A synthesis approach to investigate and validate carbon sources and sinks of a mega city of developing country

This study is a preliminary approach in estimating sectoral carbon dioxide (CO2) sources using actual energy use data from a mega city of developing country. The main objective of this paper is to estimate CO2 sources and sinks of the mega city and validate them through land cover/land use (LCLU) change analysis. For this purpose, a set of integration of multiple tools/models is utilized. Through this study, it was made possible to establish baseline information of energy use and CO2 emissions of the city. It is found through the analyses that use of multiple techniques/approaches produce a better picture of few but similar dimensions. It is also witnessed that CO2 sources have increased almost eight times of the city from 1971 to 2011. On the other hand, CO2 sinks are depleting day by day showing a share of almost 0% among the total sources and sinks classes estimated through CO2 sequestration method. In this way, it was also possible to get net CO2 emissions of the city. The forecast analysis portrays the same trends as well. Built-up area validated the CO2 sources increment in the city while sparse trees and grasses validated the CO2 sources related changes occurred from the past to present. Thus, it is suggested to the local policymakers of the city to ponder the unattended increment of the built-up areas in the city and put attention in increasing the green spaces such as trees, grasses, and plantation in the city.

► An integrated approach is utilized to assess CO2 sources and sinks nexus. ► Industrial sector is largest CO2 source in the city. ► Total CO2 sinks reduced from 35% to 12% since 1975–2011. ► Integration of models/tools helps in analyzing the various angles of an issue.