को लकत्या त उष्णतेत वा ढ; ‘सी एसई’चा अहवा ल सी एसई’ने दि ल्ली , मुंबई, को लकता , हैदरा बा द, बंगळूर आणि चेन्नई या महा नगरां ती ल जा नेवा री २००१ ते एप्रि ल २०२४ या का ला वधी त उन्हा ळ्या ती ल हवेचे तसेच जमि नी चे ता पमा न आणि आर्द्रतेच्या डेटा चे वि श्लेषण करून हा नि ष्कर्ष का ढला .
New Delhi: Increasing concretisation and humidity levels are exacerbating heat stress in India’s megacities, which are not cooling down at night at the same rate as a decade ago, according to a new report by the Centre for Science and Environment (CSE). The CSE analysed summer air temperature, land surface temperature, and relative humidity data for six megacities -- Delhi, Mumbai, Kolkata, Hyderabad, Bengaluru and Chennai -- from January 2001 to April 2024. The think tank found that increased humidity is worsening heat stress across all climate zones, even nullifying the marginal drop in air temperatures in Delhi and Hyderabad.
Northwest experienced severe weather conditions in over 17 locations, with temperatures breaching the 48 degrees Celsius mark, testing human endurance. Notably, Delhi's Mungeshpur reported a temperature of 48.8 degrees Celsius yesterday, while Haryana's Sirsa recorded 48.4 degrees Celsius. Meanwhile, the strength of heatstroke patients in Rajasthan increased from 2809 to 3622 yesterday. The Centre for Science and Environment (CSE) tracked heat waves in six major cities in India and the dangerous trends contributing to high temperatures. The science department assessed data from Delhi, Mumbai, Bengaluru, Hyderabad, Chennai, and Kolkata. The heat waves in India have worsened the Urban Heat Island Effect, i.e. when the temperature in urban areas is higher than in rural areas, resulting in a difference, CSE showed. Sharanjeet Kaur, program officer at the Centre for Science and Environment, told NDTV that high temperature and humidity are crucial to understanding cities' heat stress. "Usually, heatwaves occur between March and July, but nowadays, we are witnessing more humidity than heat, resulting in heat stress. The temperature is relatively high at night. Pavements and concrete structures absorb the heat during the day, which gets trapped, resulting in warmer nights," she said. The CSE analysis showed that heat stress results from a deadly combination of air temperature, land surface temperature and relative humidity. This leads to acute thermal discomfort and heat stress in cities. The analysis has pointed to a worrying trend in cities that are increasing in concretisation and decreasing in green cover and water reservoirs. All cities have registered a significant increase in their built-up areas and concretisation, this contributes to the urban heat island effect. During the day, heat is absorbed by concrete, which cannot emit it and hence causing the heat to be trapped. In rural areas, where more green cover is present, the process of transpiration - absorption of water by plants and evaporation through leaves and stems, allows water to be released into the atmosphere. The analysis also revealed that relative humidity has increased in all zones, worsening heat stress in warm-humid and moderate climate zones. This has nullified the fall in air temperatures in composite and hot-dry climate zones, especially during monsoons. The average relative humidity (RH) has significantly increased in the last 10 summers compared to the 2001-10 average.
This indicated that cities were warming at almost double the rate at which the whole country was warming, they said. The authors explained that as cities are highly vulnerable to the combined effects of urbanisation and climate change, the people and the infrastructure in these areas are on the "frontlines" of climate change consequences, such as heatwaves, extreme weather events and flooding. They said the study highlighted the need for diverse mitigation efforts for effectively lowering the ongoing urban warming. According to an analysis by the Centre for Science and Environment (CSE), New Delhi, cities are not cooling down at night like they used to during 2001-2010 because they have "become more concretised in the last two decades" contributing to the rise in heat stress. They said that while increasing green cover can moderate day-time heat, it is ineffective for arresting night-time heat. According to the World Resources Institute (WRI) India Ross Center, seven out of 10 people around the world are projected to live in urban areas by 2050. While about 90 per cent of the growth is expected to happen in the Global South, a significant fraction of this will occur in India, it said. Currently, 36 per cent of India's population, or about 40 crore, is urban and will double to 80 crore by 2050, according to the WRI India Ross Center. With India projected to become the fastest growing economy globally, and expected to witness the greatest urban growth, the latest findings could help urban planners and policymakers better allocate resources and understand the scale of planning required for building sustainable cities, the authors said.
According to an analysis by the Centre for Science and Environment (CSE), New Delhi, cities are not cooling down at night like they used to during 2001-2010 because they have 'become more concretised in the last two decades' contributing to the rise ... Read more at: https://www.deccanherald.com/india/urbanisation-led-to-60-more-night-time-warming-in-indian-cities-than-non-urban-areas-study-3041679
According to an analysis by the Centre for Science and Environment (CSE), New Delhi, cities are not cooling down at night like they used to during 2001-2010 because they have "become more concretised in the last two decades" contributing to the rise in heat stress. They said that while increasing green cover can moderate day-time heat, it is ineffective for arresting night-time heat. According to the World Resources Institute (WRI) India Ross Center, seven out of 10 people around the world are projected to live in urban areas by 2050. While about 90% of the growth is expected to happen in the Global South, a significant fraction of this will occur in India, it said. Currently, 36% of India's population, or about 40 crore, is urban and will double to 80 crore by 2050, according to the WRI India Ross Center. With India projected to become the fastest growing economy globally, and expected to witness the greatest urban growth, the latest findings could help urban planners and policymakers better allocate resources and understand the scale of plann
According to an analysis by Centre for Science and Environment (CSE), New Delhi, cities are not cooling down at night like they used to during 2001-2010 because they have “become more concretised in the last two decades” contributing to the rise in heat stress. They said that while increasing green cover can moderate day-time heat, it is ineffective for arresting night-time heat. According to World Resources Institute (WRI) India Ross Centre, seven out of 10 people around the world are projected to live in urban areas by 2050. While about 90 per cent of the growth is expected to happen in the Global South, a significant fraction of this will occur in India, it said. Currently, 36 per cent of India’s population, or about 40 crore, is urban and will double to 80 crore by 2050, according to the WRI India Ross Centre. With India projected to become the fastest growing economy globally, and expected to witness the greatest urban growth, the latest findings could help urban planners and policymakers better allocate resources and understand the scale of planning required for building sustainable cities, the authors said.
New Delhi — Scorching daytime temperatures due to the intense heat wave sweeping large parts of India and Pakistan are not the only problem facing tens of millions of people in cities. A new study warns that hotter nights and rising humidity levels are worsening heat stress on tens of millions of people, posing a growing health hazard. The study by the New Delhi-based Center for Science and Environment (CSE) points out that cities are not coolin…
Increasing concretization and humidity levels are exacerbating heat stress in India’s megacities, which are not cooling down at night at the same rate as a decade ago, according to a new report by the Centre for Science and Environment (CSE). The CSE analysed summer air temperature, land surface temperature, and relative humidity data for six megacities — Delhi, Mumbai, Kolkata, Hyderabad, Bengaluru and Chennai — from January 2001 to April 2024. The think tank found that increased humidity is worsening heat stress across all climate zones, even nullifying the marginal drop in air temperatures in Delhi and Hyderabad. Barring Bengaluru, summertime average relative humidity has increased by 5-10 per cent in the other five megacities from 2014-2023 compared to the 2001-2010 average. The CSE report comes at a time when blistering heatwaves are affecting health and livelihoods in large parts of India. “Assessing the changing trend in heat, relative humidity, and land surface temperature along with day and night-time temperatures is necessary to develop a comprehensive heat management plan for urban centres,” said Anumita Roychowdhury, executive director of research and advocacy at CSE. Avikal Somvanshi, senior programme manager at CSE’s Urban Lab, said addressing the combination of high heat and humidity is particularly important as it can compromise the human body’s main cooling mechanism, sweating. “The evaporation of sweat from the skin cools our bodies, but higher humidity levels limit this natural cooling. As a result, people can suffer heat stress and illness, and the consequences can even be fatal at much lower ambient temperatures,” he explained. The study showed that megacities are not cooling down at night. The land surface temperature during the summers of 2001-2010 would drop by 6.20-13.20 degrees Celsius from the daytime peak to the nighttime low. In the last 10 summers (2014-2023), night-time cooling has reduced to 6.20-11.50 degrees Celsius, the CSE said. “Hot nights are as dangerous as midday peak temperatures. People get little chance to recover from daytime heat if temperatures remain high overnight,” Somvanshi said. “A study published in ‘The Lancet Planetary Health’ noted that the risk of death from excessively hot nights could increase nearly six-fold in the future. This prediction is much higher than the mortality risk from daily average warming suggested by climate change models,” he said. The study said that rising humidity levels have also made monsoons in Delhi, Mumbai, Kolkata, and Chennai hotter than pre-monsoon periods. It noted that all megacities have become more concretized in the last two decades, increasing heat stress. The CSE highlighted that an increase in green cover is not effective in mitigating nighttime heat. The study showed that Kolkata has the highest percentage of land under concrete and the lowest green cover among the megacities, while Delhi has the least area under concrete and the maximum green cover. Green cover has declined in Mumbai, Kolkata, and Chennai. The built-up area in Chennai has doubled in the last two decades, while its green cover shrank by almost 14 percentage points. (PTI)
नई दिल्ली। लगातार गर्मी बढ़ रही है और ग्रीष्म ऋतु अब कोमल न होकर जलने-झुलसने वाली हो गई है। दिल्ली में तापमान 47 डिग्री को पार कर चुका है। प्रमुख बात यह है कि दिल्ली के हर इलाके में तापमान अलग-अलग दर्ज किया जा रहा है। मौसम विभाग की बेवसाइट के अनुसार 27 मई को शाम पांच बजे नजफगढ़ में तापमान 48.3 डिग्री सेल्सियस दर्ज किया गया तो लोधी रोड में तापमान 36.7 डिग्री सेल्सियस रिकॉर्ड किया गया। वहीं दिल्ली के विभिन्न क्षेत्रों जफरपुर, पूसा रोड, आयानगर, नई दिल्ली, नरेला और पीतमपुरा आदि में तापमान में अंतर दिख रहा था। वैज्ञानिकों का मानना है कि जलवायु परिवर्तन, अर्बन हीट आईलैंड और हीट स्ट्रैस की वजह से दिल्ली के क्षेत्रों में तापमान में अंतर बढ़ रहा है और दिल्ली आग की भठ्ठी बनती जा रही है। सेंटर फॉर साइंस एंड इंवायरनमेंट के अनुसार भले ही जलवायु क्षेत्रों में हवा के तापमान में भिन्नता हो और कुछ भागों में गिरावट भी दर्ज की गई हो, लेकिन अन्य दो कारक – सापेक्ष आर्द्रता और भूमि की सतह का तापमान मिलकर असुविधा और गर्मी से संबंधित बीमारियों का बोझ बढ़ा रहे हैं। अमेरिकी राष्ट्रीय मौसम सेवा के अनुसार, हीट इंडेक्स एक माप है कि वास्तविक तापमान के साथ आर्द्रता को जोड़ने पर वास्तव में कितनी गर्मी महसूस होती है। ऐसा माना जाता है कि 41 डिग्री सेल्सियस का हीट इंडेक्स मानव स्वास्थ्य के लिए खतरनाक है। मुंबई, कोलकाता, बेंगलुरु और चेन्नई में परिवेशी हवा गर्म हो गई है, जबकि दिल्ली और हैदराबाद में यह रुझान उलटा दिख रहा है: मुंबई, बेंगलुरु और चेन्नई में दशकीय गर्मियों के औसत परिवेशी तापमान में 2001-10 की तुलना में लगभग 0.5 डिग्री सेल्सियस की वृद्धि हुई है। कोलकाता का दशकीय औसत भी 0.2 डिग्री सेल्सियस बढ़ा है। दिल्ली और हैदराबाद, दो महानगर जो मिश्रित जलवायु क्षेत्रों में स्थित हैं, जिन्हें सबसे शुष्क और कठोर गर्मियों के लिए जाना जाता है, ने 2001-10 की तुलना में कम दशकीय औसत दर्ज किया है। 2001-10 की तुलना में दिल्ली के लिए दशकीय गर्मियों का औसत 0.6 डिग्री सेल्सियस और हैदराबाद के लिए 0.9 डिग्री सेल्सियस कम है।
नई दिल्ली, सेंटर फॉर साइंस एन एनवायरनमेंट (सीएसई) की एक नई रिपोर्ट के अनुसार, भारत के मेगासिटीज में कंक्रीटीकरण और आर्द्रता का स्तर बढ़ने से भारी तनाव बढ़ रहा है, जो एक दशक पहले की तुलना में रात में ठंडा नहीं हो रहा है। सीएसई ने जनवरी 2001 से अप्रैल 2024 तक छह मेगासिटी - दिल्ली, मुंबई, कोलकाता, हैदराबाद, बेंगलुरु और चेन्नई - के लिए ग्रीष्मकालीन हवा के तापमान, भूमि की सतह के तापमान और सापेक्ष आर्द्रता डेटा का विश्लेषण किया। थिंक टैंक ने पाया कि बढ़ी हुई आर्द्रता सभी जलवायु क्षेत्रों में गर्मी के तनाव को बढ़ा रही है, यहां तक कि दिल्ली और हैदराबाद में हवा के तापमान में मामूली गिरावट को भी कम कर रही है। बेंगलुरु को छोड़कर, 2001-201 के औसत की तुलना में 2014-2023 तक अन्य पांच मेगासिटीज में गर्मियों की औसत सापेक्ष आर्द्रता 5-1 प्रतिशत बढ़ गई है। सीएसई की रिपोर्ट ऐसे समय में आई है जब भारत के बड़े हिस्से में भीषण गर्मी स्वास्थ्य और आजीविका को प्रभावित कर रही है। सीएसई में अनुसंधान और वकालत के कार्यकारी निदेशक अनुमित रॉयचौधरी ने कहा, "शहरी केंद्रों के लिए व्यापक गर्मी प्रबंधन योजना विकसित करने के लिए दिन और रात के तापमान के साथ-साथ गर्मी, सापेक्ष आर्द्रता और भूमि सतह तापमान में बदलती प्रवृत्ति का आकलन करना आवश्यक है।" सीएसई की अर्बन लैब के वरिष्ठ कार्यक्रम प्रबंधक अविकल सोमवंशी ने कहा कि उच्च गर्मी और आर्द्रता का संयोजन विशेष रूप से महत्वपूर्ण है क्योंकि यह मानव शरीर के मुख्य शीतलन तंत्र, पसीने से समझौता कर सकता है। “त्वचा से पसीने का वाष्पीकरण हमारे शरीर को ठंडा करता है, लेकिन उच्च आर्द्रता का स्तर इस प्राकृतिक ठंडक को सीमित कर देता है। परिणामस्वरूप, लोग गर्मी के तनाव और बीमारी से पीड़ित हो सकते हैं, और बहुत कम परिवेश के तापमान पर परिणाम घातक भी हो सकते हैं,'' उन्होंने समझाया। अध्ययन से पता चला कि मेगासिटीज रात में ठंडी नहीं हो रही हैं। 2001-2010 की गर्मियों के दौरान भूमि की सतह का तापमान दिन के चरम से रात के न्यूनतम तापमान तक 6.20-13.20 डिग्री सेल्सियस तक गिर जाएगा। सीएसई ने कहा कि पिछली 10 गर्मियों (2014-2023) में रात के समय ठंडक घटकर 6.20-11.5 डिग्री सेल्सियस हो गई है। “गर्म रातें दोपहर के चरम तापमान जितनी ही खतरनाक होती हैं। सोमवंशी ने कहा कि अगर रात में तापमान अधिक रहता है तो लोगों को दिन की गर्मी से उबरने का बहुत कम मौका मिलता है। 'द लैंसेट प्लैनेटरी हेल्थ' में प्रकाशित एक अध्ययन में कहा गया है कि अत्यधिक गर्म रातों से मृत्यु का खतरा भविष्य में लगभग छह गुना बढ़ सकता है। यह भविष्यवाणी जलवायु परिवर्तन मॉडल द्वारा सुझाए गए दैनिक औसत वार्मिंग से होने वाली मृत्यु जोखिम से कहीं अधिक है, ”उन्होंने कहा। अध्ययन में कहा गया है कि आर्द्रता के बढ़ते स्तर ने दिल्ली मुंबई, कोलकाता और चेन्नई में मानसून को प्री-मानसून अवधि की तुलना में अधिक गर्म बना दिया है। इसमें कहा गया है कि पिछले दो दशकों में सभी मेगासिटी अधिक ठोस हो गए हैं, जिससे गर्मी का तनाव बढ़ गया है। सीएसई ने इस बात पर प्रकाश डाला कि रात की गर्मी को कम करने के लिए ग्रीन कवर में वृद्धि प्रभावी नहीं है। अध्ययन से पता चला कि महानगरों में कोलकाता में कंक्रीट के नीचे भूमि का प्रतिशत सबसे अधिक और हरित क्षेत्र सबसे कम है, जबकि दिल्ली में कंक्रीट के नीचे सबसे कम और हरित क्षेत्र सबसे अधिक है। मुंबई, कोलकाता और चेन्नई में हरित आवरण में गिरावट आई है। पिछले दो दशकों में चेन्नई का निर्मित क्षेत्र दोगुना हो गया है, जबकि इसका हरित आवरण लगभग 14 प्रतिशत कम हो गया है।
New Delhi - Scorching daytime temperatures due to the intense heat wave sweeping large parts of India and Pakistan are not the only problem facing tens of millions of people in cities. A new study warns that hotter nights and rising humidity levels are worsening heat stress on tens of millions of people, posing a growing health hazard. The study by the New Delhi-based Center for Science and Environment (CSE) points out that cities are not cooling down at night as much as they used to. It looked at six of India's megacities, Delhi, Mumbai, Kolkata, Hyderabad, Chennai and Bengaluru over 23 years.
A new study by Delhi-based think tank Centre for Science and Environment (CSE) has uncovered a pressing issue in India’s major cities: Heat waves are intensifying due to a combination of rising temperatures, increasing humidity and urban expansion. The research reveals a disturbing trend: cities are not cooling down at night as much as they did during 2001-2010. This trend poses a serious threat to public health and urban life. The study, Decoding the Urban Heat Stress among Indian cities, analysed data from six major cities – Delhi, Mumbai, Kolkata, Hyderabad, Chennai and Bengaluru — over 23 years (January 2001- April 2024). It found that while air temperatures haven’t risen significantly in some cities, increased humidity is worsening the heat stress people experience. Heat stress, a condition resulting from a combination of air temperature, land surface temperature, and relative humidity, is not just about discomfort. It leads to acute thermal discomfort and increases the risk of heat-related diseases in cities. Even if air temperatures vary, high relative humidity and land surface temperatures can exacerbate this discomfort, posing a serious threat to human health. The United States National Weather Service states that the heat index, which includes humidity, indicates how hot it feels, with a heat index of 41 degrees Celsius being dangerous for human health. Assessing the changing trend in heat, relative humidity, land surface temperature, and day and nighttime temperatures is necessary to develop a comprehensive heat management plan for urban centres. Further, it is necessary to implement emergency measures during heat waves to protect public health. She also added that she would develop longer-term strategies to mitigate heat by increasing green areas and waterbodies, improving thermal comfort in buildings, and reducing waste heat from vehicles, air conditioners, and industries. As a result, people can suffer heat stress and illness, occasionally with fatal consequences even at much lower ambient temperatures. Interestingly, nighttime temperature remains elevated in cities, he added. The culprit behind rising humidity? Uncontrolled urban sprawl. The study found a direct correlation between an increase in built-up area and a rise in urban heat stress in all six cities. For example, Chennai has seen its green cover shrink by nearly 14 percent in the last two decades, while concretisation has doubled. This trend creates a harmful cycle as concrete absorbs and retains heat, contributing to the "urban heat island effect" in cities, making them significantly warmer than surrounding areas. Hotter nights are another worrying finding. While cities used to cool down considerably at night, the study shows that nighttime cooling has significantly reduced in recent years. This means people get little respite from the daytime heat, further impacting their health. The consequences of this deadly combination are dire. The study has flagged a surge in the number of days with a heat index exceeding 41°C (considered dangerous for human health) in cities like Kolkata and Chennai. Moreover, monsoons are no longer providing relief, with some cities experiencing hotter and more humid conditions during this period compared to pre-monsoon months. This underscores the urgent need for action and the potentially catastrophic outcomes of inaction. The CSE study underscores the need for immediate action to combat this escalating threat. It advocates for the implementation of city-specific heat management plans that extend beyond emergency response during heat waves. These plans should focus on reducing heat generation from buildings, vehicles, and industries and increasing green cover and water bodies in cities to create a cooling effect. The time for action is now. The study also called for reversing land use by increasing green cover and water bodies in cities to create a cooling effect. Strengthening scientific monitoring of heat-related factors like land use and surface temperatures and developing emergency action to shield vulnerable communities from heat waves is also important.
A new study by Delhi-based think tank Centre for Science has revealed a dangerous trend in India's biggest cities th becoming deadlier due to a combination of rising tempera humidity and urban expansion. The research has also unc phenomenon that cities are not cooling down at night as 2001-2010
सीएसई की अर्बन लैब के वरिष्ठ प्रोग्राम मैनेजर अविकल सोमवंशी का कहना है कि बढ़ते तापमान और उमस के चलते मानव शरीर में पसीने का वाष्पीकरण नहीं हो पा रहा है और उस वजह से शरीर की जो खुद अपने आप को ठंडा करने की प्रक्रिया थी, वो नहीं हो पा रही है। ऐसे में शरीर में गर्मी संबंधित समस्याएं बढ़ रही हैं।