Lessons to learn from Karachi Heatwave 2015
Cool breezes, frothy clouds, plentiful trees, clean roads with less traffic and trams running on some – this is how the old generation Karachiites remember their beloved city – a memory cherished often and prompted by the recent harsh heat wave.
This beautiful memory of pre-1990 era is long gone and so is the pleasant weather which along with the sea breeze and hospitality of city compelled many to leave their hometowns and families behind to realize their dreams and make a living in this city once known as the city of lights.
What happened in the last 3 decades that turned Karachi from the City of Lights to City of Chaos and Crowd?
Violence, crimes, electricity and water shortage, political crises have made the citizens somewhat resilient to hardships. But they were never prepared for the killing heat wave which brought city temperature up to 45 degree Celsius and left thousands dehydrated and about 1200 dead.
It was 45 degrees but felt like 50 because of the hot air trapped inside the city, explained climatologist Qamar-Uz-Zaman Chaudhry adding: “The city is like a furnace that captures the heat without letting it escape” which makes citizens swelter, suffer or even die.
Heatwave was recently witnessed in India recently where the highest recorded temperature of 47 degrees Celsius killed over 2400 people. The worst heat wave that gripped Europe in 2003 killed more than 70,000 over 4 months.
The analysis of heat wave and meteorological trends reveal that global warming is happening fast, heat wave can have drastic impact on lives and old or sick people are especially at risk. Climatologist term the Karachi heat wave an ‘urban heat island’ phenomenon.
What is the Urban Heat Island Effect?
The fabric of building and roads, all the steel, concrete and tarmac, in our cities absorb solar energy which it releases night. This absorption and radiation of heat make urban areas warmer at night than rural surrounding areas, creating a city-specific phenomenon called urban heat island (UHI).
A study of Urban Heat Island of Karachi by Sajjad et al (2015) observed presence of urban heat island (UHI) in Karachi which ranged from 5 – 13 °C and the highest UHI was observed during night times.
This problem was also highlighted during a recent conference UN climate talks in Bonn where researchers suggested a number of ways from planting trees to designing breeze-channelling buildings.
Factors behind Karachi heat wave 2015
Rapid urbanization, industrialization, population and automobiles growth play a critical role in the energy consumption in Karachi, says a study on urbanization in Karachi (2010).
Multiple factors that increase Karachi’s vulnerability from heat wave are: lack of green urban areas, little shadowing, population density, less ventilation, insufficient building insulation, heat generation by factories, transport, soil sealing, lack of awareness, health education, power outages and water scarcity.
Pakistan is acutely vulnerable to climate change and its vulnerability is set to increase between 2010 and 2030 according to DARA – Climate Vulnerability Monitor 2012. Climate change now poses a threat so serious that it could reverse the last 50 years of progress in global health and development, a new study by UK medical journal Lancet (June 2015) has warned.
Lessons to be learned from Karachi heat wave 2015 – What can we do to roll back urban heat?
Karachi, world’s third-largest sprawling city of 20 million with more buildings and very few parks, is especially vulnerable to climate change and UHI which is why it needs immediate attention of all authorities to take desirable measures.
Disaster is also an opportunity for nations to learn and take necessary steps to prevent future threats. Here are some solutions to adopt to make Karachi a livable city again:
Health warning system
The current disaster requires a war footing strategy for heat wave preparedness to protect our people and cities from the impact of heat and climate change. Pakistan needs to implement integrated strategies just as France formulated a heat health watch warning system after the 2003 heat wave to combat heat illness in case of abnormally hot weather.
Green and Cool Roofs
Planting trees and shrubs on the tops of buildings, or covering roofs to reflect sunlight is a low-cost method which Pakistan can adopt to keep buildings cool in summer. Green roofs are common in Germany, Australia. Canada approved a law in 2009 making it mandatory for industrial and residential buildings to adopt green roofs. Rooftops on new buildings in France are required by law to have either roof gardens or solar panels. But such measures only work when employed on large-scale.
Plant Trees – the natural air conditioners
One of the inexpensive and excellent way to repel heat wave is to plant trees – which are rightly termed the lungs of the city. Trees provide shade, diminish air pollution, reduce energy costs, add beauty, provide homes for wildlife, it simply makes a place livable. “The concrete buildings have compromised the city’s breathing and we need to grow trees to revive it” suggests Rafi ul Haq, an ecologist and climate change expert. He calls trees natural air conditioners. But it is equally important to know what to grow as wrong plants can be harmful.
Another quick and moderately cheap way is water streams running through cities. Water streams are not only a source of pleasure but also absorb a significant amount of heat from the air. “We have the Nehre-e-Khayyam running across the town and we have natural drainage channels which can be revived and the water treated; or you can build artificial ones” suggests Anwar.
Focus on modern Public Transport
At a time when global cities are planning to go car-free, Pakistan’s roads are getting crowded with cars every day. From 1990 to 2008, the number of vehicles added on the roads of Karachi was greater than our population growth, according to research published in African Journal of Biotechnology (2010). About 92% vehicles are for personal use (cars and motorcycles) while only 8% vehicles are used for used for passengers transport (buses, taxis and rickshaws).
Efficient subway train, transport policy that discourages the use of private vehicles, sustainable public transport is what Pakistan needs to reduce the traffic and car-dependency.
Rethinking Building design
Significant industrial development in Karachi and high buildings with closed natural wind tunnels and traffic fumes have intensified the heat problem. “It is time to revisit how buildings are designed and the material used” says Farhan Anwar, and urban planner. Pakistani city planners need to improve their understanding of urban development trends and focus on buildings with proper ventilation, green roofs, improved building materials, and shaded areas.
The heat wave stimulated debateto induce artificial rain which was employed in Tharparkar in 2000. Scientific research shows no serious health or environmental hazards of cloud seeding but experts suggest Pakistan should focus on establishing heat trauma centers and restoring water and electricity supplies. “Since these measures are more practical and potentially less costly than cloud-seeding technology,” says Pervaiz Amir, country director of the Pakistan Water Partnership.
Climate change has arrived in our cities, on our streets, making people feel the heat. It is about time that we take our climate change discussions, strategies and actions from conference rooms to our cities.