If structures were biodegradable…
Whenever a building needs to be demolished, the debris should not pollute the earth. But the reality is different.
The human race appears to be very good in doling out data and statistics, including about impending disasters. If we wonder what we are doing with those doomsday forecasts, ironically, too often we do nothing about it. Among the best examples for this studied indifference is the research about the fate of modern products that we are recklessly manufacturing.
Try experimenting with banana peels in our household compost pit, where it will visually disappear in a week’s time, at fine particle level may rot the second week and finally at the molecular level, may completely decompose within the next fortnight. Slightly harder items like pumpkin skin or harder part of fruits may take a month to disappear and another month to decompose.
It will be curious to see how long a modern building would take to decompose and completely return to the earth. Of course, we do not have detailed research to answer this query, yet someday this may become an important issue in rating the sustainability of a design or construction approach.
Imagine a mall with elaborately designed shop interiors filled with Indian and foreign materials. We can appreciate them all as a great achievement of our generation and wish that such malls should thrive for generations serving our grandchildren.
Alternatively, we may also calculate the resources consumed, energy consumed, waste generated and the impact of the mall project on our times.
More seriously, we may wonder what will happen when the building and materials cease to serve any purpose and needs to be demolished.
Technically we can demolish everything; try recycling them to whatever quantity possible and the rest can be piled as debris somewhere on earth.
What will happen next? The materials need to decompose and return to nature. Is it easy for the un-natural products to return to nature?
If yes, how long will it take? For sure, we know that we cannot live that long to be on the day when a product of our time completely decomposes to join the earth. So, do we ignore the bio-degradability of what we are doing?
Today, there are tests like respirometry, where solid waste is placed with micro-organisms and soil to check the quantity of carbon dioxide emitted due to digestive activity of the micro-organisms.
Though not exact, it gives fair idea of bio-degradation rate, so researchers predict that leather takes 50 years, aluminium can take 200 years, plastic beverage bottles take 450 years, plywood takes 3 years or glass bottle may take up to 1 million years.
The time taken also depends on specific material compositions and context of degradation.
Imagine a time when humans have gone extinct from the Universe. Will our mortal remains be the non-biodegradable manufactured materials? Can we be proud if the earth is full of leftovers of our times? Can our lasting contribution to nature be unnatural construction debris?
It is time to think of the footprints we are leaving behind.