What drives the weather on earth

Does the weather drive people to suicide?

In spring, more people put an end to their own lives. Longer days give them enough drive to do such an act

Droughts and other extreme weather conditions increase suicide rates - but only indirectly

The eleventh month of the year has a bad reputation: The cold, wet November weather in our latitudes is suspected of causing gloomy moods and then making them unbearable. It does not seem absurd that the decision to put an end to one's life is also strongly influenced by certain weather factors. But this is where the argument among scientists begins: There are tons of studies looking at the relationship between weather and suicide frequency, but not all of them come to the same conclusion.

In certain forms of depression that are associated with suicidal intentions, the time of year does appear to actually play a role. "The connection has been clearly proven for Northern Europe," says Christina Koppe, medical meteorologist at the German Weather Service. “In the cold season of the year, the lack of light depression increases, but therapeutic remedies are possible.” If the missing rays of the sun are replaced with artificial UV light, the levels of anti-depressant vitamin D and melatonin remain stable. The mood does not drop dramatically.

But why do suicides worldwide reach a maximum in late spring, when the hours of sunshine increase? A low in winter, followed by an increase in the suicide rate in the warmer months, is shown by an overview study from the 1990s that compares industrialized and developing countries, mostly from the northern but also the southern hemisphere. Finnish, Belgian, Slovenian and British analyzes confirm the pattern, even from Inner Mongolia, Taiwan and Korea the seasonal suicide distribution is known, usually followed by a slight second increase in autumn.

"Depressed people tend to compare themselves with others whose upscale spring mood makes their own look even darker, and they feel deeper in the basement," says Koppe, summarizing the results of some studies, which above all contrast the moods more depressed with healthy people than theoretical Describe explanatory patterns. More sun has a stimulating effect, but the mood only improves after two weeks. Until then, however, the increased drive could lead to suicidal intentions being put into practice.

But there are also other reasons that scientists try to explain the lower suicide rate in inhospitable weather conditions. A Swiss study of 128,322 suicides from 1877 to 2000 underscores the clear connection between temperature and various types of suicide: In moderate weather, significantly more people who want to commit suicide jump from a high-rise or in front of a train than in cold weather, storms and rain. The so-called “lack of cold” hypothesis states that in the case of suicide attempts outdoors, very low temperatures tend to have an inhibiting effect.

It is of course always a complex web of all sorts of individual factors that directly and indirectly influence the suicide rate. Biological, physiological, and neurochemical processes are implicated, and the association of suicide with mental illness has been established. The influence of weather conditions seems indisputable, but anything but precise can be determined. After all, 1.8 percent of total global mortality can be traced back to suicides; in Germany around 10,000 people committed suicide in 2010, 75 percent of whom were men.

A study of 50,000 suicides in England and Wales between 1993 and 2003, published in the British Journal of Psychiatry in 2007, found an average temperature of 18 degrees Celsius - and every additional degree dropped the suicide rate over those ten years increase by four percent each time.

A study that was recently published in the American journal “PNAS” is looking for the causes of the dramatic increase in suicide rates during extended periods of drought. Ivan Hanigan of the National Center for Epidemiology and Public Health at the Australian National University took a closer look at suicide rates in rural areas of South Australia. Accordingly, the suicide rate rises to eight percent if there is 300 millimeters less rain than the average. Four fifths of them are men, most of them between the ages of 30 and 49. It is mostly farmers and farm workers who put an end to their lives - and so suicides are responsible for nine percent of all deaths in this age group. This proportion applies to the entire 38 years of the study period from 1970 to 2007.

"Suicide increases with high temperatures," summarizes Ivan Hanigan and expands the view of the causes beyond physiological or psychological findings. "A number of environmental factors influence mental health, and if the environmental conditions worsen, increasing rates of mental illness are to be expected." A connection between humidity and lack of concentration and fatigue is proven, and rising temperatures are associated with increasing crime rates, aggression and suicides.

"The results of these studies may be contradictory, but there is a consensus that extreme or unusually low and high temperatures are associated with mental problems," says Hanigan. "Global warming leads to the expectation that the level of aggression, suicides and hospital admissions will rise," he refers to a first American study on this connection, which was published in the Journal of the American Psychological Association in 1998. Long periods of drought with high temperatures cause financial stress for farmers and rural communities: interest rates rise, prices fall, exports fall.

Environmental deterioration is reflected in psychological stress, which increases sharply during the drought. Selling or killing hungry and thirsty animals, drying up fields, pastures, gardens or vineyards, which have sometimes been in the family for generations, are a burden for farmers and their families. "Men in particular are at risk," says Ivan Hanigan. In doing so, he is addressing a second major difference in suicide rates around the world. If only the weather were the trigger for suicides, both sexes would have to hit the same, because before the weather, men and women are the same. But far more men than women take their own lives.

For Australia, Ivan Hanigan suspects “that women can cope better with stress. They have better access to social support networks, have personal responsibility for their families and also for their depressed partners. They approach difficult times more pragmatically and show more resilience, ”he explains. Destroyed livelihoods, abandoned homeland, lost property, debts, social decline, disintegrating family groups and shrinking rural communities are direct consequences of climatic conditions that primarily affect agriculture and have particularly drastic effects on the eleven South Australian regions with already long periods of drought and high temperatures .

"Climate change is worsening the situation in rural areas," emphasizes Ivan Hanigan and believes that further increases in suicide rates are likely. The combination of less rain, greater evaporation, parched soil and huge crop losses damages agriculture - and threatens the people who live from it not only physically but also mentally.

Due to climate change, the trend of increasing warming and the shift of the low pressure systems in the direction of both poles in the world regions between the 25th and 40th degree of longitude could have dramatic consequences, which are not only reflected economically and socially, but also emotionally and socially - in the world regions between the 25th and 40th parallel, but also beyond.