It takes just two dozen culprits to ruin it for the rest of us. A study published by Frontiers in Sustainable Cities wanted to keep an inventory of pollution and distribution of greenhouse gas emissions and it took 167 globally distributed cities as a “sample”. The chosen locations were mostly large urban areas from 53 countries in Europe, North America, South America, Asia, Africa, and Oceania.
Even though some locations are in developed countries and others in developing countries, both types have cities that emit high quantities of greenhouse gases and those were the cities the study focused on the most.
The results concluded that more than half of these emissions (52 percent) were produced by just 25 megacities, with cities in China topping the list, followed by some in Japan and Europe. Handan, Shanghai, Suzhou in China were found to be big polluters, along with Tokyo in Japan, Moscow in Russia, Istanbul (Turkey), Rio de Janeiro, Johannesburg (South Africa), and Venice (Italy). Major cities in the U.S., Korea, Germany, and Singapore also proved to be big emitters.
Emissions from fuel combustion, electricity use in both commercial as well as residential buildings contributed to up to 80 percent of all the emissions in the cities of North America and Europe. Over 30 percent of those came from on-road transportation in one-third of the cities, while railways, aviation, and waterways were responsible for less than 15 percent.
On the opposite side, we find cities such as Oslo (Norway), Houston, Seattle, Bogotá (Columbia) which proved to have the largest per capita reduction in emission levels during the study, which was conducted between 2012 and 2016.
The authors of the study consider their research very important as identifying these biggest polluters is a first step in tackling the problem and coming up with a mitigation plan. As a next step, researchers recommend working on achieving global carbon neutrality by 2050.