Search Results (515)

Compound extreme events can cause serious impacts on both the natural environment and human beings. This work aimed to explore the changes in compound drought–heatwave and heatwave–extreme precipitation events (i.e., CDHEs and CHPEs) across China using daily-scale gauge-based meteorological observations, and to examine their future projections and potential risks using the Coupled Model Intercomparison Project (CMIP6) under the shared socioeconomic pathway (SSP) scenarios (i.e., SSP1-2.6, SSP2-4.5, and SSP5-8.5). The results show the following: (1) The frequencies of CDHEs and CHPEs across China showed a significant increasing trend from 1961 to 2020, with contrasting trends between the first half and second half of the period (i.e., a decrease from 1961 to 1990 and an increase from 1991 to 2020). Similar trends were observed for four intensity levels (i.e., mild, moderate, severe, and extreme) of CDHEs and CHPEs. (2) All the frequencies under three SSP scenarios will show increasing trends, especially under higher emission scenarios. Moreover, the projected intensities of CDHEs and CHPEs will gradually increase, especially for higher levels. (3) The exposure of the population (POP) and Gross Domestic Product (GDP) will be concentrated mainly in China’s coastal areas. The GDP exposures to the CDHEs and CHPEs will reach their highest values for SSP5-8.5, while the POP exposure will peak for SSP2-4.5 and SSP5-8.5, respectively. Our findings can offer scientific and technological support to actively mitigate future climate change risks. Full article

This study investigates the impact of building insulation standards on indoor thermal environments and the risk of heat-related illnesses during heatwaves in South Korea. Indoor temperatures were measured in residential buildings located in Chuncheon and Gwangju during the 2022 heatwave, with outdoor temperature data sourced from the Korea Meteorological Administration. Probability distribution fitting was used to estimate the likelihood of indoor temperatures exceeding the critical threshold of 27 °C. Additionally, a linear regression analysis was conducted to examine the relationship between the probability of exceeding the threshold and heat-related illness data from 2017 to 2023 provided by the Korea Disease Control and Prevention Agency. The findings reveal significant variations in indoor thermal conditions during heatwaves, influenced by factors such as building type, year of construction, and climate region, which affect the thermal insulation performance. Buildings with a lower thermal insulation performance were associated with higher indoor temperatures, increasing the likelihood of exceeding the critical threshold and contributing to a higher incidence of heat-related illnesses, particularly in provincial non-metropolitan areas. These results underscore the need for region-specific building insulation standards that address both winter energy efficiency and summer heatwave resilience. Enhancing thermal insulation in vulnerable regions could significantly reduce the risk of heat-related illnesses and improve public health resilience to extreme heat events. Full article

South America has experienced significant changes in climate patterns over recent decades, particularly in terms of precipitation and temperature extremes. This study analyzes trends in climate extremes from 1979 to 2020 across South America, focusing on their relationships with sea surface temperature (SST) anomalies in the Pacific and Atlantic Oceans. The analysis uses precipitation and temperature indices, such as the number of heavy rainfall days (R10mm, R20mm, R30mm), total annual precipitation (PRCPTOT), hottest day (TXx), and heatwave duration (WSDI), to assess changes over time. The results show a widespread decline in total annual precipitation across the continent, although some regions, particularly in the northeast and southeast, experienced an increase in the intensity and frequency of extreme precipitation events. Extreme temperatures have also risen consistently across South America, with an increase in both the frequency and duration of heat extremes, indicating an ongoing warming trend. The study also highlights the significant role of SST anomalies in both the Pacific and Atlantic Oceans in driving these climate extremes. Strong correlations were found between Pacific SST anomalies (Niño 3.4 region) and extreme precipitation events in the northern and southern regions of South America. Similarly, Atlantic SST anomalies, especially in the Northern Atlantic (TNA), exhibited notable impacts on temperature extremes, particularly heatwaves. These findings underscore the complex interactions between SST anomalies and climate variability in South America, providing crucial insights into the dynamics of climate extremes in the region. Understanding these relationships is essential for developing effective adaptation and mitigation strategies in response to the increasing frequency and intensity of climate extremes. Full article

Global climate change and rapid urbanization have brought unprecedented environmental challenges, especially in rapidly expanding cities like Xi’an, posing potential challenges to sustainable development if not accompanied by adequate greenery, thoughtful layouts, and pollution control measures. The increasing frequency and intensity of urban air pollution (e.g., PM_2.5, PM₁₀, O₃) and extreme climate events (e.g., heatwaves) have heightened health risks for residents. Existing studies mostly focus on single pollution or climate factors, neglecting the compounded effects of these factors. To fill this research gap, this study presents a health risk assessment model, specifically by analyzing the compounded effects of heatwaves and air pollution. By integrating hazard, exposure, and vulnerability factors using the entropy weight–TOPSIS method, the results reveal significant spatial differences in health risks across various regions of Xi’an. The findings provide valuable guidance for urban planners and policymakers to better address environmental hazards, reduce health risks, and promote sustainable urban development. Full article

The summer of 2024 witnessed record-high sea surface temperatures (SST) across the Aegean, Ionian, and Cretan Seas (AICS), following unprecedented air heatwaves over the sea under a long-term warming trend of 0.46 °C/decade for the mean atmospheric temperature (1982–2024). The respective mean SST trend for the same period is even steeper, increasing by 0.59 °C/decade. With mean summer surface waters surpassing 28 °C, particularly in the Ionian Sea, the southern Cretan, and northern Aegean basins, this summer marked the warmest ocean conditions over the past four decades. Despite a relatively lower number of marine heatwaves (MHWs) compared to previous warm years, the duration and cumulative intensity of these events in 2024 were the highest on record, reaching nearly twice the levels seen in 2018, which was the warmest until now. Intense MHWs were recorded, especially in the northern Aegean, with extensive biological consequences to ecosystems like the Thermaikos Gulf, a recognized MHW hotspot. The strong downward atmospheric heat fluxes in the summer of 2024, following an interannual increasing four-decade trend, contributed to the extreme warming of the water masses together with other met-ocean conditions such as lateral exchanges and vertical processes. The high temperatures were not limited to the surface but extended to depths of 50 m in some regions, indicating a deep and widespread warming of the upper ocean. Mechanisms typically mitigating SST rises, such as the Black Sea water (BSW) inflow and coastal upwelling over the eastern Aegean Sea, were weaker in 2024. Cooler water influx from the BSW decreased, as indicated by satellite-derived chlorophyll-a concentrations, while upwelled waters from depths of 40 to 80 m at certain areas showed elevated temperatures, likely limiting their cooling effects on the surface. Prolonged warming of ocean waters in a semi-enclosed basin such as the Mediterranean and its marginal sea sub-basins can have substantial physical, biological, and socioeconomic impacts on the AICS. This research highlights the urgent need for targeted monitoring and mitigation strategies to address the growing impact of MHWs in the region. Full article

Marine heatwaves (MHWs) have intensified in frequency, duration, and severity over recent decades. These events, defined by unusually warm sea surface temperatures (SSTs), can cause significant ecological impacts. This is particularly so for Pacific Island countries, such as Vanuatu, where communities rely on marine resources for their food and livelihoods. A common ecological response to MHWs is the movement of oceanic species to cooler waters. Predicting such shifts through monitoring SST isotherms can help identify thermal boundaries that marine species favor. This study explores the connection between MHWs, SST isotherm movement, and tuna abundance in Vanuatu. The displacement of the 28 °C isotherm was analyzed across three major MHW events (2008–2009, 2016, and 2021–2022). It was found that MHWs with longer duration and greater intensity caused more significant isotherm displacement. Additionally, the El Niño–Southern Oscillation had an important influence on MHW formation and isotherm movement. The effects of these displacements on tuna distribution varied between events. The ability to monitor MHWs and SST isotherm movement could be an effective instrument for the prediction of areas of suppressed or abundant tuna activity and can be used to aid in the proactive management of food security and fishery sectors. Full article

This study investigates the impact of green roof (GR) implementations as a mitigation strategy for urban heating during an extreme heat wave event in Athens, Greece, from 28 July to 5 August 2021. Three GR scenarios were simulated, namely 100% grass coverage, 100% sedum coverage, and 50% grass coverage, using the Weather Research and Forecasting model (WRF) in conjunction with the multi-layer urban-canopy-model BEP&BEM (Building Effect Parameterization/Building Energy Model) and extra urban land-use categories from Local Climate Zones (LCZ). Based on the results, GRs alter the local heat balance in the Greater Area of Athens (GAA), leading to a total temperature reduction. The 100% grass coverage proved to be the most effective, particularly during daytime, reducing the 2 m temperature field by approximately 0.7 ∘C (mean value) in the GAA. In some locations, temperature reductions exceeded 2 ∘C, depending on the local characteristics and the direction of the prevailing winds. Grass offered superior cooling effects compared to sedum, although sedum is more resilient to dry and moderate climates. The extent of vegetation coverage played an important role in the effectiveness of GRs. Reducing the coverage by 50% significantly reduced the cooling benefits, highlighting the importance of maximizing vegetation coverage to achieve notable temperature reductions. Full article

The topic of energy poverty is a vast and complex one warranting extensive research. During the XX century, numerous research articles, books, and documents were published with the aim of defining energy poverty, measuring it, and proposing solutions to tackle it. The phenomenon of energy poverty can be studied using a variety of research methods, including the usual economic and econometric analyses, as well as energy policy. Research can also be conducted on the measurement of energy poverty and its social and health impact on disadvantaged communities. This can be explored in depth within specific subject areas, such as engineering, energy, environmental science, and social science. This brief review of literature focuses on energy poverty and poor buildings, thermal comfort, and the phenomenon of cooling poverty. The aim of this brief literature review is to show to a young researcher a previous framework and, through some keywords, that it is useful to drive future research using keywords. Full article

Urban public space comfort is essential for improving quality of life, particularly as climate change affects outdoor thermal environments. This study utilizes ENVI-met, a 3D microclimate simulation tool, to assess thermal comfort concerning demographic factors such as age and gender. The findings indicate significant disparities in thermal stress vulnerability among demographic groups. On the hottest day of July 2023, at 10 a.m., children’s PET values were approximately 2 °C higher than those of other groups. By 3 p.m., females experienced slightly higher upper-range thermal stress than males. Elderly individuals aged 80 exhibited a broad range of PET values, from 38.14 °C to 62.39 °C, with prevailing values above 56.9 °C, indicating greater vulnerability to extreme heat. Children aged 8 showed PET values ranging from 40.20 °C to 59.34 °C, with prevailing estimates between 54.2 °C and 55.7 °C. Minimum PET values for children were significantly higher than those for adults, suggesting a greater baseline level of thermal stress. Despite cooling effects in the evening, children remained exposed to more pronounced stress than elderly individuals, males, and females. The UTCI values recorded indicate a period of extreme heat stress for all demographic groups assessed. While individuals aged 35 may encounter considerable discomfort, the severity of the impact is notably more pronounced for both older adults and children. This study underscores the need for tailored management strategies and advocates for expanding ENVI-met’s capabilities to enhance urban resilience and well-being amid rising temperatures. Full article

This work proposes a new unsupervised method to evaluate the behavior of urban green areas in the presence of heatwave scenarios by analyzing three indices extracted from satellite data: the Normalized Difference Vegetation Index (NDVI), the Normalized Difference Moisture Index (NDMI), and Land Surface Temperature (LST). The aim of this research is to analyze the behavior of urban vegetation types during heatwaves through the analysis of these three indices. To evaluate how these indices characterize urban green areas during heatwaves, an unsupervised classification method of the three indices is proposed that uses the Elbow method to determine the optimal number of classes and the Jenks classification algorithm. Each class is assigned a Gaussian fuzzy set and the green urban areas are classified using zonal statistics operators. The membership degree of the corresponding fuzzy set is calculated to assess the reliability of the classification. Finally, for each type of greenery, the frequencies of types of green areas belonging to NDVI, NDMI, and LST classes are analyzed to evaluate their behavior during heatwaves. The framework was tested in an urban area consisting of the city of Naples (Italy). The results show that some types of greenery, such as deciduous forests and olive groves, are more efficient, in terms of health status and cooling effect, than other types of urban green areas during heatwaves; they are classified with NDVI and NDMI values of mainly High and Medium High, and maximum LST values of Medium Low. Conversely, uncultivated areas show critical behaviors during heatwaves; they are classified with maximum NDVI and NDMI values of Medium Low and maximum LST values of Medium High. The research results represent a support to urban planners and local municipalities in designing effective strategies and nature-based solutions to deal with heat waves in urban settlements. Full article

The urban heat island effect (UHI) is among the major challenges of urban climate, which is continuously intensifying its impact on urban life and functioning. Against the backdrop of increasingly prolonged heatwaves observed in recent years, practical questions about adaptation measures in cities are growing—questions that traditional meteorological monitoring can hardly answer adequately. On the other hand, UHI has long been the focus of research interest, but due to the technological complexity of providing accurate spatially referenced data at high spatial resolution and the requirement to survey at strictly defined parts of the day, information provision is becoming a major challenge. This is one of the main reasons why UHI research results are less often used directly in urban spatial planning. However, advances in geospatial technologies, including unmanned aerial systems (UASs), are providing more and more reliable tools that can be applied to achieve better and higher-quality information resources that adequately characterize the UHI phenomenon. This paper presents a developed and tested methodology for the rapid and efficient assessment and mapping of the effects of surface urban heat island (SUHI). It is entirely based on the integrated use of data from unmanned aerial systems (UAS)-based remote sensing methods, including thermal photogrammetry and GIS-based analysis methods. The study follows the understanding that correct SUHI research depends on a proper understanding of the urban geosystem, its spatial and structural heterogeneity, and its functional systems, which in turn can only be achieved by supporting the research process with accurate and reliable information resources. In this regard, the possibilities offered by the proposed methodological scheme for efficient geospatial registration of SUHI variations at the microscale, including the calculation of intra-urban SUHI intensity, are discussed in detail. The methodology builds on classical approaches for using local climate zoning (LCZ), adding capabilities for precise delineation of individual zone types and for geostatistical characterization of the urban surface heat island (SUHI). Finally, the proposed scheme is based on state-of-the-art technological tools that provide flexible and automated capabilities to investigate the phenomenon at microscales, including by enabling flexible observation of its dynamics in terms of heat wave manifestation and evolution. Results are presented from a series of sequential tests conducted on the largest residential area in Bulgaria’s capital city, Sofia, in terms of area and population, over a relatively long period from 2021 to 2024. Full article

In the framework of planning and designing resilient housing under a changing climate, the present study constitutes a comprehensive literature review exploring climate-proofing solutions for the built environment concerning energy supply and water availability. This study delved into a multitude of sources that included scientific papers and reports and European Union guidelines and tools. The identified solutions covered building, urban, and territorial scales. The hazards of interest included heatwaves, heavy precipitation, droughts, earthquakes, wildfires, and storms. Several types of solutions were found (e.g., nature-based, education/capacity-building, engineering/built environment, etc.) with different times of application and timescales of action (e.g., defensive measures, short-term solutions, long-term adaptive, etc.). The maturity of the identified solutions was assessed based on the Technology Readiness Level (TRL) and Societal Readiness Level (SRL). Moreover, each solution’s contribution to climate mitigation was investigated. The solutions were assessed in terms of self-sustainability and other key criteria, namely, effectiveness, contribution to resilience maturity and climate change mitigation, adaptive nature, financing access, risk reduction, and social cohesion. In total, 85 energy and water solutions were determined from the desk review analysis and 67 (30 for the energy sector and 37 for the water sector) solutions were finally retained and proposed. Full article

This systematic review evaluates the health impacts of climate-induced extreme weather events and the effectiveness of various adaptation strategies. Seventeen studies were analyzed, focusing on adaptation measures such as agricultural adjustments, renewable energy, ecosystem restoration, infrastructure redesign, and public health interventions. Significant health impacts were identified, including increased morbidity and mortality due to heatwaves, floods, and vector-borne diseases. The success of adaptation strategies was found to be highly dependent on local context, implementation capacity, and sustainability. This review underscores gaps in data quality, the generalizability of findings, and the integration of adaptation measures into public health policies. An urgent need exists for interdisciplinary approaches and community engagement to ensure sustainable, equitable health outcomes in the face of climate change. Future research should focus on these areas to strengthen public health resilience. Full article

The emerging threats of climate change and their impacts on cities and residents are increasingly highlighting the need to assess whether countries are adequately prepared for the potential consequences of this process. While many international agreements on climate change, sustainable development and environmental protection have been adopted, countries often face various local obstacles that hinder their implementation. To address these issues, this paper reviews the climate change projections, emerging threats and hazards in Lithuania and their potential impacts on the country’s cities and highlights the main challenges in preparing for these growing threats. This article presents an evaluation of the climate change forecasts and past climate events in three selected Lithuanian cities—Vilnius, Kaunas and Klaipėda. The study includes a diagnostic assessment of the climate changes since 1961 and climate change forecasts up to 2100, based on the RCP4.5 and RCP8.5 scenarios, using regional and global climate models. It identifies the impacts of potential climate change consequences on cities, forming the basis for the evaluation of the urban situation in the country. The urban situation is assessed in terms of legislation, urban development, environmental requirements and the development of safety infrastructure. Based on the evaluation of urban development, preliminary proposals are provided for the creation of a resilient living environment. One of the key proposals in shaping the living environment—which could be particularly significant in adapting to emerging threats—is the complex formation of new, sustainable urban structures that take into account the social, ecological and economic factors of climate change and other rising threats. Full article

Based on the properties of Rossby waves at the tropopause resonantly forced by solar declination in harmonic modes, which was the subject of a first article, case studies of heatwaves and extreme precipitation events are presented. They clearly demonstrate that extreme events only form under specific patterns of the amplitude of the speed of modulated airflows of Rossby waves at the tropopause, in particular period ranges. This remains true even if extreme events appear as compound events where chaos and timing are crucial. Extreme events are favored when modulated cold and warm airflows result in a dual cyclone-anticyclone system, i.e., the association of two joint vortices of opposite signs. They reverse over a period of the dominant harmonic mode in spatial and temporal coherence with the modulated airflow speed pattern. This key role could result from a transfer of humid/dry air between the two vortices during the inversion of the dual system. Finally, focusing on the two period ranges 17.1–34.2 and 8.56–17.1 days corresponding to 1/16- and 1/32-year period harmonic modes, projections of the amplitude of wind speed at 250 mb, geopotential height at 500 mb, ground air temperature, and precipitation rate are performed by extrapolating their amplitude observed from January 1979 to March 2024. Projected amplitudes are regionalized on a global scale for warmest and coldest half-years, referring to extratropical latitudes. Causal relationships are established between the projected amplitudes of modulated airflow speed and those of ground air temperature and precipitation rate, whether they increase or decrease. The increase in the amplitude of modulated airflow speed of polar vortices induces their latitudinal extension. This produces a tightening of Rossby waves embedded in the polar and subtropical jet streams. In the context of climate change, this has the effect of increasing the efficiency of the resonant forcing of Rossby waves from the solar declination, the optimum of which is located at mid-latitudes. Hence the increased or decreased vulnerability to heatwaves or extreme precipitation events of some regions. Europe and western Asia are particularly affected, which is due to increased activity of the Arctic polar vortex between longitudes 20° W and 40° E. This is likely a consequence of melting ice and changing albedo, which appears to amplify the amplitude of variation in the period range 17.1–34.2 days of poleward circulation at the tropopause of the Arctic polar cell. Full article