scholarly journals The Mediterranean climate change hotspot in the CMIP5 and CMIP6 projections

2021 ◽  
Author(s):  
Josep Cos ◽  
Francisco Doblas-Reyes ◽  
Martin Jury ◽  
Raül Marcos ◽  
Pièrre-Antoine Bretonnière ◽  
...  
Keyword(s):  
Climate Change ◽  
21St Century ◽  
Mediterranean Region ◽  
Model Performance ◽  
Warming Trend ◽  
Weighting Scheme ◽  
The Mediterranean ◽  
Model Ensembles ◽  
Projected Changes ◽  
Model Weighting

Abstract. The increased warming trend and precipitation decline in the Mediterranean region makes it a climate change hotspot. We compare projections of multiple CMIP5 and CMIP6 historical and scenario simulations to quantify the impacts of the already changing climate in the region. In particular, we investigate changes in temperature and precipitation during the 21st century following scenarios RCP2.6, SSP1-2.6, RCP4.5, SSP2-4.5, RCP8.5 and SSP5-8.5, as well as the HighResMIP high resolution experiments. A model weighting scheme is applied to obtain constrained estimates of projected changes, which accounts for historical model performance and inter-independence of the multi-model ensembles, using an observational ensemble as reference. Results indicate a robust and significant warming over the Mediterranean region along the 21st century over all seasons, ensembles and experiments. The Mediterranean amplified warming with respect to the global mean is mainly found during summer. The temperature changes vary between CMIPs, being CMIP6 the ensemble that projects a stronger warming. Contrarily to temperature projections, precipitation changes show greater uncertainties and spatial heterogeneity. However, a robust and significant precipitation decline is projected over large parts of the region during summer for the high emission scenario. While there is less disagreement in projected precipitation between CMIP5 and CMIP6, the latter shows larger precipitation declines in some regions. Results obtained from the model weighting scheme indicate increases in CMIP5 and reductions in CMIP6 warming trends, thereby reducing the distance between both multi-model ensembles.

Mediterranean climate change projections: an update from CMIP5 and CMIP6.

2021 ◽  
Author(s):  
Josep Cos ◽  
Francisco J Doblas-Reyes ◽  
Martin Jury
Keyword(s):  
Climate Change ◽  
21St Century ◽  
Hot Spot ◽  
Weighting Scheme ◽  
Temperature And Precipitation ◽  
High Emission ◽  
The Mediterranean ◽  
Model Ensembles ◽  
Projected Changes ◽  
Model Weighting

<p>The Mediterranean has been identified as a climate change hot-spot due to increased warming trends and precipitation decline. Recently, CMIP6 was found to show a higher climate sensitivity than its predecessor CMIP5, potentially further exacerbating related impacts on the Mediterranean region.</p><p>To estimate the impacts of the ongoing climate change on the region, we compare projections of various CMIP5 and CMIP6 experiments and scenarios. In particular, we focus on summer and winter changes in temperature and precipitation for the 21st century under RCP2.6/SSP1-2.6, RCP4.5/SSP2-4.5 and RCP8.5/SSP5-8.5 as well as the high resolution HighResMIP experiments. Additionally, to give robust estimates of projected changes we apply a novel model weighting scheme, accounting for historical performance and inter-independence of the multi-member multi-model ensembles, using ERA5, JRA55 and WFDE5 as observational reference. </p><p>Our results indicate a significant and robust warming over the Mediterranean during the 21st century irrespective of the used ensemble and experiments. Nevertheless, the often attested amplified Mediterranean warming is only found for summer. The projected changes vary between the CMIP5 and CMIP6, with the latter projecting a stronger warming. For the high emission scenarios and without weighting, CMIP5 indicates a warming between 4 and 7.7ºC in summer and 2.7 and 5ºC in winter, while CMIP6 projects temperature increases between 5.6 and 9.2ºC in summer and 3.2 to 6.8ºC in winter until 2081-2100 in respect to 1985-2005. In contrast to temperature, precipitation changes show a higher level of uncertainty and spatial heterogeneity. However, for the high emission scenario, a robust decline in precipitation is projected for large parts of the Mediterranean during summer. First results applying the model weighting scheme indicate reductions in CMIP6 and increases in CMIP5 warming trends, thereby reducing differences between the two ensembles.</p>

Relative impact of irrigation techniques and climate change on hydroclimatic regimes in the Mediterranean region

2021 ◽  
Author(s):  
Sandra Pool ◽  
Félix Francés ◽  
Alberto Garcia-Prats ◽  
Manuel Pulido-Velazquez ◽  
Carles Sanichs-Ibor ◽  
...  
Keyword(s):  
Climate Change ◽  
Impact Assessment ◽  
Drip Irrigation ◽  
Mediterranean Region ◽  
Control Period ◽  
Irrigated Agriculture ◽  
Flood Irrigation ◽  
The Mediterranean ◽  
Projected Changes ◽  
The Impact

<p>Irrigated agriculture is the major water consumer in the Mediterranean region. Improved irrigation techniques have been widely promoted to reduce water withdrawals and increase resilience to climate change impacts. In this study, we assess the impact of the ongoing transition from flood to drip irrigation on future hydroclimatic regimes in the agricultural areas of Valencia (Spain). The impact assessment is conducted for a control period (1971-2000), a near-term future (2020-2049) and a mid-term future (2045-2074) using a chain of models that includes five GCM-RCM combinations, two emission scenarios (RCP 4.5 and RCP 8.5), two irrigation scenarios (flood and drip irrigation), and twelve parameterizations of the hydrological model Tetis. Results of this modelling chain suggest considerable uncertainties regarding the magnitude and sign of future hydroclimatic changes. Yet, climate change could lead to a statistically significant decrease in future groundwater recharge of up -6.6% in flood irrigation and -9.3% in drip irrigation. Projected changes in actual evapotranspiration are as well statistically significant, but in the order of +1% in flood irrigation and -2.1% in drip irrigation under the assumption of business as usual irrigation schedules. The projected changes and the related uncertainties will pose a challenging context for future water management. However, our findings further indicate that the effect of the choice of irrigation technique may have a greater impact on hydroclimate than climate change alone. Explicitly considering irrigation techniques in climate change impact assessment might therefore be a way towards better informed decision-making.</p><p>This study has been supported by the IRRIWAM research project funded by the Coop Research Program of the ETH Zurich World Food System Center and the ETH Zurich Foundation, and by the ADAPTAMED (RTI2018-101483-B-I00) and TETISCHANGE (RTI2018-093717-B-I00) research projects funded by the Ministerio de Economia y Competitividad (MINECO) of Spain including EU FEDER funds.</p>

scholarly journals A multi-model, multi-scenario, and multi-domain analysis of regional climate projections for the Mediterranean

2019 ◽  
Vol 19 (8) ◽  
pp. 2621-2635 ◽  
Author(s):  
George Zittis ◽  
Panos Hadjinicolaou ◽  
Marina Klangidou ◽  
Yiannis Proestos ◽  
Jos Lelieveld
Keyword(s):  
Climate Change ◽  
Regional Climate Model ◽  
Mediterranean Region ◽  
Climate Model ◽  
Regional Climate ◽  
Climate Change Signal ◽  
Climate Projections ◽  
Temperature And Precipitation ◽  
The Mediterranean ◽  
Projected Changes

AbstractObservation and model-based studies have identified the Mediterranean region as one of the most prominent climate change “hot-spots.” Parts of this distinctive region are included in several Coordinated Regional Downscaling Experiment (CORDEX) domains such as those for Europe, Africa, the Mediterranean, and the Middle East/North Africa. In this study, we compile and analyze monthly temperature and precipitation fields derived from regional climate model simulations performed over different CORDEX domains at a spatial resolution of 50 km. This unique multi-model, multi-scenario, and multi-domain “super-ensemble” is used to update projected changes for the Mediterranean region. The statistical robustness and significance of the climate change signal is assessed. By considering information from more than one CORDEX domains, our analysis addresses an additional type of uncertainty that is often neglected and is related to the positioning of the regional climate model domain. CORDEX simulations suggest a general warming by the end of the century (between 1 and 5 °C with respect to the 1986–2005 reference period), which is expected to be strongest during summer (up to 7 °C). A general drying (between 10 and 40%) is also inferred for the Mediterranean. However, the projected precipitation change signal is less significant and less robust. The CORDEX ensemble corroborates the fact that the Mediterranean is already entering the 1.5 °C climate warming era. It is expected to reach 2 °C warming well within two decades, unless strong greenhouse gas concentration reductions are implemented. The southern part of the Mediterranean is expected to be impacted most strongly since the CORDEX ensemble suggests substantial combined warming and drying, particularly for pathways RCP4.5 and RCP8.5.

scholarly journals Mediterranean Olive Orchards under Climate Change: A Review of Future Impacts and Adaptation Strategies

Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 56
Author(s):  
Helder Fraga ◽  
Marco Moriondo ◽  
Luisa Leolini ◽  
João A. Santos
Keyword(s):  
Climate Change ◽  
Mediterranean Basin ◽  
Olive Tree ◽  
Climatic Conditions ◽  
Adaptation Strategies ◽  
Adaptation Measures ◽  
The Mediterranean ◽  
Projected Changes ◽  
The Mediterranean Basin ◽  
Impacts Of Climate Change

The olive tree (Olea europaea L.) is an ancient traditional crop in the Mediterranean Basin. In the Mediterranean region, traditional olive orchards are distinguishable by their prevailing climatic conditions. Olive trees are indeed considered one of the most suitable and best-adapted species to the Mediterranean-type climate. However, new challenges are predicted to arise from climate change, threatening this traditional crop. The Mediterranean Basin is considered a climate change “hotspot,” as future projections hint at considerable warming and drying trends. Changes in olive tree suitability have already been reported over the last few decades. In this context, climate change may become particularly challenging for olive growers. The growing evidence for significant climate change in the upcoming decades urges adaptation measures to be taken. To effectively cope with the projected changes, both short and long-term adaptation strategies must be timely planned by the sector stakeholders and decision-makers to adapt for a warmer and dryer future. The current manuscript is devoted to illustrating the main impacts of climate change on olive tree cultivation in the Mediterranean Basin, by reviewing the most recent studies on this subject. Additionally, an analysis of possible adaptation strategies against the potentially negative impacts of climate change was also performed.

scholarly journals The Mediterranean Region: between terrorism, tourism and security

2018 ◽  
Vol 1 (2) ◽  
pp. 135-148
Author(s):  
Nicoletta Varani ◽  
Enrico Bernardini
Keyword(s):  
Natural Disasters ◽  
21St Century ◽  
Mediterranean Region ◽  
Tourism Industry ◽  
Terrorist Attacks ◽  
The Political ◽  
International Conflicts ◽  
Tourist Destinations ◽  
The World ◽  
The Mediterranean

Abstract Tourism remains a very vulnerable sector and sensitive to both internal and external impacts, such as economic and social crises, natural disasters, epidemics and diseases, national and international conflicts. Among these, the most alarming threat in the 21st century remains terrorism. In this sense, this paper aims to study the effects of the increasingly frequent terrorist attacks by the extremist factions of Al-Qaeda and ISIL on the tourism industry in the Mediterranean Region. The contribution, after having discussed in general the tourism market in the Mediterranean Region, intends to highlight the impacts and repercussions of the terrorist attacks on tourism, presenting the example of Egypt and one of its best-known tourist destinations, Sharm el-Sheikh. In this sense, it is shown how, in a few years, the political instability of the country and the attacks of 2005 and 2016 have significantly reduced the influx of tourists, transforming it from one of the most visited destinations in the world in a place of increasing abandonment.

scholarly journals Mediterranean irrigation under climate change: more efficient irrigation needed to compensate increases in irrigation water requirements

2015 ◽  
Vol 12 (8) ◽  
pp. 8459-8504 ◽  
Author(s):  
M. Fader ◽  
S. Shi ◽  
W. von Bloh ◽  
A. Bondeau ◽  
W. Cramer
Keyword(s):  
Climate Change ◽  
Irrigation Water ◽  
Mediterranean Region ◽  
Eastern Mediterranean ◽  
Water Requirements ◽  
Co2 Fertilization ◽  
Fertilization Effect ◽  
Co2 Fertilization Effect ◽  
The Mediterranean ◽  
Irrigation Requirements

Abstract. Irrigation in the Mediterranean is of vital importance for food security, employment and economic development. This study systematically assesses how climate change and increases in atmospheric CO2 concentrations may affect irrigation requirements in the Mediterranean region by 2080–2090. Future demographic change and technological improvements in irrigation systems are accounted for, as is the spread of climate forcing, warming levels and potential realization of the CO2-fertilization effect. Vegetation growth, phenology, agricultural production and irrigation water requirements and withdrawal were simulated with the process-based ecohydrological and agro-ecosystem model LPJmL after a large development that comprised the improved representation of Mediterranean crops. At present the Mediterranean region could save 35 % of water by implementing more efficient irrigation and conveyance systems. Some countries like Syria, Egypt and Turkey have higher saving potentials than others. Currently some crops, especially sugar cane and agricultural trees, consume in average more irrigation water per hectare than annual crops. Different crops show different magnitude of changes in net irrigation requirements due to climate change, being the increases most pronounced in agricultural trees. The Mediterranean area as a whole might face an increase in gross irrigation requirements between 4 and 18 % from climate change alone if irrigation systems and conveyance are not improved (2 °C global warming combined with full CO2-fertilization effect, and 5 °C global warming combined with no CO2-fertilization effect, respectively). Population growth increases these numbers to 22 and 74 %, respectively, affecting mainly the Southern and Eastern Mediterranean. However, improved irrigation technologies and conveyance systems have large water saving potentials, especially in the Eastern Mediterranean, and may be able to compensate to some degree the increases due to climate change and population growth. Both subregions would need around 35 % more water than today if they could afford some degree of modernization of irrigation and conveyance systems and benefit from the CO2-fertilization effect. Nevertheless, water scarcity might pose further challenges to the agricultural sector: Algeria, Libya, Israel, Jordan, Lebanon, Syria, Serbia, Morocco, Tunisia and Spain have a high risk of not being able to sustainably meet future irrigation water requirements in some scenarios. The results presented in this study point to the necessity of performing further research on climate-friendly agro-ecosystems in order to assess, on the one side, their degree of resilience to climate shocks, and on the other side, their adaptation potential when confronted with higher temperatures and changes in water availability.

scholarly journals Are we using the right fuel to drive hydrological models? A climate impact study in the Upper Blue Nile

2018 ◽  
Vol 22 (4) ◽  
pp. 2163-2185 ◽  
Author(s):  
Stefan Liersch ◽  
Julia Tecklenburg ◽  
Henning Rust ◽  
Andreas Dobler ◽  
Madlen Fischer ◽  
...  
Keyword(s):  
Climate Change ◽  
Bias Correction ◽  
Climate Models ◽  
Regional Climate ◽  
Model Performance ◽  
Climate Impact ◽  
Hydrological Models ◽  
Blue Nile ◽  
Projected Change ◽  
Model Ensembles

Abstract. Climate simulations are the fuel to drive hydrological models that are used to assess the impacts of climate change and variability on hydrological parameters, such as river discharges, soil moisture, and evapotranspiration. Unlike with cars, where we know which fuel the engine requires, we never know in advance what unexpected side effects might be caused by the fuel we feed our models with. Sometimes we increase the fuel's octane number (bias correction) to achieve better performance and find out that the model behaves differently but not always as was expected or desired. This study investigates the impacts of projected climate change on the hydrology of the Upper Blue Nile catchment using two model ensembles consisting of five global CMIP5 Earth system models and 10 regional climate models (CORDEX Africa). WATCH forcing data were used to calibrate an eco-hydrological model and to bias-correct both model ensembles using slightly differing approaches. On the one hand it was found that the bias correction methods considerably improved the performance of average rainfall characteristics in the reference period (1970–1999) in most of the cases. This also holds true for non-extreme discharge conditions between Q20 and Q80. On the other hand, bias-corrected simulations tend to overemphasize magnitudes of projected change signals and extremes. A general weakness of both uncorrected and bias-corrected simulations is the rather poor representation of high and low flows and their extremes, which were often deteriorated by bias correction. This inaccuracy is a crucial deficiency for regional impact studies dealing with water management issues and it is therefore important to analyse model performance and characteristics and the effect of bias correction, and eventually to exclude some climate models from the ensemble. However, the multi-model means of all ensembles project increasing average annual discharges in the Upper Blue Nile catchment and a shift in seasonal patterns, with decreasing discharges in June and July and increasing discharges from August to November.

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