Climate change and cities: It's not too late to bring green buildings in policy making
Can cities, which witness population influx, rising levels of pollution and haphazard encroachments daily, endure it any further? Here's how climate change has started affecting cities and why we need green buildings
Urban areas and metros have lured thousands who give up their rural livelihoods due to low agricultural returns or growing divisions in family land holdings in order to seek greener pastures in concrete jungles. Given the spurt in migration, managing dynamics of the cities and urban spaces is undoubtedly a multi-thronged challenge to counter.
When we read names of our cities in ‘smart cities’ list, what we should really think about is – are our cities really smartly built? Can cities, which witness population influx, rising levels of pollution, haphazard encroachments on a daily basis, endure it any further? Environmental concerns, as seen so far, have taken a back seat in the name of ‘development’. Buildings that are being so rapidly erected today are, however, not energy-efficient. Are people aware of the concept of “green buildings”? There’s indeed awareness but it’s not enough.
Green buildings efficiently use basic resources like energy, water, and electricity reducing water wastage and pollution. These buildings are developed considering the building layout for adequate solar orientation and proper ventilation which in turn reduces the heat intake and maximises the glare-free daylight. They are also efficient in treating waste water.
Cities, by their very nature, are energy intensive i.e. they need more supply of electricity, water, and land. Besides, the changing lifestyles that allow people to splurge – shopping in malls, living in high-rises with spas, swimming pools, gyms, etc. – definitely shoots up the requirements of essential resources like water and electricity. This explains why builders are always tempted to construct buildings with larger Floor Space Index (FSI), especially in the metros?
However, the question is: Can our cities or urban spaces afford buildings which are constructed without the due understanding of its carrying capacities and available resources? No, they definitely can’t.
For instance, the seven lakes, which have been providing water to Mumbai for over decades, have become redundant today because the city – with a total land area of 603 sq.km and a population density of 30,900 per sq.km – is no longer capable of carrying the growing population and meet even the basic requirements. What happens in such situations is crucial ecosystems like wetlands, cultivable lands etc., which supply basic necessities like food and water to the city, are reclaimed. How much of these resources will be available to feed our city in coming decades? Does this mean that the cities will then have to look for their own resources? These are some of the questions, which the civic authorities should ponder on before these basic resources run dry.
How unplanned urban spaces and migration affect cities
According to World Bank, nearly 6.2 billion people – 70 percent of the world’s total population – would be living in cities by 2050. If the recent statistics of the Planning Commission are to be believed, a staggering 377 million Indians are currently living in towns and cities and within 20-25 years, another 300 million people will follow suit.
The economic census of Maharashtra says that the agricultural establishment in Mumbai has seen a decline by 58 percent whereas the non-agricultural establishment has increased by 33 percent. In a city like Delhi, the average decadal population growth since 1951 has been 45.8 percent, where migration accounted for more than 23 percent of the total increase in population. It’s the same story with other metros like Bengaluru, Chennai, and Gurugram.
An uncontrolled built environment, (simply put: the haphazard spurt of city slums and encroachments), acts as a parasite surviving on the already threatened resources. Take the example of Sanjay Gandhi National Park (SGNP) in Mumbai. According to the state government’s action plan 2014-2023, over three million people are staying on the outskirts of SGNP. The encroachment, which began in the 1970s in the protected areas, has only been increasing with no definite control mechanisms in place. The report states that 200 hectares of reserved forest lands of SGNP have been encroached by about 61,000 families. This has destroyed the park’s biodiversity to an extent that it has caused some critical environmental damages. Unfortunately, we have no mechanisms in place to reverse these damages which are very much required to protect the park’s space from further shrinking.
Furthermore, the provisional data of Population Census 2011 shows how Mumbai has seen a significant jump in the population from 59,70,575 to 1,24,78,447 over the span of 40 years.
So, questions like – how are these migrants settling themselves; what makes them chose a place for settlement; who monitors and regulates their settlements – will demand a prudent response from the state governments. Such unplanned and sporadic settlements may soon make us run out of all crucial resources and prove us completely unsustainable.
While the global literature is showing increasing evidence of global warming, losing out on such eco-sensitive areas, like national parks, wetlands and so on, may only aggravate the damage caused to the city’s microclimate.
Climate change and urban disasters
It’s now common knowledge that the problem of climate change is staring in the face of the cities as well as the state governments. It will only compound the complexities of urban dynamics. According to IPCC (Intergovernmental Panel on Climate Change) AR5 (Assessment Report 5) Synthesis Report, climate change will increase risks like heat stress, storms and extreme precipitation, inland and coastal flooding, landslides, air pollution, drought, water scarcity, the rise in the sea-level and storm surges in the cities. According to the Twelfth Five Year Plan, India loses up to 2 percent of its GDP due to natural disasters of which floods and high winds account for 60 percent.
The nature of our built environments or urban spaces shaping our future cities also determines our vulnerability to disasters. The civic authorities will have to bear some major economic implications if the city encounters extreme rainfall events like flash flooding which could do serious damage to the city’s infrastructure during any ongoing developmental project
Over the past two-three years, Indian cities have also experienced erratic heavy flooding followed by urban mobility disruptions like slowing down of the railways and traffic congestion. In 2013, cities in the state of Uttarakhand, and Mumbai and Kolkata witnessed extreme floods; in 2014, it was Chennai and Srinagar. Flood situations are only expected to increase given the increase in the watertight surfaces owing to rapid concretisation.
This will, in turn, affect the groundwater table recharging by throwing litres of fresh rain water down the drains. So while we talk of utilisation of resources, their management is an equally important issue.
As per the MMR ESR (Mumbai Metropolitan Region’s Environmental Status Report) by TERI, the number of very heavy rainy days saw a jump of 27 percent from 19 (recorded in 1971- 80) to 26 (recorded in 2001-10). Similarly, there was an increase in the moderate, rather heavy, heavy, very heavy categories of rainy days; while the very light and light rainy days saw a comparative decrease. This clearly indicates the climatic variations over the MMR.
Urban Heat Island Effect
Concrete surfaces, which form more than 60 percent of the surface materials in urban areas today, tend to retain heat more than their surrounding rural areas due to higher reflective surfaces. The increase in temperatures further triggers the overall temperatures making urban areas as the island of heat, where the temperatures are 2-3 degrees higher than the peripheral areas. This is called as Urban Heat Island Effect. This further increases the demand for cooling systems like air conditioners eventually escalating the energy consumption and use of greenhouse gases like hydrofluorocarbons adding to the climate change.
Thus, protection of natural resources like water bodies, wetlands, salt pans, and mangroves play a significant role as they have the capacity to absorb such climatic shocks; failing which the cities would be washed away in no time. Here's where green buildings come into the picture as they are more sustainable and can help in retaining vital resources. It's never too late in bringing green buildings in policy making.
The author is an Associate Fellow with Sustainable Habitat Division of The Energy and Resources Institute (TERI), Navi Mumbai
Note: This is first of the two-part series. The second part would explain the need for green buildings in urban landscapes and solutions.
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