Fragile ecosystem

Nature’s bounty: Trees provide services worth $500 million to the world’s megacities

By naturally reducing pollution, processing stormwater and helping in energy saving, nature helps planning authorities avoid cut down certain expenses.

Most people probably don’t think of megacities – urban areas with 10 million or more residents – as being part of nature and hence in need of conservation efforts. New research shows that this perception is not just erroneous but counter-productive, however, as trees actually provide ecosystem services worth millions of dollars to the megacities of Earth every year and have the potential to be doing even more.

Just as they do in forests and other natural ecosystems, trees deliver a variety of ecosystem services in cities. They sequester carbon and reduce air pollution and stormwater runoff, for instance. They cut winter winds and help cool their surroundings in summer via shade and transpiration, as well, leading to avoided greenhouse gas emissions and lower energy bills for owners of homes and buildings.

“Trees have direct and indirect benefits for cooling buildings and reducing human suffering during heat waves,” Theodore Endreny of the College of Environmental Science and Forestry in Syracuse, New York, the lead author of a study published this month in the journal Ecological Modelling, said in a statement. “The direct benefit is shade which keeps the urban area cooler, the indirect benefit is transpiration of stormwater which turns hot air into cooler air.”

Economic value

In order to determine how much these services are worth to megacities, Endreny and team looked at 10 megacities on five continents that lie in five different biome types: Beijing, China; Buenos Aires, Argentina; Cairo, Egypt; Istanbul, Turkey; London, UK; Los Angeles, United States; Mexico City, Mexico; Moscow, Russia; Mumbai, India; and Tokyo, Japan.

The researchers used a tool called i-Tree Canopy to survey each megacity and estimate their levels of tree cover, which ranged from 8.1% in Cairo to 36% in Moscow. On average, about 20% of the 10 megacities examined for the study were covered in tree-based ecosystems.

The team also looked at the potential for each city to increase tree cover, and found that an addition 19% of the land area of each city would provide suitable terrain, on average.

Using detailed estimates of the magnitude and value of tree-based ecosystem services, Endreny and his colleagues determined that all of those trees provide an average of $505 million in benefits to each megacity every year, or about $1.2 million per square kilometre of trees. That’s $35 in free services provided by trees to each megacity resident.

The bulk of that $505 million annual average value of urban trees, some $482 million, is due to reduction of pollutants like carbon monoxide, nitrogen dioxide, sulfur dioxide, and particulate matter released by the burning of fossil fuels. The stormwater processing that is avoided by wastewater facilities thanks to trees is worth another $11 million per year, while carbon sequestration is worth $8 million and energy savings are worth $0.5 million, the researchers found

Endreny suggests that these benefits could be nearly doubled if those cities were to make use of additional land areas that are suitable for planting more trees.

“Megacities can increase these benefits on average by 85%,” he said. “If trees were to be established throughout their potential cover area, they would serve to filter air and water pollutants and reduce building energy use, and improve human well-being while providing habitat and resources for other species in the urban area.”

Endreny and his colleagues note that, as of 2016, there were 40 megacities with a combined 722 million residents, which is nearly 10% of the total human population, all of whom “would benefit from nature conservation plans where they work and live.”

The researchers write in the study that a shift in how we think about trees’ place in urban landscapes may be necessary to unlock the full potential benefits of urban trees, however: “The most common mind set separates cities from the rest of nature, as if they were not special kinds of natural habitats. Instead, awareness that urban systems are also nature and do host biodiversity and ecosystem services opportunities, should push urban people towards increased urban forest conservation and implementation strategies.”

Sergio Ulgiati, a professor at the University Parthenope of Naples, Italy and a co-author of the study, said in a statement that, in order to follow up on the findings of the present research, the University had created an Urban Wellbeing Laboratory to be jointly run by researchers and local stakeholders.

“A deeper awareness of the economic value of free services provided by nature may increase our willingness to invest efforts and resources into natural capital conservation and correct exploitation, so that societal wealth, economic stability and well-being would also increase,” Ulgiati said.

This article first appeared on Mongabay.

Support our journalism by subscribing to Scroll+ here. We welcome your comments at
Sponsored Content BY 

Get ready for an 80-hour shopping marathon

Here are some tips that’ll help you take the lead.

Starting 16th July at 4:00pm, Flipkart will be hosting its Big Shopping Days sale over 3 days (till 19th July). This mega online shopping event is just what a sale should be, promising not just the best discounts but also buying options such as no cost EMIs, buyback guarantee and product exchanges. A shopping festival this big, packed with deals that you can’t get yourself to refuse, can get overwhelming. So don’t worry, we’re here to tell you why Big Shopping Days is the only sale you need, with these helpful hints and highlights.

Samsung Galaxy On Nxt (64 GB)

A host of entertainment options, latest security features and a 13 MP rear camera that has mastered light come packed in sleek metal unibody. The sale offers an almost 40% discount on the price. Moreover, there is a buyback guarantee which is part of the deal.

Original price: Rs. 17,900

Big Shopping Days price: Rs. 10,900

Samsung 32 inches HD Ready LED TV

Another blockbuster deal in the sale catalogue is this audio and visual delight. Apart from a discount of 41%, the deal promises no-cost EMIs up to 12 months.

Original price: Rs. 28,890

Big Shopping Days price: Rs. 10,900

Intel Core I3 equipped laptops

These laptops will make a thoughtful college send-off gift or any gift for that matter. Since the festive season is around the corner, you might want to make use of this sale to bring your A-game to family festivities.

Original price: Rs. 25,590

Big Shopping Days price: Rs. 21,900


If you’ve been planning a mid-year wardrobe refresh, Flipkart’s got you covered. The Big Shopping Days offer 50% to 80% discount on men’s clothing. You can pick from a host of top brands including Adidas and Wrangler.

With more sale hours, Flipkart’s Big Shopping Days sale ensures we can spend more time perusing and purchasing these deals. Apart from the above-mentioned products, you can expect up to 80% discount across categories including mobiles, appliances, electronics, fashion, beauty, home and furniture.

Features like blockbuster deals that are refreshed every 8 hours along with a price crash, rush hour deals from 4-6 PM on the starting day and first-time product discounts makes this a shopping experience that will have you exclaiming “Sale ho to aisi! (warna na ho)”

Set your reminders and mark your calendar, Flipkart’s Big Shopping Days starts 16th July, 4 PM and end on 19th July. To participate in 80 hours of shopping madness, click here.


This article was produced by the Scroll marketing team on behalf of Flipkart and not by the Scroll editorial team.