Observación espacial y análisis de la relación entre las emisiones atmosféricas de CO2 y el tamaño de las ciudades en Chile

Abstract

Urban growth rates have had an explosive development strongly impacting our planet’s life support system. Therefore, measuring and understanding the relationship between urban growth and greenhouse gas emission rates is essential to ensure the sustainability of the urban environment. More so if we acknowledge that 67% of the world’s population will live there by 2050. This article seeks, on the one hand, to establish the possibility of evaluating emissions from independent sources and, on the other, to describe the relationship between CO₂ emissions and the size of urban systems in Chile. CO₂ emissions and their anomalies for continental Chile were characterized using remote sensors (OCO-2). The bivariate relationship between CO₂ emissions declared in the local inventories of the Pollutant Emissions and Transfer Registry (RETC in spanish) and urban development indicators of 20 Chilean cities was also evaluated. Although it is possible to estimate CO₂ emissions from remote sensors on a regional scale, the low resolution and spatial coverage of valid data captured by the satellite limits the association of emissions to urban environments in Chile. However, the data declared in RETC show that emissions at the city level present a sublinear relationship for the three variables considered: Population (β=0.89; r²=0.73), Urban area (β=0.99; r²=0.74) and GDP (β=0.68; r²=0.55). These results coincide with descriptions available in the literature, and suggest that CO₂ emissions in cities of increasing size are associated with economies of scale in which urbanites share emission costs, as a result of greater efficiency in the use of infrastructure and services as the city grows in population, area and production. This ultimately translates into lower per capita emission rates.