Fig 1.
Upon identification of knowledge gaps and parameters affecting urban GHGs, the research methodology utilizes a mix of quantitative techniques (in analysing trends, correlations) and bibliometric/ systematic scoping techniques (in analysing urban CAPs).
Table 1.
The average variation of key urban indicators and GHGs of 41 megacities.
Fig 2.
Longitudinal assessment of population, affluence and technological contributions to megacities carbon footprint.
Fig 3.
The carbon emissions (in 107 tCO2) in 2012 plotted for 41 megacities across the globe.
These vary considerably by a factor of 129, from an abysmal 3.50 (Bogota) to 451.73 (Shanghai), the mean being 27.95 MtCO2. Image source: https://commons.wikimedia.org/wiki/File:World_map_blank_shorelines_semiwikimapia.svg, available under the Creative Commons Attribution 4.0 International (CC BY 4.0) License.
Fig 4.
Average megacity CO2 range by a factor of 129 between the maximal and minimal values, the residential emissions showing least variation while agricultural emissions showing the greatest range.
Fig 5.
Sectoral composition of carbon emissions in global megacities (per-capita and total- with percentage contribution).
Fig 6.
There is a strong correlation of megacity emissions with urban area and built-up area.
Fig 7.
Megacity’s per-capita emissions- transport and residential are strongly correlated with income.