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People in the chemical field will understand the concept of ‘irreversibility’. Certain chemical reactions can go only in one direction and but not in the reverse direction. But some reactions can go on either direction and we can manipulate such reactions to our advantages. This concept has been successfully used in designing many chemical reactions in the past and many innovative industrial and consumer products emerged out of it. But such irreversible reactions also have irreversible consequences because it can irreversibly damage the environment we live in. There is no way such damage can be reversed. That is why a new branch of science called ‘Green Chemistry’ is now emerging to address some of the damages caused by irreversible chemical reactions. It also helps to substitute many synthetic products with natural products. In the past many food colors were made out of coal-tar known as coal-tar dyes. These dyes are used even now in many commercial products. Most of such applications were merely based on commercial attractiveness rather than health issues. Many such products have deleterious health effects and few of them are carcinogenic. We learnt from past mistakes and moved on to new products with less health hazards. But the commercial world has grown into a power lobby who can even decide the fate of a country by influencing political leaders. Today our commercial and financial world has grown so powerful that they can even decides who can be the next president of a country rather than people and policies. They can even manipulate people’s opinion with powerful advertisements and propaganda tactics by flexing their financial muscles.

Combustion of fossil fuel is one such example of ‘irreversibility’ because once we combust coal, oil or  gas,  it will be decomposed into oxides of Carbon, oxide of  Nitrogen and also oxides of Sulfur and Phosphorous depending upon the source of fossil fuel  and purification methods used. These greenhouse gases once emitted into the atmosphere we cannot recover them back. Coal once combusted it is no longer a coal. This critical fact is going to decide our future world for generations to come. Can we bring back billions of tons of Carbon we already emitted into the atmosphere from the time of our industrial revolution? Politicians will pretend not to answer these question and financial and industries lobby will evade these question by highlighting the ‘advancement made by industrial revolutions’. People need electricity and they have neither time nor resources to find an alternative on their own. It is open and free for all. People can be skeptical about these issues because it is ‘inconvenient for them’ to change But can we sustain such a situation?

Irreversibility does not confine only to chemical reactions but also for the environment and sustainability because all are intricately interconnected.Minig industries have scared the earth, power plants polluted the air with greenhouse emission and chemical industries polluted water and these damages are irreversible. When minerals become metals, buried coal becomes power and water becomes toxic effluent then we leave behind an earth that will be uninhabitable for our future generations and all the living species in the world. Is it sustainable and can we call it progress and prosperity? Once we lose pristine Nature by our irreversible actions then that is a perfect recipe for a disaster and no science or technology can save human species from extinction. One need not be scientist to understand these simple facts of life. Each traditional land owners such as Aborigines of Australia or Indians of America and shamans of Indonesia have traditionally known and passed on their knowledge for generations. They too are slowly becoming extinct species in our scientific world because of our irreversible actions. Renewability is the key to sustainability because renewability does not cause irreversible damage to Nature.

Chemistry has revolutionized human life and it has affected each and every one of us in some way or other for the past several decades. We were happily using these chemicals in our everyday life without really understanding their side effects.Individuls and companies who invented and commercialized chemical products were keen to offer end products to consumers often without explaining the side effects of such chemicals.They themselves were not fully aware of long-term consequences of such chemicals. Classical examples are Chlorine and its derivatives.

Chlorine is a common chemical that is used even today in many countries to disinfect drinking water in water treatment plants. Their usage is sill continued though they found that Haloethanes, which are formed by the action of Chlorine on decayed organic leaves in water storage, causes cancer (carcinogenic). DDT is another chemical that was used widely as a pesticide, known as “atom bomb of pesticides”,  until their side effects proved deadly for human beings and to the environment. It was officially banned in USA in 1972 by EPA, though it is still continued in some third world countries. Bleaching powder in another example of powder disinfectant ( a popular form of disinfectant used on roads in India when  prominent political leaders visit municipalities; though they are only chalk  powder with no traces of residual Chlorine).

A whole range of dyes known as coal-tar dyes derived from coal  were used in many applications including ‘food colors’, later substituted by petroleum-based organic chemicals. These ‘food colors’ are now substituted with ‘natural organic colors’ such as vegetable colors derived from vegetables and fruits. Industrial chemicals, both organic and inorganic have caused serious environmental damages all over the world for several decades, but Governments, companies and EPA did not realize the deadly consequences of some these chemicals for a long time. The ‘Bhopal Gas tragedy’ in India is one such grim reminder of such consequences.

Chemicals are not natural products even though one can separate them into various organic chemical molecules but some of the consequences of such separation and usage are not fully understood. Many natural herbs have outstanding medicinal values and when consumed in a Natural form, it has absolutely no side effects and they show tremendous therapeutic values. But when you isolate certain molecules from such herbs (Alkaloids) and used as a drug, they can cure a disease but at the same time, they create many side effects. Nature offers such drugs in a diluted form that is quite compatible to human beings. One such example is ‘Vinblastine’ and “Vincristine’, anti-cancer drugs derived from a herb called ‘vinca rosea’.

Of late there is awareness among companies, people and Governments about Green technologies that can help protect the environment. Greenhouse gas and global warming is one such issue. When Petrol or Diesel, an organic chemical known as Hydrocarbon is burnt, it not only generates power but also emits greenhouse gases such as Carbon dioxide and oxides of Nitrogen, that cause globe to warm. We were happily burning away such fossil fuels until scientists raised an issue on emission of ‘greenhouse gases’ in recent past. When we deal with chemicals and chemical reactions, the molecule is transformed into a new molecule and often such reaction cannot be reversed.It is not a physical change but a chemical change. When we convert water into steam, we can get back water by condensing steam; but when you convert Chlorine into PVC (Poly vinyl chloride) plastic, there are environmental consequences and reversing PVC into Chlorine gas in not easy, though it is technically possible with environmental consequences.

One has to observe and learn from Nature what is good and what is bad when developing a new technology, because such development will not only affect the environment but also many generations to come. When Nature teaches how to turn sugar into Alcohol by fermentation using air-borne microorganisms, we should follow Nature to make alcohol. We know how to turn Alcohol into PVC, but we do not know how to make biodegradable PVC from Alcohol. Companies call it ‘Green Chemistry’, but not until we can make a biodegradable PVC. Human knowledge is imperfect and we can learn ‘Green chemistry and Clean Technologies’ only from Nature and not by deviating from the path of Nature.

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