So how do the UK's cities compare on factors such as air pollution, river water quality and other ecological factors? The charity 'Forum for the future' runs an annual check on British cities and has created a league table of the best and worst cities.
Plymouth comes out top and unsurprisingly, it is the big cities; London, Birmingham and Manchester that come out worse. See the full league table or a rundown of the top four followed by the worst four cities below.
The harbour city of Plymouth currently tops the list as the most environmentally-friendly city within the UK with particularly high ratings for air and water quality in comparison to the others.
Despite its reputation as an industrial town, Bradford scores highly for air and water quality showing that cities can improve their green rating with the right policies.
Equal third position with Sunderland, Cardiff has a slightly inferior air quality rating but scores highly in other categories. Another harbour city scoring highly.
Joint third with Cardiff, Sunderland is also a surprise entry considering its industrial heritage. But it has the best air quality of any city in the UK. So if you want clean, fresh air move to the North-East.
Birmingham got the fourth worst rating of any city in the UK with particularly bad ratings for water quality in comparison to other cities.
London, pictured here on a smoggy summer's day, was third worst with low ratings for air and water quality in comparison to other UK cities.
Second-bottom Manchester also scored low for air and water quality compared to other cities.
Bottom of the pile Leeds was rated the worst city in the UK on its environmental performance. The ranking of the England's four largest cities in the bottom four places is an indication that smaller cities such as Plymouth and Bradford currently offer the best location for people seeking a green and healthy life.