Chaos in Estimates of Climate Change Impacts

2020 ◽  
Author(s):  
Emanuele Massetti ◽  
Emanuele Di Lorenzo
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Initial Conditions ◽  
Climate Change Impacts ◽  
Internal Variability ◽  
Future Climate ◽  
Climate System ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Exogenous Forcing

<p>Estimates of physical, social and economic impacts of climate change are less accurate than usually thought because the impacts literature has largely neglected the internal variability of the climate system. Climate change scenarios are highly sensitive to the initial conditions of the climate system due the chaotic dynamics of weather. As the initial conditions of the climate system are unknown with a sufficiently high level of precision, each future climate scenario – for any given model parameterization and level of exogenous forcing – is only one of the many possible future realizations of climate. The impacts literature usually relies on only one realization randomly taken out of the full distribution of future climates. Here we use one of the few available large scale ensembles produced to study internal variability and an econometric model of climate change impacts on United States (US) agricultural productivity to show that the range of impacts is much larger than previously thought. Different ensemble members lead to significantly different impacts. Significant sign reversals are frequent. Relying only on one ensemble member leads to incorrect conclusions on the effect of climate change on agriculture in most of the US counties. Impacts studies should start using large scale ensembles of future climate change to predict damages. Climatologists should ramp-up efforts to run large ensembles for all GCMs, for at least the most frequently used scenarios of exogenous forcing.</p>

scholarly journals Evidence for changes in historic and future groundwater levels in the UK

2015 ◽  
Vol 39 (1) ◽  
pp. 49-67 ◽  
Author(s):  
Christopher R. Jackson ◽  
John P. Bloomfield ◽  
Jonathan D. Mackay
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Climate Change Impacts ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Indices ◽  
Groundwater Levels ◽  
Groundwater Drought ◽  
The One ◽  
The Uk

We examine the evidence for climate-change impacts on groundwater levels provided by studies of the historical observational record, and future climate-change impact modelling. To date no evidence has been found for systematic changes in groundwater drought frequency or intensity in the UK, but some evidence of multi-annual to decadal coherence of groundwater levels and large-scale climate indices has been found, which should be considered when trying to identify any trends. We analyse trends in long groundwater level time-series monitored in seven observation boreholes in the Chalk aquifer, and identify statistically significant declines at four of these sites, but do not attempt to attribute these to a change in a stimulus. The evidence for the impacts of future climate change on UK groundwater recharge and levels is limited. The number of studies that have been undertaken is small and different approaches have been adopted to quantify impacts. Furthermore, these studies have generally focused on relatively small regions and reported local findings. Consequently, it has been difficult to compare them between locations. We undertake some additional analysis of the probabilistic outputs of the one recent impact study that has produced coherent multi-site projections of changes in groundwater levels. These results suggest reductions in annual and average summer levels, and increases in average winter levels, by the 2050s under a high greenhouse gas emissions scenario, at most of the sites modelled, when expressed by the median of the ensemble of simulations. It is concluded, however, that local hydrogeological conditions can be an important control on the simulated response to a future climate projection.

scholarly journals Making rainfed crops adapted to potential climate change impacts: Modeling sustainable options

2020 ◽  
Vol 183 ◽  
pp. 03002
Author(s):  
Youssef Brouziyne ◽  
Abdelghani Chehbouni ◽  
Aziz Abouabdillah ◽  
Jamal Hallam ◽  
Fouad Moudden ◽  
...  
Keyword(s):  
Climate Change ◽  
Food Security ◽  
Sustainable Management ◽  
Swat Model ◽  
Management Strategies ◽  
Climate Change Impacts ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Projections ◽  
Climate Change Scenarios

Rainfed agriculture is becoming increasingly vulnerable to climate change. This situation is expected to worsen under most future climate projections, which might increase the risks linked to food security and economies which depend on it. Providing insights about the potential responses of rainfed crops to climate change will helps on designing future adaptation strategies. In this study, large amount of data and the agro-hydrological model SWAT have been used to investigate future climate change impacts on rainfed wheat and sunflower crops in a semiarid watershed in Morocco (R’dom watershed). Downscaled CORDEX climate projections were used in generating future plants growth simulation for R’dom watershed in the 2031 to 2050 horizon under two Representative Concentration Pathways (RCPs): 4.5 and 8.5. The main results of climate change scenarios highlighted that R’dom watershed will undergo significant decrease in water resources availability with more impact under the scenario RCP 8.5. Water productivities of both studied crops could be lower by up to -21% in comparison with baseline situation. Different sustainable management strategies have been simulated using SWAT model under climate change context. The adopted approach succeeded in building up sustainable management strategies toward secured food security in the future.

scholarly journals Global distribution of Sapindus habitats under current and future climate change scenarios

2021 ◽  
Author(s):  
Jiming Liu ◽  
Lianchun Wang ◽  
Caowen Sun ◽  
Benye Xi ◽  
Doudou Li ◽  
...  
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Future Climate ◽  
Environmental Data ◽  
Future Climate Change ◽  
Climate Projections ◽  
Suitable Habitat ◽  
Climate Change Scenarios ◽  
Mean Temperature ◽  
Suitable Habitats

Abstract Sapindus (Sapindus L.) is a widely distributed economically important tree genus that provides biodiesel, biomedical and biochemical products. However, with climate change, deforestation, and economic development, Sapindus germplasm resources have been lost. Therefore, utilising historical environmental data and future climate projections from the BCC-CSM2-MR global climate database, we simulated the present and future global distributions of suitable habitats for Sapindus using a Maximum Entropy (MaxEnt) model. The estimated ecological thresholds for critical environmental factors were: a minimum temperature of 0–20°C in the coldest month, soil moisture levels of 40–140 mm, a mean temperature of 2–25°C in the driest quarter, a mean temperature of 19–28°C in the wettest quarter, and a soil pH of 5.6–7.6. The total suitable habitat area was 6059.97 × 104 km2, which was unevenly distributed across six continents. As greenhouse gas emissions increased over time, the area of suitable habitats contracted in lower latitudes and expanded in higher latitudes. Consequently, surveys and conservation should be prioritised in southern hemisphere areas which are in danger of becoming unsuitable. In contrast, other areas in northern and central America, China, and India can be used for conservation and large-scale cultivation in the future.

scholarly journals Applicability of ensemble pattern scaling method on precipitation intensity indices at regional scale

2011 ◽  
Vol 8 (3) ◽  
pp. 5227-5261 ◽  
Author(s):  
Y. Li ◽  
W. Ye
Keyword(s):  
Climate Change ◽  
Regional Scale ◽  
National Level ◽  
Internal Variability ◽  
Future Climate ◽  
Precipitation Intensity ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Scaling Method ◽  
Model Variability

Abstract. Pattern scaling constructs future climate change scenarios using the normalized change patterns of GCMs, offers the possibility of representing the whole range of uncertainties involved in future climate change projection. This paper investigates the applicability and uncertainty associated with the pattern scaling method in constructing the changes of future precipitation intensity indices at regional scale, using a two-step ensemble approach. In the first step, the linearity accuracy and GCM internal variability were examined explicitly. The inter-model variability of the GCMs and associated confidence intervals were produced in the second step ensemble. Australia and its 7 administrative regions was selected as the study area and three precipitation intensity indices, including two precipitation extreme indices, were used for the examination: i.e., the 99th percentile daily precipitation intensity (P99), the 20-yr-return extreme precipitation intensity (RP20), and the mean precipitation intensity (precipitation amount per wet day) (RPD). A total of 12 IPCC AR4 GCMs with 6 simulation samples were used for the ensemble. For the 3 precipitation intensity indices, good linear relationships between precipitation intensity indices change and global mean temperature change at the national level were found for most GCMs, however, the linear relationship weakened when the analysis was applied to the administrative regions. In addition, the GCM internal signal-to-noise ratios for each GCM tended to decrease at the regional and grid cell levels, along with the reduction in spatial scale. Both GCM-internal and inter-model variability was significant, and the inter-model variability was larger than GCM-internal variability. The final result of the inter-model ensemble median results show that for Australia, in general, all three indices will increase under global warming, with the change rates being 3.56, 7.62 and 2.26 % K−1 for P99, RP20 and RPD respectively at the national level.

scholarly journals Spatiotemporal responses in crop water footprint and benchmark under different irrigation techniques to climate change scenarios in China

2021 ◽  
Author(s):  
Zhiwei Yue ◽  
Xiangxiang Ji ◽  
La Zhuo ◽  
Wei Wang ◽  
Zhibin Li ◽  
...  
Keyword(s):  
Climate Change ◽  
Crop Production ◽  
Large Scale ◽  
Water Footprint ◽  
Negative Impact ◽  
Sprinkler Irrigation ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Crop Water

Abstract. Adaptation to future climate change with limited water resources is a major global challenge to sustainable and sufficient crop production. However, the large-scale responses of crop water footprint and its associated benchmarks under various irrigation techniques to future climate change scenarios remain unclear. The present study quantified the responses of maize and wheat water footprint per unit yield (WFP, m3 t−1) and corresponding WFP benchmarks under two representative concentration pathways (RCPs) in the 2030s, 2050s, and 2080s at a 5-arc minute grid level in the case for China. The differences among rain-fed and furrow-, micro-, and sprinkler-irrigated wheat and maize were identified. Compared with the baseline year (2013), maize WFP will increase under both RCP2.6 and RCP8.5, by 17 % and 13 %, respectively, until the 2080s. Wheat WFP will increase under RCP2.6 (by 12 % until the 2080s), while decrease by 12 % under RCP8.5 until the 2080s. WFP will increase the most for rain-fed crops. Relative to rain-fed crops, micro irrigation and sprinkler irrigation result in the smallest increases in WFP for maize and wheat, respectively. These water-saving managements will more effectively mitigate the negative impact of climate change. Furthermore, the spatial distributions of WFP benchmarks will not change as dramatically as those of WFP. The present study demonstrated that the visible different responses to climate change in terms of crop water consumption, water use efficiency, and WFP benchmarks under different irrigation techniques must be addressed and monitored. It also lays the foundation for future investigations into the influences of irrigation methods, RCPs, and crop types on WFP and its benchmarks in response to climate change in all agricultural regions worldwide.

scholarly journals Mapping current and potential future distributions of the oak tree (Quercus aegilops) in the Kurdistan Region, Iraq

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Nabaz R. Khwarahm
Keyword(s):  
Climate Change ◽  
Habitat Suitability ◽  
Environmental Variables ◽  
Climate Changes ◽  
Future Climate ◽  
Annual Precipitation ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Kurdistan Region ◽  
Oak Tree

Abstract Background The oak tree (Quercus aegilops) comprises ~ 70% of the oak forests in the Kurdistan Region of Iraq (KRI). Besides its ecological importance as the residence for various endemic and migratory species, Q. aegilops forest also has socio-economic values—for example, as fodder for livestock, building material, medicine, charcoal, and firewood. In the KRI, Q. aegilops has been degrading due to anthropogenic threats (e.g., shifting cultivation, land use/land cover changes, civil war, and inadequate forest management policy) and these threats could increase as climate changes. In the KRI and Iraq as a whole, information on current and potential future geographical distributions of Q. aegilops is minimal or not existent. The objectives of this study were to (i) predict the current and future habitat suitability distributions of the species in relation to environmental variables and future climate change scenarios (Representative Concentration Pathway (RCP) 2.6 2070 and RCP8.5 2070); and (ii) determine the most important environmental variables controlling the distribution of the species in the KRI. The objectives were achieved by using the MaxEnt (maximum entropy) algorithm, available records of Q. aegilops, and environmental variables. Results The model demonstrated that, under the RCP2.6 2070 and RCP8.5 2070 climate change scenarios, the distribution ranges of Q. aegilops would be reduced by 3.6% (1849.7 km2) and 3.16% (1627.1 km2), respectively. By contrast, the species ranges would expand by 1.5% (777.0 km2) and 1.7% (848.0 km2), respectively. The distribution of the species was mainly controlled by annual precipitation. Under future climate change scenarios, the centroid of the distribution would shift toward higher altitudes. Conclusions The results suggest (i) a significant suitable habitat range of the species will be lost in the KRI due to climate change by 2070 and (ii) the preference of the species for cooler areas (high altitude) with high annual precipitation. Conservation actions should focus on the mountainous areas (e.g., by establishment of national parks and protected areas) of the KRI as climate changes. These findings provide useful benchmarking guidance for the future investigation of the ecology of the oak forest, and the categorical current and potential habitat suitability maps can effectively be used to improve biodiversity conservation plans and management actions in the KRI and Iraq as a whole.

scholarly journals Future climate change vulnerability of endemic island mammals

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Camille Leclerc ◽  
Franck Courchamp ◽  
Céline Bellard
Keyword(s):  
Climate Change ◽  
Pacific Ocean ◽  
Adaptive Capacity ◽  
Climate Change Impacts ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Change Vulnerability ◽  
Vulnerability To Climate Change ◽  
Insular Ecosystems

Abstract Despite their high vulnerability, insular ecosystems have been largely ignored in climate change assessments, and when they are investigated, studies tend to focus on exposure to threats instead of vulnerability. The present study examines climate change vulnerability of islands, focusing on endemic mammals and by 2050 (RCPs 6.0 and 8.5), using trait-based and quantitative-vulnerability frameworks that take into account exposure, sensitivity, and adaptive capacity. Our results suggest that all islands and archipelagos show a certain level of vulnerability to future climate change, that is typically more important in Pacific Ocean ones. Among the drivers of vulnerability to climate change, exposure was rarely the main one and did not explain the pattern of vulnerability. In addition, endemic mammals with long generation lengths and high dietary specializations are predicted to be the most vulnerable to climate change. Our findings highlight the importance of exploring islands vulnerability to identify the highest climate change impacts and to avoid the extinction of unique biodiversity.

Selection of models to describe the temperature-dependent development of Neoleucinodes elegantalis (Lepidoptera: Crambidae) and its application to predict the species voltinism under future climate conditions

2021 ◽  
pp. 1-9
Author(s):  
Hevellyn Talissa dos Santos ◽  
Cesar Augusto Marchioro
Keyword(s):  
Climate Change ◽  
Linear Model ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Temperature Dependent ◽  
Dependent Development ◽  
Degree Day ◽  
Non Linear ◽  
The Impact

Abstract The small tomato borer, Neoleucinodes elegantalis (Guenée, 1854) is a multivoltine pest of tomato and other cultivated solanaceous plants. The knowledge on how N. elegantalis respond to temperature may help in the development of pest management strategies, and in the understanding of the effects of climate change on its voltinism. In this context, this study aimed to select models to describe the temperature-dependent development rate of N. elegantalis and apply the best models to evaluate the impacts of climate change on pest voltinism. Voltinism was estimated with the best fit non-linear model and the degree-day approach using future climate change scenarios representing intermediary and high greenhouse gas emission rates. Two out of the six models assessed showed a good fit to the observed data and accurately estimated the thermal thresholds of N. elegantalis. The degree-day and the non-linear model estimated more generations in the warmer regions and fewer generations in the colder areas, but differences of up to 41% between models were recorded mainly in the warmer regions. In general, both models predicted an increase in the voltinism of N. elegantalis in most of the study area, and this increase was more pronounced in the scenarios with high emission of greenhouse gases. The mathematical model (74.8%) and the location (9.8%) were the factors that mostly contributed to the observed variation in pest voltinism. Our findings highlight the impact of climate change on the voltinism of N. elegantalis and indicate that an increase in its population growth is expected in most regions of the study area.

Sign in / Sign up

Export Citation Format

Share Document