Hot years and serious and deadly assault: Empirical tests of the heat hypothesis.

Abstract

Two archival studies examined the relation between year-to-year shifts in temperature and violent and property crime rates in the United States. Study 1 examined the relation between annual average temperature and crime rate in the years 1950-1995. As expected, a positive relation between temperature and serious and deadly assault was observed, even after time series, linear year, poverty, and population age effects were statistically controlled. Property crime was unrelated to annual average temperature. Study 2 examined the relation between the average number of hot days (> or = 90 degrees F) and the size of the usual summer increase in violence for the years 1950-1995. As expected, a positive relation was observed between number of hot days and magnitude of the summer effect, even after time series and linear year effects were statistically controlled. For property crime, the summer effect was unrelated to number of hot days.

Warming increases the risk of civil war in Africa

“…Finally, because economic welfare is the single factor most consistently associated with conflict incidence in both crosscountry and within-country studies (1, 2, 14-16), it appears likely that the variation in agricultural performance is the central mechanism linking warming to conflict in Africa. Yet because our study cannot definitively rule out other plausible contributing factors-for instance, violent crime, which has been found to increase with higher temperatures (22), and nonfarm labor Projections are for all of sub-Saharan Africa for 3 emissions scenarios, based on 10,000-run bootstrap of models 1 and 2 in Table 1 productivity, which can decline with higher temperatures (23)-further elucidating the relative contributions of these factors remains a critical area for future research.…”

Crimes of Opportunity or Crimes of Emotion? Testing Two Explanations of Seasonal Change in Crime

“…is not clear: while some studies have used 90 degrees Fahrenheit (Anderson, Bushman & Groom 1997;DeFronzo 1984;Rotton 1993), this has been criticized as arbitrary (Cohn 1990a). We sidestep this issue by focusing on the climatic patterns of communities and suggest that looking at the typical range of temperatures within a community can yield a clue to which of these theoretical mechanisms is at work.…”

The influence of weather on local geographical patterns of police calls for service

“…Some neighbourhoods are more vulnerable to assault through heat stress than others relatively coarse temporal unitsö for example, monthly, quarterly, or annual records (eg Anderson et al, 1997). Exceptions include the studies by Ceccato (2005), Van Koppen and Jansen (1999), Lab and Hirschel (1988), and Harries et al (1984), all of which used daily weather patterns in their analysis.…”