According to a recently published study by Dan Hoornweg, a lead urban specialist at the World Bank, Rotterdam is one of the "dirtiest" cities in the world. The European city releases around 29,8 tonnes of greenhouse gas emissions per capita every year and as a result Rotterdam gets a top position among the 100 different cities examined.

The study looks at how much CO2 and methane emissions the citizens and the industries inside the city borders generate every year. Hoornweg and the other co-authors base their study on 100 different cities from 33 different countries around the world. The study, titled "Cities and greenhouse gas emissions: moving forward", shows that the emissions varies greatly between poor and rich cities around the world. The per capita greenhouse gas emissions vary with more than 15 tonnes in wealthy industrialized cities such as Sydney, Calgary, Stuttgart and several major US cities to less than half a tonne in poorer cities such as Nepal, India and Bangladesh.

According to the study the top 9 "dirtiest" cities in the world are: (1) Rotterdam in the Netherlands with 29,8 tonnes per capita, (2) Austin in USA with 24 tonnes, (3) Denver in USA with 21,5 tonnes, (4) Washington DC in USA with 20 tonnes, (5) Minneapolis in USA with 18 tonnes, (6) Calgary in Canada with 18 tonnes, (7) Menlo Park in USA with 16 tonnes, (8) Dallas in USA with 15 tonnes and (9) Stuttgart in Germany with 12 tonnes per capita.

This study helps strengthen activists calls for "climate justice" to help stop the huge inequality between rich and poor nations that fuels a climate of mistrust and sabotages efforts to secure a climate deal.