As climate-related disasters around the world increase, so too does the burden of accumulated trauma on global mental health.
As a result of increasing greenhouse gas emissions, global average temperatures are rising. Since records began in Australia in around 1910, the temperature has warmed on average by 1.44°C.
Warming weather increases the frequency, severity and intensity of weather and climate extremes, such as heat waves, droughts, bushfires and extreme precipitation events leading to flooding.
Experiencing a climate disaster has previously demonstrated detrimental impacts on mental and physical health. At-risk groups, including women, those with a disadvantaged socio-economic status and those with pre-existing mental or physical health conditions, are disproportionately affected.
Despite the increase in intensity and frequency of climate disasters, there has been limited research to examine the impact of experiencing repeated disasters on mental health. Our research was designed to investigate the impact of cumulative trauma, and whether mental health declined, or individuals developed resilience.
![Climate change is one of the greatest threats to global mental health. - Featured Image](https://insightplus.mja.com.au/wp-content/uploads/2024/07/shutterstock_1653421102.jpg)
Our study
Our research, published in The Lancet Regional Health, uses longitudinal data from the Household, Income and Labour Dynamics in Australia (HILDA) survey to look at individuals who had their homes damaged or destroyed as a result of a weather-related disaster such as a flood, bushfire or cyclone. We examined their mental health pre- and post-disaster over an 11-year period from 2009 to 2019. This is the first study in Australia that uses longitudinal data to investigate the impacts of repeated weather exposure on health.
The study cohort had slight female predominance, consisted of mainly individuals from regional and remote Australia, from lower socio-economic backgrounds and lower levels of education. This correlates with previous studies, and highlights the vulnerability of communities exposed to climate disasters in our country.
Our research demonstrated that exposure to repeated climate disasters led to declining mental health scores. This finding was not demonstrated in individuals who only experienced one disaster.
These findings add to longitudinal studies from the United States and China, which have looked at mental health post-recurrent hurricanes and earthquakes respectively. Each study has demonstrated that experiencing the trauma of an additional disaster worsens mental health.
Unemployment was identified as a strong risk factor for worsening mental health outcomes, with unemployed individuals experiencing moderate declines in mental health after experiencing a single or repeated disasters.
The main limitation of the study is that it only analyses individuals who have experienced property damage from weather events, which limits the sample size and spectrum of experiences from climate disasters.
This study has implications for disaster-prone regions of Australia.
Climate change has the capacity to widen pre-existing inequalities within society, by predominantly affecting those already at risk, who do not necessarily have the social and financial capital to withstand such great shocks.
In light of our results, there is a need for targeted mental health interventions and support services to populations affected by cumulative trauma, such as multiple climate events. There is still limited evidence on how to best support the communities and individuals exposed to repeated disasters, so this should be a priority for further research and policy design.
Unemployed individuals are at particular risk post-disaster, highlighting the need for services to be targeted towards this group, to reduce inequity in mental health outcomes seen between those employed and unemployed.
Our findings are important to support the necessity for the Australian Government to uphold existing commitments to limit global warming, as outlined in the Paris Agreement. There needs to be additional attention focused on disaster risk mitigation, and development of policy focused on minimising risk from climate disasters to already vulnerable communities.
As clinicians, we have a responsibility to protect the health of our communities. It is vital we use our relative position of power to advocate for better climate action, to minimise the poor health outcomes from climate change for current and future generations. This study will aid mental health clinicians to understand risk factors for deteriorating mental health after disasters, and be able to identify people who will require additional mental health assistance.
Dr Anna Mitchell is a physician trainee at the Alfred Hospital, having completed a Master of Public Health with an interest in Planetary Health.
The statements or opinions expressed in this article reflect the views of the authors and do not necessarily represent the official policy of the AMA, the MJA or InSight+ unless so stated.
Subscribe to the free InSight+ weekly newsletter here. It is available to all readers, not just registered medical practitioners.
If you would like to submit an article for consideration, send a Word version to mjainsight-editor@ampco.com.au.