The hills are losing their capability of acting as an effective barrier to the expansion of the Thar Desert towards Delhi and Haryana as authorities have failed to curb the erosion of green cover in the area

The national capital hit an all-time high temperature of 48 degree Celsius on Monday, leaving residents reeling amid a blistering heatwave. And breathing easy was not an option with the air remaining toxic, according to government records.

Delhi is starved of clean air throughout the year. Around winter, the capital turns into a “gas chamber”, a descriptor offered by many at different times, including the chief minister and the Supreme Court. In 2018, a day after Diwali, the Air Quality Index – used by government agencies to communicate the extent of prevalent pollution to the public – hit “severe” for the first time in the season. Levels of particulate matter 2.5 (PM2.5), which are microscopic particles that can harm the lungs, cause cancer, worsen asthma and damage other organs, witnessed a massive rise. On the morning after Diwali, at about 7 am, the PM2.5 readings near Dwarka sector 8 hit 646. Now, in the middle of this torrid spell, the PM2.5 levels reached 691 on Tuesday.

A key generator of the winter smog that chokes Delhi every year is the burning of stubble by farmers in neighbouring states such as Punjab and Haryana. But there are many unresolved problems within the capital as well.

One of the reasons for the dust build-up in Delhi that’s worsening the air quality is the damaged Aravallis. It is a range of mountains running in the north-west direction between the city and Palanpur in Gujarat, constituting a vital corridor between the Asola Bhatti Wildlife Sanctuary in the capital and the Sariska Tiger Reserve in Rajasthan. The 700-kilometre-long range and its thick forest cover protect the national capital region (NCR) and fertile plains of India from desertification.

Conservation biologist Lima Rosalind told Firstpost that recent studies found deforestation of the Aravalli Range led to the expansion of the Thar Desert towards Delhi and Haryana. “There are about a dozen well-marked gaps in the Aravallis where the forest cover has almost totally vanished. The protective belt is now facing disintegration due to the felling of trees to make room for urbanisation and mining projects,” she said. “The area under human settlements on these hills expanded from 247 square kilometres in 1980 to 638 square kilometres in 2016. Industries, which were almost non-existent in 1980, now occupy about 46 square kilometres.”

The natural conservation zone (NCZ), as defined in the Regional Plan 2021 for NCR, covers the entire Aravalli Range. But the capital is paying the price for Haryana’s disregard of the NCZ. Earlier this year, even the Supreme Court came down heavily on the Haryana government for passing amendments to the Punjab Land Preservation Act enacted by the Punjab government in 1900 that provided for conservation of subsoil water and prevention of erosion in areas found to be vulnerable.

Today, the area under perennial water courses in this region has contracted by nearly a third and that under seasonal water flows by an even more alarming 97 percent. According to the Central Ground Water Board’s (CGWB) findings in 2006, the Gurugram block had already withdrawn 300 percent more water than the sustainable groundwater recharge level. Rosalind also pointed out that the cooling abilities of larger, older trees is undermined. “The greater the tree cover and less impervious the surface, the more ecosystem services are produced in terms of reducing storm water runoff, increasing air and water quality, storing and sequestering atmospheric carbon and reducing energy consumption due to direct shading of residential buildings,” she said.

The carbon-related function of trees is typically measured in two ways. The first is storage, or the total amount currently stored in tree biomass. The second is sequestration, which is the rate of absorption per year. Tree age greatly affects the ability to store and sequester carbon. Older trees store more total carbon in their wood and younger ones sequester more carbon annually. The storage of carbon reduces the greenhouse effect that is linked to problems of global climate change.

The situation has been complicated by Delhi’s unique position of a Union Territory functioning as the national capital that has led to a jumble of agencies often vying for jurisdiction. For instance, a piece of land here could be under the control of the Delhi Development Authority (DDA) — a central government body — while the planning and usage of that parcel could be determined by the Delhi government. The Public Works Department (PWD) manages roads over 60 feet in width and narrower ones are controlled by the municipal corporation. The filth in the Yamuna is often talked about but the fact that there is no unified body to handle the issue is little known. There are a dozen authorities to oversee the river, which is the source of 70 percent of the capital’s water needs: these include the Delhi government's revenue department, the irrigation and flood control department, the Delhi Jal Board, and the DDA, along with civic bodies.

China’s capital Beijing brought down its air pollution levels with the help of a decentralised governance model. The regional government of the city is well-funded and its decentralised plans for incorporating local data on air quality has succeeded in areas that are 25-times the size of Delhi. The Chinese capital has deployed a large number of sensors to crowdsource localised data into official statistics sourced from expensive instruments. In Delhi, the multiplicity of governance bodies makes it harder to implement a single pollution plan that integrates hyperlocal bodies.

Even a year ago, the PM10 level, which is the presence of particles with diameter less than 10 micrometres, reached beyond “severe” at 796 in NCR and 830 in Delhi. Under the direction of Lieutenant-Governor Anil Baijal, the secretary of environment and forests, AK Singh, passed a notification on 23 April, 2018, stating that “in exercise of the powers conferred by Section 29 of the Delhi Preservation of Trees Act, 1994, the government of National Capital Territory of Delhi, hereby, in public interest exempts an area of total 44.24 hectares for construction for redevelopment of GPRA colony at Netaji Nagar, New Delhi”. It also stated that the total number of trees at the project site was 3,906. The number of trees felled was 2,294 and the compensatory plantation required was of 24,500. While the older banyan, peepul, neem, mango, amaltas, guava and jambul trees were being cut, ornamental palms and hard ficus were being planted in their place. The size and age of a tree determine its capacity to cool the environment and retain water in the soil. Cosmetic replacement of trees damages the ecosystem.

In 2016, the Wildlife Institute of India conducted a study in southern Haryana and found that the hills there were losing their capability of acting as an effective green barrier to the expansion of the Thar Desert. It pointed out a dozen gaps — forested areas that fill intervals in Haryana and Rajasthan’s rocky ranges whose green cover has declined. The Aravallis, which performed the role of a barrier to sand migration, are now losing vegetation and there is increased rainwater runoff without recharging groundwater.

According to CGWB data, 76 percent of the assessment units were found to be “over-exploited” in Punjab while the figure was almost 66 percent in Rajasthan. Extraction of groundwater was calculated to be much more than the amount recharged. In May 2019, the National Green Tribunal (NGT) directed a joint committee of the Central Pollution Control Board (CPCB), the Delhi Pollution Control Committee (DPCC) and the CGWB to take samples of groundwater and study the methodology of its recharge and furnish a report to the tribunal within a month. However, right before the eyes of the CPCB and the governments of Haryana and Delhi, the capital is turning into a dust chamber.