Heat Waves

This research aims to examine changes in heat waves (HWs) over Chile from 1961 to 2016 using daily maximum (TX) and minimum temperature (TN) data recorded at 13 weather stations. Based on three HW-definitions and five aspects for each definition some 15 indices were calculated and analyzed for the extended summer period (November-March). The three definitions of the HWs employed in this study were based on: (1) the TX exceeding the 90th percentile for at least three consecutive days, (2) the TN exceeding the 90th percentile for at least three consecutive days, and (3) the positive values of excess heat factor (EHF) maintaining for at least three consecutive days. The five aspects calculated for each of the definitions provided information related to the frequency , duration, and intensity of HWs. Trends (be them increasing or decreasing), magnitude (change per decade) and statistical significance (p < 0.05) were identified using the ordinary least square method and the t-test. Therefore, in terms of HW aspects, the results of the HWs climate regime analysis showed that the most extreme region of Chile is the Atacama Desert, followed by the Santiago metropolitan area. Change analysis revealed that Chile experienced increasing trends in most of the HW data sets. Thus, the frequency of trend types of all HW indices time series showed an increasing trend of 79%. About 24% of the time series showed statistically significant increasing trends. Decreasing trends were found in about 20% of the analyzed data, less than 1% of which being statistically significant. Stationary trends were detected in only 2% of the series. The highest frequency of statistically significant increasing trends was found in the HWs identified based on TX, followed by those computed based on EHF. Regarding their aspects, the number of events had the highest frequency of significant increasing trends. In terms of spatial distribution, the most important changes were found in central Chile.

Han pasado 27 años desde que la Convención Marco de las Naciones Unidas sobre el Cambio Climático fuera adoptada en Nueva York, el 9 de mayo de 1992. A pesar de que en ese camino ha habido enormes dificultades para construir consen-sos globales, no cabe duda de que se avanzó, y mucho, en varios aspec-tos. Ya nadie duda de la responsabi-lidad de la actividad humana industrial y de que hay que hacer algo (o más) al respecto, lo que constituye un enorme paso adelante. En ese sentido, los informes cien-tíficos son cada vez más certeros y los frutos de esa atención empiezan a verse en la vida cotidiana, como por ejemplo en el esfuerzo por tra-tar de mover la economía con de energías menos "sucias". Desde 2015, la mayoría de los países (146 de los 196 que forman parte de la Convención) presentaron compro-misos unilaterales para contribuir a la acordada necesidad de reducir emisiones. Y, aunque la acción co-mienza oficialmente en 2020, todos toman medidas preventivas. Según los análisis científicos de las reducciones en emisiones de gases con efecto invernadero comprome-tidas de manera unilateral por cada país, la temperatura igual aumen-taría 2,7°C sobre final del siglo, lo que sería catastrófico para la bio-diversidad, la provisión de agua para el consumo y la producción, la economía y tantas otras actividades humanas. El límite total de riesgo es 2°C res-pecto de la situación preindustrial; es más, muchos querrían que no se llegara a ese número, que liquida-ría el ya escaso potencial agrícola de muchas zonas de África e inun-daría a varias islas del Pacífico, por citar los casos más extremos de un colapso que, como todos, afectaría más a países pobres y a los más po-bres dentro de los países ricos. efectos previsibles Una de las consecuencias esperadas es el aumento de la frecuencia de los llamados "eventos extremos", entre los que se cuentan las olas de calor (OC), fenómeno sobre el cual todavía no hay una definición inter-nacionalmente consensuada 1 , pero Las temperaturas máximas que provocan mortalidad varían de un lugar a otro, condiciones meteorológicas como baja presión y humedad aumentan el peligro.

FOR CITATIONS:
Salem, H.S., 2008. Abstract of the Paper "Impacts of Climate Change on Biodiversity and Food Security in Palestine - Pages: 49, 130". In: Singh, Gurharminder., Jerath, Neelima and Ladhar, S.S. 2008. Abstracts. International Conference on Climate Change, Biodiversity and Food Security in theSouth Asian Region. Punjab State Council for Science and Technology, Chandigarh
and United Nations Educational, Scientific & Cultural Organization, New Delhi; 133 Pages.

ABSTRACT:
Global warming in the last century was fast enough that the resultant
shifts in species ranges may have led to extensive biodiversity losses. The
biodiversity of Historical Palestine (including the Occupied Palestinian
Territories (OPT)) is considered one of the 25 recently-de?ned as “global
biodiversity hot spots”. The biodiversity in this region of the world is
predominantly rich, as it is positioned at a cross-road between African,
Asian and Mediterranean bio-geographic regions, each contributing to its
different species. The speed and magnitude of climate change may elicit
different responses at different levels of ecological organizations, namely
the population, the species, and the community, as well as the whole
ecosystem level. On the other hand, as a result of global warming, the
agricultural sector in Palestine has been badly affected, particularly in the
last two to three decades, which has been reflected on the food security.
The climate change, added to the severe water shortages and the political
instability in the region, has resulted in endangering or even loss of the
biodiversity, and in the prices escalation of agricultural and other
products. These consequences have certainly led to further instability in
the Middle East, in general, and to the increase in poverty and
unemployment levels in Palestine, in particular. It is important to mention
here that the political actions taken by Israel against the Palestinian
people and their lands, such as the confiscation of lands, on which Israel
has illegally built the Segregation Wall and the hundreds of settlements,
has badly deteriorated the environmental status, including the water
shortages, which has directly affected the biodiversity and the food
security in the Occupied Palestinian Territories. The predicted climate
change will have many negative impacts on the OPT. These impacts would
include increased scarcity of water resources, droughts, desertification,
increased salinity of surface water and groundwater, greater frequency of
sever climate events (such as heat waves, storms' intensity, rapid spread of
diseases, etc.), and decrease in, and even loss of, biodiversity, as well as
sea-level rise. All of these climate-change impacts have led and will also
lead to, among many other consequences, agricultural reduction, crop
failure, higher prices of products, and migration of population, known as
“environmental migration”, which will create “environmental refugees”
who will be pushed inward to lands that are currently heavily populated.

In the last two decades many climate change studies have focused on extreme temperatures as they have a significant impact on environment and society. Among the weather events generated by extreme temperatures, heat waves are some of the most harmful. The main objective of this study was to detect and analyze changes in heat waves in Romania based on daily observation data (maximum and minimum temperature) over the extended summer period (May–Sept) using a set of 10 indices and to explore the spatial patterns of changes. Heat wave data series were derived from daily maximum and minimum temperature data sets recorded in 29 weather stations across Romania over a 55-year period (1961–2015). In this study, the threshold chosen was the 90th per-centile calculated based on a 15-day window centered on each calendar day, and for three baseline periods (1961–1990, 1971–2000, and 1981–2010). Two heat wave definitions were considered: at least three consecutive days when maximum temperature exceeds 90th percentile, and at least three consecutive days when minimum temperature exceeds 90th percentile. For each of them, five variables were calculated: amplitude, magnitude, number of events, duration, and frequency. Finally, 10 indices resulted for further analysis. The main results are: most of the indices have statistically significant increasing trends; only one index for one weather station indicated statistically significant decreasing trend; the changes are more intense in case of heat waves detected based on maximum temperature compared to those obtained for heat waves identified based on minimum temperature; western and central regions of Romania are the most exposed to increasing heat waves.

Resumo: O clima possui uma variabilidade natural, que resulta das interações entre o sistema terra-atmosfera e que culmina, muitas vezes, com a deflagração de eventos extremos que são intensificados pela ação humana, que podem causar grandes impactos negativos à sociedade. O objetivo deste estudo foi produzir uma análise da variabilidade das temperaturas máximas anuais no estado do Paraná no período de 1976 a 2015, visando identificar períodos mais quentes. As análises constantes no trabalho foram feitas por meio da aplicação de diferentes índices: 1- primavera - verão (P-V); 2 - índice diário (ID) e 3 - índices de extremos térmicos propostos pela OMM. Como resultado da análise da variabilidade anual das temperaturas, o Método Gráfico Cronológico de Tratamento de Informação (MGCTI) possibilitou uma análise conjunta dos dados das estações e mostra um aquecimento após a década de 2000. O índice P-V detecta somente os eventos mais extremos que ocorrem com frequência nos meses de novembro a fevereiro. O índice ID identifica os eventos de aquecimento anômalo que ocorrem durante todo o ano e, no Paraná, foi verificado que os maiores registros ocorrem nas estações de outono e inverno. Por meio da análise dos índices dos extremos térmicos da OMM foi possível identificar que as estações localizadas na região norte e oeste do estado, principalmente, aquelas localizadas ao norte do trópico de Capricórnio apresentaram ondas de calor mais significativas, de maior duração e com temperaturas mais elevadas. Por outro lado, as estações situadas no centro-sul do estado demonstram ondas de calor com menor intensidade e duração. Pelo fato de que as ondas de calor são caracterizadas de formas diferentes pelos métodos aplicados, destaca-se que os resultados são dependentes do índice utilizado, sendo assim, a seleção do critério para determinar as ondas de calor depende do propósito do estudo.

Abstract: The climate has a natural variability, which results from the interactions between the earth-atmosphere system and culminating, often, with the outbreak of extreme events that are intensified by human action, which can cause great negative impacts to society. The objective of this study was to produce an analysis of the variability of annual maximum temperatures in the state of Paraná from 1976 to 2015, seeking to identify warmer periods. The analyzes in the work were done through the application of different indexes: 1 - spring - summer (P-V); 2 - daily index (ID) and 3 - thermal extremes indices proposed by WMO. As a result of the analysis of the annual variability of temperatures, the chronological graphic method of information processing (MGCTI) allowed a joint analysis of the data of the seasons and shows a warming after the decade of 2000. The P-V index detects only the more extreme events that occur frequently in the months of November to February. The ID index identifies the events of anomalous warming occurring throughout the year, and in Paraná, it was verified that the largest records occur in the autumn and winter seasons. Through the analysis of the thermal extremes indexes of the WMO, it was possible to identify that the stations located in the north and west of the state, mainly those located north of the Tropic of Capricorn, presented more significant heat waves of longer duration and with higher temperatures. On the other hand, the stations located in the center-south of the state show heat waves with less intensity and duration. Because the heat waves are characterized in different ways by the applied methods, it is emphasized that the results are dependent on the index used, so, the selection of the criterion to determine the heat waves depends on the purpose of the study.

Meteorological (T and RH values) and air pollution data (PM 10 , NO 2 and O 3 concentrations) observed in Athens, Thessaloniki and Volos were analyzed to assess the air quality and the thermal comfort conditions and to study their synergy, when extreme hot weather prevailed in Greece during the period 2001–2010. The identification of a heat wave day was based on the suggestion made by the IPCC to define an extreme weather event. According to it, a heat wave day is detected when the daily maximum hourly temperature value exceeds its 90th percentile. This temperature criterion was applied to the data recorded at the cities center. Air quality was assessed at three sites in Athens (city center, near the city center, suburb), at two sites in Thessaloniki (city center, suburb) and at one site in Volos (city center), while thermal comfort conditions were assessed at the cities center. Mean pollution levels during the heat wave days and the non-heat wave days were calculated in order to examine the impact of the extreme hot weather on air quality. For this purpose, the distributions of the common air quality index and the exceedances of the air quality standards in force during the heat wave days and the non-heat wave days were also studied. Additionally, the variation of the daily maximum hourly value of Thom's discomfort index was studied in order to investigate the effect of extreme hot weather on people's thermal comfort. Moreover, the values of the common air quality index and Thom's discomfort index were comparatively assessed so as to investigate their synergy under extreme hot weather.

As a multi-disciplinary research analysis, this dissertation asks the question if green infrastructure is a necessary adaptive approach to climate change in terms of urban-heat health impacts on an ageing population.

Fundamental understanding of this compounding problem is brought together in terms of a number of key issues facing urban environments over the next 50 years. Importantly, the demographic shift experienced in Australia is examined drawing sobering outcomes when overlain with the vulnerability and exposure of an ageing cohort against a background of a changing climate. In particular, as evidenced through the literature research in Section 2, the nature of heat waves and the increasing risks which climate change brings is especially recognised in terms of the frequency of and length of ‘heat days’.

Analysis of the literature review (in Section 2) identified the primary research had very limited research findings or research outcomes undertaken with respect an ageing population and green infrastructure. In particular, while these two factors are ‘research rich’ in their own right, the limitation comes about when bringing these together through a multi-disciplinary approach. In bringing together a better understanding of combining key factors the aim of this dissertation is to understand the relevant cause and effects so an appropriate adaptation response such as green infrastructure is warranted.

Through international and Australian case studies analysis of the key elements, for the cause and effects were selected for their relevance to ageing and heat waves respectively. In order to derive the relevance of each case study a number of key factors were selected to draw out the identified planning problem (Section 3). Importantly, through a multi-disciplinary cause and effect analysis identified in particular around the notion of vulnerability capability (see Section 5). This is summarised and reapplied against the factors to test green infrastructure’s applicability as an opportunity to address the planning problem.

Recommendations along with current planning policy relevance and discussion (Section 6) are checked against the literature to present a better understanding of the current planning policy concerns, along with confirmation against The London Plan to inform the importance of the role of strategic planning of green infrastructure. Notwithstanding this, further confirming the necessity, which the notion of an age friendly city is required in which green infrastructure is uniquely placed to provide multiple benefits and adaptive solutions.

Relevant research questions are then provided as necessary to understanding green infrastructure’s adaptive capacity as a response to heat waves, but also to more importantly help provide additional clarity with respect to the governance arrangements, to better inform planning policy.

In summary, the outcomes have effectively identified having an ageing population’s health impacts moderated through increased vegetation throughout the urban environment is an antidote to heat waves and a necessary step to preventative adaptive and strategic planning for the next 50
years.

It was reported in the summer of 2016, India is going through its hottest decade, but also it has broken all its record this year. The heat strokes have been increasing since long and it was a day in May when the mercury hit it off at 51 degrees Celsius in Phalodi, Rajasthan beating its own record of 50.6 degrees in 1956. Well, no doubt that the temperature has risen and affected the rainfall too but the impacts are devastating. The climatic conditions are constantly changing which is going to alter the human life. Reports show that the number of deaths that occurred due to heat strokes have increased this year, reason being excess heating of certain proteins in the human body that disturb the healthy functioning of human brain. No doubt, the deaths were mainly of the people who are homeless. Droughts have become a common sight in many areas of India and the immediate effect is dehydration and no crops again leading on to health issues and water shortage among estimated 330 million people. This heat stroke can be considered a reason of the recent calamities that have been occurring around. The temperature level has risen even in the hilly areas resulting in the melting of glaciers and depletion of underground water. These sudden heavy monsoon showers are also the aftereffects of these climatic changes which have ended up taking many lives of people in India and Pakistan recently. Going deep in the roots, scientists claim that the reasons for these rising temperatures and sudden climatic changes can be attributed to deforestation. The carbon dioxide levels have increased and this is a serious threat to the human life. India is moving ahead on the paths of smart cities, but its environmental impacts are yet to be worked upon. Urbanization alone can never be beneficial to us as it is what is ending our lives as well. The impacts of this heat stroke need to be acted upon smartly than ever. Considering the strong heat waves in parts of India, development of solar technology is one of the most effective steps that must be taken. Though India is developing in this field to an extent, it must be paced to make the best use of the sunlight available. Solar energy will in turn reduce load on our power stations for generation of electricity. Similarly, to tackle the climatic issues and drought situations, tree plantation serves the best because we all know that plants cause rains.

The scorching heat wave of the year 2021 in Moscow has not occurred in 120 years, according to the news. The temperature often exceeded 36°C during the day. The heat wave was followed by huge electrical activity, thunder and lightning. Then came the apocalyptic winds and cloudbursts.

Analysis of these events yields the picture that Nature is showing us a particularly powerful reactor here. One without emissions of gases and radioactivity. What is needed is a heat wave, some trees and water, which together form a kind of heat wave reactor (HWR).

In this module we talk about a heat wave and its (often unwanted) energetic aspects that lead to climate problems such as forest fires, heavy rainfall and floods but also the melting of the polar ice...
To keep the mood up, the module will end with music, books and movies that are somehow related to the topic covered.

Ante las recientes ondas de calor registradas en el hemisferio norte, se está produciendo una mayor preocupación de los efectos que éstas tienen en la salud humana. Sin embargo, ante la falta de información de que dispone la sociedad respecto a este fenómeno, es necesario difundir el conocimiento científico disponible. La comprensión de la comunidad de los efectos del cambio climático es una de las mejores maneras de incrementar la resiliencia. En este texto se analiza el concepto de onda de calor, los métodos para establecer su peligrosidad y las tendencias observadas y esperadas de éste fenómeno en México, en condiciones de cambio climático.

Nadiruzzaman, M. 2020. European Heat Wave, 2003, in Bimal Paul (edited), Natural Hazards and Disasters: From Avalanches and Climate Change to Water Spouts and Wildfires, ABC-CLIO: Santa Barbara, USA.  Volume 2, pp. 105-9. http://publisher.abc-clio.com/9781440862144

In July 1995, a heat wave struck the City of Chicago causing 739 heat-related deaths in few days. This paper provides a comprehensive analysis of the outdoor and indoor environmental conditions that occurred in July of 1995. We selected three sites in which two residents have perished which represent different architectural and urban conditions. Site climate data were synthesized using microclimate simulation. The generated climate data is then used to estimate the internal conditions. Estimated interior conditions have shown a two-day time lag between the outdoor and indoor peak heat stress. This research established that heat-related fatalities are likely to occur in extreme heat episodes if the air-conditioning fails and the residents were frail, unable, or unwilling to spend the nights elsewhere. The results also demonstrated that trees and vegetation may reduce the impact of Urban Heat Island (UHI), but will not negate the extraordinary conditions created by a heat wave.

According to climate change scenarios, the average annual temperature will increase by around 4°C if current trends continue. Maximum temperatures, however, have already registered higher values in different regions of the world, increasing the number, duration and intensity of heat waves. With the increase of maximum temperatures and the increase of significance of heat wave events, reports of mortality episodes due to heat effects have been increasing. According to the information from the Centre for Research on Epidemiology of Disasters (CRED), 5 of the 20 deadliest disasters between 1996 and 2015 were heat wave events. This chapter analyzes heat wave events, the criteria for determining dangerous temperature thresholds, as well as trends already observed, and those expected due to climate change. Heat wave events are correlated with observed increases on mortality rates, and recommendations are suggested to prevent their effects on human health.

Abstract Elevated urban temperatures and heatwaves are a serious threat to the health and wellbeing of the continuously growing urban population and are projected to worsen under climate change. For this reason well-informed disaster risk reduction (DRR) actions, where science and technology play a key role, are required. However insufficient communication between scientific and policy-making communities (known as the science-policy gap) hampers the use of science in DRR. Hence there is a strong need to interpret existing scientific knowledge into actionable knowledge, i.e. science that is useful, usable and used. This article presents a series of services and tools that build-upon existing scientific knowledge and aim to provide actionable knowledge to authorities and citizens for reducing the risks of elevated urban temperatures. The above were implemented in the context of the European Commission’s Thermal Risk rEduction Actions and tools for secURE cities (TREASURE) project, and address many of the goals and priorities for action set in the Sendai framework for disaster risk reduction (SFDRR) of the United Nations. A key policy-making user of the implemented services and tools is the City of Athens in Greece, which is one of the largest metropolitan areas in Europe.

The purpose of the work is to determine the number of hours when the air temperature during hourly measurements in Lublin-Radawiec (LR) and in Włodawa (W) exceeded the next thresholds starting at 25.0°C. The thresholds are named next temperature values for the step equal to 0.1°C (up to the highest recorded value of 35.3°C LR and 35.6°C W). On average per year, for the period 1994-2018, it was obtained for the threshold of 25.0°C – 243.7 (LR) and 293.5 (W) hours. For a threshold 28.0°C – 75.4 (LR) and 101.0 (W). "Frequency curves" were used for the graphic presentation. This method allows a clear comparison of frequencies, both for different stations and for different years (multiannual periods). The highest frequency of exceeding individual thresholds concerned 13 and 14 UTC. The 25.0°C threshold was not exceeded from 21 (LR) and 23 (W) to 5 UTC. There were 11 (LR) and 15 (W) situations when the 33.0°C threshold was exceeded during at least 4 adjacent hourly measurements. With reference to thermal waves 1994 and 2015, considered the most extreme heatwaves (Mega-heatwaves) in Poland after II World War, the frequency of exceeding the 25.0°C threshold was 49-55%.. On August 7-9, 2015, the total number of hourly measurements with exceeding 33.0°C in Włodawa was 18. However, on July 31, 1994. in Włodawa the temperature exceeded 33.0°C during the next 8 hourly measurements.
Key words: biometeorology, hot day, very hot day, heat wave, frequency curves.

Changes in the frequency, intensity and duration of heatwaves are found to be responsible for increasing ecological and societal impacts. However, few studies have investigated heatwave climatology with methods that can be used to compare local heatwave events to national or international sites. In this paper, a number of indices were observed in four station sites within the Sydney basin, Australia, using a relatively new Excess Heat Factor (EHF) Index to provide an overview of variations concerning frequency, intensity and duration within the region. It was expected the Urban Heat Island (UHI) effect would cause a variation in trends within the basin. It was found maximum EHF thresholds had increased, but there were no significant trends observed for heatwaves. Rather, interannual frequency and intensity cycles were found to be significant on five-year moving average trends, which correlated with the El-Niño Southern-Oscillation (ENSO) sea surface temperature (SST) off the east coast of Australia. Parramatta showed less extreme interannual variability in comparison to the other sites due to a probable UHI effect. This emphasised the complex nature of the Sydney basin and the need for extra classification for heatwave analysis within the region with awareness that future studies consider cyclic trends rather than linear trends.

The effects of the anomalously warm European summer of 2003 highlighted the importance of understanding the relationship between elevated atmospheric temperature and human mortality. This review is an extension of the brief evidence examining this relationship provided in the IPCC’s Assessment Reports. A comprehensive and critical review of the literature is presented, which highlights avenues for further research, and the respective merits and limitations of the methods used to analyse the relationships. In contrast to previous reviews that concentrate on the epidemiological evidence, this review acknowledges the inter-disciplinary nature of the topic and examines the evidence presented in epidemiological, environmental health, and climatological journals. As such, present temperature–mortality relationships are reviewed, followed by a discussion of how these are likely to change under climate change scenarios. The importance of uncertainty, and methods to include it in future work...

Investigating on society-related heat wave hazards is a global issue concerning the people health. In the last two decades, Europe experienced several severe heat wave episodes with catastrophic effects in term of human mortality (2003, 2010 and 2015). Recent climate investigations confirm that this threat will represent a key issue for the resiliency of urban communities in next decades. Several important mitigation actions (Heat-Health Action Plans) against heat hazards have been already implemented in some WHO (World Health Organization) European region member states to encourage preparedness and response to extreme heat events. Nowadays, social media (SM) offer new opportunities to indirectly measure the impact of heat waves on society. Using the crowdsensing concept, a micro-blogging platform like Twitter may be used as a distributed network of mobile sensors that react to external events by exchanging messages (tweets). This work presents a preliminary analysis of tweets relat...

Heatwaves are a major public health concern causing more fatalities than any other natural hazard. In Australian prisons, extreme temperatures have been recorded and heat related deaths have occurred. While some countries have identified ‘optimum’ thermal conditions for custodial accommodation, there are no national thermal standards, guidelines or recommendations for the design of custodial environments and management of prisoners. This article examines the existing national and international literature to demonstrate that prisoners are a poorly identified subgroup of the population ‘at risk’ of heat-related illnesses. Thermal conditions within prisons and other types of custodial accommodation across Australia vary considerably. This article finds that even if current thermal comfort standards were employed, the prison environments may not be safe or suitable as current methods of devising thermal comfort standards for buildings are flawed as the standards do not take into account...

Climate change has an effect on human well-being. Weather extremes, heat waves in particular, are occurring more often. Heat waves cause increases in hospitalisation and mortality rates as well as reductions in labour productivity and comfort levels. These effects become apparent with retrospective statistical analysis.
Cities are warmer than their surrounding rural areas. The difference in temperature is greatest at night, especially after sunny daytime conditions, and can reach about 10°C. In winter, this „urban heat island‟ (UHI) effect keeps cities warm and therefore saves energy.
Recently, throughout north-western Europe, summers have been extremely hot. During the last six years, six heat waves were recorded in the Netherlands. Public health authorities have mounted special information campaigns to warn vulnerable groups such as the elderly, the infirm and children of the risks of heat stress.
Traditionally, northern and mid-European city buildings are built to withstand cold and are not usually air-conditioned. However, as a result of the recent hot summers, sales of air-conditioners are growing rapidly.
What promising options are available that could curb a strong rise in energy consumption for summer cooling in north and mid-European cities?
Summer heat reduction in urban areas can be carried out at various levels, including:
passive energy or energy-efficient cooling equipment;
building materials, roofing and construction;
building orientation and environs: shading, vegetation and pavement;
city planning: building density, parks, ponds, canals.
The construction sector has long been focused on the conservation of heat. Many buildings and blocks have been constructed with the utilisation of passive solar energy in mind. Obviously, solutions for urban heat problems must also take the problems of winter into account. In this report we discuss possible solutions for urban heat in terms of their
compatibility with other demands.
For example, increasing the amount of urban vegetation and number of ponds as well as improving heat insulation in buildings could be win-win options. However, these should be implemented carefully to achieve their optimal benefits and reduce the risk of negative side effects.
Increasing solar reflection in an urban area can be done at relatively low cost but this option may have aesthetic considerations as well as a probable impact on safety. It will increase winter energy consumption slightly.

The objective of this paper is to assess the bioclimatic conditions in Serbia during summer in order to identify biothermal heat hazard. Special emphasis is placed on the bioclimatic index UTCI (Universal Thermal Climate Index), whose purpose is to evaluate the degree of thermal stress that the human body is exposed to. For this research, mean daily and hourly (07:00 and 14:00 CET) meteorological data from three weather stations (Zlatibor, Novi Sad and Niš) have been collected for the period from 1998 to 2017. In order to identify patterns of biothermal heat stress conditions, the thresholds of the daily UTCI (UTCI ≥38 ∘C, referred to as very strong heat stress, VSHS) at 14:00 CET are compared with the thresholds of daily maximum air temperature (tmax⁡≥35 ∘C, referred to as hot days, HDs), which are further termed as heat wave events (HWEs). The findings show that the UTCI heat stress category “very strong heat stress“ at 14:00 CET indicates heat waves. The most extreme heat wave events occurred in 2007, 2012, 2015 and 2017. Moreover, three HWEs at Niš that occurred in July 2007 lasted 3, 10 and 4 d. HWEs and very strong heat stress events (VSHSEs) recorded in July 2007 (lasted 10 d each), 2012 (lasted 9 and 12 d) and 2015 (lasted 7 and 10 d) were of the longest duration and are considered to be the indicators of biothermal heat hazard. The daily UTCI14 h heat stress becomes more extreme in terms of severity and heat wave duration up to very strong heat stress.

Heat waves (HWs) represent a major danger to society and natural environment. The increasing occurrence of high magnitude and impact HWs has raised concerns worldwide and has attracted an increasing interest on this issue among climatologists over the past decade. In this review the research from 2007-2018 period on HWs definitions, driving mechanisms, present changes, future changes, and impact on human mortality is summarized. By reviewing the recent literature, it was found that whilst the atmospheric dynamic is considered to be the primary driver in HW occurrence, the sea surface temperature (SST) and land surface conditions are also essential driving components. The vastness of HW-definitions raises difficulties in selecting the appropriate methodology to identify heat episodes and to compare results from studies which used different definitions. However, by analyzing a sample of 109 papers, a preference for percentile-based definitions was observed. Therefore, 71.6% of the analyzed articles used only percentile-based definitions to identify HWs. Despite the wide variety of definitions, the analysis of changes in HWs converged to similar results. Thus, the existing recent literature provided extensive evidence of significant increase in HWs characteristics across large regions of the planet. Available scientific literature indicated that HWs have been responsible for a considerable increase in mortality in many regions of the world. In the future HWs are predicted to increase in their main characteristics leading to a greater impact on human mortality. Nevertheless, the implementation of rigorous adaptation measures can mitigate the negative impact on mortality. In conclusion, it was noted that a substantial progress has been done in the HW research, but there are still important gaps in this issue which need to be addressed. Rezumat. O revizuire a studiilor recente privind definițiile, mecanismele, schimbările undelor de căldură și impactul asupra mortalității Valurile de căldură (HWs) reprezintă un pericol major pentru societate și mediul înconjurător. Creșterea frecvenței HWs cu magnitudine și impact ridicate a generat preocupare la nivel global și a atras interes asupra problemei în rândul climatologilor în ultimul deceniu. În articol sunt inventariate studiile realizate în perioada 2007-2018 privind definiţiile HWs, factorilor declanșatori, schimbărilor prezente și viitoare și impactul asupra mortalității. Prin inventarierea literaturii de specialitate recente, a fost evdențiat că deși dinamica atmosferei este principalul factor generator al HWs, temperatura apei de suprafață (SST) și condițiile date de suprafața terenurilor sunt de asemenea factori generatori importanți. Diverstatea definițiilor atribuite HWs determină dificultăți în selectarea unor metodologii potrivite pentru identificarea fenomenelor respectve și compararea rezultatelor unor studii care utilizează definiții diferite. Totuși, analizând un eșantion de 109 lucrări, a fost observată o preferință asupra unor definiții bazate pe percentile. Așadar, în 71.6% din articolele analizate au fost utilizate doar definiții bazate pe percentile pentru identificarea HWs. În ciuda marii varietăți de definiții, rezultatele analizelor au fost similare. Astfel, literatura recentă furnizează dovezi ample care atestă o creștere semnificativă a caracteristicilor HWs pe suprafeţe extinse ale planetei. Literatura științifică indică faptul că HWs au fost unul dintre factorii responsabili pentru creșterea mortalității în multe părți ale lume. În viitor este anticipată o amplificare a caracteristicilor HWs, conducând la o creștere a impactului pe care acestea îl vor avea asupra mortalității. Cu toate acestea, prin implementarea unor măsuri riguroase de adaptare, poate fi diminuat impactul negativ care conduce la mortalitate. În concluzie, a fost remarcat faptul că s-a realizat un progres substanţial în cercetarea HWs, rămânând însă lacune importante care necesită abordare. Cuvinte-cheie: schimbări climatice, temperaturi extreme, val de căldură, factorul excesului de căldură

This report gives an overview of heat stress problems in urban areas of the Netherlands and various options for mitigating this stress. Climate change is causing more occurrences of heat waves. Urban areas in particular will suffer the most, as they are warmer than the countryside. * What is known about the magnitude of heat stress in Dutch urban areas? * What are the consequences? * What research is needed to clarify its effects? * Which options in particular could do with further study in order to prevent fatalities, maintain comfort levels and avoid increases in energy consumption for summer cooling? This report aims at identifying: * the foreseeable problems of urban heat in the Netherlands; * the specifics (geographic, cultural, economic, technological) that apply to the Netherlands; * the most promising options for mitigating urban heat; and * the priorities for further research.

The effects of the anomalously warm European summer of 2003 highlighted the importance of understanding the relationship between elevated atmospheric temperature and human mortality. This review is an extension of the brief evidence examining this relationship provided in the IPCC’s Assessment Reports. A comprehensive and critical review of the literature is presented, which highlights avenues for further research, and the respective merits and limitations of the methods used to analyse the relationships. In contrast to previous reviews that concentrate on the epidemiological evidence, this review acknowledges the inter-disciplinary nature of the topic and examines the evidence presented in epidemiological, environmental health, and climatological journals. As such, present temperature–mortality relationships are reviewed, followed by a discussion of how these are likely to change under climate change scenarios. The importance of uncertainty, and methods to include it in future work, are also considered.

The paper describes the occurrence of hot (tmax 25.1–30.0°C) and very hot days (t max >30°C) in Lublin-Felin and Czesławice in the years 1966–2010. The analysis covers the long-term variability of such days, and duration of heat waves. Their circulation conditions were also determined, with indication of circulation types during which the probability of occurrence of hot and very hot days was the highest. In the study area, hot days occurred from April to September, and very hot days from May to August, with the highest frequency in July in both cases. In the period from 1991 to 2010, a considerably higher number of cases of very hot days were recorded than in the 1970s and 1980s. Moreover, they occurred in increasingly long sequences, contributing to more frequent occurrence of unfavourable thermal and humid conditions during the growing season of plants. The highest probability of occurrence of hot and very hot days was determined for circulation types with airflow from the southern sector, and the lowest from the northern sector. Should the upward trend in the frequency of very hot days continue, the risk of the effect of such unfavourable thermal conditions on the health and well-being of tourists and patients of the health resort in Nałęczów will also increase.

Investigating on society-related heat wave hazards is a global issue concerning the people health. In the last two decades, Europe experienced several severe heat wave episodes with catastrophic effects in term of human mortality (2003, 2010 and 2015). Recent climate investigations confirm that this threat will represent a key issue for the resiliency of urban communities in next decades. Several important mitigation actions (Heat-Health Action Plans) against heat hazards have been already implemented in some WHO (World Health Organization) European region member states to encourage preparedness and response to extreme heat events. Nowadays, social media (SM) offer new opportunities to indirectly measure the impact of heat waves on society. Using the crowdsensing concept, a micro-blogging platform like Twitter may be used as a distributed network of mobile sensors that react to external events by exchanging messages (tweets). This work presents a preliminary analysis of tweets relat...