On October 6, 2024, hundreds of people had gathered at Chennai’s Marina Beach to watch an air show by the Indian Air Force. The temperature had soared to 35 degrees Celsius; the extreme heat eventually claimed five lives and at least 300 spectators collapsed while watching the air show. Heat stress, or heat exhaustion, had taken more lives in a city where outdoor activities have been a part of daily life and songs celebrating sunlight are on people’s lips.
However, increasing heat-related morbidity, particularly among children and people above 65 years old, as highlighted in the Lancet Countdown, has been a growing concern. The recent survey on heat waves that we, at Poovulagin Nanbargal, have done point to a significant reduction in outdoor activity affecting people’s physical and emotional well-being. This is an example of the broader impact of climate vulnerability on people’s daily life and underlines the importance of climate vulnerability mapping.
This becomes more important when done by communities themselves, especially the marginalised communities, as climate vulnerability seen in the rising risks of heat- and flood-related mortality, become more pronounced in Tamil Nadu. Recognising the state’s diverse geography—encompassing mountains, forests, agricultural lands, seashores and deserts—the state shows a varying vulnerability to climate change.
With a coastline spanning approximately 1,076 kilometres – or 15 percent of India’s entire coastline – Tamil Nadu faces significant risks from rising sea levels and extreme weather events. The increasing frequency of cyclones, particularly since the devastating floods in Chennai in 2015, makes the need for climate vulnerability mapping urgent. As is well acknowledged now, the marginalised communities will bear the brunt of climate events.
The climate vulnerability mapping in Tamil Nadu that we have done has been instrumental in identifying regions most at risk from floods, droughts, thermal discomfort, and sea level rise. By downscaling global climate models to include localised data, our comprehensive risk assessments focused on factors such as city climate risks, shoreline changes, and habitat suitability. These mappings have highlighted vulnerable districts and regions which can help in planning adaptive strategies such as modifying agricultural practices. Areas predicted to face severe droughts can shift towards more drought-tolerant crops while regions at risk of flooding may plan infrastructure accordingly.
Chennai developed a climate action plan addressing both current climate issues and future projections. It includes solutions aimed at mitigation and adaptation, and integrated inputs from various civil society organisations (CSOs) and the public. However, while the plan is forward-thinking, the challenge lies in translating the strategy into actionable results. This is where organisations like ours, Poovulagin Nanbargal, play a role.
Photo: Poovulagin Nanbargal
Climate issues as part of larger advocacy
Poovulagin Nanbargal (Friends of the Earth) is among Tamil Nadu’s distinguished environmental organisations with four decades of work to educate the youth on the significance of environmental issues and climate change. We have used a multifaceted approach that includes campaigns, seminars, webinars, television discussions, YouTube videos, and the publication of informative books in Tamil. Poovulagin Nanbargal is also actively involved in litigation and policy advocacy on environmental issues. I train young leaders to spearhead impactful climate actions.
Poovulagin Nanbargal is entirely volunteer-driven where individuals contribute their unique skills for environmental advocacy. Our diverse team includes engineers, artists, lawyers, journalists, and doctors; we publish a monthly magazine, Poovulagu, which reaches more than 3,000 readers including in government schools, colleges, policy makers, and the public making climate news accessible in Tamil. Additionally, we organise events every month such as climate courses and conferences besides doing policy advocacy. Our volunteers have also contributed to government papers.
Our advocacy work has focused on opposing unsustainable development projects such as the Koodankulam Nuclear Power Plant, tungsten mining, neutrino exploration, atomic mineral mining, and polluting thermal power plants. Climate mapping became a part of the work. Our recent work has been in Neyveli, 217 kilometres from Chennai, where communities live in proximity with thermal power stations. These communities had sacrificed their land for the nation’s energy needs but they now suffer from severe pollution. Once known for its artesian wells, the region now grapples with poor air quality and water scarcity, affecting even children and pregnant women.
Climate change and its impacts form a significant part of our work with fishermen and farmers. The livelihoods of the fisherfolk are increasingly jeopardised by pollution, overfishing, plastic pollution, and climate-induced challenges such as sea level rise, coastal erosion, and ocean acidification. Farmers face dual threats of extreme heat which can devastate crops in days and recurring floods which inundate their fields. Frequent cyclones make it difficult for urban dwellers. Common to all these communities is their struggle with wet-bulb conditions—a dangerous combination of high temperature and humidity which severely impairs the body’s ability to cool itself and could lead to potentially fatal heat strokes.
Photo: Wikimedia Commons
How climate vulnerability mapping is done
Many community members recognise that something is fundamentally changing with the climate, as evidenced by altered monsoon patterns, extreme rainfall, and rising temperatures. However, there is a pervasive sense of helplessness and many believe that these changes are beyond their control, that adaptation is their only recourse. In some cases, entire villages have been abandoned due to water scarcity, drought, and flooding, highlighting the urgent need for more proactive climate adaptation and resilience-building efforts. Their involvement in climate mapping comes from all this.
When we do climate vulnerability mapping with them, we primarily rely on data from global projections and reputable sources like NASA and the Intergovernmental Panel on Climate Change (IPCC). These datasets provide broad overviews but lack the localised focus necessary for effective micro-level policy and action. Understanding local projections and regional nuances is essential for creating targeted solutions. Tamil Nadu provides vulnerable communities with training and capacity-building through various departmental programmes focusing on Sustainable Development Goals (SDGs) but indigenous knowledge and innate skills of these communities are invaluable for climate adaptation and resilience.
Their traditional understanding of weather patterns, seasonal changes, and the biodiversity of plants and animals plays a critical role in fostering adaptive strategies. These communities understand climate vulnerability in their daily lives. It is increasingly evident, for example, through the rising risks of heat-related mortality or anxiety about floods.
We do climate vulnerability mapping in various ways. Lokesh Parthiban, a geologist, uses remote sensing satellite data to look at past and present data to make predictions about temperature, green cover, built up index, sea-level rise. We have natural resources in Tamil Nadu – the Western Ghats, Eastern Ghats, a large stretch of the sea, and several rivers; the reduction of green cover, agricultural lands, the increase in temperatures, increases the possibility of forest fires and drought. We use these predictions to identify vulnerable areas.
We have volunteers all over Tamil Nadu who help us verify data from the ground. One of these places is Nagapattinam where sea level rise has meant that land has gone under the sea and salt water intrusion is high, reducing agricultural productivity. Fisherfolk are getting impacted too. Our volunteers are spread out all over the state and we conduct youth conferences, climate training programmes, kaalanilai palli (climate school), and public meetings. The data is compiled and assessed by the team. Experts like Lokesh contribute to this.
Locals from districts all over the state are invited to take part in kaalanilai palli which is an online programme for farmers, fisherfolk, lawyers, doctors, college students, PhD students, and housewives who want to change the places they belong to, as well as professionals in the climate space. We start with the basics of the history of earth, biodiversity and climate change beyond fossil fuels, as the impact of capitalist structures – overproduction, consumerism that is destroying the environment. We also teach about issues from the local to international level, and become well-versed with conventions like the Conference of Parties (COP). At the end of this course, we discuss solutions. About 70 volunteers have joined our climate vulnerability mapping from these programmes.
Our Youth and Climate programme for college students goes to two-three new districts where we meet about 1,000 students every year; of these, about 20 join us. This way, there is always at least one person we can reach out to from every district. We coordinate with them and collect data through them. It is not easy to get replies from communities to our surveys but having our network makes this possible. The Climate Studio in Anna University gives localised data which we use.
Photo: Wikimedia Commons
Mapping influences action
We are constantly looking at data to identify climate hotspots given that farmers and coastal communities may not know how to interpret data or the impact of climate change. We also offer them litigation support. An example is the report from Neyveli called Powering Pollution which was talked about in the mainstream media after which the National Green Tribunal took suo motu cognisance. The case is ongoing.
Our mapping work to identify vulnerable spots is always ongoing. This also helps us to identify environmental threats like the proposal for tungsten mining in Madurai, which was put on hold after the locals protested against it. [1] Poovulagin Nanbargal started the conversation about this.
The Comprehensive Heat Mitigation strategy put together by the Tamil Nadu government draws from our work and advocacy on wet bulb conditions and heat waves. Recently the government declared the heat wave a disaster. It would not have happened without interventions and advocacy from CSOs like ours. Our team member Sundarrajan is a part of the Tamil Nadu Green Climate Company.
Women and other marginalised groups are key participants in climate resilience efforts. As part of a specific initiative, women from Self-Help Groups (SHGs) are being equipped with e-autos, becoming ‘climate warriors’ who raise awareness and promote sustainable practices within their communities. These women play a central role in spearheading environmental awareness campaigns while also benefiting from new livelihood opportunities that support their families and communities.
Photo: Poovulagin Nanbargal
The state government has been taking several steps to address climate-related challenges and aligning these with climate vulnerability mapping. For example, heat-related deaths have been officially recognised as a state-specific disaster, which allows for disaster relief to be provided to affected communities. This also means that heat is no longer considered a normal phenomenon and has led to the establishment of heat-specific healthcare facilities.
Additionally, the government is evolving strategies to mitigate heat risks and is embracing the concept of “One Health”—a preemptive approach to addressing the intertwined health risks to people, animals, and the environment in the context of climate change. The state is also working on developing state-specific action plans, district action plans, greenhouse gas inventories, and vulnerability assessments.
To empower communities affected by climate events, the key focus should be on adaptation and resilience. It is clear that Tamil Nadu, like many other regions, will continue to face the adverse effects of climate change in various forms. The state must prioritise building infrastructure which safeguards for vulnerable regions. A major challenge is the gap between adaptation finance needs and the funding available.
The impacts of climate change are disproportionately felt by the poor and vulnerable, making it critical that adaptation efforts are not only well-financed but also equitable. To truly build resilience, the state must focus on training and providing alternative livelihood opportunities for groups like fishermen and farmers, helping them bounce back from disasters. However, localised vulnerability mapping, monitoring and early warning systems will be crucial to address climate risks in the future.
Jenny Mariadhas is a climate change activist and researcher with over seven years of experience in environment laws and climate advocacy. She completed her education in engineering with a Masters in Environmental Management from CES, Anna University, and was part of the climate literacy team which created modules to be circulated to around 12,000 eco-clubs in Tamil Nadu. As a member of the environmental organisation, Poovulagin Nanbargal, she trains young leaders to spearhead impactful climate actions.
Cover photo: Wikimedia Commons
