2015 Paris Climate Summit: How Skyscrapers Help Keep Metropolises Green

Novelist-philosopher Ayn Rand once spoke through a character, “I would give the greatest sunset in the world for one sight of New York's skyline. Particularly when one can't see the details. Just the shapes. The shapes and the thought that made them. Is it beauty and genius they want to see? Do they seek a sense of the sublime? Let them come to New York, stand on the shore of the Hudson, look and kneel. When I see the city from my window - no, I don't feel how small I am - but I feel that if a war came to threaten this, I would throw myself into space, over the city, and protect these buildings with my body.”

In a world that romanticises villages, it may seem that Rand was bending the stick the other way, projecting all virtues onto cities. But, it is undeniable that it is the buildings of today that makes modern day cities more beautiful than cities of the past. It is the buildings, or more precisely, the abundance of “floor space” that allows economic activity to be concentrated in cities. However, the question remains: are we sacrificing nature to build greater floor space in our cities?

The 2015 Paris Climate Summit or the 21st Session of the Conference of Parties (COP21) starts today (November 30) and this will be among the topics world leaders would discuss. Prime Minister Narendra Modi has reached Paris to attend it.

While the debate goes on, a look at how real estate and geography contribute to emission of pollutants:

The debate on carbon emission between developed and developing countries is a bitter one. Developed nations argue that developing countries like India and China emit more carbon and their fossil fuel usage is higher. However, even in the greenest metropolitan areas in the US, carbon emissions are over ten times greater than the carbon emissions in a typical metropolitan area in China or India. The reason is that American cities are car-based. In developing nations, low-income levels and traffic congestion make car-based living almost impossible for most people. If car usage per person rises in Indian cities to American levels, carbon emissions here will be much higher than in the US. The reason is that Indian cities are densely populated. Data also show that Indian cars emit more carbon than the cars in the United States.

Globally, skyscrapers actually help keep the environment greener than low-rises. It is the taller buildings in city centres that keep forests and green spaces intact. If population density in a country is high, all things being equal, there will be more people travelling through the roads. Taller buildings and shorter distances between two points would bring down transport usage to a large extent, cutting down carbon emission in turn. David Owen, the author of Green Metropolis, once said that the office of his Manhattan dentist was in the lobby of his apartment building, an elevator ride away. But the office of his Connecticut dentist was two towns away, a 32-mile drive away. Harvard economist Edward Glaeser points out that his family started consuming more energy when he moved to the suburbs. The reason was that they were compelled to drive more. Their large suburban home needed more energy to keep itself warm during winters. Glaeser says that if you love the environment, you should leave plants and trees alone.

When buildings are taller in certain parts of a city, the average commute would fall and people would either walk or bicycle to work. Taller building would concentrate greater population. Now, per surface area carbon emissions in Manhattan and New York are extremely high, while per person carbon emissions in these cities are much lower than in the rest of the US. Taller buildings can help cut the emission levels down this way, too. 

Most Indians already walk, bicycle or use public transport to work, but they do it out of deprivation, not as a result of calculated reasoning. They live in areas where it is easier to walk, bicycle or travel in public transport, at great cost to themselves and the environment. But, high population density by itself does not lead to greater emission of pollutants. Indian cities face greater constraints, like land masses not being contiguous. When land masses are not contiguous, higher building density does not by itself lead to lower pollution. But, Hong Kong and Singapore manage face similar constraints too. They allow high-rises more than Indian cities do. Cars in Hong Kong and Singapore are more efficient, while public transit ridership ratios are among the highest in the world.