Environmental Issues/Problems & Their Management/Measures : Pollution, Biodiversity Loss & Climate Change

⇒ In the early period of human history, human beings were just like any other animal beings dependent on the environment. Food gathering, hunting and fishing could not sustain a large population. With the development of agriculture (Agricultural Revolution in Neolithic Period), food was available in abundance and permanent settlement came into existance.

⇒ Minining of coal, iron and other minerals heralded the Industrial Revolution (after 1750). These led to the increased production from fields and factories and the colonisation of new landmasses like America and others.

⇒ With the tools at his command, man became a of the environment. Human activities were aimed at satisfying their increasing needs from the environment.

⇒ With rapid increasing in human population 20th century, their needs have increased enormously leading to an adverse impact on environment. Such impacts are pollution, biodiversity loss & climate change [‘Triple planetary crisis’-as mentioned in ‘Making Peace With Nature’ report, 2021 (UNO)] and others. These environmental changes pose a major threat to survival of human on the earth.

⇒ Often developed countries like America, England etc are blaming developing countries like India & China (new emergenteconomic powers) for the environmental crisis and makes pressure to reduce the emission of green house gases. As the early industrializers, the nations of the West were the original culprits; that said, the two giants are rapidly making up for lost time.

⇒ There is an urgent need for protecting the environment from unsuitable interference of humans. Human beings have to learn to live in natural harmony with the environment so that the earth continues to be habitable future generations as well.

⇒ Generally speaking, environmental management means  the management of natural resources of environment-

⇒ There can be two ways/approaches to environmental management Preservative & Conservative approach

(i) Preservative Approach: According to preservative approach, man should not disturb the natural system and should adapt to it. But in the era of Globalisation, it is not possible because for development activities man will have to use nature and its component resulting in eco-imbalance of varied intensity.

(ii) Conservative Approach: According to conservative approach, there should not be over exploitation of nature and conservation of natural resources is essential for sustainable development.

⇒ Thus, proper utilisation and conservation of resources is the prime objective of environmental management

⇒ Various efforts had taken by individuals, organisations, governments, United Nation (UN) at their own levels in the past toward environmental management to create a habitable planet for the coming generation.

⇒ Three major crisis of Environment are – Pollution, Biodiversity Loss & Climate Change.

Note: For Details, see Pollution’ topic of Biology.

Note: For Details, see ‘Biodiversity’ topic of Environment.

⇒ Climate change refers to long term shifts in temperature and weather patterns. These shifts may be natural, but since the 1800s, human activities have been the main driver of climate change. Since 1900s the conditions become more worse. Now-a-days climate change is a major environmental issue. It is the biggest threat huminity has ever faced.

⇒ There are two types of causes of climate changeAnthropogenic (man-made) & Natural causes.

1. Anthropogenic (man-made) Causes: At present, anthropogenic cause (i.e. human activities) is considered largely responsible for climate change.

(a) Burning of fossil fuels & emmission of carbon dioxide (CO₂) : Climate change, occured by human activities is primarily due to the burning of fossil fuels (like coal, oil and gas), which produces heat trapping gases.

(b) Emission of Methane (CH₂)

(c) Emission of Chlorofluorocarbons (

(d) Emission of Nitrous oxide (N₂O),

(e) Emission through land use change viz deforestation, (conversion of land in grazing land, cropland and etc. desertification, urbanisation etc.)

2. Natural Causes: Some Examples of Natural causes of climate change are –

(a) Changes in the Sun’s intensity

(b) Volcanic eruptions

(c) Natural processes within the climate system such as changes in ocean current circulation etc.

⇒ The atmosphere cover around the earth acts like a window glass pane. The earth’s atmosphere is made up of major gases namely, nitrogen and oxygen, and minor constituents such as carbon dioxide and water vapour. These gases play a crucial role in moderating the Earth’s atmosphere. This is because these gases are relatively transparent to incoming visible light from the sun, but absorb the heat radiation given off by the ground and object exposed to the Sun. As a result they produce a heating of the atmosphere by what is know as the green house effect. The name is derived from the fact inside a glass enclosed green house, temperature is warmer than outside. Such green houses are used for growing plants especially in winter season that required higher temperature for growth. Green house looks like a small glass house. In a greenhouse the glass panel lets the light in, but does not allow heat to escape. Therefore, the green house warms up, very much like inside a car that has been parked in the sun for a few hours.

Without the green house gases in the atmosphere and the resulting green house effect, the Earth’s average surface temperature would have been a chilly-18°C to 20°C rather than the present average of 15°C.

⇒ But what is of concern today is the ever increasing level of carbon dioxide and other green house gases (methane, CFCs, nitrous oxide) in the atmosphere during the past several decades (increased by 0.6°C). Estimates suggest that by the middle of 21st century, the Earth may be 2° to 9°C warmer. This global warming will result in many climatic changes such as sea level rise, severe weather etc.

⇒ The trends in the increase in concentrations of green house gases since pre-industrial times are briefly described below –

(a) Carbon dioxide (CO₂): Carbon dioxide is the most abundat green house gas in the atmosphere. The level of carbon dioxide in the atmosphere has increased from the pre-industrial level of 280 ppm (parts per million) to about 368 ppm in 2000.

This has been largely the result of fossil fuel burning, deforestation and change in land use. The carbon dioxide persists for 5 to 200 years in the atmosphere.

(b) Methane (CH₂): Methane concentration in atmosphere has more than doubled [from 700 ppb (part per billion) to 1750 ppb]. Methane is largely a product of incomplete decomposition and is produced by a group of bacteria called methanogene, under anaerobic conditions.

The major sources of methane include freshwater wetlands, enteric fermentation in cattle, and flooded rice fields. Biomass burning also produces methane. Methane persists for 12 years in the atmosphere.

(c) Chloroflurocarbons (CFCs) Chloroflurocarbons are non-toxic and non-flammable, highly stable and synthetic gaseous compounds of carbon and halogenes. Although these compounds were synthesised during the 20th century, their concentration in the atmosphere has increased. For example, the concentration of CFC11 and HFC-23 in the air is approx. 282 ppt (parts per trillion) in 2000 that was 0 ppt means absent before industrialisation (i.e. before 1750).

The major sources of chloroflurocarbons are leaking air conditioners, refrigeration units and evaporation of industrial solvents, and production of plastic foams and propellants in aerosol spray cans. The chloroflurocarbons persists for 45 to 260 years or more in the atmosphere.

(d) Nitrous oxide (N₂O): The concentration of nitrous oxide in the atmosphere has increased from approx. 270 ppb in pre-industrial time to approx. 316 ppb in recent times.

The main source of nitrous oxide are agriculture, biomass burning and industrial processes. Nitrous oxide is produced during nylon production burning of nitrogen-rich fuels, livestock waste, breakdown of nitrogen-rich fertilisers in soil and nitratecontaminated ground water.

⇒ The relative sharing of different greenhouse gases to global warming is shown in fig. 15.

⇒ It is estimated that Carbon dioxide (CO₂) contributes about 60% of the total global warming.

⇒ The share of Methane (CH), Chloroflurocarbons (CFCs) and Nitrous oxide (N₂O) is 20%, 14% and 6% respectively.

⇒ The increasing abundance of green house gases in the atmosphere has both positive and negative effects.

Example of positive effect-Carbon dioxide fertilisation effect on plants etc.

Example of negative effect-Global warming, Ozone Depletion etc.

⇒ The measurements made at Mauna Loa Observatory in USA have shown that atmospheric carbon dioxide concentration has been rapidly rising since 1959.

⇒ If this rising trend continues, it is expected that the atmospheric carbon dioxide concentration shall increase between 540-970 ppm by the end of the 21st century.

⇒ With a doubling of the atmospheric carbon dioxide concentration, the growth of many plants, particularly the C, species could increase by about 30% on average in a few years.

⇒ The response of plants to elevated concentration of carbon dioxide is known as carbon dioxide fertilisation effect.

⇒ However, under natural conditions, the positive effects of carbon dioxide may not be actually realised because of negative effects of global warming.

⇒ Global warming is the phenomenon of gradual overall increase in the average temperature of the Earth’s atmosphere due to accumulation of certain gases.

⇒ The term ‘Global warming’ was popularised by British environmentalist Wallace Smith Broecker (1931-2019) in 1970

⇒ Increase in the level of green house gases has led to considerable heating of Earth leading to global warming

⇒ The global warming affects the sea level, weather and climate and the distribution and phenology of organism, food production and fishery resources in the oceans.

(a) Sea Level Rise : Sea level has been raised by 1 to 2 mm per year during the 20th century. It is predicated that by the year 2100, the global mean sea level can increase up to 0.88m over the 1990 level.

The global warming causes to sea level rise due to the thermal expansion of occean as it warms and melting of glaciers and ice sheets for example, melting of hanging glaciers in 2021 in Uttarakhand and in 2022 in Chile etc. A rise of even half a meter in sea level would profoundly affect human population one-third of which lives within 60 km of a coastline. Many of the world’s important cities and coastal areas will come under the threat of flood. Several low-lying islands is submerging in water, for example, Tebungianko, a village on the central Pacific island nation of Kiribati is disappeared in recent. Similarly, Ghoramara, a tiny island in the Sundarban Delta, will soon vanish under the sea. Between 1972 and 2010, Ghoramara lost at least half of its land to the sea. Two other island in the Sundarban Delta region have already disappeared and more likely to follow. The islands of Sundarban are not single example of submergence due to sea level rise. All over the world countries consisting of small low-lying islands, such as Tuvalu, Kiribati and the Soloman island are facing the effect of the rising sea level. The Bangladesh and Maldives could also face severe erosion in the future.

Inundation of coastal salt marshes and estuaries may deprive many important birds and fish their breeding ground, forcing their extinction. Thus, sea level rise is projected to negative impacts on human settlements, tourism, freshwater supplies, fisheries, exposed in frastructure, agricultural lands and wetlands.

(b) Severe Weather and Climate: The global mean temperature has increased by about 0.6°C in the 20th century. The average temperature may incresase by 1.4°C 5.8°C by the year 2100 from the 1990 level. Temperature changes are expected to be most marked in regions of middle and higher latitudes. Warming of atmosphere will considerably increase its moisture carrying capacity while the troposphere warms up, the stratosphere will cool down. This would cause widespread changes in precipitation patterns due to changed patterns of air-mass movement. Precipitation is expected to increase at higher latitudes in both summer and winter and in southern and eastern Asia in summer. Winter precipitation may decrease at lower latitudes.

Besides, the frequency of extreme events (e.g. droughts, floods, etc.) is expected to increase substantially. The climate change will increase threats to human health, particulary in tropical (warm) counties, due to change in ranges of disease vectors, water-borne pathogens etc.

(c) Change in distribution pattern of organism (flora and fauna): The global warming is likely to shift the temperature ranges and, therefore, would affect altitudinal and lattitudinal distribution pattern of organism.

With increasing global warming many species are expected to shift slowly poleward, or toward high elevations in mountain areas. For example, with a global temperature rise by 2°C to 5°C during the 21st century, the temperate region vegetation may extend 250-600km poleward. Since trees are sensitive to temperature stress, a rapid rise in temperature may cause large scale death of trees and their replacement by scrub vegitation.

Many species may not be able to migrate fast enough to track temperature changes and may disappear.

(d) Decline in Food Production: Increased temperature will cause eruption of plant diseases and pests, explosive growth of weeds and increased basal rate of respiration of plants. A combination of all these factors will decrease the crop production. Small temperature increase may slightly enhance crop productivity in temperate regions, but larger temperature changes will reduce crop productivity there. In all tropical regions, even a small temperature rise will have detrimental effect on crop productivity. Rice yield alone, in south-east Asia will reduce by 5% for each 1°C increase in temperature. Despite beneficial carbon dioxide fertilisation effect, the overall world crop productivity will, in all probabilities, decline considerably due to projected global warming. This will have alarming consequences on world food supply.

⇒ Some of the strategies that could reduce the global warming are –

(i) Reducing the green house gas emission by limiting the use of fossil fuels, and by developing alternative renewable sources of energy (e.g. solar energy, wind energy etc.)

(ii) Increasing the vegetation cover, particularly the forests, for photosynthetic utilisation of carbon dioxide.

(iii) Minimizing the use of nitrogen fertilisers in agriculture for reducing nitrous oxide emission.

(iv) Developing substitutes for chlorofluorocarbons.

Apart from the above mitigation stratategies, adaptations to address localised impacts of climatic change will be necessary.

⇒ There is a thin layer of ozone that circles the Earth at a height of 15-50 km above the sea level. Its protective presence shields life of organism by absorbing the high energy ultraviolet radiation of the Sun.

⇒ During the period 1956 to 1970, the spring time ozone ayer thickness above Antarctica varied from 280 to 325 Dobson Unit (1DU = 1 ppb). The thickness was sharply reduced to 225 DU in 1979 and to 136 DU in 1985. Later, the ozone layer thickness continued to decline to 94 DU in 1994.

⇒ The decline in spring-time ozone layer thickness is termed Ozone Hole.

⇒ The ozone hole was first discovered in 1985 over Antarctica. The existence of ozone hole was also confirmed above Arctic in 1990.

⇒ The (CFCs, Chemical Chemical name-Freon), composition-CCF₂Cl₂, 22 methane (CH₄) and nitrous oxide (N₂O) escape into the stratosphere and cause destruction of ozone (O₃) there. Of the many chemicals blamed for causing the ozone hole, the chlorofluorocarbons, widely used by the refrigeration industry have been held primarily responsible.

⇒ Most damaging is the effect of CFCs which produce active chlorine (Cl and ClO radicals) in the presence of ultra violet radiation. These radicals catalytically destroy ozone, converting it into oxygen.

⇒ Methane (CH₄) and nitrous oxide (N₂O) also cause ozone destruction through a complicated series of reactions

⇒ For making these discoveries related to ozone destruction, Sherwood Rowland and Mario Molina, along with Paul Crutzen were honoured with Nobel Prize for Chemistry in 1995.

⇒ The thinning of the ozone layer results in an increase in UV-B radiation reaching the earth surface.

⇒ A 5% loss of ozone results in a 10% increase in UV-B radiation.

⇒ There are three basic lypes of UV rays : UV-A, UV-B and UV-C in which UV-A and UV-B rays reach the earth’s surface but UV-C rays are blocked by ozone layer of atmosphere. A 5% of UV-A (wavelength 315400 nm) and 95% of UV-B (wavelength 280-315 nm) are absorbed by ozone layer and the rest percentages of UV-A and UV-B reach the surface, where as 100% of UV-C (wavelength 100-280 nm) is absorbed by ozone layer. UV-C radiation of wavelength shorter than UV-B, are almost completely absorbed 1 Earth’s atmosphere, given that the ozone layer is intact. But UV-B (Ultraviolet of type B) rays are the middle energy between tanning rays (UV-A) and the intense germicidal rays (UV-C) and highly injurious to living organisms. UV-B damages DNA and mutation may occur. It causes aging of skin, damage to skin cells and various types of skin cancers (including melanoma). In human eye, cornea absorbs UV-B radiation, and a high dose of UV-B causes inflammation of cornea, called snow-blindness, cataract, etc. Such exposure may permanently damage the cornea. UV-B also diminishes the functions of immune system

⇒ Elevated levels of UV-B radiation affect photosynthesis, as well as damage nucleic acids in living organisms.

⇒ UV-B radiation inhibits photosynthesis in most phytoplankton (Plankton plant) as it penetrates through the clear open ocean waters. This in turn, can affect the whole food chain of organism that depend on phytoplankton.

⇒ Recognising the deleterious affects of ozone depletion, an international treaty, known as Montreal Protocoal, was signed at Montreal (Canada) in 1987 (effective in 1989) to control the emission of ozone depleting substances.

⇒ Subsequently many more efforts have been made and protocols have laid down definite roadmaps, separately for developed and developing countries, for reducing the emission of CFCs and other ozone depleting chemicals.

⇒ Earth Summit (1992) held at Rio de Janeziro, Brazil, United Nation Conference on Environment and Development (UNCED)

⇒ Kyoto Protocol (1997) held at Kyoto, Japan

⇒ Cancun Agreement (2010), held at Cancun, Mexio, United Nations Climate Change Conference

⇒ Paris Agreement (2015), held at Paris, France

⇒ Environment & Indian Constitution: The constitution of India (42nd Amendment Act, 1976) explicitly incorporates environmental protection improvement.

Article 48A: The state shall endeavour to protect and improve environment and to safeguard the forests and wildlife of the country.

Article 51A (g): It shall be duty of every citizen of India to protect and improve the natural environment including forests, lakes, rivers and wildlife and to have compassion for living creatures.

* In 1980, the Union Government of India established the Department of Environment.

* In 1985, it renamed the Ministry of Environment and Forests.

* In 2014, it renamed again the Ministry of Environment, Forests and Climate Change.

* National Forest Policy, 1988

* National Conservation Strategy and Policy Statement on Environment and Development, 1992

* Policy Statement on Abarement of Pollution, 1992

* National Environmental Action Programme, 1994

* National Agriculture Policy, 2000

* National Population Policy, 2000

* National Water Policy, 2002

* Wildlife Conservation Strategy, 2002

* National Environment Policy, 2006

* Wildlife Protection Act, 1972

* Water Prevention and Control of Pollution Act, 1974

* Forest Cconservation Act, 1980

* Air Prevention and Control of Pollution Act, 1981

* Environment (Protection) Act, 1986

* Environment (Protection) Rules, 1986

* Environment Impact Assessment-EIA, 1994 (In 1994, EIA was made mandatory for certain types of projects e.g. nuclear power, river valley project, ports, harbours etc. Under this regulation, the project proponent requires to submit an EIA report to Environment Ministry and after granting clearance from ministry he can begin the project. This clearance letter is valid for 5 years.)

⇒ Central Pollution Control Board (CPCB) 1974: The CPCB provides technical services to the environment ministry with regard to the provisions of Environment (Protection) Act, 1986.

⇒ Eco-mark 1991: Eco-mark is a certification mark issued by the Bureau of Indian Standards (the national standards organization of India) to products conforming to a set of standards aimed at the least impact on the ecosystem. The marking scheme was started in 1991. The earthen pot is chosen as the symbol of Eco-mark, because it is renewable source and doest not produce any hazardous waste. In other words it is eco-friendly.

⇒ National Green Tribunal (NGT), 2010: National Green Tribunal is a tribunal exclusively dedicated to environmental issues/matters. The Indian government established NGT in October 2010, headed by a former judge of Supreme Court. This body is established by Parliament (National Green Tribunal Act, 2010). It is based on ‘Polluter Pays’ principle and the principle of sustainable development.

⇒ Environmental Ethics: Environmental ethics try to define the moral basis of environmental responsibility. There are three possible view points _

1. Anthropocentric (Man-centric): This is the development environmental responsibility is to ensure that the earth remains hospitable and pleasant for human beings.

2. Biocentric: This is the preservation ethic. All forms of life-plants & animals (including human) have an inherent right to exist and live without hindrance.

3. Ecocentric : This is the conservation ethic. Environment deserves care and consideration by itself and not out of the interests of plants & animals (including man). It should be our aim to move from the current anthropocentric view to an ecocentric view.

⇒ Environmental Justice: An equal justice and equal protection for all under the environment laws and regulations without any discrimination based on race, cast, ethnicity or socio-economic status is known as Environmental Justice.

* Amrita Devi Bishnoi/Beniwal (d. 1730) : Amrita Devi, a follower of Bishnoi cult established by Jambhoji, sacrificed her life along with her three daughters namely Inn Asu, Rani & Bhagu on 10th day of Shukla Paksha, Bhadra Month, in year 1730 AD to save green trees being felled by Abhay Singh, the Maharaja of Jodhpur at a place known as khejarli in Marwar, Rajasthan. Along with her more than 363 other Bishnois of khejarli village died saving the kherji trees. [Khejarli/Khejadli : It is a village in Jodhpur district of Rajasthan. The name of the village. (now town) is derived from khejri (prospis cineraria) trees, which were in abundance in the village.] Government of India have started the national level Amrita Devi Bishnoi wildlife protection award (also known as Amrita Devi Bishnoi National Award) for wildlife conservation. The award consists of cash Rs. 1,00,000 and given to individuals or institution involved in wildlife protection. Government of Rajasthan have started the prestigious state level Amrita Devi Vishnoi Smriti Award for excellent contribution to the protection and conservation of wild animals. Award consists of cash 25,000 and a prashasti.

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