52% of the world's greenhouse gas emissions come from just 25 cities
Source: World Economic Forum | Suzanna Burgelman, Science Writer, Frontiers
Despite covering just 2% of the Earth’s surface, cities are major greenhouse gas emission contributors.
25 mega-cities produce 52% of urban greenhouse gas emissions, according to a new study.
Although Asian cities emit the most greenhouse gasses, cities in Europe, Australia, and the US had significantly higher per capita emissions.
Of the 167 cities studied, 113 have set varying types of GHG emission reduction targets but just 40 have set carbon neutrality goals.
New research published by the open access publisher Frontiers inventories greenhouse gas emissions of 167 globally distributed cities. The study shows that just 25 mega-cities produce 52% of the greenhouse gas emissions from the studied cities. Asian cities emit the most greenhouse gasses (GHG), and most cities of developed countries had significantly higher per capita GHG emissions than those of developing countries. The authors propose three key policy recommendations.
In 2015, 170 countries worldwide adopted the Paris Agreement, with the goal limiting the average global temperature increase to 1.5°C. Following the agreement, many countries and cities proposed targets for greenhouse gas mitigation. However, the UNEP Emissions Gap Report 2020 shows that, without drastic and strict actions to mitigate the climate crisis, we are still heading for a temperature increase of more than 3°C by the end of the 21st century.
A new study published in the journal Frontiers in Sustainable Cities presents the first global balance sheet of greenhouse gasses (GHGs) emitted by major cities around the world. The aim was to research and monitor the effectiveness of historical GHG reduction policies implemented by 167 globally distributed cities that are at different developmental stages.
While only covering 2% of the Earth’s surface, cities are big contributors to the climate crisis. But current urban GHG mitigation targets are not sufficient to achieve global climate change targets by the end of this century. “Nowadays, more than 50% of the global population resides in cities. Cities are reported to be responsible for more than 70% of greenhouse gas emissions, and they share a big responsibility for the decarbonization of the global economy. Current inventory methods used by cities vary globally, making it hard to assess and compare the progress of emission mitigation over time and space,” says co-author Dr Shaoqing Chen, of Sun Yat-sen University, China.
Greenhouse gas emissions - key findings
1. The top 25 cities accounted for 52% of the total urban greenhouse gas emissions.
2. Cities in Europe, Australia, and the US had significantly higher per capita emissions than cities in developing areas.
3. Stationary energy and transportation were the two main sources of emissions.
4. Of the 42 cities that had time-series traceable data, 30 decreased the annual GHG emissions over the study period. Though in several cities, there was an increase in emissions.
5. 113 out of the 167 set varying types of GHG emission reduction targets, while 40 have set carbon neutrality goals.