Suicide rates in Australia increase with prolonged temperature increases, according to Xin Qi, a researcher from Queensland University of Technology in Brisbane, who suggests that climate change will result in increased suicide rates.
As part of his Ph.D. research, Qi and his collaborators analyzed the socioenvironmental drivers of suicide rates in Australia over the last two decades, finding that variations in temperature, paired with spikes in unemployment, had a correlation to increased instances of suicide.
"What we found was that when the difference of the monthly average temperature in the current month compared with the previous one month increased by 1 degree [Celsius], there was a 3 percent increase in suicide in Brisbane and Sydney," Qi said in a statement.
Qi cited Sydney as an example, where the temperature difference between September and October (2.55 C) was 1.5 C higher than the difference between August and September temperatures (1.05 C). This revealed a 4.5 percent increase of suicide in October compared to September.
"Based on Australia's climate the high risk seasons for Brisbane and Sydney are spring and early summer, so it is therefore necessary to strengthen current monitoring systems on attempted suicide especially in areas with high unemployment rates," Qi said. "As global climate change and financial recession continue, it is vital to develop local interventions to reduce suicidal risk."
The rate of unemployment also correlated with increased suicides.
"For example a 1 percent increase in unemployment rate is associated with a 5 percent risk of higher suicide in Brisbane and Perth," Qi said. "In months with a higher unemployment rate, the temperature difference between adjacent months had more of a significant association with suicide in Brisbane compared with months with a low unemployment rate."
Qi's data do not suggest any reason for this correlation, but other studies have linked temperature to seasonal changes in physiological conditions of the body such as levels of serotonin - which is related to wellness and happiness.
"Even though Australia has suicide control and prevention plans, few consider the impact of environmental factors in suicide prevention programs," he said. "There needs to be more attention to the potential of increased suicide risks posed by climate change, especially in vulnerable groups like the unemployed or Indigenous communities."
Qi's full research thesis is available here.