Editorial: advances in understanding marine heatwaves and their impacts

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Benthuysen, J. A., Oliver, E. C. J., Chen, K., & Wernberg, T. Editorial: advances in understanding marine heatwaves and their impacts. Frontiers in Marine Science, 7, (2020): 147, doi:10.3389/fmars.2020.00147.Editorial on the Research Topic Advances in Understanding Marine Heatwaves and Their Impacts In recent years, prolonged, extremely warm water events, known as marine heatwaves, have featured prominently around the globe with their disruptive consequences for marine ecosystems. Over the past decade, marine heatwaves have occurred from the open ocean to marginal seas and coastal regions, including the unprecedented 2011 Western Australia marine heatwave (Ningaloo Niño) in the eastern Indian Ocean (e.g., Pearce et al., 2011), the 2012 northwest Atlantic marine heatwave (Chen et al., 2014), the 2012 and 2015 Mediterranean Sea marine heatwaves (Darmaraki et al., 2019), the 2013/14 western South Atlantic (Rodrigues et al., 2019) and 2017 southwestern Atlantic marine heatwave (Manta et al., 2018), the persistent 2014–2016 “Blob” in the North Pacific (Bond et al., 2015; Di Lorenzo and Mantua, 2016), the 2015/16 marine heatwave spanning the southeastern tropical Indian Ocean to the Coral Sea (Benthuysen et al., 2018), and the Tasman Sea marine heatwaves in 2015/16 (Oliver et al., 2017) and 2017/18 (Salinger et al., 2019). These events have set new records for marine heatwave intensity, the temperature anomaly exceeding a climatology, and duration, the sustained period of extreme temperatures. We have witnessed the profound consequences of these thermal disturbances from acute changes to marine life to enduring impacts on species, populations, and communities (Smale et al., 2019). These marine heatwaves have spurred a diversity of research spanning the methodology of identifying and quantifying the events (e.g., Hobday et al., 2016) and their historical trends (Oliver et al., 2018), understanding their physical mechanisms and relationships with climate modes (e.g., Holbrook et al., 2019), climate projections (Frölicher et al., 2018), and understanding the biological impacts for organisms and ecosystem function and services (e.g., Smale et al., 2019). By using sea surface temperature percentiles, temperature anomalies can be quantified based on their local variability and account for the broad range of temperature regimes in different marine environments. For temperatures exceeding a 90th-percentile threshold beyond a period of 5-days, marine heatwaves can be classified into categories based on their intensity (Hobday et al., 2018). While these recent advances have provided the framework for understanding key aspects of marine heatwaves, a challenge lies ahead for effective integration of physical and biological knowledge for prediction of marine heatwaves and their ecological impacts. This Research Topic is motivated by the need to understand the mechanisms for how marine heatwaves develop and the biological responses to thermal stress events. This Research Topic is a collection of 18 research articles and three review articles aimed at advancing our knowledge of marine heatwaves within four themes. These themes include methods for detecting marine heatwaves, understanding their physical mechanisms, seasonal forecasting and climate projections, and ecological impacts.We thank the contributing authors, reviewers, and the editorial staff at Frontiers in Marine Science for their support in producing this issue. We thank the Marine Heatwaves Working Group (http://www.marineheatwaves.org/) for inspiration and discussions. This special issue stemmed from the session on Advances in Understanding Marine Heat Waves and Their Impacts at the 2018 Ocean Sciences meeting (Portland, USA)

Executive summary climate change and the East Midlands economy

This report examines the way in which the weather has influenced the East Midlands economy in recent years and considers how climate change may influence this relationship during the 21st century. It considers how changing weather patterns will impact upon energy, water and flood risk, transport, agriculture, the built environment, tourism and health in the region

The Impact of Heatwaves on Community Morbidity and Healthcare Usage: A Retrospective Observational Study Using Real-Time Syndromic Surveillance.

We investigated the impact of a moderate heatwave on a range of presenting morbidities in England. Asthma, difficulty breathing, cerebrovascular accident, and cardiovascular symptoms were analysed using general practitioner in hours (GPIH), out of hours (GPOOH) and emergency department (ED) syndromic surveillance systems. Data were stratified by age group and compared between a heatwave year (2013) and non-heatwave years (2012, 2014). Incidence rate ratios were calculated to estimate the differential impact of heatwave compared to non-heatwave summers: there were no apparent differences for the morbidities tested between the 2013 heatwave and non-heatwave years. A subset of GPIH data were used to study individuals at higher risk from heatwaves based on their pre-existing disease. Higher risk patients were not more likely to present at GPs or ED than other individuals. Comparing GPIH consultations and ED attendances for myocardial infarction/ischaemia (MI), there was evidence of a fall in the presentation of MI during the heatwave, which was particularly noted in the 65-74 years age group (and over 75 years in ED attendances). These results indicate the difficulty in identifying individuals at risk from non-fatal health effects of heatwaves and hot weather

Physical drivers of the summer 2019 North Pacific marine heatwave.

Summer 2019 observations show a rapid resurgence of the Blob-like warm sea surface temperature (SST) anomalies that produced devastating marine impacts in the Northeast Pacific during winter 2013/2014. Unlike the original Blob, Blob 2.0 peaked in the summer, a season when little is known about the physical drivers of such events. We show that Blob 2.0 primarily results from a prolonged weakening of the North Pacific High-Pressure System. This reduces surface winds and decreases evaporative cooling and wind-driven upper ocean mixing. Warmer ocean conditions then reduce low-cloud fraction, reinforcing the marine heatwave through a positive low-cloud feedback. Using an atmospheric model forced with observed SSTs, we also find that remote SST forcing from the central equatorial and, surprisingly, the subtropical North Pacific Ocean contribute to the weakened North Pacific High. Our multi-faceted analysis sheds light on the physical drivers governing the intensity and longevity of summertime North Pacific marine heatwaves

Quantile-based bias correction and uncertainty quantification of extreme event attribution statements

Extreme event attribution characterizes how anthropogenic climate change may have influenced the probability and magnitude of selected individual extreme weather and climate events. Attribution statements often involve quantification of the fraction of attributable risk (FAR) or the risk ratio (RR) and associated confidence intervals. Many such analyses use climate model output to characterize extreme event behavior with and without anthropogenic influence. However, such climate models may have biases in their representation of extreme events. To account for discrepancies in the probabilities of extreme events between observational datasets and model datasets, we demonstrate an appropriate rescaling of the model output based on the quantiles of the datasets to estimate an adjusted risk ratio. Our methodology accounts for various components of uncertainty in estimation of the risk ratio. In particular, we present an approach to construct a one-sided confidence interval on the lower bound of the risk ratio when the estimated risk ratio is infinity. We demonstrate the methodology using the summer 2011 central US heatwave and output from the Community Earth System Model. In this example, we find that the lower bound of the risk ratio is relatively insensitive to the magnitude and probability of the actual event.Comment: 28 pages, 4 figures, 3 table

Including the urban heat island in spatial heat health risk assessment strategies: a case study for Birmingham, UK

Background Heatwaves present a significant health risk and the hazard is likely to escalate with the increased future temperatures presently predicted by climate change models. The impact of heatwaves is often felt strongest in towns and cities where populations are concentrated and where the climate is often unintentionally modified to produce an urban heat island effect; where urban areas can be significantly warmer than surrounding rural areas. The purpose of this interdisciplinary study is to integrate remotely sensed urban heat island data alongside commercial social segmentation data via a spatial risk assessment methodology in order to highlight potential heat health risk areas and build the foundations for a climate change risk assessment. This paper uses the city of Birmingham, UK as a case study area. Results When looking at vulnerable sections of the population, the analysis identifies a concentration of "very high" risk areas within the city centre, and a number of pockets of "high risk" areas scattered throughout the conurbation. Further analysis looks at household level data which yields a complicated picture with a considerable range of vulnerabilities at a neighbourhood scale. Conclusions The results illustrate that a concentration of "very high" risk people live within the urban heat island, and this should be taken into account by urban planners and city centre environmental managers when considering climate change adaptation strategies or heatwave alert schemes. The methodology has been designed to be transparent and to make use of powerful and readily available datasets so that it can be easily replicated in other urban areas

Nexus of thermal resilience and energy efficiency in buildings: A case study of a nursing home

Extreme weather events become more frequent and severe due to climate change. Although energy efficiency technologies can influence thermal resilience of buildings, they are traditionally studied separately, and their interconnections are rarely quantified. This study developed a methodology of modeling and analysis to provide insights into the nexus of thermal resilience and energy efficiency of buildings. We conducted a case study of a real nursing home in Florida, where 12 patients died during Hurricane Irma in 2017 due to HVAC system power loss, to understand and quantify how passive and active energy efficiency measures (EEMs) can improve thermal resilience to reduce heat-exposure risk of patients. Results show that passive measures of opening windows and doors for natural ventilation, as well as miscellaneous load reduction, are very effective in eliminating the extreme dangerous occasions. However, to maintain safe conditions, active measures such as on-site power generators and thermal storage are also needed. The nursing home was further studied by changing its location to two other cities: San Francisco (mild climate) and Chicago (cold winter and hot summer). Results revealed that the EEMs' impacts on thermal resilience vary significantly by climate and building characteristics. The study also estimated the costs of EEMs to help stakeholders prioritize the measures. Passive measures that may not save energy may greatly improve thermal resilience, and thus should be considered in building design or retrofit. Findings from this study indicate energy efficiency technologies should be evaluated not only by their energy savings performance but also by their influence on a building's resilience to extreme weather events

Heat-Ready: heatwave awareness, preparedness and adaptive capacity in aged care facilities

AbstractThis study identifies the current policies and strategies Australian ACFs use to keep residents well, and highlights the barriers to heatwave adaptation and maintaining wellness in the residential aged during periods of extreme heat. As the Australian population ages, planning for the health effects of extreme heat in elderly residents is critical to ensure wellness in this population group is maintained.Aims were to: 1) investigate current heat-wave planning, policies, staff knowledge and heat prevention strategies and 2) identify barriers to adaptation and successful implementation of adequate heat-wave health care in ACFs in three Australian states (NSW, Queensland and South Australia).Residential ACFs were identified across three states using Department of Health and Ageing databases, white pages and internet searching. After removal of duplicates, 1,561 facilities were invited to participate in the study. Each participating facility was asked to provide informed consent and invited to select one administrative and one clinical staff member to participate in a 15 minute Computer Assisted Telephone Interview (CATI). Participants were asked about their knowledge of the effects of heat on the elderly and to detail current plans and policies which addressed residents’ health during heat-waves, and barriers to care during periods of extreme heat. Data was entered into a purpose-built database and analysed using Statistical Package for the Social Sciences (SPSS) Version 19.Two hundred and eighty seven (287) facilities (18%) participated in the telephone interview. The ACFs enrolled represented 20,928 Australian aged care residents.  Ninety percent of facilities had a current ACF emergency plan, although only 30% included heat-wave emergency planning. Heatwave policies were not routine in all ACFs in any state. Staff used a range of strategies to keep residents cool in extreme heat, although strategies were not consistent across all states or facilities. The issues raised in relation to clinical care in this group can be synthesised into four key messages; cooling, hydration, monitoring and emergency planning, which, at a practical level are essential to maintain the health of older people in very hot weather.Please cite this report as: Black, DA, Veitch, C, Wilson, LA, Hansen, A 2013 Heat-Ready: Heatwave awareness, preparedness and adaptive capacity in aged care facilities in three Australian states: New South Wales, Queensland and South Australia, National Climate Change Adaptation Research Facility, Gold Coast, 47 pp.AbstractThis study identifies the current policies and strategies Australian ACFs use to keep residents well, and highlights the barriers to heatwave adaptation and maintaining wellness in the residential aged during periods of extreme heat. As the Australian population ages, planning for the health effects of extreme heat in elderly residents is critical to ensure wellness in this population group is maintained.Aims were to: 1) investigate current heat-wave planning, policies, staff knowledge and heat prevention strategies and 2) identify barriers to adaptation and successful implementation of adequate heat-wave health care in ACFs in three Australian states (NSW, Queensland and South Australia).Residential ACFs were identified across three states using Department of Health and Ageing databases, white pages and internet searching. After removal of duplicates, 1,561 facilities were invited to participate in the study. Each participating facility was asked to provide informed consent and invited to select one administrative and one clinical staff member to participate in a 15 minute Computer Assisted Telephone Interview (CATI). Participants were asked about their knowledge of the effects of heat on the elderly and to detail current plans and policies which addressed residents’ health during heat-waves, and barriers to care during periods of extreme heat. Data was entered into a purpose-built database and analysed using Statistical Package for the Social Sciences (SPSS) Version 19.Two hundred and eighty seven (287) facilities (18%) participated in the telephone interview. The ACFs enrolled represented 20,928 Australian aged care residents.  Ninety percent of facilities had a current ACF emergency plan, although only 30% included heat-wave emergency planning. Heatwave policies were not routine in all ACFs in any state. Staff used a range of strategies to keep residents cool in extreme heat, although strategies were not consistent across all states or facilities. The issues raised in relation to clinical care in this group can be synthesised into four key messages; cooling, hydration, monitoring and emergency planning, which, at a practical level are essential to maintain the health of older people in very hot weather.&nbsp

The heat is on: climate change, extreme heat and bushfires in WA

Climate change is increasing the intensity and frequency of heatwaves in Western Australia and driving up the likelihood of very high fire danger weather. Western Australia is experiencing a long-term increase in average temperatures and in 2014 the state recorded its highest ever annual average maximum temperature. The number of heatwave days in Perth has increased by 50% since 1950. Nine of Western Australia’s hottest Januarys on record have occurred in the last 10 years. The number of days per year with severe fire danger weather is projected to almost double in south west Western Australia by 2090 if global carbon emissions are not drastically reduced. Recent fires in Western Australia have been influenced by record hot dry conditions. The long-term trend to hotter weather in Western Australia has worsened fire weather and contributed to an increase in the frequency and severity of bushfires. The concept of a normal bushfire season is rapidly changing as bushfires increase in number, burn for longer and affect larger areas of land. By 2030, the number of professional firefighters in WA will need to more than double to meet the increasing risk of bushfires. 3. The economic, social and environmental costs of increased extreme heat and bushfire activity is likely to be immense. In Perth, from 1994-2006, there were over 20 heat attributable deaths per year. If average maximum temperatures were 2°C warmer, this number would almost double to 40 deaths. Some of Western Australia’s most fire-prone regions may become unlivable as the risks to lives and property caused by bushfires continue to increase. Without effective action on climate change, there will be 20 times the number of dangerous days for outdoor workers by 2070, reducing productivity. 4. Tackling climate change is critical to protecting Western Australia’s prosperity. As a nation we must join the global effort to substantially reduce emissions and rapidly move away from fossil fuels to renewable energy if we are to limit the severity of extreme heat and bushfires both in Western Australia and nationally