on average) and composition, especially for most niche ecosystems (i.e., pastures dominated by Carex firma and Festuca gr. Rubra); (iii) areas suited to hardier but less palatable pastures (i.e., dominated by Nardus stricta and xeric species) will expand over the Alps in the near future. These impacts will likely determine risks for biodiversity loss and decreases of pastoral values for livestock feeding, both pivotal aspects for maintaining the viability and profitability of the Alpine pastoral system as a whole.

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Evaluating Nature-Based Solution for Flood Reduction in Spercheios River Basin under Current and Future Climate Conditions

Sustainability ◽

10.3390/su13073885 ◽

2021 ◽

Vol 13 (7) ◽

pp. 3885

Author(s):

Christos Spyrou ◽

Michael Loupis ◽

Νikos Charizopoulos ◽

Ilektra Apostolidou ◽

Angeliki Mentzafou ◽

...

Keyword(s):

Climate Change ◽

River Basin ◽

Maximum Velocity ◽

Weather Conditions ◽

Future Climate ◽

Future Climate Change ◽

Climate Change Scenarios ◽

Climate Conditions ◽

The Impact

Nature-based solutions (NBS) are being deployed around the world in order to address hydrometeorological hazards, including flooding, droughts, landslides and many others. The term refers to techniques inspired, supported and copied from nature, avoiding large constructions and other harmful interventions. In this work the development and evaluation of an NBS applied to the Spercheios river basin in Central Greece is presented. The river is susceptible to heavy rainfall and bank overflow, therefore the intervention selected is a natural water retention measure that aims to moderate the impact of flooding and drought in the area. After the deployment of the NBS, we examine the benefits under current and future climate conditions, using various climate change scenarios. Even though the NBS deployed is small compared to the rest of the river, its presence leads to a decrease in the maximum depth of flooding, maximum velocity and smaller flooded areas. Regarding the subsurface/groundwater storage under current and future climate change and weather conditions, the NBS construction seems to favor long-term groundwater recharge.

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The Impacts of Climate Change in the MENA Region and the Water-Energy Nexus

10.20944/preprints201810.0197.v1 ◽

2018 ◽

Cited By ~ 1

Author(s):

Manfred A. Lange

Keyword(s):

Climate Change ◽

Heat Waves ◽

Eastern Mediterranean ◽

Mena Region ◽

Large Variability ◽

Climate Conditions ◽

Mitigation And Adaptation ◽

Water Energy Nexus ◽

The Impact ◽

Impacts Of Climate Change

The present paper aims to elucidate the impact of climate change on the availability and security of water and energy in the Middle East and North Africa Region (MENA Region). The region is particularly challenged by a number of factors including a large variability of bio-geographical characteristics, extreme population growth over the last few decades and substantial societal and economical transitions as well as armed conflicts in some of the countries of the region. Anticipated changes in climate conditions will exacerbate the challenges with regard to providing sufficient amounts of water and energy to the communities in the region. Impacts of climate change will materialize as an increasing number of heat waves, primarily in urban structures and the decline in water availability as a result of enhanced droughts and a growing numbers of dry spells. The interrelationships between energy and water and their mutual dependencies are addressed by the Water-Energy-Nexus concept. With regard to the challenges addressed here, Cyprus and the Eastern Mediterranean are a particular point in case. Mitigation and adaptation strategies include enhanced efficiency of energy and water use, integrated technology assessments regarding electricity generation and the production of potable water and electricity through concentrated solar power.

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Future climate scenarios project a decrease in the risk of fall armyworm outbreaks

The Journal of Agricultural Science ◽

10.1017/s0021859617000314 ◽

2017 ◽

Vol 155 (8) ◽

pp. 1219-1238 ◽

Cited By ~ 13

Author(s):

N. Y. Z. RAMIREZ-CABRAL ◽

L. KUMAR ◽

F. SHABANI

Keyword(s):

Climate Change ◽

General Circulation ◽

Fall Armyworm ◽

General Circulation Models ◽

Future Climate ◽

Future Climate Change ◽

Risk Category ◽

Agricultural Pest ◽

Climate Conditions ◽

The Impact

SUMMARYSpodoptera frugiperda, or the fall armyworm (FAW) (Lepidoptera: Noctuidae), is an endemic and important agricultural pest in America. Several outbreaks have occurred with losses estimated at millions of dollars. Insects are affected by climate factors, and climate change may affect geographical range, growth rate, abundance, survival, mortality, number of generations per year and other characteristics. These effects are difficult to project due to the complex interactions among insects, hosts and predators. The aim of the current research is to project the impact of climate change on future suitability for the expansion and final range of FAW as well as highlight the risk of damage due to the pest under current and future conditions. The modelling was carried out using two general circulation models (GCMs), CSIRO Mk3.0 and MIROC-H, for 2050 and 2100 under the A2 Special Report on Emissions Scenarios (SRES), using the known distribution of the species and the CliMond meteorological database. The possible number of generations was estimated to exceed five in the south-eastern USA by 2100. A unique modelling approach linking environmental suitability and number of generations was developed to project the risks of FAW damage. The results show changes in suitability and risk across America, with an increase in the northern hemisphere and decreases or extinction in the southern hemisphere, except for southern Brazil, Uruguay, Paraguay and northern Argentina, which indicate high future levels of risk. The current study highlights the possible extinction of a tropical pest in areas near the Equator. The two GCMs both projected increases in the low-risk category of 40% by 2050 and 23% by 2100, with the medium- and high-risk categories decreasing by >50% by 2050 and >39% by 2100, compared with the current risk. In general, agricultural pest management may become more challenging under future climate change and variation, and thus, understanding and quantifying the possible impacts of FAW under future climate conditions is essential for the future economic production of crops.

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Ensemble-based analysis of regional climate change effects on the cabbage stem weevil (Ceutorhynchus pallidactylus (Mrsh.)) in winter oilseed rape (Brassica napus L.)

The Journal of Agricultural Science ◽

10.1017/s0021859611000529 ◽

2011 ◽

Vol 150 (2) ◽

pp. 191-202 ◽

Cited By ~ 19

Author(s):

J. JUNK ◽

M. EICKERMANN ◽

K. GÖRGEN ◽

M. BEYER ◽

L. HOFFMANN

Keyword(s):

Climate Change ◽

Oilseed Rape ◽

Stem Elongation ◽

Regional Climate ◽

Regional Climate Change ◽

Future Climate ◽

Brassica Napus L ◽

Climate Conditions ◽

Ceutorhynchus Pallidactylus ◽

The Impact

SUMMARYThe impact of projected regional climate change on the migration of cabbage stem weevil (Ceutorhynchus pallidactylus) to oilseed rape crops in the Grand Duchy of Luxembourg is evaluated for past and future time spans. Several threshold-based statistical models for the emergence and the main migration of C. pallidactylus were chosen from the literature and combined with selected regional climate change projections of the EU ENSEMBLES project. Additionally, a simple degree-day based model was used to assess the plant development under expected climate change conditions. An earlier onset as well as a prolongation of the possible emergence times and the main migration periods was detected. The onset of stem elongation of oilseed rape was predicted to occur 3·0 days earlier per decade, while emergence of C. pallidactylus was expected to occur between 3·0 and 3·3 days earlier per decade. The main migration period of the weevil to the field may start 2·0 days earlier per decade under future climate conditions. Additionally, the time span of possible migration is prolonged for about 30 days under projected future climate conditions.

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Does the weighting of climate simulations result in a more reasonable quantification of hydrological impacts?

10.5194/hess-2019-24 ◽

2019 ◽

Author(s):

Hui-Min Wang ◽

Jie Chen ◽

Chong-Yu Xu ◽

Hua Chen ◽

Shenglian Guo ◽

...

Keyword(s):

Climate Change ◽

Bias Correction ◽

Hydrological Model ◽

Climate Change Impacts ◽

Impact Studies ◽

Hydrological Responses ◽

Hydrological Impacts ◽

Climate Simulations ◽

The Impact ◽

Equal Weighting

Abstract. With the increase in the number of available global climate models (GCMs), pragmatic questions come up when using them to quantify the climate change impacts on hydrology: Is it necessary to weight GCM outputs in the impact studies, and if so, how to weight them? Some weighting methods have been proposed based on the performances of GCM simulations with respect to reproducing the observed climate. However, the process from climate variables to hydrological responses is nonlinear, and thus the assigned weights based on their performances in climate simulations may not be translated to hydrological responses. Assigning weights to GCM outputs based on their ability to represent hydrological simulations is more straightforward. Accordingly, the present study assigns weights to GCM simulations based on their ability to reproduce hydrological characteristics and investigates their influence on the quantification of hydrological impacts. Specifically, eight weighting schemes are used to determine the weights of GCM simulations based on streamflow series simulated by a lumped hydrological model using raw or bias-corrected GCM outputs. The impacts of weighting GCM simulations are investigated in terms of reproducing the observed hydrological regimes for the reference period (1970–1999) and quantifying the uncertainty of hydrological changes for the future period (2070–2099). The results show that when using raw GCM outputs with no bias correction, streamflow-based weights better represent the mean hydrograph and reduce the bias of annual streamflow. However, when applying bias correction to GCM simulations before driving the hydrological model, the climate simulations become rather close to the observed climate, so that compared to equal weighting, the streamflow-based weights do not bring significant differences in the multi-model ensemble mean and uncertainty of hydrological impacts. Since bias correction has been an indispensable procedure in hydrological impact studies, the equal weighting method may still be a viable and conservative choice for the studies of hydrological climate change impacts.

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The impact of climate change on the productivity of conservation agriculture

10.21203/rs.3.rs-63752/v1 ◽

2020 ◽

Author(s):

Yang Su ◽

Benoît Gabrielle ◽

David Makowski

Keyword(s):

Climate Change ◽

Crop Production ◽

Management Practices ◽

Conservation Agriculture ◽

Crop Productivity ◽

Global Scale ◽

Future Climate ◽

Climate Conditions ◽

Geographical Regions ◽

The Impact

Abstract Conservation agriculture (CA) is being promoted as a set of management practices that can sustain crop production while providing positive environmental externalities. However, its impact on crop productivity is still hotly debated, and how this productivity will be affected by climate change remains uncertain. Here we compared the productivity of CA vs. conventional tillage (CT) systems under current and future climate conditions using a probabilistic machine-learning approach at the global scale. We reveal large differences in the probability of yield gains with CA across crop types, climate zones, and geographical regions. We show that, for most crops, CA performed better in continental, arid and temperate regions than in tropical ones. Under future climate conditions, the relative productive performance of CA is expected to increase for maize in almost all cropping areas within the tropical band, thus improving the competitiveness of CA for this major crop.

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Climate Change Impacts on the Potential Distribution and Range Shift of Dendroctonus ponderosae (Coleoptera: Scolytidae)

Forests ◽

10.3390/f10100860 ◽

2019 ◽

Vol 10 (10) ◽

pp. 860

Author(s):

Zhou ◽

Ge ◽

Zou ◽

Guo ◽

Wang ◽

...

Keyword(s):

Climate Change ◽

Bark Beetles ◽

Dendroctonus Ponderosae ◽

Climate Change Impacts ◽

Future Climate ◽

Range Shift ◽

Pest Species ◽

Climate Data ◽

Climate Conditions ◽

The Impact

Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae) is one of the most important bark beetles in North America and causes considerable economic and ecological losses during outbreaks. The distribution of this pest species is likely to be altered by climate change, which may threaten currently unaffected areas. In this study, we used CLIMEX to project the potential global distribution of D. ponderosae according to both historical climate data (1987–2016) and future climate warming estimates (2021–2100) to evaluate the impact of climate change on this species. Regions with suitable climate for D. ponderosae are distributed in all continents except Antarctica under both historical and future climate conditions, and these are predicted to change continuously with climate change. Overall, climate suitability will increase in middle- and high-latitude regions and decrease in low-latitude regions, and regions most sensitive to climate change are located in the mid-latitude zone. Moreover, the shift directions and ranges of climate-suitable regions under future conditions will differ among continents, and the shift distances in the north–south direction are larger than these in the east–west direction for Africa, Asia, Europe, South America, and Oceania, indicating that shift direction is possibly mainly affected by temperature. These projected distributions may provide theoretical guidance for early-warning intervention and risk assessment.

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Climate change impacts on potential maize yields in Gambella Region, Ethiopia

Regional Environmental Change ◽

10.1007/s10113-021-01773-3 ◽

2021 ◽

Vol 21 (2) ◽

Author(s):

Azeb W. Degife ◽

Florian Zabel ◽

Wolfram Mauser

Keyword(s):

Climate Change ◽

Climate Model ◽

Total Yield ◽

Climate Change Impacts ◽

Future Climate ◽

Yield Potential ◽

Limiting Factor ◽

Climate Conditions ◽

Rcp 8.5 ◽

The Impact

AbstractChanging climate conditions are supposed to have particularly strong impacts on agricultural production in the tropics with strong implications on food security. Ethiopia’s economy is profoundly dominated by agriculture, contributing to around 40% of the gross domestic product. Thereby, Ethiopia is one of the most vulnerable countries to the impact of climate change and has a wide gap in regional climate change impact studies. In this study, we systematically investigate climate change impacts on yields for the Gambella region in Ethiopia, exemplarily for maize. Here, we show how yields change until 2100 for RCPs 2.6, 4.5, and 8.5 from a climate model ensemble under rainfed and irrigated conditions. While rainfed yields decrease by 15% and 14% respectively for RCPs 2.6 and 4.5, yields decrease by up to 32% under RCP 8.5. Except for RCP 8.5, yields are not further decreasing after 2040–2069. We found that temperature increase, changing soil water availability, and atmospheric CO2 concentration have different effects on the simulated yield potential. Our results demonstrate the dominance of heat response under future climate conditions in the tropical Gambella region, contributing to 85% of total yield changes. Accordingly, irrigation will lose effectiveness for increasing yield when temperature becomes the limiting factor. CO2, on the other hand, contributes positively to yield changes by 8.9% for RCP 8.5. For all scenarios, the growing period is shorted due to increasing temperature by up to 29 days for RCP 8.5. Our results suggest that new varieties with higher growing degree days are primarily required to the region for adapting to future climate conditions.

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Potential Impact of the Current and Future Climate on the Yield, Quality, and Climate Suitability for Tea [Camellia sinensis (L.) O. Kuntze]: A Systematic Review

Agronomy ◽

10.3390/agronomy11040619 ◽

2021 ◽

Vol 11 (4) ◽

pp. 619

Author(s):

Sadeeka Layomi Jayasinghe ◽

Lalit Kumar

Keyword(s):

Climate Change ◽

Future Climate ◽

Mitigation Strategies ◽

Extreme Weather Events ◽

Impact Of Climate Change ◽

Advantages And Disadvantages ◽

Tea Quality ◽

Climate Suitability ◽

Yield Quality ◽

The Impact

Even though climate change is having an increasing impact on tea plants, systematic reviews on the impact of climate change on the tea system are scarce. This review was undertaken to assess and synthesize the knowledge around the impacts of current and future climate on yield, quality, and climate suitability for tea; the historical roots and the most influential papers on the aforementioned topics; and the key adaptation and mitigation strategies that are practiced in tea fields. Our findings show that a large number of studies have focused on the impact of climate change on tea quality, followed by tea yield, while a smaller number of studies have concentrated on climate suitability. Three pronounced reference peaks found in Reference Publication Year Spectroscopy (RYPS) represent the most significant papers associated with the yield, quality, and climate suitability for tea. Tea yield increases with elevated CO2 levels, but this increment could be substantially affected by an increasing temperature. Other climatic factors are uneven rainfall, extreme weather events, and climate-driven abiotic stressors. An altered climate presents both advantages and disadvantages for tea quality due to the uncertainty of the concentrations of biochemicals in tea leaves. Climate change creates losses, gains, and shifts of climate suitability for tea habitats. Further studies are required in order to fill the knowledge gaps identified through the present review, such as an investigation of the interaction between the tea plant and multiple environmental factors that mimic real-world conditions and then studies on its impact on the tea system, as well as the design of ensemble modeling approaches to predict climate suitability for tea. Finally, we outline multifaceted and evidence-based adaptive and mitigation strategies that can be implemented in tea fields to alleviate the undesirable impacts of climate change.

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