Majority of the major cities across the world have largely been able to decouple their economic growth from the use of polluting fossil fuels, but many large cities that are still dependent upon fossil fuels for their development are located in India, a new study has revealed.
The study analysed 5,435 cities globally over 2019–2024 and significant trends were identified for 2,475 cities. “We find that 80 per cent of these cities, mainly located in China, Europe and North America, enjoy relative decoupling, whereas 16 per cent, mainly located in India and the Middle East, experience fossil fuel-dependent growth,” the study stated.
Undertaken by seven researchers from Norwegian Institute for Air Research (NILU), Norway, Tohoku University, Japan and Aalto University, Finland, the study was published in Nature Cities, a peer reviewed international journal, on May 11.
Pointing out that urban areas are at the heart of the global economy and central to the sustainable development trajectory of the world, the researchers observed that today, more than half the global population resides in cities but rapid urbanisation and economic growth often come at the cost of increased air pollution, greenhouse gas (GHG) emissions and ecological degradation, raising questions about the compatibility of growth with environmental sustainability.
“As cities and metropolitan regions account for 60 per cent of global gross domestic product generation and 70 per cent of GHG emissions, city-level policies will be essential for decoupling growth in prosperity from growth in associated environmental impacts,” the researchers said.
“In response to climate change and increasing environmental pressures, the global community has embraced the goals of green growth and zero emissions. These aim to decouple economic growth from worsening environmental impacts. Green growth describes a situation where increased productivity, reduced poverty and well-being are achieved with reduced environmental impact,” they added.
During the study, the cities were classified into four categories – ‘Green’ that were cleaner and richer with declining pollution and increasing GDP; ‘Brown’ that were dirtier but richer with increasing pollution as well as increasing GDP, ‘Grey’ that were cleaner but poorer with declining pollution as well as declining GDP; and ‘Red’ that were dirtier as well as poorer with increasing pollution and declining GDP.
The researchers found that the Middle East, Central Asia and India had the highest number of cities with significant nitrogen dioxide (NO2) and Tropospheric Vertical Column Density (TVCD) increase. TVCD is the total amount of a specific trace gas located in an atmospheric column directly above a particular area. Over 15 per cent of survey cities in India having a population of 1,00,000 showed a significant increase in NO2 and TVCD factors.
About 35 per cent of the cities that fell into the ‘Brown’ category were concentrated in India, the highest proportion in this group that included urban centers where economic expansion is being fueled by sectors closely tied to fossil fuel consumption and urban sprawl, such as automobile-dependent transport, heavy industry and fossil fuel-based electricity generation.
Of the 18 cities, accounting for one per cent of the overall survey, cities that fell in the ‘Red’ category, two are in India that came below Iran, Libya and Angola. These cities show rising NO2 TVCD levels, which could be related to diesel generators, traffic growth and unregulated industrial activity, while GDP declined or remained stagnant, the study said.
