We all know warm weather can make us hot and bothered, but the dangers might be bigger than previously thought.
Wars, murders, and other acts of violence will likely become more commonplace in coming decades as the effects of global warming cause tempers to flare worldwide, a new study warns.
Hot climates with little seasonal variation cause us to put less focus on the future and behave with less self-control, leading to higher violence and aggression, say members of a research team from Vrije Universiteit in Amsterdam.
“Climate shapes how people live, it affects the culture in ways that we don't think about in our daily lives,” said Paul Van Lange, lead author and professor of psychology at Vrije Universiteit Amsterdam.
“We believe our model can help explain the impact of climate on rates of violence in different parts of the world.”
It’s not the first time global warming has been linked to violence. Previous studies back up the notion that rising temperatures could heighten aggression.
In 2013, scientists synthesised findings scattered across diverse fields ranging from archaeology to economics to paint a clearer picture of how global warming-related shifts in temperature and rainfall could fuel acts of aggression.
In all major regions of the world, the researchers found similar patterns of human aggression fuelled by climate factors.
Examples included spikes in domestic violence in India and Australia, increased assaults and murders in the United States and Tanzania, ethnic violence in Europe and South Asia, land invasions in Brazil, and police using force in the Netherlands.
"This study shows that the value of reducing [greenhouse gas] emissions is actually higher than we previously thought," said lead author Solomon Hsiang, an economist at Princeton University in New Jersey.
Brad Bushman, a psychologist at the University of Michigan who was not involved in the new report, notes that heat has the strange effect of upping physiological conditions—increasing heart rate, for example—while simultaneously making people think they are less energetic.
"The fact that hot people are more aroused but think they are less aroused means that they overreact to provocations."