The increasing frequency of extreme temperatures and heatwaves across the globe is no longer an abstract concept but a harsh reality, particularly in the Global South. According to the IPCC Working Group II Sixth Assessment Report on Impacts, Adaptation, and Vulnerability, the relentless rise in greenhouse gas emissions will inevitably push human tolerance to its limits. The combination of escalating heat and humidity is poised to create perilous conditions, compromising the human body's ability to regulate temperature and increasing the risk of heat-related deaths.
This global scenario is acutely felt in the developing nations of the Global South, where cities are most vulnerable to the impacts of climate change. Rapid urbanisation, inadequate infrastructure, and socio-economic challenges are magnifying the effects of rising temperatures. Cities in these regions experience extreme weather patterns that strain infrastructure and public health systems, creating an urgent need for comprehensive climate mitigation efforts.
The predicament of one city in particular, the 12th largest in the world — Karachi, exemplifies these broader challenges. The city's sweltering heatwave of June 2015 remains a grim reminder of the escalating crisis, resulting in the tragic deaths of 1,200 people (these remain the official figures but first responders reported at the time that there were more than 6,000 causalities) and leaving hundreds more with lasting health issues. The torrential rain that followed inundated homes, causing widespread devastation and financial losses in August 2020. It is sobering to consider that this level of destruction stemmed from just a few degrees rise in temperature. However, other factors exacerbated the crisis, including energy and water shortages, the lack of green spaces, high population density, inadequate housing, and insufficient policies for outdoor workers.
The recent surge in temperatures, which have once again transformed the city into a furnace, are not isolated events but a troubling chapter in the broader narrative of global warming, climate change, and environmental crisis. The alarming reality is that these extreme temperatures are no longer fleeting anomalies; they have become the new norm, pushing Karachi and other cities in the Global South to the brink.
From 2015 to 2024, the absence of comprehensive data on heatwave-related fatalities and chronic impacts on communities in Karachi underscores significant gaps in our understanding. Despite experiencing numerous heat waves of varying intensity and profound consequences, our institutions lack vital statistics on human casualties and the broader health impacts of prolonged heat exposure.
The complexity of rising temperatures in Karachi is exacerbated by high humidity levels, which amplify the heat index—a critical metric in assessing thermal discomfort. Beyond this, the wet-bulb globe temperature (WBGT) emerges as a crucial indicator. With temperatures often exceeding 35 degrees Celsius (95°F), the threshold of human survivability, WBGT measures the combined effects of temperature, humidity, and radiant heat on the human body. For individuals, particularly in well-ventilated or shaded environments, WBGT levels above this threshold impede the body's ability to regulate internal heat, posing severe health risks that can lead to fatal outcomes within a few hours. The persistent heatwaves gripping Karachi now are a stark reminder of the escalating climate emergency. A rise of just a few degrees in temperature can profoundly alter the city's environment, exacerbating existing vulnerabilities. The city's infrastructure, already strained by rapid urbanisation and inadequate planning, is ill-equipped to handle these increasingly common and intense heat events.
This local crisis is but a microcosm of the global climate challenge. Karachi's plight underscores what lies ahead for many urban centres if the world fails to urgently address this pressing issue with comprehensive climate mitigation strategies. As temperatures soar across the world, the impacts of climate change are becoming more pronounced and too real to ignore. The world is witnessing an environmental emergency that demands immediate and sustained action. The imperative for global solidarity and decisive action to combat climate change has never been clearer.
Challenge of extreme heat
Emerging research on extreme heat in South Asia underscores the complexities and severe implications for vulnerable populations, particularly those living in informal settlements. These areas typically have poorly ventilated homes and limited access to essential infrastructure such as water, electricity, and shade, all critical for cooling.
The Pakistan Meteorological Department has forecast continued hot and humid weather for the end of June 2024, with humidity levels potentially reaching up to 80% in the mornings and 60% in the evenings. Although rain and gusty winds may provide temporary relief, the underlying issues remain unaddressed. This forecast follows a recent trend of historically high temperatures, driven by a mix of natural, cyclical events like El Niño and persistent greenhouse gas emissions. Despite the resurgence of La Niña offering a potential respite, the relief may be fleeting as global temperatures consistently exceed thresholds outlined in the Paris Agreement.
The IPCC report highlighted the urgent need for rapidly eliminating greenhouse gas emissions to prevent further escalating these life-threatening conditions. For Karachi and many other cities in the Global South, the intersection of climate change, rapid urbanisation, and socio-economic vulnerabilities demands immediate and comprehensive action.
As the world looks towards mitigating climate change, Karachi's experiences underscore the critical need for adopting resilience-building measures tailored to the unique challenges of the Global South. The city's struggle against rising temperatures and humidity is not just a local issue but a part of a global narrative of climate change impacting millions. This is a call for global solidarity and taking swift, decisive actions to protect the most vulnerable populations from the ravages of a warming planet.
Solving Karachi's heat stress
State institutions and Karachi's local government must address several critical issues pertaining to the unique challenges that rising temperatures pose for a city of 30 million, with a particular focus on the harms inflicted upon the poor, marginalised, and vulnerable communities. These harms encompass direct and indirect impacts, including increased chronic disease burdens, exacerbation of respiratory conditions, heat stress-related injuries, displacement, and infrastructural damage. To effectively address these issues, it is imperative to engage with the communities most affected by these adverse conditions and develop comprehensive, context-specific strategies that can mitigate the impacts of rising temperatures and enhance the resilience of these communities.
To effectively mitigate the impact of heatwaves and safeguard communities in Karachi, the government can adopt a comprehensive, multi-tiered approach. A series of targeted actions can be implemented at all administrative levels, from the provincial government down to the union councils and the district disaster management authorities. Stop electricity load-shedding for the most vulnerable population - on a hot day, something as simple as a fan and a small electric icebox to provide cold water can be invaluable. Establishing cooling centres equipped with air conditioning, water, and basic medical facilities across Karachi is crucial, especially for the vulnerable populations. Free transportation to these centres would ensure that those with limited mobility, including the elderly and the specially-abled, can access them.
Additionally, distributing fans to low-income households through partnerships with local NGOs can help those in the greatest need. Public education campaigns about the dangers of extreme heat and effective cooling strategies should be disseminated via social media, radio, television, and community meetings. Encouraging community engagement by promoting a culture of checking on neighbours, particularly the elderly and medically vulnerable, is essential.
Deploying enhanced early warning systems using SMS, social media, and public announcements can alert residents about impending heat waves. Urban planning improvements, such as increasing green spaces and tree canopies and promoting better-ventilated building designs, can reduce the urban heat island effect. Regularly updating heatwave emergency response plans and conducting drills will ensure preparedness among emergency responders and the community. Collaborating with healthcare facilities to prepare for an influx of heat-related illnesses and training healthcare professionals to recognise and treat heatstroke and dehydration is also critical.
Karachi's struggle is emblematic of the urgent climate crisis facing the world. As global temperatures continue to rise, cities like Karachi will increasingly bear the brunt of extreme weather. Its plight serves as a stark warning. However, by implementing these measures and engaging the community, Karachi can build resilience against heatwaves, protect its citizens from the severe impacts of rising temperatures, and provide a model for other cities facing similar challenges.