Spatial Patterns of European droughts under a moderate emission scenario

Meteorological drought is generally defined as a prolonged deficiency of precipitation and is considered one of the most relevant natural hazards as the related impacts can involve many different sectors. In this study, we investigated the spatial patterns of European droughts for the periods 1981-2010, 2041-2070, and 2071-2100, focusing on the projections under a moderate emissions scenario. To do that, we used the outputs of the KNMI-RACMO2 model, which belongs to the A1B family and whose spatial resolution is 0.25°x0.25°. By means of monthly precipitation and potential evapo-transpiration (PET), we computed the Standardized Precipitation Index (SPI) and the Standardized Precipitation-Evapotranspiration Index (SPEI) at12-month accumulation scale. Thereafter, we separately obtained drought frequency, duration, severity, and intensity for the whole of Europe, excluding Iceland. According to both indicators, the spatial drought patterns are projected to follow what recently characterized Europe: Southern Europe, who experienced many severe drought events in the last decades, is likely to be involved by longer, more frequent, severe, and intense droughts in the near future (2041-2070) and even more in the far future (2071-2100). This tendency is more evident using the SPEI, which also depends on temperature and consequently reflects the expected warming that will be highest for the Mediterranean area in Europe. On the other side, less severe and fewer drought events are likely to occur in Northern Europe. This tendency is more evident using the SPI, because the precipitation increase is projected to outbalance the temperature (and PET) rise in particular in Scandinavia. Regarding the mid-latitudes, the SPEI-based analyses point at more frequent drought events, while the SPI-based ones point at less frequent events in these regions.JRC.H.7-Climate Risk Managemen

Projections of indices of daily temperature and precipitation based on bias-adjusted CORDEX-Africa regional climate model simulations

AbstractWe present a dataset of daily, bias-adjusted temperature and precipitation projections for continental Africa based on a large ensemble of regional climate model simulations, which can be useful for climate change impact studies in several sectors. We provide guidance on the benefits and caveats of using the dataset by investigating the effect of bias-adjustment on impact-relevant indices (both their future absolute value and change). Extreme threshold-based temperature indices show large differences between original and bias-adjusted values at the end of the century due to the general underestimation of temperature in the present climate. These results indicate that when biases are accounted for, projected risks of extreme temperature-related hazards are higher than previously found, with possible consequences for the planning of adaptation measures. Bias-adjusted results for precipitation indices are usually consistent with the original results, with the median change preserved for most regions and indices. The interquartile and full range of the original model ensemble is usually well preserved by bias-adjustment, with the exception of maximum daily precipitation, whose range is usually greatly reduced by the bias-adjustment. This is due to the poor simulation and extremely large model range for this index over the reference period; when the bias is reduced, most models converge in projecting a similar change. Finally, we provide a methodology to select a small subset of simulations that preserves the overall uncertainty in the future projections of the large model ensemble. This result can be useful in practical applications when process-based impact models are too expensive to be run with the full ensemble of model simulations

Meteorological Droughts in Europe: Events and Impacts - Past Trends and Future Projections

Observational records from 1950 onwards and climate projections for the 21st century provide evidence that droughts are a recurrent climate feature in large parts of Europe, especially in the Mediterranean, but also in western, south-eastern and central Europe. Trends over the past 60 years show an increasing frequency, duration and intensity of droughts in these regions, while a negative trend has been observed in north-eastern Europe. With a changing climate, this tendency is likely to be reinforced during the 21st century, affecting a wide range of socioeconomic sectors. The report provides a detailed description of the characteristics of drought events (i.e. their frequency, duration, intensity, severity) across Europe, and their evolution over the period 1950 to 2012, as well as projections until the end of the 21st century. A pan-European database of meteorological drought events for the period 1950-2012 and of their related sectorial impacts was built and a framework developed that links drought severity to expected damages under present and future climate.Fil: Spinoni, Jonathan. European Commission Joint Research Centre; ItaliaFil: Naumann, Gustavo. European Commission Joint Research Centre; Italia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vogt, Jürgen. European Commission Joint Research Centre; ItaliaFil: Barbosa, Paulo. European Commission Joint Research Centre; Itali

Global warming and windstorm impacts in the EU

Windstorms are amongst the most damaging natural hazards in Europe, with approximately 5 €billion of estimated annual losses in the EU. The number of reported windstorms significantly increased over the last decades, yet there is no consensus about a climate-induced trend in windstorms over Europe. Climate model projections of extreme wind are highly uncertain, but they suggest that windstorms will not become more intense or happen more frequent with global warming over most of the European land. As a consequence, it is expected that risks from windstorms in the EU will not rise due to climate change. Future impacts of wind extremes could be reduced by a range of measures, such as the development and implementation of enhanced windstorm-resilient standards and building codes.JRC.E.1-Disaster Risk Managemen

Towards estimates of future rainfall erosivity in Europe based on REDES and WorldClim datasets

The policy requests to develop trends in soil erosion changes can be responded developing modelling scenarios of the two most dynamic factors in soil erosion, i.e. rainfall erosivity and land cover change. The recently developed Rainfall Erosivity Database at European Scale (REDES) and a statistical approach used to spatially interpolate rainfall erosivity data have the potential to become useful knowledge to predict future rainfall erosivity based on climate scenarios. The use of a thorough statistical modelling approach (Gaussian Process Regression), with the selection of the most appropriate covariates (monthly precipitation, temperature datasets and bioclimatic layers), allowed to predict the rainfall erosivity based on climate change scenarios. The mean rainfall erosivity for the European Union and Switzerland is projected to be 857 MJ mm ha −1 h −1 yr −1 till 2050 showing a relative increase of 18% compared to baseline data (2010). The changes are heterogeneous in the European continent depending on the future projections of most erosive months (hot period: April–September). The output results report a pan-European projection of future rainfall erosivity taking into account the uncertainties of the climatic models

Global population‐weighted degree‐day projections for a combination of climate and socio‐economic scenarios

AbstractThe projected global temperature increase in the 21st century is expected to have consequences on energy consumption due to increase (decrease) in energy demand to cool (heat) the built environments. Such increase (decrease) also depends on the number of end users for such energy, thus it is crucial to include population into the analyses. This study presents population‐weighted (w) cooling (CDD), heating (HDD), and energy (EDD) degree‐day projections at global, regional, and local scales for the 21st century. We used a large ensemble of high‐resolution (0.44°) climate simulations from the COordinated Regional‐climate Downscaling EXperiment (CORDEX) to compute degree‐days for baseline (1981–2010) and global warming levels (GWLs from 1.5°C to 4°C), based on two representative concentration pathways. We used population projections from the NASA‐SEDAC datasets, driven by five socio‐economic scenarios (SSPs). The progressive increase in CDD outbalances the decrease in HDD in Central and South America, Africa, and Oceania and the opposite situation is likely to occur in North America, Europe, and Asia; at global scale, they are balanced. However, if results are weighted according to population, the increase in wCDD outbalances the decrease in wHDD almost everywhere for most GWLs and SSPs. Few regions show a decreasing tendency in wEDD at high GWLs for all SSPs: central Europe, northwestern, northeastern, and eastern Asia. Globally, wEDD are likely to double at 2°C compared to 1981–2010 independently of the SSP. Under the worst‐case scenario (SSP3), at 4°C wCDD are approximately 380% higher and wHDD approximately 30% lower than in the recent past, leading to an increase in wEDD close to 300%

Vulnerability of European forests to natural disturbances

European forests provide a set of fundamental services that contribute to climate change mitigation and human well-being. At the same time, forests are vulnerable systems because the long life-span of trees limits the possibility of rapid adaptation to drastic environmental changes. Climate-driven disturbances in forests, such as fires, windstorms and insect outbreaks, are expected to rise drastically under global warming. As a result, key forest services, such as carbon sequestration and supply of wood materials, could be seriously affected in the near future. Despite the relevance and urgency of the issue, little is known about the vulnerability of European forests to multiple climate-related hazards and the adaptation benefits of alternative forest management strategies. To fill this knowledge gap we investigated the susceptibility of European forests when exposed to a given natural disturbance under different forest management scenarios. For this purpose, we assessed forest vulnerability by integrating in a data-driven framework satellite observations, national forest inventories, land surface climatic data and records of disturbances over the 2000-2017 period. The integration of these data streams is meant to capture the key drivers of vulnerability and to quantify, for the first time, the vulnerability of European forests to fires, windstorms and insect outbreaks in a systematic and spatially explicit manner. We point out that, the term vulnerability is used in this study to express to what degree a forest ecosystem is affected when exposed to a given disturbance. In order to derive risk estimates, vulnerability estimates should be integrated with hazard and exposure components, according to typical impact assessment frameworks. Results of this analyses show that in average at Europe level forest vulnerability to windstorms appears the disturbance with larger biomass loss both in relative and absolute terms (~38%, ~17 t ha-1) compared to fires (~24%, ~12.5 t ha-1) and insect outbreaks (~21%, ~9 t ha-1). Substantial spatial variations in vulnerability emerge and depict generally higher values in norther and Mediterranean regions. Overall, forest structural properties play a larger control on the vulnerability of European forests to natural disturbances compared to climate and landscape features. However, increases in temperature and changes in precipitation patterns occurred over the last two decades, have contributed substantially to make European forests more vulnerable to natural disturbances. We found that these changes in climate led to a limited increase in vulnerability at Europe for fires and windstorms and to a strong increase for insect outbreaks. However, contrasting regional trends emerging over Europe mask relevant temporal changes in vulnerability occurring at local scale. When analyses of single disturbances are combined together, results show that large part of the European forests are substantially vulnerable to at least one natural disturbance and that many of the areas more vulnerable have been subject to an amplification of vulnerability over the observational period due to changes in climate. Reducing tree age and tree density appear effective forest management strategies to reduce the vulnerability of European forests to climate-driven disturbances. The magnitude of the potential benefits appears strongly dependent on local environmental conditions. Previous assessments of future climate risks to European forests, based on catalogues of disturbances collected at country level, have showed that damage from fires, windstorms and insect outbreaks is likely to increase further in coming decades. Such intensification could offset the impact of land-based strategies aiming to increase the forest carbon sink. However, the country scale approach used in such studies do not allow to explore in detail the underlying physical processes and to elaborate adaptation strategies at appropriate local scales. It is therefore fundamental to elaborate new modelling approaches that address in explicit manner the high spatial and temporal variability of forest disturbances. In this respect, machine learning approaches and the increasing availability of multi-platform satellite observations of land surface in combination with high regional climate model simulations, represent valuable opportunities to appraise the impact of forest disturbances at a spatial and temporal resolution relevant for forest management strategies. This explorative study represents a first step towards such integrated framework.JRC.D.1-Bio-econom

Climate Change and Critical Infrastructure - Storms

Infrastructure systems are the backbone of modern economies, and critical infrastructure resilience is essential to sustainable development. Natural hazards can affect the electricity supply and result in power outages which can trigger accidents, bring economic activity to a halt and hinder emergency response until electricity supply is restored to critical services. The risk environment facing critical infrastructures is complex and in constant flux. This study attempts to elucidate the vulnerability of critical electric infrastructure to storms. First, we discuss the impact of storms on the power grid and outline how certain characteristics of this type of hazard affect the resilience of the power grid based on forensic analysis. Storms can cause widespread damage to the electricity grid. Wind loading and debris impact are the main causes of storm damage. Tall, slender structures, such as transmission towers, distribution poles and wind turbines are most affected. Transmission and distribution assets can also be damaged by the impact of flying debris. Moreover, freezing rain forms glaze ice which accumulates on power lines and increases their catenary load. The added weight can cause the line to break or distribution poles and transmission towers to collapse. Substations were also found to be affected by storms, particularly by inundation and airborne debris. However, damage from flying debris was less compared to that sustained by transmission and distribution lines. Storms in coastal areas may affect transmission and distribution networks by increasing the amount of saltwater deposits on electrical equipment. Given adequate preparedness, early warning can help expedite recovery by allowing TSOs and DSOs to activate disaster response plans, including surge mechanisms and mutual aid agreements, before the storm hits. Second, we present a methodology to investigate the impact of climate change on the risk posed by storms to critical electric infrastructure. Our approach combines a future projection of the recurrence interval of selected storm scenarios and the assessment of the estimated economic losses incurred by critical infrastructure and those resulting from the disruption of daily economic activity. A case study was conducted to demonstrate the methodology in a large urban area in Western Europe. We derived the projected peak wind gust of the 10-, 50- and 100-year storm scenarios for five time periods. For each recurrence interval, the cost to repair the damage to overhead lines and the economic losses from the interruption of the daily economic activity amount each to about half of the total losses. The proportion of the repair cost increases by approximately 10% for the 50-year and the 100-year storms compared to the 10-year scenario. This increase causes the total expected losses from the 50-year and the 100-year storms to rise as well. The duration of the power outage has a major impact on the estimated losses for all scenarios across all time periods. In this case study, the increase of the duration of the power outage from 3 days to 10 days increases the total expected losses 3.5 times. With longer-term power outages, the economic losses caused by interruption of the daily economic activity progressively become the main determinant of the total impact. The scope of this study is limited to demonstrating the feasibility of the methodology and inductively drawing preliminary conclusions regarding the impact of storms on critical infrastructure given climate change conditions. It is not intended to supplement, replace or challenge existing risk assessment and management plans prepared by Member States. The following recommendations emerged from the findings of this study: — Consider increasing transmission tower design requirements for resistance to wind loading in standards and regulations. — Consider the risk from climate change in investment analyses. — Consider events with recurrence intervals longer than 100 years in hazard mitigation and emergency planning. — Standardize mutual aid resources. — Plan for surge capabilities and external contractors.JRC.E.2-Technology Innovation in Securit

Emergent vulnerability to climate-driven disturbances in European forests

Forest disturbance regimes are expected to intensify as Earth's climate changes. Quantifying forest vulnerability to disturbances and understanding the underlying mechanisms is crucial to develop mitigation and adaptation strategies. However, observational evidence is largely missing at regional to continental scales. Here, we quantify the vulnerability of European forests to fires, windthrows and insect outbreaks during the period 1979-2018 by integrating machine learning with disturbance data and satellite products. We show that about 33.4 billion tonnes of forest biomass could be seriously affected by these disturbances, with higher relative losses when exposed to windthrows (40%) and fires (34%) compared to insect outbreaks (26%). The spatial pattern in vulnerability is strongly controlled by the interplay between forest characteristics and background climate. Hotspot regions for vulnerability are located at the borders of the climate envelope, in both southern and northern Europe. There is a clear trend in overall forest vulnerability that is driven by a warming-induced reduction in plant defence mechanisms to insect outbreaks, especially at high latitudes. Natural disturbances imperil healthy and productive forests, but quantifying their effects at large scales is challenging. Here the authors apply machine learning to disturbance records and satellite data to quantify and map European forest vulnerability to fires, windthrows, and insect outbreaks through 1979-2018.Peer reviewe

Annual Progress Report of the European and Global Drought Observatories

With this report, the reader finds an overview of the changes, upgrades and new features created in the European Drought Observatory (EDO) and the Global Drought Observatory (GDO) and made in 2019. The year proved relatively quiet concerning drought events in Europe; the subcontinent was only affected in the Baltics, although fires broke out vigorously in the Balkans, Spain and Russia. Thanks to the recent juvenile concern with regard to the heating up of the climate, drought events and forest fires drew more public-attention. Our reaction upon this concern in the Global Drought Observatory is the development of a new group of data, which we call Drought Mitigation. With more people genuinely concerned in the effect of our alternation of the properties of the lower atmosphere, we take up the task to provide guidelines for repair and adaptation. Higher temperatures imply that air depletes more vapour from vegetation and soil, leading to more intense droughts or floods. Consient management of our fresh water resources and massive tree planting are measures that can have significant impact on the effects of a Drought, Forest Fires or also Flood events. Therefore, we started with including the results of the often-cited research result regarding reforestation potential of the Crowther Lab as a layer in the Global Drought Observatory. We completed our work with enriching data describing dams with data regarding the location, name and quantitative characteristics of dams as an additional layer. We worked on the integration of the GRACE Dataset, which gives us an actualized satellite born, insight in the depletion of groundwater resources. We created a new index, alerting drought impacts on protected wetlands. Droughts events in these areas might affect rare species living in these protected wetlands, thus creating a link to the biodiversity crisis. The drought alerting mechanism we developed thus far were human centred. With this new index and with the Crowther Lab reforestation inventory we hope to correct this one species view of the past, learning to share our territory with all species, also during hard times of a drought disaster. With these additions, we hope that EDO and GDO will give you a better overview of the impacts of drought events, not only for our economy but also for our shared ecosystems and their services to us. Finally note that we engage in a project to export EDO and GDO knowledge and software to African regional partners. Thus enabling them to set up drought observatories in Africa just as if we did for South- and Central America. Such a collaboration works both ways, we understand better the impacts of Drought events in their region and we learn from their practical skills with regard to make things work in a challenging environment, whilst we can give them working drought observatory software, practical manners to, almost, fully automate the filling and updating of the systems combined with our specific expertise on droughts build up in the last 12 years.JRC.E.1-Disaster Risk Managemen