Building Evidence to Meet the Heat Challenge

This year’s Climate and Society class is out in the field (or lab or office) completing a summer internship or thesis. They’ll be documenting their experiences one blog post at a time. Read on to see what they’re up to.

Cindy Chiang, C+S ’16

Each month in 2016 continues to break global temperature records. As the impacts of climate change become clearer, public health officials, scientists, and policy makers around the world are scrambling to keep up with the impacts of a warming planet. The health hazards associated with changing weather and climate patterns are significant and varied.

With climate change, the intensity, and frequency of extreme temperatures become less predictable and their effects more alarming. According to the U.S. Global Change Research Program, climate change “affect(s) human health in two main ways: first, by changing the severity or frequency of health problems that are already affected by climate or weather factors; and second, by creating unprecedented or unanticipated health problems or health threats in places where they have not previously occurred.” That’s why increasing knowledge and capacity for communities to respond to and recover quickly from natural disasters is a critical component to prepare communities for the impacts of a changing climate.

Source: NOAA

Heat related deaths have become an increasing concern in the past decade. Both developing and developed countries have suffered unusually high mortality and morbidity rates during the summer in recent years.

Despite this, it’s sometimes hard to determine just how many deaths can be attributed to a specific heat wave. From a medical perspective, very rarely is the cause of death classified as heat exposure. Pre-existing, chronic conditions can be worsened by the environmental impacts of extraordinary heat exposure and be the direct cause of death. That’s why a widely used method to quantify heat-related deaths is the concept of excess deaths — mortality above what is typical during normal conditions.

In 1995, more than 700 people died in just three days of relentless high temperature in Chicago (read Eric Klinenberg’s compelling social autopsy of the phenomena). In 2003, nearly 15,000 more people than typical died during the blistering August heat wave in France. In the city of Ahmedabad in India, 1,344 additional deaths were registered during record temperature highs in May 2010 and across India, more than 2,300 deaths were directly linked to the 2015 heat wave that passed through the country’s coastal region. Nearly 1,000 lives were claimed during the few days of smoldering heat in England in 2013.

In North America, heat waves kill more people than earthquakes, floods, hurricanes, tornadoes, and lightning combined. An average of 400 deaths per year are directly related to heat, and thousands more die from illnesses exacerbated by heat including heat exhaustion, heat stroke, cardiovascular disease, and kidney disease. These numbers paint a dire picture, but they could be just the tip of the iceberg. A 2015 joint World Meteorological Organization and World Health Organization report on heat health suggests that these numbers underestimate the true rate of heat-related deaths, as there’s currently no robust method to quantify this effect.

Building the Evidence

To help communities brace for extreme heat, scientists are working to build evidence of heat wave impacts through analysis of the relationship between temperature and mortality and morbidity data and increase understanding of heat wave variables such as thresholds, durations, and spatial variation of temperature in a given location. These efforts combined can enhance scientists’ ability to forecast heat waves well before they hit.

The Red Cross Red Crescent Climate Center, as part of the International Research Applications Project, hope to develop an early warning system that helps communities in Bangladesh reduce negative health outcomes during unusually hot periods. This is one of several heat health initiatives in the Southeast Asia region and it presents particular set of challenges. Data availability, accessibility, and quality are issues especially in the public health sector where patient privacy safeguards information. On the climate side, defining meteorological thresholds that warrant early action require daily temperature data at a tight spatial scale, which is hard to find and process.

In addition to quantitative evidence, a successful early warning system will rely on in-depth knowledge and assessing vulnerability factors like social conditions and networks, cultural norms, public perception, healthcare infrastructure and policy, and political landscape.

The Most Vulnerable Populations

Marginalized populations are generally the most vulnerable to heat-related mortality. In the U.S, this is often the elderly, the urban poor, those living alone, and people who do not have access to air conditioning. People with chronic medical conditions such as obesity, cardiovascular and psychiatric diseases are also more susceptible to adverse health effects of intense heat.

In Bangladesh the deadly combination of heat, humidity, and air pollution routinely sends hundreds to the hospital for diarrhea treatment, while leaving hundreds dead each summer season. News articles cite eating and drinking roadside food and juices that have spoiled due to extreme heat as the main source of contamination. Those affected are often the poor working class, those living in slums, women, and children. In 2015, nearly 500 children were admitted to city clinics for heat related illnesses, and cab drivers and farmworkers perished during the May temperature surge.

Earlier this month, in a series of six studies published by the UN University of Kuala Lumpur on the impact of climate change on human health, researchers found that increased heat stress restrict the work hours of those living in the poorest countries. Unsurprisingly, the economic brunt of more intense heat will be felt most by low-wage earners such as street vendors, farmers, and construction workers whose job require them to stay outdoors.

The Silver Lining of Climate

At a recent Climate and Health Colloquium hosted by the International Research Institute of Climate and Society (IRI), the director of IRI’s Health Program Madeleine Thompson said that climate is both a challenge and a resource. Because climate data is organized in time and space, it can be incorporated relatively easily into existing health preparedness and prevention measures. It is also measured routinely, climate models are improving, and our access to high quality satellite data is increasing.

We have the scientific knowledge and technology to warn people about how new climate patterns can affect their everyday lives. And, as world leaders demonstrated during the Paris climate talks last year, there is a new willingness to meet the challenges posed by climate change. Now what we need is funding for better data, more measurement and collection tools, more communicators who can convey the validity and uncertainty of analysis to decision makers, more designers who can bring a human-centered approach to early warning implementation, and more interdisciplinary programs like the International Research Applications Project. If you still need a boost of optimism enduring the forecasted high heat in New York City this weekend, check out Time to Choose, a new documentary focused more on solutions and less on doom.