Violence in hot weather: will climate change exacerbate rates of violence in South Africa?

Worldwide, violence claims more than 1.4 million lives each year, accounting for 1 in 40 of all deaths globally. Alarmingly, South Africa (SA) recorded a homicide rate of 35.8 per 100 000 people in 2017/18, which is the second highest rate in sub-Saharan Africa and among the top 10 in the world, including among countries at war. While violence in SA has been attributed to the unique historical, social and economic characteristics of the country, the potential contribution of physical environmental factors, such as heat, has largely been ignored. Understanding connections between heat and violence is increasingly important as we witness the warming of our planet, and anticipate more intense and longer-lasting heatwaves in the coming decades. Exposure to extreme heat is already common in many parts of SA; temperatures frequently exceed 40C in Northern Cape Province, for example, but can also reach those levels in areas with a more temperate climate, such as Johannesburg. In this editorial, we examine evidence on the connections between temperature and interpersonal violence, and consider the implications of these connections for SA.