Defining Events

Set up

The following text is the result of many conversations between the listed authors and many other individuals about ‘heat waves’. In situations where limited resources or rapidly shifting social and/or environmental conditions make exacting analyses impossible - what are some ways to use existing tools and publicly available data to be more proactive about responding to the dangers of extreme temperatures? The question seems very worthwhile and straight forward, but it raises another tricky question: When all you have is large scale indicators, what are you really ‘on the look out for’? Experiences and circumstances are varied, it’s not uncommon for people get sun stroke on ski slopes and hypothermia while out walking in mild weather. What is extreme and/or dangerous can vary from place to place and person to person. Typically such factors are dissected as part of the research and decision making processes. Such nuanced analyses however, require nuanced records of stationary environments. So what can you hope to say when you don’t have that luxury? Often there’s not much that can be said definitively, or with general applicability. The questions become less focused on “what do we need to know, in order to be sure?” and more on “are we able to understand how much we actually do/don’t know?” and “what are we prepared to do with that information, given that what we have is more than nothing, but still opaque at best?” We wanted to provide a work through of some of our efforts and thought process(es), both to illustrate the complications of this sort of analysis, and to provide some starting points for people interested in expanding on these ideas.

What do you mean by “heat wave”?

Extreme high temperature events, or “heat waves”, have always presented a danger to people’s well being. Discussions of climate change have brought about an increasing global concern regarding the dangers of these phenomena (Kovats 2008), which are expected to become more common and severe over the coming years (Meehl 2004, Weisheimer 2005, Akhtar 2007, Mishra 2015, Roldán 2015). Heat waves are responsible for large numbers of deaths in vulnerable regions; the Indian heat wave in May 2015 was reported to have caused 2,500 deaths. Since most heat related deaths can be prevented with adequate preparation (Hutter 2007), there is much emphasis and ongoing work in forecasting extreme heat hazards. To identify these hazards, climatologists typically focus on regional weather patterns and base their definitions around long term averages and the probability of exceeding a set metric; e.g., (Hunt 2007) and (Kent 2013).