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Chilling Facts: What Science Says About India’s Proposed AC Temperature Limits

Sugeet Grover, programme manager at the Centre for Science and Environment, explained that raising the set temperature of an AC by just 1°C can save about 6% in electricity, according to the Bureau of Energy Efficiency (BEE). Union Minister of Housing and Urban Affairs Manohar Lal Khattar recently announced that India will soon launch a pilot project to standardise temperature settings in air conditioners (AC). This, he said, was in a bid “to help reduce excessive power consumption due to extremely low cooling settings”. Under the proposed regulation, the temperature range will be capped between 20°C and 28°C. While the move is seen as a step toward energy efficiency, experts argue that limiting AC temperature alone won't significantly curb energy use. They stress the need for improved building design, stricter enforcement, and a stronger scientific basis to achieve meaningful results. The announcement comes as the India Meteorological Department continues to issue heatwave alerts across several states, with much of the country enduring an intense and prolonged hot spell. In this context, BOOM spoke to energy and climate experts to understand the science behind thermal comfort and why better building design must complement any temperature control measures. How Does The Proposed Plan Affect You? Once the new rule is implemented, all newly manufactured AC units in India will be hardcoded to operate only within the 20°C to 28°C range. This means air conditioners that currently allow settings as low as 16°C or 18°C will no longer offer those options. Instead, 20°C will be the lowest setting for cooling and 28°C the highest for heating. The restriction is expected to impact both residential and commercial usage, and authorities plan to monitor compliance and assess its impact post-implementation. This proposed shift builds on earlier efforts to improve energy efficiency in cooling practices. In 2018, the Bureau of Energy Efficiency (BEE)—which operates under the Power Ministry—introduced voluntary guidelines for large commercial spaces such as airports, hotels, malls, and government buildings, recommending optimal temperature settings to reduce electricity use. A survey was planned to evaluate the results of that advisory. Two years later, in 2020, the government made it mandatory for all new ACs sold in India to come with a default temperature setting of 24°C. However, users retained the ability to manually change the setting. The current proposal goes a step further by eliminating user override options altogether and fixing the temperature range, with the goal of promoting more energy-conscious cooling habits. Does The Temperature Range Make Sense? Sort of. Sugeet Grover, programme manager at the Centre for Science and Environment, explained that raising the set temperature of an AC by just 1°C can save about 6% in electricity, according to the Bureau of Energy Efficiency (BEE). "It’s a rough estimate, but it shows how small changes can have a big impact," he said. Grover backed the idea of setting a minimum temperature for ACs because people often set them too low. “In cabs, the AC is usually at the coldest setting. Hotels often default to 18°C, which is much colder than needed,” he said. However, he questioned how the government determined the specific temperature range of 20°C to 28°C. He speculated that 28°C may have been chosen to avoid overheating in colder climates or to reduce emissions in places that use heating. “We’ve been given no real scientific basis for this number,” he noted. Grover also pointed out how hard it is to cool a room to 18°C when it’s 45°C outside. “That puts a huge strain on the AC. If you set it to 26°C and use a fan, you’ll still feel comfortable,” he said. This ties into the idea of adaptive comfort——our bodies’ ability to adjust to ambient conditions over time. “If you’ve been living in 40°C weather for weeks, you’ll feel okay in a room with the air-conditioner set at 27°C,” he explained. This idea, he noted, is already recognised in India’s National Building Code. Professor Per Becker from Lund University raised similar concerns about the 20°C to 28°C band, calling it “scientifically unsubstantiated”. Research shows people work best in temperatures between 21°C and 25°C, with the ideal range being 22°C to 24°C. “Below that, you’re just wasting energy unless the setting is for physical labour,” he said. He agreed that fans can help improve comfort at slightly higher temperatures. “Even 26°C can work with proper circulation. But beyond that, especially around 28°C, cognitive and physical productivity tends to drop.” While Becker acknowledged that human bodies do adapt to heat over time, he argued that 28°C is too warm for most indoor work environments. “A single national range ignores local weather differences,” he added. “Cooling a space to 24°C when it’s 45°C outside takes far more energy than doing the same when it’s 30°C. A fixed band doesn’t reflect that complexity.”

Erratic weather is hurting Indian rms in the biggest consumer market

India experienced extreme weather events on 88 per cent of days in 2024 in one or more parts of the country, according to a database maintained by Centre for Science and Environment and Down To Earth. Between 1993 and 2022, the South Asian nation lost about $180 billion (Rs 15.57 lakh crore) to severe heat and rains, the Climate Risk Index 2025 report said. Weather forecasting in India has been plagued by outdated technology and modeling systems that make it difcult to get accurate data.

Chilling Facts: What Science Says About India’s Proposed AC Temperature Limits

Union Minister of Housing and Urban Affairs Manohar Lal Khattar recently announced that India will soon launch a pilot project to standardise temperature settings in air conditioners (AC). This, he said, was in a bid “to help reduce excessive power consumption due to extremely low cooling settings”. Under the proposed regulation, the temperature range will be capped between 20°C and 28°C. While the move is seen as a step toward energy efficiency, experts argue that limiting AC temperature alone won't significantly curb energy use. They stress the need for improved building design, stricter enforcement, and a stronger scientific basis to achieve meaningful results. The announcement comes as the India Meteorological Department continues to issue heatwave alerts across several states, with much of the country enduring an intense and prolonged hot spell. In this context, BOOM spoke to energy and climate experts to understand the science behind thermal comfort and why better building design must complement any temperature control measures. How Does The Proposed Plan Affect You? Once the new rule is implemented, all newly manufactured AC units in India will be hardcoded to operate only within the 20°C to 28°C range. This means air conditioners that currently allow settings as low as 16°C or 18°C will no longer offer those options. Instead, 20°C will be the lowest setting for cooling and 28°C the highest for heating. The restriction is expected to impact both residential and commercial usage, and authorities plan to monitor compliance and assess its impact post-implementation. This proposed shift builds on earlier efforts to improve energy efficiency in cooling practices. In 2018, the Bureau of Energy Efficiency (BEE)—which operates under the Power Ministry—introduced voluntary guidelines for large commercial spaces such as airports, hotels, malls, and government buildings, recommending optimal temperature settings to reduce electricity use. A survey was planned to evaluate the results of that advisory. Two years later, in 2020, the government made it mandatory for all new ACs sold in India to come with a default temperature setting of 24°C. However, users retained the ability to manually change the setting. The current proposal goes a step further by eliminating user override options altogether and fixing the temperature range, with the goal of promoting more energy-conscious cooling habits. Does The Temperature Range Make Sense? Sort of. Sugeet Grover, programme manager at the Centre for Science and Environment, explained that raising the set temperature of an AC by just 1°C can save about 6% in electricity, according to the Bureau of Energy Efficiency (BEE). "It’s a rough estimate, but it shows how small changes can have a big impact," he said. Grover backed the idea of setting a minimum temperature for ACs because people often set them too low. “In cabs, the AC is usually at the coldest setting. Hotels often default to 18°C, which is much colder than needed,” he said. However, he questioned how the government determined the specific temperature range of 20°C to 28°C. He speculated that 28°C may have been chosen to avoid overheating in colder climates or to reduce emissions in places that use heating. “We’ve been given no real scientific basis for this number,” he noted. Grover also pointed out how hard it is to cool a room to 18°C when it’s 45°C outside. “That puts a huge strain on the AC. If you set it to 26°C and use a fan, you’ll still feel comfortable,” he said. This ties into the idea of adaptive comfort——our bodies’ ability to adjust to ambient conditions over time. “If you’ve been living in 40°C weather for weeks, you’ll feel okay in a room with the air-conditioner set at 27°C,” he explained. This idea, he noted, is already recognised in India’s National Building Code. Professor Per Becker from Lund University raised similar concerns about the 20°C to 28°C band, calling it “scientifically unsubstantiated”. Research shows people work best in temperatures between 21°C and 25°C, with the ideal range being 22°C to 24°C. “Below that, you’re just wasting energy unless the setting is for physical labour,” he said. He agreed that fans can help improve comfort at slightly higher temperatures. “Even 26°C can work with proper circulation. But beyond that, especially around 28°C, cognitive and physical productivity tends to drop.” While Becker acknowledged that human bodies do adapt to heat over time, he argued that 28°C is too warm for most indoor work environments. “A single national range ignores local weather differences,” he added. “Cooling a space to 24°C when it’s 45°C outside takes far more energy than doing the same when it’s 30°C. A fixed band doesn’t reflect that complexity.”

India ‘disappointed’ with exclusion of finance obligation from agenda at Bonn

Avantika Goswami, programme manager at the Climate Change Centre for Science and Environment, said the European Union and its allies had blocked the G77’s demand to discuss developed countries’ climate finance obligations. “The fight is not over, as the LMDC bloc and India have vowed to bring focus back to this at COP30,” she said. India and several developing countries have expressed disappointment after a key climate finance discussion was excluded from the Bonn Climate Talks agenda, vowing to raise the issue at November’s COP30 summit in Brazil. The dispute centred on Article 9.1 of the Paris Agreement, which mandates that developed countries provide financial resources to assist developing nations with both mitigation and adaptation efforts. The debate over the 9.1 agenda item proposal led to a 30-hour delay before talks could begin. “We are extremely disappointed with the reluctance of developed countries to discuss their legal obligations to provide finance to developing countries,” said Amandeep Garg, additional secretary at ministry of environment, forests and climate change, who represented the Indian delegation. The Like Minded Developing Countries (LMDC) group and the G77 and China had proposed agenda items on both the legal obligation of wealthy countries to provide climate finance and another on unilateral trade measures. However, these were not adopted after the European Union and other developed nations refused to agree. “Without enough affordable financial support, developing countries cannot address the challenges posed by climate change,” Garg said during his intervention at the agenda adoption session, backing the LMDC position. “This is completely unacceptable. We do not understand how this process can engage in article 9.1 without which climate action in developing countries cannot be taken in scale, scope and speed” Garg added: “It has been 10 years of the Paris Agreement and still the items which are required to be discussed, we are not discussing them.” Diego Pacheco, Bolivia’s negotiator and spokesperson for the LMDC group, warned that the issue would resurface at COP30. “Public finance from developed countries is a necessary condition for implementation of the Paris Agreement,” he said. “You can deny us the starting point but be rest assured, the LMDC will raise these items at COP30.” The African Group also highlighted the implementation of Article 9.1 as critical to their region, emphasising the need to address resource provision for nationally determined contributions, national adaptation plans, and just transition measures. EU negotiators said their “positions and motivations being mischaracterised” and urged parties to respect all positions in a constructive spirit. The agenda was finally adopted on Tuesday evening after extensive behind-closed-doors consultations. Simon Stiell, the UN climate chief, acknowledged the difficulty of the negotiations whilst urging progress on mandated items. “The past 30 hours have been hard and have not reflected the urgency that we face,” Stiell said. “Through cooperation and compromise, we have resolved the impasse. We must now move the work ahead.” This year’s Bonn talks agenda includes discussions on Global Goal on Adaptation indicators under the UAE–Belém Work Programme, the UAE Dialogue on implementing global stocktake outcomes, the UAE Just Transition Work Programme, and the Baku to Belem roadmap to 1.3 trillion dollars. Avantika Goswami, programme manager at the Climate Change Centre for Science and Environment, said the European Union and its allies had blocked the G77’s demand to discuss developed countries’ climate finance obligations. “The fight is not over, as the LMDC bloc and India have vowed to bring focus back to this at COP30,” she said. The dispute comes as climate change appears to be losing prominence in some international forums. The International Institute of Sustainable Development noted that G7 statements following recent talks between leaders in Kananaskis omitted references to climate change, with only the chair’s summary making a passing reference to the issue. “The G7 sidestepped climate change in the leaders’ statements, despite acknowledging increased wildfires,” said Patricia Fuller, IISD president and chief executive. “Previous G7 commitments to action on climate change remain on the books and must be delivered.”

Rain, winds give Delhi best AQI since Sept 29

New Delhi: Rain accompanied by gusty winds helped Delhiites inhale the purest air they had access to in 261 days. The city's AQI on Wednesday was 81 and ‘satisfactory', with the index lower than this only on Sept 29 last year at 76. This year so far, Delhi has witnessed just three ‘satisfactory' days and there has been no ‘good' air day. The last ‘good' air day was Sept 10, 2023, when the AQI read 45 due to rains and the restrictions imposed for the G20 Summit. The Central Pollution Control Board defines a ‘good' air day as one when AQI is below 51, while a ‘satisfactory' level has AQI reading 51-100. The city's AQI was 104 on Tuesday. Delhi logged 29mm of rainfall in the last 24 hours till 8.30am on Wednesday. The rain was accompanied by winds with speed up to 45 kmph. These aided in settling the pollutants. Experts said on Wednesday that pollution has to be dealt at the source level to ensure similar AQI readings throughout the year. "Weather and climate will always impact daily short-term trends. But irrespective of this variation and climatic influence, we need to achieve sustained longer-term reduction with scale and speed of clean air action," said Anumita Roychowdhury, executive director (research and advocacy), Centre for Science and Environment. Sunil Dahiya, founder and lead analyst, EnviroCatalysts, said, "The fact that sustained rain and good wind speed could bring AQI down to the ‘satisfactory' level says loudly that emissions from contributing sectors, transport, industry, construction, and waste, etc., are so high that even the wind and rain washing the pollutants couldn't provide breathable 'good' air quality." Dahiya added that while the slightly better air quality was a respite for the citizens, aggressive actions towards reducing emission load from contributing sectors were the only solutions that can help reduce pollution throughout the year. In March, the city enjoyed two consecutive ‘satisfactory' air days on March 15 and 16 with AQI, respectively, of 85 and 99. CPCB's data shows that between Jan 1 and June 17, Delhi recorded 80 ‘moderate' days, 68 ‘poor' days and 18 ‘very poor' days. In the same period last year, there were 84 ‘moderate' days, 49 ‘poor' days, 32 ‘very poor' days and three ‘severe' days. CPCB classifies AQI between 101 and 200 as ‘moderate', between 201 and 300 as ‘poor', between 301 and 400 as ‘very poor' and over 400 as ‘severe'.

Erratic Weather Is Hurting Indian Firms in The Biggest Consumer Market

India experienced extreme weather events on 88% of days in 2024 in one or more parts of the country, according to a database maintained by Centre for Science and Environment and Down To Earth. Between 1993 and 2022, the South Asian nation lost about $180 billion to severe heat and rains, the Climate Risk Index 2025 report said. Some of India’s largest companies, already hit by a demand slump, are facing a new threat in wooing the country’s 1.4 billion consumers: unpredictable weather. A cooler-than-usual summer this year — followed by the earliest onset of rain since 2009 — has hurt companies selling everything from talcum powder to air conditioners. Blue Star Ltd., one of the largest AC sellers in the country, had to cut production by as much as 25% between April and June, as it saw fewer buyers. It also delayed imports of compressors, a key input, and extended credit to some dealerships saddled with unsold inventories. Rivals Havells Ltd. and Tata-owned Voltas Ltd. also flagged a sales slowdown. A four-fold jump in frequency, unpredictability and intensity of extreme weather events in India over the past four decades has made planning and preparedness more demanding for companies. From Hindustan Unilever Ltd. to food delivery app Zomato-owner Eternal Ltd. to engineering giant Larsen & Tourbro Ltd., it’s affecting everything from sales to labor and supply chain management in the world’s biggest consumer market. India’s situation as one of the most affected nations by climate change provides a glimpse of what’s in store for other major economies as environmental change accelerates. As record-breaking temperatures, rains and other extreme weather occur worldwide, companies are likely to be left scrambling to predict and plan for the future. Earnings Calls On earnings calls over the last six months, top management and equity analysts discussed “delayed summer” and “delayed winter” the most in five years, according to transcripts analyzed by Bloomberg News. “This quarter is slightly challenging as far as the summer portfolio is concerned,” Mohan Goenka, vice chairman of Emami Ltd., whose products include talc powder, told investors on an earnings call last month. The company will try to make up for the setback through its other segments, he added. Varun Beverages Ltd., which bottles Pepsi in India, had said in April that it was ramping up production for the summer, expecting higher demand. Instead, unseasonal rains likely hurt performance at the beverage maker, according to analysts at Jefferies. The brokerage also flagged weaker demand at Dabur Ltd., which sells fruit juices, and Tata Consumer Products Ltd., which sells cold drinks. Time-sensitive summer demand, “once missed, is difficult to recover,” analysts at Nuvama, led by Abneesh Roy, said in a note to clients. Labor Shortage Rising incidence of heat waves, for example, was among factors causing a shortage of labor at Larsen, even as it split shifts between early morning and late afternoon. Eternal, which operates Zomato and Blinkit, said it faces a seasonal shortage of delivery workers in the summer. Hindustan Unilever, which sells skincare brands including Ponds and Vaseline, said it saw muted performance in the December quarter partly due to a delayed winter. India experienced extreme weather events on 88% of days in 2024 in one or more parts of the country, according to a database maintained by Centre for Science and Environment and Down To Earth. Between 1993 and 2022, the South Asian nation lost about $180 billion to severe heat and rains, the Climate Risk Index 2025 report said.

पीएम नहीं बल्कि ओजोन दिल्ली में सबसे बड़ा प्रदूषक : सीएसई

इस गर्मी में दिल्ली की हवा में पार्टिकुलेट मैटर (पीएम) नहीं बल्कि ओजोन सबसे बड़ा प्रदूषक बनकर उभरा है। यह एक बड़ा बदलाव है, जो राष्ट्रीय राजधानी क्षेत्र (एनसीआर) में स्वास्थ्य के लिए खतरनाक है। इसका खुलासा दिल्ली स्थित थिंक टैंक सेंटर फॉर साइंस एंड एनवायरमेंट (सीएसई) ने अपनी नई रिपोर्ट में किया है। नए विश्लेषण से पता चला है कि जमीनी स्तर पर ओजोन मार्च और मई 2025 के बीच लगभग हर दिन राष्ट्रीय सुरक्षा सीमाओं के तय मानक से अधिक रहा। साथ ही, पिछले वर्षों की तुलना में इसका भौगोलिक विस्तार अधिक होगा और अवधि भी अधिक लंबी होगी। रिपोर्ट के अनुसार, 25 मई से 11 जून के बीच 18 दिनों में से 12 दिनों में वायु गुणवत्ता सूचकांक (एक्यूआई) में ओजोन प्रमुख प्रदूषक रहा, जिसने इतने लंबे समय में पहली बार महीन कण पदार्थ (पीएम2.5) को विस्थापित कर दिया। इसके बावजूद मौजूदा आपातकालीन प्रतिक्रिया ढांचे, ग्रेडेड रिस्पांस एक्शन प्लान (ग्रेप) में ओजोन या इसके पूर्ववर्ती गैसों को रोकने के लिए कोई प्रावधान नहीं है। दक्षिण दिल्ली का नेहरू नगर सबसे अधिक प्रभावित रहा, जहां ओजोन का स्तर हर दिन सुरक्षित सीमा को पार कर रहा था, जबकि नोएडा के सेक्टर 125 और गाजियाबाद के वसुंधरा में राष्ट्रीय राजधानी के बाहर सबसे अधिक दिनों तक ओजोन का स्तर बढ़ा। ओजोन का स्तर रात तक भी बना रहा विश्लेषण से पता चला कि ओजोन का स्तर न केवल दिन के समय बढ़ा बल्कि अक्सर देर रात तक ऊंचा बना रहा। दिल्ली के स्टेशनों ने प्रतिदिन 14.2 घंटे ओजोन के स्तर को मानक से ऊपर दर्ज किया, जो पिछली गर्मियों में 12 घंटे था। एनसीआर के शहरों में यह आंकड़ा बढ़कर 15 घंटे हो गया। गुरुग्राम के ग्वाल पहाड़ी में रात के समय ओजोन की सबसे अधिक घटनाएं दर्ज की गईं। इस गर्मी में सबसे ज्यादा रीडिंग दिल्ली के सीआरआरआई मथुरा रोड स्टेशन से आई, जहां 19 मई को आठ घंटे का औसत 472 माइक्रोग्राम प्रति क्यूबिक मीटर दर्ज किया गया, जो राष्ट्रीय मानक से चार गुना अधिक है।

PM Modi Addresses G7 Outreach Session in Canada, Stresses Energy Security and Global Cooperation

Citing a report by the New Delhi-based Centre for Science and Environment, the AP noted that the combined share of solar, wind, small hydro, and biomass in India’s electricity generation stood at 12% — double the figure in 2014 but still below expectations for 2025. PM Modi Addresses G7 Outreach Session in Canada, Stresses Energy Security and Global Cooperation Kananaskis, Canada – Prime Minister Narendra Modi on Wednesday addressed the outreach session of the 51st G7 Leaders’ Summit held in Kananaskis, Alberta, Canada. He spoke during a session on “Energy Security: Diversification, Technology, and Infrastructure to Ensure Access and Affordability in a Changing World”, according to the Ministry of External Affairs. In his address, the Prime Minister emphasized that energy security remains one of the key challenges facing future generations. He outlined India’s commitment to inclusive growth and highlighted the four pillars of India’s energy policy: availability, accessibility, affordability, and acceptability. Modi stated that India had successfully met its Paris climate commitments ahead of schedule, despite being the world’s fastest-growing major economy. “Despite rapid growth, challenges persist. While non-fossil fuel sources now comprise 45% of India’s total installed power capacity, their share in actual electricity generation stood at 24% last year. Coal remains the dominant source, accounting for 75% of electricity generation,” the Associated Press reported weeks ahead of G7 summit. Citing a report by the New Delhi-based Centre for Science and Environment, the AP noted that the combined share of solar, wind, small hydro, and biomass in India’s electricity generation stood at 12% — double the figure in 2014 but still below expectations for 2025. The report also pointed out that while India is making progress in harnessing solar, wind, and other clean energy sources, coal continues to dominate electricity generation. However, its dominance is gradually declining: coal accounted for 60% of installed power capacity 11 years ago, compared to less than 50% today, according to data from India’s Ministry of Power. In his speech, Prime Minister Modi reiterated India’s commitment to a sustainable and green future. He mentioned several key global initiatives led or co-led by India, including the International Solar Alliance, Coalition for Disaster Resilient Infrastructure, Global Biofuels Alliance, Mission LiFE, and the One Sun, One World, One Grid initiative. He urged the international community to strengthen and support these efforts. He also underlined the severe impact of global uncertainty and conflicts on the Global South. Modi stressed that a sustainable future requires recognizing and addressing the concerns and priorities of developing nations. Turning to global security, the Prime Minister called for stronger international action against terrorism. Referring to the recent terror attack in Pahalgam, he stated that it was not just an assault on India but on all of humanity. He called for strict action against countries that support and promote terrorism. “Terrorism is a grave threat to humanity,” Modi said, posing three pressing questions to the global community: Will countries recognize the grave threat of terrorism only after becoming its victims? How can the perpetrators of terror be equated with its victims? Will global institutions remain mute spectators to terrorism? The Prime Minister also spoke on the evolving relationship between technology, artificial intelligence (AI), and energy. While calling AI a critical tool for promoting innovation and efficiency, he warned that it is also energy-intensive. He emphasized the need to develop sustainable and green AI systems. "Concluding a productive Canada visit. Thankful to the Canadian people and Government for hosting a successful G7 Summit, which witnessed fruitful discussions on diverse global issues. We remain committed to furthering global peace, prosperity and sustainability," PM Modi said in a post on X. Prime Minister Narendra Modi attended the 51st G7 Leaders’ Summit at the invitation of Canadian Prime Minister Mark Carney, who took office on March 14, 2025.

In Re: News Item titled

1. This original application is registered suo-motu based on the news item titled "Nayar river is vanishing - a yatra reveals conservation goes beyond science and policy" appearing in ‘The Down To Earth’ dated 03.06.2025.

Ground-level ozone at 5-yr high; south, northwest Delhi worst hit

New Delhi: The city experienced its highest ozone levels in five years this summer, according to a study by the Centre for Science and Environment. The eight-hour rolling average of the gas exceeded safe standards for 14.2 hours daily, increasing from 12 hours in previous summers. The analysis revealed that south and northwest Delhi were most affected, showing the broadest geographical spread of ozone exceedance since 2018. The study indicated that ground-level ozone surpassed national safety standards throughout the 92-day summer period from March 1 to May 31, with breaches occurring on 83 days. The established eight-hour standard for O3 is 100 micrograms per cubic metre. "Ground-level ozone pollution remained consistently high across the region, with the maximum concentration exceeding 100 microgram per cubic metre on each of the 92 days between March 1 and May 31, highlighting the persistent and widespread nature of the problem," the study said. "The worst day in terms of spatial spread was April 28, when 32 out of 58 monitoring stations across the region reported ozone levels above the safe limit. The highest regional intensity was recorded on April 13, with the Delhi-NCR average reaching 135." Ozone forms through chemical reactions involving nitrogen oxides, volatile organic compounds and carbon monoxide, which are released by vehicles, power plants and factories. These substances react in sunlight to create ground-level ozone. This highly reactive gas poses serious health risks. It can inflame and damage the airways, increase susceptibility to infections and worsen respiratory conditions such as asthma, chronic bronchitis and emphysema. CSE analysed summer trends from 2021 to 2025 (until May 31) using CPCB's official online portal, Central Control Room for Air Quality Management. The findings showed Nehru Nagar breached the safe level on all 92 days, followed by Najafgarh (82 days) and Okhla Phase-II (81 days). Only six locations, Anand Vihar, IHBAS, ITO, Shadipur, Narela and Knowledge Park in Greater Noida, maintained levels below the standard. On several days this summer, therefore, ozone was the lead pollutant instead of particulate matter in the daily air quality index. "Out of 18 days between May 25 and June 11, ozone was the lead pollutant on 12," said Anumita Roychowdhury, executive director, CSE. The study also said there was no system to address the ozone problem under the Graded Response Action Plan. "While the policy attention is nearly fully focused on particulate pollution, co-control of toxic gases from vehicles, industry and combustion sources that contribute to ozone formation in the air is neglected," Roychowdhury pointed out, calling for measures to curb ozone.

Ozone pollution this year highest since 2021 in Delhi: Report

Delhi has recorded its highest ozone (O3) levels this summer in the last five years, with readings breaching the safe mark for 14.2 hours on an average in a day, a report shows. This eight-hour rolling average has gone up from 12 hours in a day from the last two summers, 11.7 hours in 2022 and 12.2 hours in 2021, according to the report released by Centre for Science and Environment (CSE) on Tuesday. The eight-hour safe standard for the pollutant is 100 μg/m3. The analysis also shows that Delhi recorded its widest geographical spread of ozone exceedance in the past five years this summer, with south Delhi and northwest Delhi being the worst impacted. CSE said ground-level ozone levels exceeded the national safety standards on all 92 days in the summer period – considered as March 1 till May 31, while it exceeded the safe standards on 83 out of the 92 days in the summer. “Ground-level ozone pollution remained consistently high across the region, with the maximum concentration exceeding 100 µg/m³ on each of the 92 days between March 1 and May 31, highlighting the persistent and widespread nature of the problem. The worst day in terms of spatial spread was April 28, when 32 out of 58 monitoring stations across the region reported ozone levels above the safe limit. The highest regional intensity was recorded on April 13, with the Delhi-NCR average reaching 135 µg/m³..” said the analysis. Unlike primary pollutants (emitted directly from sources), ozone is not emitted directly from any source, but is formed through chemical reactions involving nitrogen oxides (NOx), volatile organic compounds (VOCs), and carbon monoxide — pollutants released by vehicles, power plants, factories and other combustion sources. In the presence of sunlight, these substances undergo a series of cyclic reactions that result in the formation of ozone near the ground. CSE took into account summer trends from 2021 to 2025 (up to May 31) available on the Central Pollution Control Board’s official portal. Data showed that Nehru Nagar was the worst impacted station, exceeding standards on all 92 days. This was followed by Najafgarh (82 days) and Okhla Phase-II (81 days). In comparison, six locations – Anand Vihar, IHBAS, ITO, Shadipur, Narela and Knowledge Park in Greater Noida did not exceed the standards even on a single day this summer. “This summer, several days have recorded ozone — instead of particulate matter — as the lead pollutant in the daily Air Quality Index (AQI). Out of 18 days between May 25 and June 11, ozone has been the lead pollutant on 12,” said Anumita Roychowdhury, executive director and in-charge of clean air programme at CSE. “But there is no system to address this problem under the current Graded Response Action Plan for emergency action to reduce exposure or to address its sustained mitigation with longer term clean air action plan. While the policy attention is nearly fully focused on particulate pollution, co-control of toxic gases from vehicles, industry and combustion sources that contribute to ozone formation in the air is neglected,” she said, calling for focused action against the highly reactive gas.

Delhi-NCR breaches safe ozone limits on most summer days: CSE report

Delhi’s ground-level ozone, a harmful air pollutant, remained above safe limits throughout this summer, according to a study released Tuesday by the Centre for Science and Environment (CSE), a Delhi-based environment think tank. Experts have pointed out that this summer, ozone emerged as the dominant pollutant on several days. While particulate matter remains the main focus of government efforts to combat air pollution, ozone levels topped the charts on 12 out of 18 days between May 25 and June 11. Despite this spike and its known health risks, ozone has yet to be included in the Graded Response Action Plan (GRAP), which guides emergency measures to curb air pollution. This leaves a major gap in strategies to limit both short- and long-term exposure to the gas. Advertisement “While the policy attention is nearly fully focused on particulate pollution, co-control of toxic gases from vehicles, industry, and combustion sources that contribute to ozone formation in the air is neglected,” said Anumita Roychowdhury, executive director and head of the clean air programme at the CSE. Citing the highly reactive nature of the gas, experts have warned that unchecked ozone levels could trigger a serious public health crisis. According to the study, ozone exposure poses significant respiratory risks, especially for vulnerable groups such as children with underdeveloped lungs, the elderly, and people with pre-existing respiratory conditions. Experts noted that ozone can inflame and damage the airways, reduce resistance to infections, and aggravate diseases like asthma, chronic bronchitis, and emphysema. This can increase both the frequency and severity of asthma attacks, often resulting in higher hospitalisation rates. Unlike particulate matter, which is monitored based on a 24-hour average, ozone standards are set for an eight-hour average due to the gas’s highly reactive nature. The national pollution monitoring agency also tracks hourly ozone levels across all monitoring stations. As per CPCB norms, the permissible limit is 100 µg/m³ for an eight-hour average and 190 µg/m³ for a one-hour average—both of which were breached at several stations across the Delhi-NCR region during the recorded period. The report, titled ‘Ground-level ozone – Delhi-NCR: An Invisible Threat’, found that from March 1 to May 31, ozone pollution remained consistently high across the region. The maximum concentration exceeded the safe limit of 100 µg/m³ on all 92 days, underscoring the persistent and widespread nature of the problem. Meanwhile, the surrounding NCR areas reported surges on 83 days during the same period. In Delhi, the highest ozone levels were recorded on April 13, with an average concentration of135 µg/m³. In the wider NCR region, the peak was slightly higher at 139 µg/m³ on April 25. According to CSE’s analysis, the worst-affected areas are in northwest and south Delhi, with Nehru Nagar in South Delhi exceeding the safe ozone standard on all 92 days of monitoring. It was followed by Najafgarh (82 days), Okhla Phase II (81), Ashok Vihar and Aya Nagar (77 each), and Wazirpur (72). The study also indicated significant changes in hourly ground-level ozone data this summer. Ground-level ozone pollution has intensified this summer, with the regional hourly peak rising by 9% compared to lockdown-era levels and eight-hour averages crossing 450 µg/m³ due to the removal of CPCB’s earlier data cap. Delhi’s Mathura Road station logged a record 472 µg/m³ on May 19, while hotspots across NCR—like Alipur, Ashok Vihar, Gurugram’s Gwal Pahari, and Noida Sector 62—also reported dangerously high concentrations. Ozone, unlike primary pollutants, is a secondary pollutant formed through sunlight-driven reactions involving nitrogen oxides (NOx), volatile organic compounds (VOCs), and carbon monoxide (CO) emitted from human-made sources such as vehicles, power plants, factories, and other combustion activities, as well as from natural sources like vegetation. The CSE warns that poor monitoring and oversimplified averaging methods are masking localised ozone spikes, underscoring the need for hotspot-specific strategies to reduce short-term exposure and protect public health. “Instead of only averaging out the levels for the city, which is the standard practice to estimate AQI, it is also important to capture adequately the high levels of localised exposures in the hotspots and to design mitigation strategies accordingly. Managing short-term exposures is critical to protect public health,” said Shranajeet Kaur, deputy programme manager at CSE’s Urban Lab, in a press statement. In light of the recurring rise in ozone pollution, Roychowdhury urged that ozone be formally included in Delhi-NCR’s clean air action plan. She cautioned that, unlike developed economies, which shifted to a multi-pollutant approach only after controlling particulate pollution and then facing a surge in NOx and ozone levels, India should act early to avoid falling into the same trap. To combat rising ozone pollution, experts recommend integrating ozone into GRAP and city clean air plans to enable emergency measures targeting precursor emissions from vehicles, industries, and waste burning, while promoting zero-emission vehicles and clean fuels. They also call for a regional action plan, as ground-level ozone disperses beyond city limits, affecting rural areas, agricultural productivity, and food security, demanding coordinated local and regional strategies.

दिल्ली पर मंडरा रहा बढ़ते ओजोन प्रदूषण का खतरा, क्या है CSE की रिपोर्ट?

सेंटर फॉर साइंस एंड एनवायरमेंट (सीएसई) ने अपनी नई रिपोर्ट में दिल्ली और आसपास के क्षेत्रों में ओजोन प्रदूषण के बढ़ते खतरे को लेकर चेताया है। रिपोर्ट के मुताबिक इस साल गर्मियों के दौरान दिल्ली में करीब-करीब हर दिन ओजोन प्रदूषण का स्तर सुरक्षित सीमा से ऊपर रहा। दिल्ली के आसपास के क्षेत्रों में भी उन दिनों की संख्या बढ़ी है, जब हवा में ओजोन प्रदूषण हावी था। ओजोन कोई सीधे तौर पर उत्सर्जित होने वाला प्रदूषक नहीं है, यह सूर्य की रोशनी में नाइट्रोजन ऑक्साइड, वोलेटाइल ऑर्गेनिक कंपाउंड (वीओसी) और कार्बन मोनोऑक्साइड जैसी गैसों के साथ रासायनिक प्रतिक्रिया से बनता है। रिपोर्ट के मुताबिक दिल्ली में मार्च से मई 2025 के बीच हर दिन ओजोन का स्तर 100 माइक्रोग्राम प्रति घन मीटर से अधिक रहा। 28 अप्रैल को सबसे खराब दिन रहा, जब क्षेत्र के 58 में से 32 निगरानी स्टेशनों में ओजोन का स्तर सुरक्षित सीमा से ऊपर दर्ज किया गया। वहीं जब दिल्ली-एनसीआर के शहरों के अलग-अलग देखा गया तो स्थानीय स्तर पर अलग ही रुझान सामने आए। दिल्ली में सबसे ज्यादा प्रदूषण 13 अप्रैल को दर्ज किया गया, जब ओजोन का औसत स्तर 135 माइक्रोग्राम प्रति घन मीटर रहा। इस दौरान 39 में से 25 स्टेशनों पर ओजोन का स्तर तय सीमा से अधिक रिकार्ड किया गया। एनसीआर में 25 अप्रैल को ओजोन का स्तर 139 माइक्रोग्राम प्रति घन मीटर तक पहुंच गया। इस दौरान एनसीआर के अन्य शहरों में 83 दिनों तक ओजोन का स्तर तय सीमा से अधिक दर्ज किया गया। 18 और 28 अप्रैल को एनसीआर के 10 में से 9 स्टेशनों ने सीमा से अधिक स्तर दर्ज किया। दिल्ली के ये इलाके रहे सबसे अधिक प्रभावित रिपोर्ट में यह भी सामने आया है कि गर्मियों के दौरान उत्तर-पश्चिम और दक्षिण दिल्ली में बढ़ते ओजोन से सबसे ज्यादा प्रभावित रहे। वहीं गाजियाबाद और नोएडा एनसीआर के सबसे प्रदूषित शहरों में शामिल थे। इस साल औसतन करीब 19 मानिटरिंग स्टेशनों ने रोजाना मानकों से अधिक स्तर दर्ज किया, जोकि पिछले पांच वर्षों में सबसे अधिक है। इस साल इसमें 6.8 प्रतिशत की बढ़ोतरी हुई है। इस गर्मी, ओजोन का स्तर रोजाना औसतन 14.2 घंटे तक हवा में बना रहा, जोकि पिछले साल 12 घंटों से कहीं अधिक है। इस गर्मी दिल्ली में ओजोन प्रदूषण का फैलाव बढ़कर औसतन 15.1 स्टेशनों तक पहुंच गया, जो पिछले साल के 13.2 स्टेशनों से अधिक है। ओजोन प्रदूषण का समय भी बढ़कर औसतन 12 घंटे हो गया। एनसीआर में ओजोन का प्रसार हुआ कम दूसरी तरफ एनसीआर के शहरों में ओजोन का स्थानीय प्रसार कम हुआ है, जो इस साल औसतन 3.6 स्टेशनों पर रहा, जबकि पिछले साल यह 4.4 स्टेशनों पर था। दक्षिणी दिल्ली का नेहरू नगर सबसे ज्यादा प्रभावित इलाका रहा। मार्च से मई तक सभी 92 दिनों में यहां ओजोन का स्तर तय सीमा से ऊपर रहा। इसके बाद नजफगढ़, ओखला फेज-2, अशोक विहार, आया नगर और वज़ीरपुर भी ज्यादा प्रभावित रहे। सीएसई की कार्यकारी निदेशक और क्लीन एयर प्रोग्राम की प्रमुख अनुमिता रायचौधरी ने कहा कि वाहनों, उद्योगों और कचरे के जलने से निकलने वाली गैसें ओजोन के बनने में योगदान करती हैं, लेकिन नीतियों में इन पर ध्यान नहीं दिया जा रहा। सीएसई ने सुझाव दिया है कि ओजोन को ग्रेडेड रिस्पांस एक्शन प्लान (ग्रेप) में शामिल किया जाना चाहिए। वाहनों और उद्योगों से होने वाले उत्सर्जन को रोकने के लिए स्वच्छ ईंधन और तकनीक को बढ़ावा दिया जाए।

World Day To Combat Desertification and Drought: उपजाऊ भूमि को मरुस्थल होने से बचाना होगा

सेंटर फॉर साइंस एंड एनवायरमेंट (सीएसई) द्वारा जारी “स्टेट ऑफ एनवायरमेंट इन फिगर्स 2019” की रिपोर्ट के मुताबिक 2003-05 से 2011-13 के बीच भारत में मरुस्थलीकरण 18.7 लाख हेक्टेयर बढ़ चुका है। सूखा प्रभावित 78 में से 21 जिले ऐसे हैं, जिनका 50 फीसदी से अधिक क्षेत्र मरुस्थलीकरण में बदल चुका है। मानव एवं जीव-जंतुओं का जीवन भूमि पर निर्भर है। फिर भी, पूरी दुनिया में प्रदूषण, भूमि का दोहन, जलवायु अराजकता और जैव विविधता विनाश का एक जहरीला मिश्रण स्वस्थ भूमि को रेगिस्तान में बदल रहा है और संपन्न पारिस्थितिकी तंत्र मृत क्षेत्रों में बदल रहा है। ‘हमारी भूमि’ नारे के तहत भूमि बहाली, मरुस्थलीकरण और सूखा निवारण आज की जलवायु समस्याओं का सटीक समाधान हो सकता है, इसी को ध्यान में रखते हुए विश्व मरुस्थलीकरण एवं सूखा निवारण दिवस 17 जून को मनाया जाता है। यह दिन मरुस्थलीकरण और सूखे से निपटने के लिए जागरूकता बढ़ाने और लोगों को एकजुट करने के लिए मनाया जाता है। इस वर्ष की थीम है ‘भूमि के लिए एकजुट। हमारी विरासत। हमारा भविष्य’ है, संयुक्त राष्ट्र के अनुसार यह दिवस पर भूमि के महत्व और इसे भावी पीढ़ियों के लिए संरक्षित करने की आवश्यकता पर प्रकाश डालता है। कोलंबिया गणराज्य इस वर्ष 17 जून को मरुस्थलीकरण और सूखा दिवस के वैश्विक आयोजन की मेजबानी करेगा, जो प्रकृति-आधारित समाधानों के माध्यम से भूमि क्षरण को संबोधित करने की अपनी प्रतिबद्धता को रेखांकित करता है। बोगोटा में आयोजित यह कार्यक्रम स्थिरता, शांति और समावेशी विकास के उत्प्रेरक के रूप में भूमि बहाली एवं सूखा निवारण की तत्काल आवश्यकता पर प्रकाश डालेगा, साथ ही भोजन, पानी, रोजगार और सुरक्षा सुनिश्चित करने में स्वस्थ भूमि की महत्वपूर्ण भूमिका पर जोर देगा। मरुस्थलीकरण एक तरह से भूमि क्षरण का वह प्रकार है, जब शुष्क भूमि क्षेत्र निरंतर बंजर होता है और नम भूमि भी कम हो जाती है। साथ ही साथ, वन्य जीव व वनस्पति भी खत्म होती जाती है। इसकी कई वजह होती हैं, इसमें जलवायु परिवर्तन और इंसानी गतिविधियां प्रमुख हैं। इसे रेगिस्तान भी कहा जाता है। संयुक्त राष्ट्र के अनुमान के मुताबिक 2025 तक दुनिया के दो-तिहाई लोग जल संकट की परिस्थितियों में रहने को मजबूर होंगे। उन्हें कुछ ऐसे दिनों का भी सामना करना पड़ेगा जब जल की मांग और आपूर्ति में भारी अंतर होगा। ऐसे में मरुस्थलीकरण के परिणामस्वरूप विस्थापन बढ़ने की संभावना है और 2045 तक करीब 13 करोड़ से ज्यादा लोगों को अपना घर छोड़ना पड़ सकता है। विश्व में जमीन का मरुस्थल में परिवर्तन होना गंभीर समस्या एवं चिन्ता का विषय है। भारत में भी यह चिंता लगातार बढ़ रही है। इसकी वजह यह है कि भारत की करीब 30 फीसदी जमीन मरुस्थल में बदल चुकी है। इसमें से 82 प्रतिशत हिस्सा केवल आठ राज्यों राजस्थान, महाराष्ट्र, गुजरात, जम्मू एवं कश्मीर, कर्नाटक, झारखंड, ओडिशा, मध्य प्रदेश और तेलंगाना में है। सेंटर फॉर साइंस एंड एनवायरमेंट (सीएसई) द्वारा जारी “स्टेट ऑफ एनवायरमेंट इन फिगर्स 2019” की रिपोर्ट के मुताबिक 2003-05 से 2011-13 के बीच भारत में मरुस्थलीकरण 18.7 लाख हेक्टेयर बढ़ चुका है। सूखा प्रभावित 78 में से 21 जिले ऐसे हैं, जिनका 50 फीसदी से अधिक क्षेत्र मरुस्थलीकरण में बदल चुका है।