CLIMATE LITIGATION AND URBAN HEAT ISLANDS: PIL STRATEGIES FOR COOLING MEASURES IN METRO INDIA
INTRODUCTION
India’s accelerated urbanisation has catalysed enormous progress but it has compounded environmental challenges that impact metropolitan populations, particularly Urban Heat Islands (UHIs) – the phenomenon whereby city centres experience significantly higher temperatures than surrounding peri-urban and rural areas – which have emerged as potential public health and environmental crises. In urban metros like Delhi, Mumbai, Bengaluru, and Chennai, we can observe these rising ambient temperatures exacerbated by unregulated development, loss of green space, vehicular emissions produced by dense and growing populations, and the rise of heat-absorbing hardscapes like concrete and asphalt.
Simultaneously, climate litigation is fast becoming a central instrument for environmental protection in India. Whether through the celebrated environmental lawsuits of MC Mehta or the recent Supreme Court judicial interventions arising from the poor air quality in the National Capital Region (NCR), Public Interest Litigations (PILs) have significantly impacted the trajectory of environmental jurisprudence and enforcement in India. The larger question at hand is whether we can mobilise other litigation strategies that have been employed in the past to pressure governments, municipal corporations, and private parties to adopt “cooling measures” including investments in green infrastructure, reflective building materials, improved ventilation and equitable access to public cooling space.
This article analyses the breadth of climate litigation and PILs, in addressing Urban Heat Islands in India’s metropolitan spaces. The article investigates the constitutional framework, jurisprudence on environment rights, relevant international best practices and possible ways litigants could adopt in addressing the urban heat crisis.
URBAN HEAT ISLANDS IN INDIA: UNDERSTANDING THE CHALLENGE
The Urban Heat Island effect results when one larger site in a city retains more heat than another non-urbanized area adjacent to it. Natural heat islands are produced by four types of factors:
1. Buildings in a dense area featuring hard surfaces, as well as pavements and concrete that absorb sunlight and reflect heat.
2. Loss of green and open spaces and vegetation by way of land clearing, encroachment, or high-speed urbanization by private hands.
3. Air pollution and heat emission are caused by excess and uncontrolled automobile emissions and industrial products.
4. Unplanned urbanization with no respect to climate-sensitive building or planning.
In contrast, mean average summer UHI of about 4–7°C has been registered in Delhi as against adjacent rural areas, creating-centre heat stroke, cardiovascular complications, dehydration-related mortality crises for the population at large. Similar concerns arise about heat extremes and climate change and were revealed in a study by the Indian Institute of Tropical Meteorology about Mumbai, Kolkata, and Hyderabad.
The lack of UHI makes several serious consequences on health, and energy sustainability since dependence on AC escalates power consumption.
CONSTITUTIONAL FRAMEWORK AND JUDICIAL RECOGNITION OF ENVIRONMENTAL RIGHTS
The Indian Constitution does not specifically grant “the right to a cool or safe climate” as a legal entitlement for individuals; however, the judiciary has interpreted Article 21 – the right to life – broadly, such that this right includes the right to a healthy environment. In MC Mehta v Union of India, the Supreme Court developed the Indian law of climate action, stating that environmental protection cannot be separated from the right to life.
In addition, Articles 48A and 51A(g) clarify that the State, or citizens, have a duty or obligation to protect and improve the environment. Although Directive Principles are not enforceable, courts routinely employ them as a rights basis for advancing environmental governance.
UHIs, as threats to wellbeing, the environment, and conditions for sustainable living/eco-social entitlement, fall squarely within the framework of constitutional environmental rights giving citizens a rights language and context for accessing the courts through PILs.
(Public Interest Litigations) in India is long and rich, with many attributed to activist-lawyer MC Mehta. Some key interventions by Indian courts include:
• MC Mehta v Union of India (1987): directing the closure of polluting industries in Delhi to address air pollution;
• Vellore Citizens Welfare Forum v Union of India (1996): repair the protection and restoration of environment law jurisprudence in India, recognizing “precautionary principle” and “polluter pays principle” as the underlying principles of Indian environmental law;
• Subhash Kumar v State of Bihar, India (1991): finding that the right to life implies the right to pollution free water and air;
• M.C. Mehta v Kamal Nath, (1997): the first judgement applying the public trust logics domestically to environmental resources.
Most recently, in the Delhi Air Pollution case, the Supreme Court ordered the implementation of the odd-even vehicle travel scheme, the closure of brick kilns, and new regulations on stubble burning. These cases illustrate the judiciary’s capacity to intervene when the executive branch refuses to take steps to mitigate environmental crises.
What remains unnoticed in litigation, however, are urban heat islands as a phenomenon in India. This creates an opening for climate advocates, urban planners, and others concerned with urban heat islands to advance an argument framing urban heat islands as a matter of public health and climate justice, and can demand systematic means of cooling in urban areas.
PIL STRATEGIES FOR TACKLING URBAN HEAT ISLANDS
To address UHIs through litigation, PILs must combine constitutional rights, scientific data, and comparative legal frameworks. Key strategies must advance UHIs, including the following:
1. Framing UHIs as a Right to Life and Health Issue.
Petitioners could argue that state legislation allowing urban heat impacts when urban lands are developed violates Article 21 since extreme heat causes death and/or heatstroke, and worsens health vulnerabilities. This strategy has been implemented successfully, as in the air pollution and water pollution cases.
2. Linking UHIs to International Climate Change Commitments.
India is a party to the Paris Agreement (2015), and committed to produce climate-resilient cities. Petitioners could argue that failures from Urban State in relation to UHIs disreputes India’s obligations to comply with international climate law.
3. Invoking Public Trust Doctrine.
Courts may also be persuaded that there is an express or implied obligation to protect natural resources (including trees in urban areas, lakes, green belts) entrusted to the public. Established destruction and negligence in relation to these aspects contribute to UHIs and become a duty of care that is judicially enforceable.
4. Asking for Cooling Measures through Court Orders and Directions.
Petitioners can also ask the Courts for all of the following to be ordered:
• To mandate green roofing, and/or green materials identifies to be reflective in materials, when a new structure of any size is developed, or redeveloped.
• Creating urban greening programs that particularly target slum areas as they are the areas most affected by extreme heat.
• Creation and management of cooling centres for the community in locations such as public metropolitan stations or schools, etc.
• To enhance existing tree-lined corridors as well as existing wetland conditions of meeting tree areas for summer cooling benefits.
5. Applying Precautionary Principle
It is the unanimous decision of courts that scientific doubts must not be used as justification for inaction. Under the precautionary principle, the petitioners could argue persuasive proactive cooling actions in the absence of an absolute scientific understanding of the magnitude of UHI.
COMPARATIVE PERSPECTIVES: GLOBAL LITIGATION ON URBAN HEAT
Worldwide, cities are increasingly acknowledging UHIs as a policy and governance phenomenon:
• New York City started a “Cool Roof Program” making reflective paints compulsory to help manage heat.
• Los Angeles has passed ordinances requiring “cool pavements” to reduce heat absorption.
• Japan has adopted heat island countermeasures as part of their national climate strategy.
• The European Union case law has framed actual or foreseeable heat-related deaths as a failure to protect human rights.
Indian courts, which usually follow comparative jurisprudence, could potentially use these developments in other countries to develop new forms of relief for UHIs.
CHALLENGES IN CLIMATE LITIGATION FOR UHIS
Despite the broad scope of PILs, a number of challenges remain:
1. Lack of Data – In India, there is little accurate city-specific UHI data. As a result, it is difficult to litigate against UHI.
2. Implementation Deficit – In many instances when the courts do order remedies (for example, the management of waste, vehicular bans, etc.) efforts made toward compliance often fall flat.
3. Development vs. Environment—For economic reasons, sometimes courts do not stop building developments or sometimes may even order remediation by way of mediation.
4. Fragmented Governance—It should be noted that accountability is tough due to the multiple redundancies of governance authorities, which include municipal corporations, state governments, and the central ministry.
For all these reasons, while a PIL is a very strong tool, it continues to miss its mark while still operating only in litigation mode; hence, advocacy in terms of policy, community engagement, and science-based collaboration has to be added to it.
WAY FORWARD
The approach would have to be multi-pronged in addressing the Urban Heat Islands (UHIs) through PILs:
– Judicial Intervention: Because of constitutional rights promulgated by courts for a healthy environment, cooling measures should also be imposed.
– Legislative Changes: A national environmental framework on urban climate resilience would provide support from a legal perspective.
– Administrative Responsibility: Municipality corporations must have cooling measures incorporated into the city master plan.
– Community Input: Citizens and NGOs should urge and advocate for tree plantation drives, rooftop gardens and sustainable housing.
Ultimately on the issue of UHI, it is not just about saving lives or in terms of temperature reductions, or the equity for that matter, but is also an aspect of climate adaption.
CONCLUSION
While Indian metropolises are, in a manner of speaking, very local sites of vulnerability in the climate crisis, human health, sustainability, and quality of life are becoming increasingly compromised by rising temperatures in the environment. With the advent of the Urban Heat Island effect, it has turned an ecological and social justice issue. Public interest litigation, considering their past success at spatial environmental governance, may well become a tool through which citizens can demand state accountability and a structural transformation of our cities.
In the event that litigators successfully establish a case for UHIs as an infringement of the right to life, with a healthy atmosphere and with environmental justice, the courts may have to order that the government make sufficient measures to cool down urban areas (i.e., green infrastructure, regulatory framework). Judging by the world over, litigation has sometimes resulted in forcing reforms in favour of urban cooling, and Indian cities cannot afford to be outpaced.
As India moves forward in its aspirations for sustainable urbanisation, such climate-related litigation with respect to UHIs may possibly get identified as an area of concern with environmental justice, and there must then be consideration for keeping our cities liveable under change and global warming.
REFERENCES
• Constitution of India 1950.
• MC Mehta v Union of India (1987) 1 SCC 395.
• Vellore Citizens Welfare Forum v Union of India (1996) 5 SCC 647.
• Subhash Kumar v State of Bihar (1991) 1 SCC 598.
• MC Mehta v Kamal Nath (1997) 1 SCC 388.
• M C Mehta v Union of India (2019) 17 SCC 653.
• Indian Institute of Technology Delhi, Urban Heat Island Study Report (2021).
• Indian Institute of Tropical Meteorology, Heatwave Vulnerability Assessment (2020).
• New York City Environmental Protection Agency, Cool Roof Program (2019).
• City of Los Angeles, Cool Pavements Pilot Project Report (2020).
• Ministry of Environment, Japan, Heat Island Countermeasure Strategy (2018).
• European Court of Human Rights, KlimaSeniorinnen v Switzerland (2023).
