Islington won second place in the new University of Sheffield survey, which ranked 68 councils across the UK with populations of at least 100,000, based on their tree cover, vegetation and the presence of parks.
The north London borough was beaten only by Exeter, who took it to first place.
It beat leafy Bristol, Bournemouth and Cambridge, which came third, fourth and fifth respectively.
The capital did well overall – with Chelsea in sixth, Ealing in seventh and Richmond in ninth.
Meanwhile, Glasgow came last, as the smallest green city center in Great Britain.
It was followed by Leeds in penultimate place, with Liverpool, Sheffield and Middlesborough making up the bottom five.
The researchers said their findings, published in the peer-reviewed scientific journal Plos One, “reveal a clear divide” between the greenest urban centers in southern England and the lowest-scoring former industrial cities in the north.
Dr. Paul Brindley, senior author of the study from the University of Sheffield’s Department of Landscape Architecture, said: “By 2050, almost 70% of the world’s population is expected to live in cities.
“Green spaces have been shown time and time again to boost human well-being and are essential for biodiversity, but no one has ever looked at how green our city centers are, despite the amount of time individuals spend in them on a daily basis.
“The fact that all five of the greenest city centers are in the south of England, while the five city centers with the least green characteristics are in the north of the UK, clearly underlines the need to urgently improve the greenness of the city centers at the bottom of the list and to ensure that local authorities take action to close the gap.”
To determine vegetation cover, the researchers used a measure known as the normalized vegetation index (NDVI) using satellite observations of light absorption and reflection.
The team also looked at tree cover and the presence of green spaces.
Sheffield is often cited as being Britain’s greenest city in general – with more trees per person than any city in Europe. But the researchers pointed out that its center lacks green spaces due to its industrial heritage.
“This highlights why the study is so important and the crucial need to identify green space inequalities even in the least obvious places and promote measures to address them,” added Dr. Brindley.
“For example, work is already underway in Sheffield city center to bring it in line with the green suburbs and large parks just a short walk away from the heart of the city, making it the greenest overall in the UK.”