Overview of the Research Paper
This paper integrates evidence from multiple sources to explore the intersection of physical activity and climate change. The research involved developing a conceptual model, conducting two scoping reviews, and performing a case study analysis to inform conceptual development.
PACC Conceptual Model Development
A multidisciplinary Group Model Building (GMB) process was undertaken to develop the Physical Activity and Climate Change (PACC) conceptual model.
Participants & Methodology
A core group of 7 experts developed the model, with a broader group of 8 distinguished researchers providing feedback. Participants were internationally diverse, with expertise spanning physical activity, public health, climate change, and systems science.
GMB was chosen for its foundation in systems science, allowing for the exploration of interconnections, feedback mechanisms, and potential unintended consequences associated with aligning physical activity and climate change agendas. Structured exercises identified variables and causal links, which were transcribed into a 'seed structure' and digitized using the Kumu platform.
Confidence-Building & Adaptations
The model underwent a 6-month iterative review process by group members and senior international experts to ensure the pathways were logical and sound. This rigorous process significantly enhanced the model's credibility.
The GMB process was adapted to suit the interdisciplinary and exploratory nature of the research. Initial discussions were seeded with a rough conceptual framework, and variable elicitation was broadened to include upstream climate factors. Conventional polarity notations were replaced with a narrative-based visualization to better capture complex interactions.
Final Conceptualization
The output was reframed as a conceptual feedback structure illustrating the dynamic and interconnected roles of physical activity strategies within the climate system, confirmed in October 2023.
Kumu Software Utilization
Kumu, an online visualization and systems mapping platform, was used to digitize and refine the causal loop diagrams generated during the initial GMB workshop. The software facilitated organizing complex information, visualizing relationships, and supporting the iterative co-creation and validation of the system maps.
Scoping Reviews on Built Environment and Active Transportation
Two parallel scoping reviews were conducted to investigate opportunities for simultaneously improving health and lowering greenhouse gas (GHG) emissions. These reviews focused on transport-related policies and interventions that encourage active transportation via the built environment.
Focus of the Reviews
The reviews concentrated on three built environment intervention groupings:
- Land-use mix
- Population and/or residential density
- Streetscape components (e.g., crosswalk/sidewalk improvements, traffic calming features).
Aims of the Reviews
The first aim was to identify studies reporting on the relationship between these built environment characteristics and active transport outcomes. The second aim was to identify studies quantifying the impact of these interventions on GHG measures.
Case Study: Extreme Heat's Impact on Bicycling in Denver, Colorado
A quasi-experimental case study was conducted to illustrate how extreme heat events influence physical activity patterns, using cycling data from Denver, Colorado, during June, July, and August 2022.
Data Sources
Daily maximum air temperature data were obtained from the National Oceanic and Atmospheric Administration. Bicycling data, representing the number of rides observed on street and trail segments, were sourced from Strava Metro.
Analysis
Days with measured air temperatures of at least 100°F (12 days) were classified as extreme heat ('treatment days'), while days with temperatures of 99°F or below (80 days) served as 'control days'. A linear regression model, fitted on control days, estimated daily bicycle distance ridden. This model then estimated counterfactual bicycle distance on treatment days had the temperature not been extreme, allowing for comparison with observed values to determine the effect of extreme heat. Bootstrapping was used to estimate uncertainty in the effect estimates.
Ethics Statement
The research did not require ethics approval. This determination was made after consultation with the institutional ethics office. The process did not involve identifiable personal information, behavioral interventions, or outcomes research, as no primary data were collected from individuals external to the research team. All contributors participated voluntarily and are acknowledged as co-authors.