I usually ignore Whatsapp fowards, given their dubious reputation for misinformation and worse. But when I got one that urged me to object to a harebrained plan to rip out 112 of Bangalore’s oldest trees and destroy a grand, green canopy in the city’s heart to widen a road, I forwarded away to everyone I knew.

The forward, which went viral within a couple of days – it came back to me from every local group I was on, from the neighbourhood residents’ association to my daughter’s school crowd – quoted an assistant conservator of forests as saying that objections from “public, public institutions and people’s representatives for removal of the 112 trees… may be registered along with valid reason and supporting documents either through e-mail acfsubdivision1bbmp@gmail.com or through phone (9480685381) within a period of 10 days”.

The notice was plucked from the obscurity of a government website by some alert citizen and propelled through social media into local newspaper headlines. With officials silent, reporters, scientists and worried citizens dug up details and joined the dots to reveal how the Congress’ last government in a major state is trying its best to destroy living conditions in a city that is at already at an ecological precipice.

In particular, two things were revealed. One, the government’s public notice was a charade. Not only did it quote the officer concerned as saying he had found “the removal of these trees is very much necessary (sic) for taking up the work of widening the Jayamahal Road” – which meant the government’s mind was made up and the invitation for objections was a sham – but the section of law he quoted did not exist (more on that later). Two, it soon emerged that these 112 trees were part of a larger plan to rip out 1,668 of the city’s oldest trees for the elevated, steel road, currently stayed by the National Green Tribunal.

In October 2016, I wrote about the devastation this 6.7-km-long road would cause, but I – like so many others – had underestimated the destruction. It was Harini Nagendra, a professor of sustainability at Bangalore’s Azim Premji University, who informed a stunned citizenry last week that, not 1,668, but 2,244 trees and 205 saplings from 71 species and 26 families, would be lost. And this, she said, is a conservative estimate.

From each tree, the big picture emerges

How did Nagendra arrive at these numbers? By counting each tree. With colleagues Seema Mundoli and Vijay Nishant, Nagendra checked each tree on the route of the elevated road and its ramps and wrote this paper. Its contents reveal, in the clearest detail yet, what Bangalore will lose – if the government has its way.

“We found large sacred trees like the peepal (Ficus religiosa), keystone species with important biodiversity benefits like the fig, and economically important species like red sanders (Pterocarpus santalinus) and mango (Mangifera indica),” wrote Nagendra, Mundoli and Nishant. “Further, there are several massive rain trees (Albizia saman), African tulips (Spathodea campanulata) and copper pods (Peltophorum pterocarpum) – these have very large canopies, provide shade and reduce pollution, and harbor many of the local birds, insects and wildlife species, as also indicated by the nests that we observed on some of them. From the sizes of these trees, it is clear that many of them are several decades old, and some of them are very old and extremely large in size. Cutting these trees will have major impacts on biodiversity, air pollution and temperature in this area.”

In past studies, Nagendra and her colleagues have precisely detailed these impacts. Trees in Bangalore reduced particulate matter – microscopically fine particles from vehicular exhaust, roadside and construction dust and factories – by up to 75% on roads, reducing a variety of serious health impacts. Trees, the studies revealed, also reduced ambient air temperatures on Bangalore roads by as much as 5.6°C and surface temperatures on asphalted roads by up to 27.5°C.

“Cutting trees on these roads for the proposed projects will mean an irreversible loss of this free temperature regulation provided by nature even as temperatures in Bengaluru are soaring every year,” wrote Nagendra, Mundoli and Nishant. “In April 2016, Bengaluru recorded its hottest summer in 85 years with the temperature rising to 39.2°C.”

With such warning, Bangalore’s politicians might at least agree to debate an elevated road that is only likely to somewhat speed up one route to the airport – not coincidentally, benefitting the area where most politicians live and work – at the cost of permanent ecological damage.

Instead, as scientific evidence galvanised the media and citizens, a suporter of Karnataka’s chief minister, Siddaramiah, took to Twitter to admonish Nagendra. This handle often reflects what the chief minister has already said. For instance, the chief minister claimed that the municipal corporation planted a million saplings in 2015 and 2016.

Karnataka's Water Resources minister @reachmbp is on a mission to plant 1 crore trees. Please work with him instead of stalling development. https://t.co/NePE5E79hU — Siddaramiah For CM (@Siddaramiah4CM) February 7, 2017

But if his government’s record is any indication, these 1 crore trees – 10 million – may never be planted, or may not survive if planted, or, in the unlikely scenario that they are planted and survive, they may be of little use to the city.

“Previous experience with compensatory plantation of trees in Bengaluru does not give us much confidence that this replantation will be conducted, or that it will result in the survival and growth of a majority of the saplings planted,” wrote Nagendra, Mundoli and Nishant. “If this were to be the case, the tens of thousands of trees that have been cut in Bengaluru over the past decade or so should have been replaced with millions of trees, resulting in a substantially greener city by now.”

A tree-lined street in Bangalore.

The search for ghost trees

Bangalore’s impending, great tree-chop is particularly destructive, but every Indian city is losing its trees, lakes and open spaces.

As roads, concrete expanses and closely spaced multi-storeyed buildings – often in violation of zoning and setback laws – take over Indian cities, they are turning into “heat islands”, according to this IndiaSpend review of scientific studies in five cities.

The diurnal temperature change – the difference between the daytime maximum and nighttime minimum daily temperature – my colleague Max Martin reported last year, is declining in five cities studied: Delhi, Chennai, Guwahati, Thiruvananthapuram and Kochi. This indicates that steadily concretising cores of cities and rapidly urbanising outskirts are retaining heat more deeply than ever. In Bangalore, these outskirts have lost great masses of trees, but no one knows how many: Estimates of trees brought down in India’s Silicon Valley since the turn of the century range from 55,000 to 200,000.

Think of the city’s now threatened core as one of Bangalore’s last harbours of hope.

Siddaramiah and his colleagues in the Congress clearly do not see it that way. Their only solution, as tweet indicates, is that trees must be cut for development and thousands more – 20 for each one cut is the standard response – will be planted “elsewhere”. The problem is, the government does not know where “elsewhere” is.

I asked a forest official, who requested anonymity given the government’s sensitivity, how many trees had been planted since the turn of the century, which is when Bangalore’s began to sprawl upwards and outwards. Could I see the records of these tree plantations?

“You see, the problem is, there are no such records,” said the official. Various agencies – such as the municipal corporation, the Bangalore development authority, the Bangalore Metro – have been cutting trees and, supposedly, planting many more, but no one can take you to a tree-plantation site and tell you which trees were planted to replace the giants brought down.

I asked Nagendra, who is preparing to document what she calls “ghost trees”, if she knew when these so-called mass plantations began.

“Good question,” she said. Perhaps 2002. Perhaps 2004. Perhaps before. The problem was the same: No one really knew. When she asked various government agencies to see some of the new trees, the answers were always vague: Near this lake, in this army area (which means it’s even harder to verify), by that road side. One of the more organised agencies is the Metro, but even they were not clear about their tree-planting because it’s all outsourced. “All you have,” said Nagendra, “is some vague document that says so much money was spent.” How many of these trees survive? The answer – depending on who she asked – ranged from 20% to 90%.

Keeping a record of trees is not rocket science. The world’s most liveable cities do it. Local governments do it or support it, and some Indian cities have started. “In this day and age, you should have geo-tagging,” said Nagendra, referring to the process of adding geographical information to any data. Ideally, the government should geo-tag trees, conduct a census and plant more trees – not vaguely throw down seeds wherever there is space and forget all about it.

What trees can do for a city

There is a pile of scientific evidence that shows trees reduce pollution, save lives, sequester carbon, cool cities in general, and the area around them in particular, and serve as an urban refuge for birds and animals. Some of the trees marked for destruction, for instance, have been found to host populations of the slender loris, a wide-eyed, cuddly primate. One turned up in a school locker a few months ago, enthralling the city before it returned to the high canopy.

In brief, trees make a city more liveable.

Bangalore is a case study of what not to do in a country rapidly and chaotically urbanising in a manner that threatens the quality of life and health of its citizens. “But urbanisation doesn’t have to create a health crisis,” Pascal Mittermaier, Global Managing Director, Cities, of the Nature Conservancy, an advocacy, wrote recently in a blog. It is clear, he said, what municipal leaders must do: Plant more trees.

Mittermaier said that when he had the “dubious fortune” of visiting Mumbai in the broiling summer of 2016, the temperature was 40°C for days, but “the difference between standing in the shade of a tree and standing in full sunlight was like night and day”.

So, can we identify where trees should be planted? Can we calculate their air-quality and carbon-sequestering benefits; what will specific benefits cost a city; what is the return on investment? Is it possible to answer these questions?

Yes, it is.

In 2016, the Nature Conservancy released a 136-page report called “Planting Healthy Air”, the first global arboreal cost-benefit analysis for 245 cities, including Delhi, Mumbai and Ahmedabad, which, the report said, were among the top 10 cities globally that could derive the greatest pollution- and heat-mitigation gains of planting trees. The Nature Conservancy collected geospatial information on population density, tree cover and PM 2.5 levels (the globally accepted marker for air pollution), and used scientifically established relationships to estimate how many trees were required now and in future to clean the air in these cities.

The study by Nagendra, Mundoli and Nishant also emphasised and calculated the carbon-sequestering benefits of retaining the 2,244 trees marked for destruction. Older trees, they noted, absorb more carbon from the atmosphere than young ones. This carbon is stored in tree trunks, roots, leaves and leaf litter. So, 2,176 trees – they could not calculate the biomass, or carbon stored in trees, for 68 – along the length of the elevated road and its ramps stored 257 metric tonnes of carbon. Carbon storage is especially important at a time when Indian cities are growing their carbon footprint, along with other greenhouse gases. As this 2014 study by researchers from three Indian institutes shows, Delhi is India’s largest emitter of greenhouse gases, followed by Greater Mumbai, Chennai and Greater Bangalore.

Many cities across the world, the Nature Conservancy report noted, are struggling to maintain their current stock of street trees. Their calculations emphasise the importance of investments to maintain this stock – in many cities, there are opportunities to increase tree cover – to control air pollution and summer heat and save lives. Many Indian cities were identified with potential to receive the highest return on investment from tree plantation, to become cooler and less polluted.

A key point: While other control measures such as mass transit, cleaner smokestacks help, trees provide “meaningful but locally concentrated reductions in PM and temperature, with the majority of mitigation generally within 300 metres of planting”. This means there must be people and buildings near the trees if their benefits are to be of greatest use. Even if we presume that all or many of Bangalore’s ghost trees are real, that they exist in areas unknown to scientists and citizens, these trees are, largely, useless.

In October, hundreds of Bangalore residents formed a human chain to protest against the proposed steel road.

The trees that have the greatest effect on cooling and pollution reduction are those that form canopies, such as the ones that Siddaramiah’s government wants removed. “As you move away from a canopy, temperatures slowly increase toward the ambient temperature in the surrounding area,” said the Nature Conservancy report.

Could there be an alternative to Bangalore’s great tree cull? There certainly is, if a recent set of citizen-led proposals to build a commuter-rail system on existing tracks – Bangalore has more than 80 suburban stations that are mainly used by long-distance trains – could be discussed. For the cost of the elevated road, it is likely the suburban rail system could get on track. But the government has showed little inclination to seriously plan or discuss alternatives, settling, as I said at the start of this piece, for subterfuge that raises questions about its motives.

Deception and the road back

The government’s ham-handed trickery was revealed in full measure when vigilant representatives of the Environment Support Group – an NGO that has spent years trying to enforce environmental laws –informed the city that the section of law cited in the notice to remove 112 trees on Jayamahal Road for the ramp of the elevated road did not exist.

“It is claimed that this notice was issued per Sec 8 (iii) of the Karnataka Preservation of Trees Act, 1976. There is no such section in the Tree Act,” wrote the ESG’s Leo Saldanha and Harsh Vardhan Bhati in the Bangalore Mirror last week. There is another section that mandates public consultation when more than 50 trees face the chop for “any public purpose”, but, as Saldanha and Bhati write, “the officer was sloppy on a matter of such great concern to Bengalureans...this indicates how little he has cared about laws governing the protection of our trees, and the right of the public to be involved in shaping such crucial decisions that matter not only to us, but for generations to come. After all, the trees that are now proposed to be felled were planted three generations ago!”

As time runs out this week for objections to the first felling of trees on Jayamahal Road, it is clear the government does not see trees as integral to Bangalore’s grey, grim future. There is no census on the anvil and no effort to study what might happen to a city of 10 million without the trees that created its still-pleasant climate and drew people to it in the first place.

It is left to individual groups, citizens and scientists to do what they can. Apart from those I mentioned earlier, there’s Project Vruksha, which hopes to geo-tag the trees, with no government aid of course. There’s Gubbi Labs, a research consultancy, and Neralu, a crowdfunded annual tree festival, which hope to train school children and others to measure girth, height and other characteristics while counting trees. If the government is serious about saving Bangalore, it should lead and coordinate these efforts. There is still time, Neralu reminds us, to remember what trees mean to Bangalore:

We are Bangaloreans,

we love trees,

and we want to celebrate them.

This is our time to do that.

This is our festival of trees.

Everyone lends a hand, ear or pocket

And the result is a glorious festival honouring the trees.

The Neralu festival begins this weekend. The government could do its best to help honour Bangalore’s remaining trees – by keeping them alive.