Global warming and climate change have been attributed to the increasing consumption of fossil fuel and deforestation, resulting in a continuous increase in the atmosphere’s greenhouse gases (Houghton, 2005). This change has had some undeniable effects on the environment and multiple aspects of human lives (Li et al., 2021). As the stability of the Biosphere ecological and physical systems are some of the main factors affecting the sustainability of human health on the planet (World Health Organization, 2003), the impact of climate change on human health becomes evident.
The gradual increase in overall temperature (maximum, minimum) year-round has had a clear impact on the characteristics of extreme weather conditions, increasing its severity and adversity (Mirza, 2003). Heatwaves are one of these extreme weather conditions, as they are durations of relatively extreme high temperature having a negative impact on human health, ecological conditions, urban air quality, and environmental conditions (Li et al., 2021). During the last 100 years, many extreme heatwaves have occurred throughout the globe (Trigo et al.,2005; Karoly, 2009; Barriopedro et al., 2011). The recorded heatwaves have had significant negative impacts on human health, increased energy and water demand, increased stress on the infrastructure, and caused natural and environmental disasters through the resulting wildfires (Perkins, 2014). These records agree with the studies on heatwave’s impact, which suggest that heatwaves have an impact on human mortality and morbidity (Knowlton et al., 2009). Other studies have found that heatwaves have an impact on daily energy requirement during peak hours and throughout the 24-hours cycle, and the daily water demand (Hatvani-Kovacs et al., 2016).
The diverse and significant impacts of heatwaves on human’s sustainability and day to day life have led to the heatwaves’ changes becoming a primary indicator in assessing the impact of climate change (Jones et al., 2018; Tebaldi & Lobell, 2018; Warshaw, 2018). The temporal increase in heatwave’s characteristics due to climate change had already been observed and recorded (Perkins et al., 2012). These recorded and expected impacts make understanding and analyzing heatwaves a global research priority.
While climate and heatwave changes are global issues, the impact of these changes vary based on the country’s resources and development. Studies have shown that heatwaves in developing countries will have a much higher impact on the public health and infrastructure (Luo and Lau, 2019; Russo et al. 2019; Zhao et al. ,2015). This increases the importance of studying heatwaves’ development for a developing country with limited resources like Jordan.
Future models predict that the temperature in Jordan will increase by 2.5°C to 5°C by the end of the century, while the annual precipitation is expected to drop by 10–37% (Abdulla, 2020). Even the most optimistic scenarios predict that unless the issue is tackled by proper planning, scheduling, and implementation, only a grim and an unsustainable future is lurking ahead.
There are multiple available detection criteria for heatwaves that specify different temperature thresholds values (fixed value, percentile value), different threshold calculations for percentile values (seasonal, yearly, and moving window), using maximum or mean temperature, and number of exceedance days (Li et al. 2015). All the definitions available in the literature are possible ways of detecting heatwaves, however the resulting heatwaves following each method are different. Different results lead to different correlations and trend significances which can change the interpretation of the climate change and heatwaves impact based on the type of impact being studied. We suggest that different heatwave definitions will be most suitable for different impacted sectors studies. That means that a definition might show the best correlation with wildfires while another will have best correlation with spikes in energy consumption, and so on. This unique look into the definition and correlation of heatwaves’ impact to different sectors was not suggested or discussed in the literature before to the best of our knowledge. This work will focus specifically on identifying the heatwave definition with the best correlation with human health impact. In this work we will identify and select the criteria which have shown the highest impact and correlation with human health through the available literature. A heatwave detection criterion that is formulated to identify heatwaves with the highest human health impact and correlation.
Understanding heatwaves development and trend changes due to climate change is a key factor in mitigating their impact, while having an accurate future heatwave projection can be a key factor in resources distribution and allocation during heatwaves. This work focuses on the analysis and understanding of heatwaves spatial and temporal distribution and development in Jordan using the heatwave detection criteria of highest impact on human health, as this work has never been done before.