Citizens in Bengaluru are gearing up for another fight against the government over a steel flyover that has been proposed to connect the heart of the city to the airport. While the National Green Tribunal is still hearing arguments in the case, the city’s municipal authority, the Bruhat Bengaluru Mahanagara Palike has indicated that it will start preparations for building the flyover by cutting down 112 trees in Jayamahal, a neighbourhood close to the city-end of the flyover. Citizens across the city are busy signing petitions and sending in written objections to the BBMP to stop the action.

The proposed flyover will be 6.7 km long, is estimated to cost Rs 1,791 crores and will use 55,000 tonnes of steel. What has citizens most worried is that the work will mean that hundreds of mature trees that are at least a few decades old will have to be cut down. Various government reports estimate that between 812 and 1,668 trees belonging to 45 species will be felled. But a conservative independent study by researchers from Azim Premji University reveals at least 2,244 trees from 71 species will have to be brought down in order to build this steel structure.

Given the way infrastructure projects in the city unfold, it is safe to assume that this steel flyover will cost more than estimated, take longer to build and will take down more trees than estimated.

The main aim of the steel flyover is to ease traffic and to quicken the ride to Bangalore’s new airport. But critics say that the monetary and environmental costs of the flyover are not worth gains in traffic time – saving 10 minutes of a two-hour journey for most residents.

Is this really worth cutting a few thousand trees? Many people shrug and say that these “sacrifices” have to be made for “development’”. Others have gone out on the streets to protest against tree cutting on this massive scale.

For the most part, city dwellers know trees are good but have a not-in-my-backyard approach to them. “Trees are dangerous, they can fall on your car in the rains.” “Trees are nice and all, but we need wider roads.” “Because of the trees, I cannot see the road as it blocks the streetlight”. These are typical excuses to justify chopping trees.

First, let us state the obvious. Trees produce oxygen. They prevent soil erosion. And trees, well, look nice.

Summer is not here yet and Karnataka is already struggling to source water. Like every year in the recent past, Bengaluru’s lakes will soon start drying up and its groundwater will start to fall. Trees produce rain and contribute to about half of the water cycle.

Recent scientific research shows that the benefits of having lots of tree cover in a city, or indeed anywhere, are far greater than these obvious reasons above.

What science says

Trees heal. It may seem like common sense to say fresh breezes, beautiful gardens and sunlight is good for us but research has shown on many occasions that well designed hospital gardens or even views of trees help patients heal faster and with less complications. Children with ADHD have fewer symptoms when exposed to nature. Neighborhoods and homes with trees have fewer incidents of aggression and violence than homes with no or barren gardens. This was especially noted in a study by the Chicago public housing development. There are also strong indications that motorist road rage is less in green urban versus treeless areas.

A study from Toronto, Canada shows that having 10 more trees in a city block, on average, improves health perception in ways comparable to an increase in annual personal income of $10,000 and moving to a neighbourhood with $10,000 higher median income or being 7 years younger. Trees around schools also correlate to attention and memory. Trees contribute to lower asthma rates, mortality rates and birth defects by removing air pollutants

Trees affect microclimate of localities in ways that save money. A study by a Bengaluru environmental research trust showed that trees change microclimate so much that having trees on the road around a building can reduce air-conditioning and cooling costs by as much as 30%. Meanwhile, the presence of trees increases property values with most buyers opting to live in greener neighbourhoods. Studies have shown that the more trees and landscaping a business district has, the more business will flow in. Trees cut out dust and ambient noise – a tree makes a considerable difference to local environment by absorbing dust and noise

Trees provide habitat for countless birds, small animals and insects all vital to the our ecosystem, even in a crowded urban environment like Bengaluru.

How much are some of these benefits worth? A study of Tampa’s trees estimated that they save the city nearly $35 million a year in reduced costs for public health, storm water management, energy savings, prevention of soil erosion and other services. Surely, all this is worth more than of a shorter ride to the airport.