Climate change could alter Hong Kong’s critical illness landscape by 2050. New research and analysis by RGA, detailed in this summary article, finds that cleaner air, particularly reductions in fine particulate matter, may have a greater impact on reducing cancer and cardiovascular claims than rising temperatures.
Climate change is expected to shape health outcomes around the world over the coming decades, but how significant might those effects be for Hong Kong’s critical illness (CI) insurance market?
A new analysis by RGA examined the potential impact of two major climate-related risks - non-optimal temperatures and air pollution - on the leading causes of CI claims in Hong Kong. The findings suggest that while rising temperatures may have only a limited effect on overall claims, improvements in air quality, particularly reductions in fine particulate matter (PM2.5), could meaningfully diminish future critical illness incidence.
Hong Kong is one of the world’s most established markets for CI insurance, making it important for insurers to understand how environmental changes could influence future morbidity trends. RGA’s research focused on five conditions that represent major causes of CI claims:
The study evaluated how these diseases may be affected by two key climate-related risk factors:
To estimate future impacts, RGA reviewed a broad range of academic literature linking these environmental risks to disease incidence. We then combined those findings with projections of temperature and air-quality changes in Hong Kong by 2050 under the Intergovernmental Panel on Climate Change (IPCC) SSP2-4.5 scenario. For air pollution, we also considered a more optimistic scenario based on Hong Kong’s Clean Air Plan.
RGA identified several important associations between environmental conditions and disease incidence.
Periods of extreme heat have been linked to higher rates of heart attack and stroke, while reductions in extreme cold are expected to decrease cardiovascular events. The strongest evidence, however, relates to long-term exposure to PM2.5, which consists of microscopic particles and liquid droplets from vehicle emissions, industrial activity, fuel combustion, wildfires, and atmospheric chemical reactions. Because these particles are small enough to penetrate deep into the lungs and enter the bloodstream, long-term exposure has been linked to increased risks of cancer, cardiovascular disease, stroke, and other serious health conditions.
Consequently, long-term reductions in PM2.5 levels have the potential to lower the incidence of these conditions.
The research found limited or inconclusive evidence for some other risk-disease combinations. For example, colorectal cancer did not show a sufficiently established relationship with air pollution to be included in the impact estimates.
Under the SSP2-4.5 scenario, Hong Kong is expected to experience more frequent extreme heat events. Based on climate projections, Hong Kong could see approximately 25 additional very hot days, defined as days with temperatures of 33°C or higher, by 2050. At the same time, the number of cold days, defined as days with temperatures of 12°C or lower, is expected to decline by roughly three days per year.
Changes in air pollution could be substantial. In 2024, Hong Kong’s average annual PM2.5 concentration was approximately 15.9 μg/m³. Under SSP2-4.5, PM2.5 levels across East Asia are projected to decline by about 15% by 2050.
The reduction could be even greater if Hong Kong successfully implements its Clean Air Plan. The city’s long-term goal is to move closer to World Health Organization air-quality guidelines. Recognizing practical limitations, including pollution from hill fires – wildfires that burn grassland in Hong Kong’s hills and country parks – our analysis assumes PM2.5 levels could decline by approximately 50% by 2050 under this scenario.
Ozone levels are also expected to improve, although more modestly. Under SSP2-4.5, annual ozone concentrations may decrease by around 4%. If Hong Kong achieves its current air-quality objectives, peak ozone concentrations could fall by roughly 20%.
To estimate future claim impacts, RGA applied published exposure-response relationships to the projected changes in temperature and air pollution.
One example involved heart attacks during heat events. With an additional 25 very hot days expected each year, we estimate the resulting increase in annual heart attack incidence could be about 1%. Because heart attacks account for only a portion of total CI claims, the overall effect on male CI claims is estimated at just 0.1%.
The results were striking when all climate-related risks were assessed. Most temperature-related effects and changes associated with ozone pollution had little influence on overall CI claims. Likewise, changes in short-term pollution peaks produced only small changes in estimated morbidity.
The notable exception was long-term exposure to PM2.5. Under the SSP2-4.5 scenario, reductions in PM2.5 could drive reductions in CI claims, resulting in lower overall CI claims by approximately:
The largest benefits would come from lower cancer incidence, particularly lung cancer and breast cancer.
Under the more ambitious Clean Air Plan scenario, the impact becomes significantly greater:
Again, cancer claims drive most of the improvement. For example, breast cancer claims among females could decrease by nearly 3%, while lung cancer claims could decline by approximately 3% among males.
These findings indicate that air-quality improvements may produce measurable health benefits that extend beyond environmental outcomes and into insurance experience.
Significant uncertainty remains around how climate-related risks may evolve between now and 2050, and how those changes could affect disease incidence.
Future emissions pathways, technological developments, government policies, and societal adaptation efforts remain difficult to predict. Medical research on some environmental exposures is still evolving, and not all studies reach consistent conclusions.
RGA’s assessment examines each risk independently, yet real-world interactions between temperature, pollution, and other environmental factors are more complex. Combined effects may differ from the simple sum of individual impacts.
In addition, the study assumes that findings from international research can be reasonably applied to Hong Kong’s population, an assumption that may not always hold. Future adaptation measures, such as improved healthcare, building design, and public health interventions, could further alter disease risks.
Finally, there are other climate-related risks and causes of critical illness claims that we have not covered in this report. In addition, this report considers climate change in isolation and does not take into account other drivers of CI trends, such as changes in screening, awareness, diagnosis, medical practice, or population risk factors, which may have a material impact on future incidence.
The overall conclusion is encouraging. Despite growing concern about climate change, RGA’s study suggests that non-optimal temperatures are unlikely to dramatically increase critical illness claims in Hong Kong by 2050. Instead, improvements in air quality, particularly reductions in long-term PM2.5 exposure, appear likely to have a more meaningful influence on future morbidity trends.
Under current climate projections, overall CI incidence could fall by around 1%. If Hong Kong achieves more ambitious air-quality improvements, reductions of approximately 4% may be possible. While uncertainty remains substantial, the findings highlight the significant public health and insurance benefits that could result from cleaner air and sustained environmental policy efforts.
The positive impact outlined in this paper does not absolve society from taking action to limit greenhouse gas emissions and future climate change impacts. Climate change remains a significant risk factor and a priority issue that must be addressed through collective action at the government, corporate, and individual levels. The insurance industry has an opportunity to play a leadership role in combatting the climate crisis by promoting awareness, providing education, and inspiring, motivating, and incentivizing populations to modify behaviors in ways that will benefit their health as well as the planet’s.
RGA has made all reasonable efforts to ensure that the information provided in this publication is accurate at the time of inclusion and accepts no liability for any inaccuracies or omissions. The information provided is intended for general discussion and education purposes only and should not be relied upon for making specific decisions.
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Vice President, Senior Biometric Insights Actuary, Global Research and Development