A Cross-National Examination of the Effect of Temperature Change on Homicide Trends

• In Event: Exploring the Long-term Relationships Between Homicide, Politics, and the Environment.

Abstract

Abstract: Existing theories predict that higher temperatures are positively associated with homicide rates. Research, however, has found different relationships in locations with distinct temperature and development levels. This study explores this heterogeneity using cross-national data with a similar global scope as the effects of climate change.
Methods. Leveraging the rising temperature over the past decades and the variability of climates, we combined data for 108 countries between 1990 and 2018 and used fixed effects models to test whether temperature can account for variation in homicide trends over time.
Results. We found a negative quadratic relationship such that predicted homicide rates decline until a minimum mild temperature (around 17.5°C; 63.4°F) but increase exponentially thereafter. Furthermore, we found evidence of moderation such that wealthier countries with the resources to adapt do not experience changes in their homicide rates along with a rising temperature.
Conclusions. The impact of climate change on homicide rates depends on development and on temperature level. There is little impact on countries with mild climates, cold or wealthy countries may benefit, while poorer and warmers countries may experience homicide increases. The latter typically have higher homicide rates, limited resources, and contributed little to the emissions driving climate change.

Authors

• Mateus Renno Santos, University of South Florida

• Michael J. Lynch, University of South Florida