The sanity offered by the tranquil beauty of national parks has been conservatively valued at around US$6 trillion globally per year.
The estimate, published as a peer-reviewed Perspective in the journal Nature Communications, takes into account the economic cost of dealing with poor mental health, including treatment, care, reduced workplace productivity and antisocial behaviour.
Lead author Ralf Buckley and colleagues from Australia’s Griffith University hope such a tangible benefit will spark more political and economic support for initiatives to stop encroachment into protected areas and address declining biodiversity.
“Conservation benefits everyone a little, but no individual greatly; individual health benefits individuals greatly, but society only a little,” they write.
“Ecosystem services value connects a global goal to a society-scale interest, whereas health services value connects a global goal directly to individual self-interest, which is more influential.”
In that regard, growing urbanisation is creating a disconnect between people and green spaces, in turn impacting public health.
Multi-level evidence suggests that being in nature has numerous benefits for people’s physical health, as well as mental health and wellbeing, including improved cognition, sleep, stress relief and reduced anxiety and depression.
To put a dollar value on this, Buckley and a team led by ecologists, psychologists and economists conducted three pilot trials using quality-adjusted life years – a measure of someone’s ability to carry out activities of daily life free from pain and mental disturbance. Recommended
They linked information on national park visit patterns, psychological benefits from nature and the economic costs of poor mental health in a representative sample of nearly 20,000 people, controlling for physical health, fitness, use of non-park green spaces and demographic, socioeconomic and family factors.
The authors found a direct link between visits to protected areas and individual mental health; scaling up globally, they found it is a no-brainer in terms of the bigger economic picture. But they hope the parks will remain free to all, especially disadvantaged people who need them most.
“Parks contribute US$5-31 trillion per annum to the global economy, above what has been recognised previously,” says Buckley. “That’s at least 10 times the value of park tourism and 100 times parks agency budgets.”
“From a park management perspective,” says co-author Ali Chauvenet, “it means that maximum economic return to government treasuries may be from investing in low-key hiking tracks, lookouts, and other visitor facilities, to attract people to visit with their children as often as possible.”
The annual health services value of Australia’s national parks alone came to around $US100 billion. Noting that the costs of poor mental health comprise around 10% of the country’s GDP, the authors suggest this would be 7.5% higher without protected areas.
“This value already exists, it was just not recognised,” says Buckley. “People already visit parks to recover from stress. In healthcare terms, it’s patient-funded therapy.”
“The next step will be to test how mental health benefits depend on individual personalities, and on particular aspects of park visits,” says Chauvenet.
“It’s possible that park visits could then become a routine part of the healthcare system, prescribed by doctors and funded by insurers.”
Although more research is needed to refine the estimates, the pilot studies suggest that the overall health services value is around 4% that of global ecosystems.
“This first estimate is imprecise, but that does not matter,” the authors write. “What matters is that it is large enough to merit more detailed analysis and application at national and local scales, and potentially, to become a powerful new tool in global conservation.”