Following unusually heavy rains, the Australian state of Queensland found several of its cities under persistent floods in January this year. The Queensland Police Service reported that the water killed 35 people, and the economic fallout is expected to exceed $A30 billion, according to Australian financial group AMP Ltd.
Shortly after that, floods afflicted the state of Victoria, which has also faced severe fires in recent years. The region experienced the worst blazes in Australia's history in February 2009, and experts indicate that persistent high temperatures and water shortages are increasing its fire risk.
These extreme weather events are often difficult to attribute directly to climate change, but scientists at the National Oceanic and Atmospheric Administration have observed an increase in severe weather phenomena over the past 40 years, a trend that's likely to continue. Meanwhile, public health experts are finding more evidence that conventional damage estimates don't include one troublesome category: mental health problems.
The areas in Australia have begun to rebuild, but the impact of the storms, flooding, fires and dryness may linger in the minds of many Australians, affecting their health and well-being. Public health officials there and around the world are increasingly concerned about how people mentally react to natural disasters as well as the added trauma from the prospect that these are long-term trends that are setting in, such as drought and sea-level rise.
As the climate shifts, nations will have to increasingly contend with issues like depression and post-traumatic stress disorder (PTSD) along with changes in infectious disease patterns and air quality.
'Reframing' the conventional measure of damages
"It will be a reframing of [climate change] that will be useful. It should move from being an 'environmental issue' to something that's directly linked to human health and well-being," said Thomas Doherty, a professor at the Lewis and Clark Graduate School of Education and Counseling and a practicing psychologist. He co-authored a paper earlier this year on mental health and climate change in the journal American Psychologist.
Doherty noted that climate change and psychology are both complex fields, but many individuals have an intuitive grasp of how they interact.
"Consider how the climate typically affects people's health and well-being through seasonal changes. We feel differently about seasons, and people feel changes in their lifestyle" as days get shorter and temperatures drop, explained Doherty. "We're tied into the environment at all times, even though in modern times we spend most of our time indoors. We've got our own biology and internal clock and our physiological systems are attuned to light."
"When we throw climate disruption into the mix, we get disaster psychology," said Doherty, explaining that hurricanes and cyclones can cause physical injuries as well as mental distress from experiencing violence. A 2008 study by the Hurricane Katrina Community Advisory Group said that after the hurricane, severe mental illness rates nearly doubled, rising from 6.1 percent to 11.3 percent for problems like depression, PTSD, anxiety disorder, panic disorder and various phobias.
Mild and moderate mental illness rates also increased, from 9.7 percent to 19.9 percent. Even one year after the storm, mental illness rates rose around New Orleans, defying previous disaster trends of mental illnesses decreasing over time, according to a 2008 study in the journal Molecular Psychiatry.
Though the physical harm from large disasters is limited to those in the immediate region, the mental effects can spread farther. "We're almost experiencing these things in real time because of the proliferation of technology, almost as if we are there," said Doherty. "It's like 9/11: A lot of people felt traumatized by watching those events through their TV screens."
However, gradual climate changes can also affect mental health. "When the climate shifts or the pattern that people are used to over generations shifts, that impacts people," said Doherty. "We may have anxiety about weather shifts because of our jobs and livelihoods."
Drought-triggered malaise lingers in Australia
The problem is especially acute in Australia, where in addition to the recent climate disasters, 1 in 4 rural workers -- close to 100,000 -- lost his or her job as a result of drought in the past decade, according to the Treasury.
Around the same time, the Australian Conservation Foundation observed that food prices rose 12 percent, increasing stress for those out of work. Mental health is also currently the second-largest contributor to the country's disease burden, and a paper last year in the Australian and New Zealand Journal of Psychiatry found that it costs the country $A5.9 billion ($5.99 billion) annually in lost productivity.
Because of this, Australian researchers have led investigations into how climate change and psychological well-being are linked. "I think Australia is ahead of the game compared to the United States," said Doherty. The Climate Institute, an Australian think tank, released a report this summer titled "A Climate of Suffering." The paper examines how acute and chronic climate change effects have influenced mental health in Australia, while looking at projected trends and ways to respond to these issues.
Helen Berry, deputy director of the Center for Research and Action in Public Health at the University of Canberra and one of the report's reviewers, explained that climate change-induced mental health issues follow existing patterns for psychological issues resulting from violence, migration and poor economies.
Though Berry doesn't expect many new mental diseases to emerge, she noted that there has been at least one case of climate change psychosis: In 2008, a 17-year-old boy was taken to the Royal Children's Hospital in Melbourne, Australia, for refusing to drink water. He was adamant that the world's fresh water had mostly dried up and that if he drank, millions of people would die. The hospital has since seen several other cases involving climate anxiety.
Other mechanisms for mental illness come from population movements, according to Berry. Climate shifts can lead to people seeking higher ground or more fertile land, or migrating toward cities because they lost their homes and livelihoods. The Asian Development Bank reported that 30 million people were displaced last year by extreme weather and climate across Asia alone.
Berry said wealthier people can more easily move away from an afflicted region and can more readily find help for any mental issues. The communities they leave behind often suffer as a result. "Local businesses can shutter as the population dwindles. That damages the social cohesion of the community," said Berry.
Susan Clayton, a psychology professor at the College of Wooster, said that social interactions are important to physical and mental well-being and are threatened by climate-induced migration. "We live in communities, and communities will not be transported directly, so we will lose those social lives," she said. "It affects people's resilience; it can have effects on people's immune systems."
Do we react as a community or as individuals?
Movement also disrupts people's connections to their local environment. "We don't really think about how much our personal identities are bound up in a place or sense of location," said Clayton, noting that this is especially true of farmers and others who depend on the land for their income. "If a place where you live is threatened by climate change and you have to move, that can lead to a feeling of rootlessness, even if you weren't physically harmed."
Warming weather also has direct impacts on psychological well-being. Some psychotropic drugs are not as effective when it gets hot, explained Clayton. In addition, she said "increased temperatures make people more aggressive. There's every reason to expect that [climate change] might increase people's tendencies to be more aggressive towards each other, and that might have impacts on mental health."
This can, in turn, cause friction within communities, further weakening social bonds while increasing conflicts as people compete over diminishing resources.
A population can also respond to climate-related issues as a whole, but it depends on what people see as the main source of the problem. "People respond differently to events seen as natural disasters than things that have a human causality," said Clayton. "Natural disasters bring communities together, while man-made disasters tend to divide communities."
She cited the BP PLC Deepwater Horizon oil spill in 2010, when people from towns around the Gulf of Mexico who worked on cleanup efforts were ostracized by their neighbors, viewed as agents of the company behind the spill.
However, Clayton thinks there might be a silver lining: "The positive is that [climate change] is a big problem we're all facing, and people can come together to work on. People can feel an increased sense of connectedness to their community as they come together to find solutions."
Berry agreed with this assessment. "I think because climate change is a global change and is a global problem that we created together, the solution has to be at a collective level rather than an individual level," she said. "I don't think we've yet unleashed the power of community-level action."