Actuview, the international streaming platform for actuaries, recently held a roundtable with industry insiders to discuss climate change, specifically its impact on life and health insurance and how insurers and actuaries should consider this important issue. One of the panelists was RGA’s Dr. Georgiana Willwerth-Pascutiu. This article encapsulates the insights she shared, and her full commentary can be viewed in the recording below.
In an era when climate change dominates global discussions, understanding its impact on mortality and morbidity has become crucial. Environmental health, a branch of public health, assesses how environmental factors – including climate hazards – impact human health and wellbeing. These hazards pose significant risks for major causes of death, from cardiovascular diseases to cancer. Delving deeper into this complex relationship reveals both challenges and surprising findings that shape the understanding of climate change's health implications.
The two climate drivers explored the most and accompanied by the most academic research are air pollution and rising temperatures, which includes extreme heat and heat waves. However, the two hazards that have the greatest global human toll are droughts and floods. The Lancet Countdown on health and climate change noted that the risk of death from floods remained unchanged worldwide since the 1990s; in fact, it declined in certain high-income countries.1
The global impact of climate change on mortality has produced some interesting trends over the past two decades. For example, the cold-related excess death ratio globally decreased by about 0.5%, while the global heat-related excess death ratio increased by approximately 0.2%, resulting in a net reduction in the overall ratio. Southeast Asia saw the largest decline in the overall excess death ratio.2
"Our task is to understand the epidemiological relationship between climate hazards and health, how it varies by geography and other socioeconomic factors, and then to quantify the impact of climate change on health."
- Dr. Georgiana Willwerth-Pascutiu
These trends are expected to change for some regions and under future climate scenarios. For example, in a higher emissions scenario, without accounting for population aging, most studies report a net-zero temperature-related mortality impact in the US, while a negative mortality impact is expected for Southeast Asia.3
While these findings provide valuable insights, researchers face challenges when conducting their analyses.
The Global Burden of Disease study attributed approximately 1.9 million annual deaths to non-optimal temperatures in 2021. It found most of these resulted from cold conditions, and that cold-related mortality was about nine times higher than heat-related.4 However, other reports indicate these figures vary from 1.7 million to five million deaths.5
Determining which numbers are correct is a challenge in itself. Estimates vary based on data quality, the methodology, and the assumptions made about human response to temperature changes. It requires an understanding of the data and research limitations, and how to correctly attribute, recognize, label, and code the health impacts.
Research indicates that official records underestimate the association between climate hazards and health, such as heat-related mortality. For example, an Australian study suggested that official records underestimate deaths attributed to excessive heat by a factor of 50.6
The measurement of heat-related mortality can be examined from two viewpoints: all-cause or cause-specific. When looking at all-cause mortality, the sensitivity is higher, while the specificity is higher when considering cause-specific mortality.
It is essential to consider the methodology used to report climate-related morbidity and mortality to properly estimate their impact on the insurance industry. Enhanced reporting methods can prove pivotal, including International Classification of Diseases (ICD) codes that capture the indirect as well as the direct effects of climate hazards on health.
The field of attribution science analyzes the extent to which extreme weather events (e.g., hurricanes, floods, heat waves, etc.) are influenced, or even caused, by climate change. Its practitioners report on probabilities using observational data and employing various model methods.
These climate scientists have noted that hurricane intensification is a consequence of climate change. One factor is that global ocean water temperatures have been rising due to the absorption of heat generated by increased atmospheric CO2 levels, which are now 50% higher than in the preindustrial era. This provides more energy for storms to form and intensify.7
Some climate scenario projections suggest the frequency of storms per year could increase 10%-15% by 2050.8 New studies are emerging in which researchers aim to quantify the contributing effect of climate change on excess mortality.
A new Nature report estimates nearly 100,000 deaths per year are associated with exposure to PM 2.5 caused by wildfires. It notes that about 13% of this mortality can be attributed to climate change, up from 3% in the 1990s.9
While direct mortality from climate events is concerning, the indirect impact may be more significant. A recent Nature study suggests that the overall health effects from natural disasters in the US are underestimated, concluding that an average of 24 deaths per year are attributed to each hurricane, yet the indirect mortality could be higher than 7,000 deaths.10
Other studies offer similar conclusions, but it is important to note that measuring the extended effects of catastrophes is challenging. Questions arise as to true correlation for some mortality-related outcomes, especially those developing well after a climate-related event. No definitive finding is possible at this point. Life and health insurers should monitor and analyze additional data from areas where the ramifications of natural disasters are suggested to impact long-term morbidity and mortality.
A surveillance approach searches death records for specific mentions of linkage to an extreme weather event, identifying deaths attributed to it. While this approach captures direct mortality, a substantial number of associated deaths can be overlooked. These may result from contamination of food and water, disrupted access to medical care, and mental health disorders. Studies have shown that excess mortality can be documented for at least 60 days after an event.11
Climate drivers should not be analyzed in isolation as their interactions can lead to complex and unpredictable outcomes.
Last year, the Lancet Countdown reported that heat-related mortality for people aged 65 or older increased 85% compared to the 1990s. It noted that a 38% increase was expected without higher temperatures, resulting from demographic changes, especially aging.1 In this year’s report, they found heat-related mortality increased 167%, more than 2.5 times the figure expected (65%) without a rise in temperature.12
The complexity of climate-health interactions demands a more comprehensive approach. As severe environmental events become more common, there is a need for enhanced reporting, attribution methods, and a holistic approach that considers both direct and indirect impacts – along with acute and chronic effects – associated with natural disasters.
An improved understanding of these complex relationships offers an opportunity to better prepare for and mitigate the health impacts of climate change, ultimately creating a healthier and more resilient global population.
Watch the video of Georgiana’s comments below. You can see the full roundtable discussion via actuview.
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