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

Associations between violent crime inside and outside, air temperature, urban heat island magnitude and urban green space

There are more incidents of violence in summer and on hot days, a trend likely to be exacerbated by climate change. Urban areas experience additional temperature modulation due to the urban form, however, to date, no studies have considered the effect of the urban heat island (UHI) or green space with respect to the temperature-violence relationship. This study modelled the relationship between the number of daily violent crime incidents that occurred inside or outside between July 2013 and June 2018, and the average surface UHI or percentage greencover (including grasses, shrubs and trees) within each local government area in Greater Sydney, Australia. Panelised negative binomial time series regression models indicated that the violent crime rate was associated with higher surface UHI for crimes committed outside (p = 0.006) but not inside (p = 0.072). Greater percentage of all vegetation was associated with significantly lower rates of violent crime committed outside (p = 0.011) but was not associated with violent crimes committed inside (p = 0.430). More socio-economic disadvantage was associated with higher rates of violent crime committed inside (p = 0.002) but not outside (p = 0.145). Greater temperature was non-linearly associated with higher rates of violent crime committed both inside and outside (p < 0.001). The findings of this study are important because both violence and heat exposure are critical health issues and will be stressed by urbanisation and climate change. The expansion of green space and/or reduction in UHI may mitigate these effects.

Seasonal patterns in newborns' health: Quantifying the roles of climate, communicable disease, economic and social factors

Poor health at birth can have long-term consequences for children's development. This paper analyses an important factor associated with health at birth: the time of year that the baby is born, and hence seasonal risks they were exposed to in utero. There are multiple potential explanations for seasonality in newborns' health. Most previous research has examined these in isolation. We therefore do not know which explanations are most important - and hence which policy interventions would most effectively reduce the resulting early-life inequalities. In this paper, I use administrative data to estimate and compare the magnitudes of several seasonal risks, seeking to identify the most important drivers of seasonality in the Northern Territory of Australia, a large territory spanning tropical and arid climates and where newborn health varies dramatically with the seasons. I find that the most important explanations are heat exposure and disease prevalence. Seasonality in food prices and road accessibility have smaller effects on some outcomes. Seasonal fertility patterns, rainfall and humidity do not have statistically significant effects. I conclude that interventions that protect pregnant women from seasonal disease and heat exposure would likely improve newborn health in the Northern Territory, with potential long-term benefits for child development. It is likely that similar impacts would apply in other locations with tropical and arid climates, and that, without action, climate change will accentuate these risks.

Violent assault geographies in northeastern Australia

As climate change produces more extreme weather, it is increasingly important to understand the impacts of these changes on social behaviour. The relationship between weather and crime has been studied across numerous contexts. However, few studies examine the correlation between weather and violence in southern, non-temperate climates. In addition, the literature lacks longitudinal research that controls for international changes in crime trends. In this study, we examine over 12 years of assault-related incidents in the state of Queensland, Australia. Controlling for deviations in trend for temperature and rainfall, we explore the relationship between violent crime and weather across Köppen climate classifications. Findings provide important insight into the impact of weather on violence across temperate, tropical, and arid climate regions.

Extreme climate and crime: Empirical evidence based on 129 prefecture-level cities in China

Climate change is having profound effects on natural and socio-economic systems, especially via extreme climate events. Using panel data from 129 prefectural-level cities in China from 2013 to 2019, this paper explores the effects of extreme climate on crime rates based on a climate index and manual collection of crime data. The results showed that extreme climate has a significant positive effect on crime rates, increasing by 0.035% for every 1% increase in the extreme climate index. This occurs through two mechanistic pathways: reduced agricultural output and lower employment income. The heterogeneity analysis shows that extreme climate has a greater impact on crime rates in eastern areas which are economically developed and have high levels of immigration. This study provides new perspectives on the impact of extreme climate on the economy and society, in which governments can actively participate in climate governance through environmental protection, energy conservation and emission reduction, and technological innovation to reduce crime rates by reducing the occurrence of extreme climate.

Blowing in the wind? Testing the effect of weather on the spatial distribution of crime using Generalized Additive Models

Oslo, the capital of Norway, is situated in a North European cool climate zone. We investigate the effect of weather on the overall level of crime in the city, as well as the impact of different aspects of weather (temperature, wind speed, precipitation) on the spatial distribution of crime, net of both total level of crime, time of day and seasonality. Geocoded locations of criminal offences were combined with data on temperature, wind speed, and precipitation. Generalized Additive Models (GAMs) allowed us to map level of and the spatial distribution of crime, and how it was impacted by weather, in a more robust manner than in previous studies. There was slightly more crime in pleasurable weather (i.e. low precipitation and wind speed and high temperatures). However, neither temperature, precipitation nor wind speed impacted the spatial distribution of crime in the city.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s40163-022-00171-2.

A tested method for assessing and predicting weather-crime associations

Few studies have focused on haze as a weather element and its correlation with crime. In this study, we examined haze as a weather variable to investigate its effects on criminal activity. We used both monthly crime data and weather records to build a regression model that contains a sequential statistical approach to reach the correlation coefficients between the variables. Also, we developed a prediction model to predict crime cases considering three weather factors: temperature, humidity, and haze. We applied this model in two different climate provinces in Saudi Arabia, namely, Riyadh and Makkah. Riyadh is a desert area and observes haze approximately 17 days per month on average, while Makkah is a coastal area observing haze an average of 4 days per month. We found a measurable relationship between each of these three variables and criminal activity. We found that a one-degree increase in temperature was associated with an increase in assault of 0.739, when humidity and haze were held constant. For other independent variables measured against the same crime in Riyadh, a one-degree increase in humidity was associated with a 0.164 increase in assault. An increase in the number of times that a haze phenomenon is observed was associated with an increase of 0.359 in assault cases. Haze had the most effect on theft, drug, and assault crimes in Riyadh compared to the other elements. Temperature and humidity have a significant relationship with crime in Makkah, while haze had no significant influence in that region.

Violent crimes and homicide in New York City: The role of weather and pollution

This paper studies the effect of weather and air pollution on violent crimes and homicide. We use all crimes committed in New York City between 2006 and 2020 and match each individual crime to the measures of the nearest weather, pollution station respectively. Our results show that neither weather nor pollutants have a contemporaneous effect of on homicide. In contrast, higher concentrations of carbon monoxide increase violent crimes in a U-shaped relation, that more rainfall linearly reduces violent crimes, and that sulphur dioxide has an inverted-U shaped relationship with violent crimes. Our results have implications for policing and environmental regulation.

The association between weather and crime in a township setting in South Africa

The association between various meteorological parameters and crime is well-established in developed contexts. In contrast in this study, we investigated the association between three weather parameters (temperature, relative humidity and rainfall) and three categories of crime in the developing township of Khayelitsha, in the Western Cape Province of South Africa. Distributed lag non-linear modelling was used to identify temporal relationships between temperature, relative humidity and rainfall, and violent, property and sexual crime over a 10-year period (2006-2016). We found hot days (defined as [Formula: see text] 25 °C) increased the cumulative relative risk of violent crime by up to 32% but were also found to be associated with a lagged increase in violent crime for at least a week thereafter. On very cold days (defined as [Formula: see text]), the cumulative relative risk of property crime increased by up to 50% whereas on very rainy days (defined as [Formula: see text]) the risk of property crime surprisingly increased by 40%. These findings provide some additional evidence for the relationship between the atmospheric environment and human behaviour in a developing context.

Temporal Variability of Theft Types in the Historic Centre of Porto

Criminology theories imply that time is a relevant variable, especially for the prevention and intervention of criminal occurrences. Thus, the study of criminal temporal patterns has been described as being of great relevance. The present study focuses on describing and exploring the influence of temporal and seasonal variables on the occurrence of different types of theft in the Historic Centre of Porto through the analysis of official records of the Public Security Police. Significant differences were found regarding the time of day and season of occurrence, even though it is not observed for all the types of theft analysed. Overall, theft was more prevalent at night and less frequent during winter, which is congruent with previous literature and the routine activity theory. Being the first case study in Porto city, Portugal, this research may be of extreme importance for both designing prevention and intervention policies in the area, and for inspiring future research on a criminal time analysis.

Impacts of climate variations on crime rates in Beijing, China

Previous studies suggest that climate variability and change impact both violent and property crimes. To investigate the mechanism, time series of crime rates (crime incidents per million people) and climate variables (temperature, relative humidity, rainfall, wind speed and haze) are decomposed into three components- long-term trends, seasonality and daily variations (or "noise"). Based on a 12-year dataset of daily crime (robbery, minimal violent robbery (MVR), assault, rape and homicide) numbers in Beijing, China, the correlation between climate variability and crime rate is examined for each component. The results show that in terms of seasonality, strong positive relations are observed for temperature-to-MVR, temperature-to-assault, temperature-to-rape, and relative-humidity-to-MVR but negative relations for haze-to-MVR, haze-to-assault, and haze-to-rape, which can be explained by Routine Activity Theory. In terms of daily variations, temperature, rainfall and haze are key factors. The correlations are all positive for temperature-to-assault, temperature-to-rape, temperature-to-homicide, rainfall-to-MVR, rainfall-to-robbery and rainfall-to-homicide. However, the relations between haze and crimes are more complicated. Specifically, the correlations are negative for haze-to-MVR and haze-to-robbery, but positive for haze-to-homicide, which can be interpreted by Crime Pattern Theory and also influenced by offenders' bounded rationality.

Hot and bothered? Associations between temperature and crime in Australia

Temperature and crime is one of the most extreme relationships between the atmospheric environment and human behaviour, yet our knowledge about it is primarily based on Northern Hemisphere research. This study used both temporal and spatial models to investigate the relationship between temperature and crime in New South Wales (NSW), Australia, using an 11-year data set. Results suggested that assault and theft counts were significantly higher in summer than winter (17.8 and 3.7%, respectively), while fraud counts were not significantly different. Using linear and quadratic terms for maximum daily temperature, a linear regression model indicated that daily assault counts significantly increased with rising temperature and the rate of increase slowed as temperatures exceeded 30 °C. Theft counts significantly increased with rising temperature then declined as temperatures exceeded 30°C. Again, there was no evidence of a relationship between temperature and frequency of fraud count. Spatial modelling revealed that 96% of local government areas (LGAs) in NSW had a higher summer assault rate than winter. The findings of this study provide an empirical foundation for understanding crime-temperature relationships in Australia.

Impact of climate variability and change on crime rates in Tangshan, China

Studies examining the relation between climate and human conflict often focus on the role of temperature and have diverging views on the significance of other climatic variables. Using a 6-year (from 2009 to 2014) dataset of crime statistics collected in a medium size city of Tangshan in China, we find strong, positive correlations between temperature and both violent and property crimes. In addition, relative humidity is also positively correlated with Rape and Minimal Violent Robbery (MVR). The seasonal cycle is a significant factor that induces good correlations between crime rates and climatic variables, which can be reasonably explained by the Routine Activity theory. We also show that the combined impacts of temperature and relative humidity on crime rates can be reasonably captured by traditional heat stress indices. Using an ensemble of CMIP5 global climate change simulations, we estimate that at the end of the 21st century the rates of Rape (violent crime) and MVR (property crime) in Tangshan will increase by 9.5±5.3% and 2.6±2.1%, respectively, under the highest emission scenario (Representative Concentration Pathway 8.5). The gross domestic product (GDP) is also shown to be significantly correlated with MVR rates and the regression results are strongly impacted by whether GDP is considered or not.

Impact of drought on crime in California: A synthetic control approach

Climate and weather have been linked to criminal activity. The connection between climatological conditions and crime is of growing importance as we seek to understand the societal implications of climate change. This study describes the mechanisms theorized to link annual variations in climate to crime in California and examines the effect of drought on statewide crime rates from 2011–2015. California has suffered severe drought since 2011, resulting in intensely dry winters and several of the hottest days on record. It is likely that the drought increased economic stress and shifted routine activities of the population, potentially increasing the likelihood of crime. We used a synthetic control method to estimate the impact of California’s drought on both property and violent crimes. We found a significant increase in property crimes during the drought, but no effect on violent crimes. This result was robust to several sensitivity analyses, including a negative control.

Visualization-Based Decision Tool for Urban Meteorological Modeling

We present a visualization-based decision tool that enables exploring the link between urban land use and urban weather, in particular predicting and visualizing changes in urban temperature, precipitation, and humidity. Our work combines recent work from urban planning, weather and climate studies, and visualization and computer graphics. Our approach uses an interactive tool to produce quickly and automatically plausible detailed 3D city models by means of a hybrid computational simulation of urban behavior and procedural urban geometry. From the city model, urban morphology parameters are efficiently computed and used by our custom meteorological simulator which considers the influence of the urban landscape. The result is a compelling visualization ability for understanding the complex feedback between urban land use and the regional meteorology of current cities and of potential future cities with desired greening patterns. Our work includes a case-study example spanning a 1600 km2 area.