Global Environmental Issues and Sustainable Solutions

Hello all, so in this video we are starting with the fifth unit that is the first unit of second year AEC paper EVS. Okay, the unit 5 is global environmental issues and policies. So this is the fifth unit because in second year you are having a continuation of EVS from the first year. In the first year you had four units, so this is a continuation in the second year. So we are starting with Unit 5, Global Environmental Issues and Policies. So the first quarter portion of this unit is same as what you have studied in the first unit. That is in first year, you have studied the same thing. And majority of this unit is somewhat almost same as you have covered in your other units as well. So this won't be a Herculean task. So we live in a natural as well as social world. Development cannot be of only the rich nor it means only high living standards and also not just economic development. Millions of people of developing countries are still lying at extreme poverty condition. In developing countries extreme poverty still afflicts the lives of millions of people. 47 least developed countries exist on less than 0.5% of world's income. More than 2 billion people do not have access to adequate sanitation. 1 billion people do not have access to clean water. 1.3 billion people are breathing air below the air quality set by World Health Organization. Poverty and socio-economic inequality raise serious issue of sustainability. High rates of poverty are associated with various social evils like disease, family breakdown, endemic crime and use of narcotic drugs. Therefore, there is an urgent need to interlink the social aspects with development and environment. It has to be a holistic approach. So let's see some intended and unintended results of human activities. First let's check the intended results. So the human activities that we are referring here are land clearing, agriculture, fisheries, grazing, water diversion, mineral extraction, fuel consumption, industrialization, urbanization and recreation. So in intended results we have food production which helps in fiber production so it is an improved quality of life. Then we have shelter from land clearing and all we are having more shelter, house construction of buildings, flats and all. It also helps in water supply. Then consumer goods from agriculture. It helps in enjoyment. Then culture which improves the quality of our life by providing knowledge. Then we speak of unintended results and their environmental cost. You know with food production or shelter, let's say, the unintended result is habitat destruction of the wild animals. It leads to social degradation. Then deforestation for grazing, for industrialization, urbanization, recreation. We cut down trees. which leads to pollution then desertification which leads to eutrophication so all these terms we have studied in the first year what eutrophication is bio magnification bioaccumulation everything we have covered all these topics in first year so i won't be repeating them the video gets more and more lengthy then that's why next is acid precipitation loss of biodiversity we studied what precipitation is and all the what to say ph level change everything then climate change There is no more environmental cost. It itself is the issue. Next, nearly two-thirds of the services provided by nature to humankind are found to be on decline worldwide. Let's see what are they. I'll minimize the slide so you can see the whole. Sorry, I'm unable to minimize the slide. Global environmental challenges. First we can go through the declining resources. Overfishing, food system stress, fresh water scarcity, loss of forests, loss of biodiversity. The declining resources what to say also leads to altered biogeochemistry. In both ways they are affected. Altered biogeochemistry, also on depletion, elevated carbon dioxide, global warming, nitrogen loading, eutrophication. Then when we come to the social impacts, one is social disintegration, unemployment, health crisis, family breakdown, regional armed conflicts. Then human population, 9 billion by 2025, refugees. We studied what the absorbing capacity and the non-renewable resources, renewable resources, everything in the last year. So you can connect those concepts here. Refugees, urbanization, income inequality and poverty. Now the unemployment is because of 9 billion population by 2025. As the people increase, jobs are less. Then health crisis, refugees, then family breakdown due to urbanization, regional armed conflicts leading to income inequality and income inequity and poverty. Okay, so you can note down them. Next is the same thing that we have covered in the first unit. Okay, introduction to environmental science. I'm repeating that again, but not explaining. I'm just reading out them. From unsustainable to sustainable. The natural resources which require our existence are getting badly. which require for our existence are getting badly polluted and it is dwindling due to our exploitation. Therefore, a fear of unsustainable growth and development started in 1970s. The UN conference on human environment or Stockholm conference held in Stockholm, Sweden from June 5th to 16th 1972 was the first UN major conference on international environmental issues and marked a turning point in the development of international environment politics the development was inclined toward more use of earth resources and continued as economic development the u.n established a commission called world commission on environment and development in 1983 it is called the bruntland commission it was headed by the norwegian prime minister gro harlem bruntland The Commission proposed a global agenda to address the world's environmental problem and people's concern relating to living conditions, resources, population, pressures, international trade, education and health. The Brundtland Commission report, Our Common Future, defined sustainable development as development that meets the needs of the present without compromising the ability of future generations to meet their own needs. The concept of sustainable development in Brundtland report was the landmark for UN conference on environment and development, later known as, I mean popularly known as Earth Summit in Rio de Janeiro, Brazil in 1992. Following five are the, what to say, just give me a second, I'll come now. So the five significant agreement was the result of Earth Summit. Which are they? We studied the same thing, same topic, same definitions in the first unit. So, Agenda 21, Rio Declaration on Environment and Development, Statement of Forest Principles, UNFCC, the United Nations Convention on Biological Diversity. So out of these five significant agreements, Agenda 21 proposes a global program of action on sustainable development in social, economic, political context for the 21st century. Refer to this diagram. I won't be explaining them. Just refer to this diagram. We have already gone through all these in the first, I mean, last syllabus, I mean, first year, yeah. The definition of sustainable development can also be stated as development that meets the needs of the present while safeguarding Earth's life support system on which the welfare of current and future generation depends. Concept of sustainable development has three pillars, economic, social and environment, which this diagram depicts. So, note them, okay? Take a screenshot or print screen. Now, the key aspects of sustainable development are Intergenerational equity, that is stop overuse, reduce impacts, maintain ecological balance, handover a safe, healthy and resourceful environment to our future generation. Intergenerational, that is generation to generation. Then intragenerational equity, that is between the nations. Here we need to minimize gap between and within nations, the global south, global north, everything. Then... support economic growth of poorer countries, provide technological help that will support economic growth of poor countries and help in narrowing the wealth gap. Next is measure of sustainable development. So this we had studied in the second unit or land resources, third unit. I am not remembering it exactly but we have covered this. So, For sustainable development we need to use the technology appropriately. For that we need to adopt eco-friendly, locally adoptable, resource efficient and culturally suitable technology. Indigeneous technologies are most useful, cost effective and sustainable. Then three are approach to minimize waste generation, reduce, reuse, recycle. Then prompting environmental education and awareness. that what we are having that's the only reason why we are studying environmental science in your undergraduate levels then resource utilization as per carrying capacity we know what supporting capacity is capacity to regenerate then assimilating assimilative capacity the capacity to tolerate different stresses both combines to carrying capacity okay that is any system can sustain a limited number of organisms on a long-term basis Now in order to attain sustainability it is very important to utilize the resources based upon the above two properties of system. As Gandhiji said, nature can provide all your needs but not your greed. So the Indian scenario, we have covered this also. Emphasis on framing a well-planned strategy, tremendous population, tremendous natural diversity, hence makes planning sustainably all the more important but complex. Ministry of Environment and Forests set up in 1985 has formulated guidelines for various developmental activities keeping in view the sustainability principles. Now, climate change. So, climate change. New topic. So, till this, all over what we have already studied. But now, it's something new we are going to study. Okay. So, climate change. We know what climate change is. average weather of climate is an average weather of an area okay climate is the average uh weather of an area it is the general weather conditions seasonal variation and extremes of weather in a region okay i'm stressing this here because and the last um question paper that will say quest the question was like this differentiate between climate and weather okay um that was a three or four marks question i guess four marks question yeah so it's important so climate is the average weather of an area it is the general weather condition seasonal variation and extremes of weather in a region such condition which average over a long period at least 30 years is called climate you Okay, the long term long period thing is climate and the short period one is weather. The change in weather condition is I mean the change average weather of an area all this comes under climate. Okay, the global surface temperature has increased by 0.6 plus or minus 0.2 degree Celsius that is in the poles it will be decreased and I mean it varies right. equatorial region and also it is the data is by indoor uh ipcc okay in the governmental panel on climate change 1998 was the warmest year and 1990s was the warmest decade on record many countries have experienced increases in rainfall particularly in the countries situated in the mid to high latitudes It was observed that the earth temperature has changed considerably during the geological times. It has experienced several glacial and interglacial period. You can check the change in temperature with respect to the years. So the anthropogenic that is man-made activities are the major driver of present climate which are upsetting the established balance between various components of the environment. We know now in... In winter also sometimes we experience a high temperature. There are no rains but in sudden sometimes there a flood happens. So these all are the indications. The greenhouse gases are increasing enormously into the atmosphere and as a result the average global temperature of earth is increasing. This may disturb the hydrological cycle. We study the cycles in the second unit I guess. Water cycle, the evaporation, condensation, precipitation and everything. So the water cycle result in floods and droughts in different region in the world. Because sea level rise changes in agricultural productivity that leads to famines and death of humans as well as livestock. Okay, got that change. Sea level rise, change in agricultural productivity leads to famine, leads to death of Next is impact of climate change. The global change in temperature will not be uniform everywhere and will fluctuate in different regions. The places at higher latitudes will be warmed up more during late autumn and winter than the places in tropics. The increased warming at poles will reduce the thermal gradient between the equator and high latitude regions. that will disturb the global pattern of winds and oceans, currents as well as timing and distribution of rainfall. That will lead to shifting the ocean current that can change the climate of Ireland and Britain. Then, that is when the temperature is increased by 1.5 degree Celsius to 4.5 degree Celsius, the global water cycle is expected to intensify by 5 to 10 percent. It will lead to disturbed rainfall that will result in some areas becoming more wet or dry. Although rainfall may increase, higher temperature will result in the evapotranspiration. We studied what that is, a combination of evaporation and transpiration leading to annual water deficit in crop fields. Now, potential climate change impacts. The climate changes that we are referring here that is the temperature variation in temperature precipitation sea level rise so that will lead to health impacts weather related mortality we know with tsunami flood and all there is a high death occurrence okay then infectious diseases air quality respiratory illness then agricultural impacts crop yield irrigation demand Forest impacts, change in forest composition, shift in geographic range of forest. Forest health and productivity Water resources impacts changes in water supply water quality increased competition for water impacts on coastal areas erosion of beaches inundate coastal lands caused to defend coastal communities Then species and natural areas. Okay cause to defend coastal communities means if the coastal areas are Many erosion of beaches and everything happened We need to protect the people who are living in the coastal region. Rehabilitation and everything, their livelihood, all have to be cared for. Then species and natural areas shift in ecological zones, loss of habitat and species. So in 1989, the World Conference on Changing Atmosphere in Toronto led to formation of Intergovernmental Panel on Climate Change. From here on, I'll be referring to... to this as IPCC only okay so this was jointly established by UN environmental program and the world meteorological organization expect a one word from here okay UNEP plus world meteorological organization led to the formation of IPCC the initial report of IPCC was focused on basics of climate change the work of IPCC continued through the 1990s with the supplementary assessment in 1992 and a major reassessment in 1995. The third and fourth assessment reports of the IPCC that is in 2001 and 2007 respectively give most comprehensive information about on the atmospheric abundance of greenhouse gases and its possible impacts on climate, ecological systems, global carbon cycle and other related issues. Okay, so next is global warming. We know what it is the increase in greenhouse gases mainly from the burning of fossil fuels it Traps more heat in Earth's system So that is global warming this extra heat has resulted in higher temperatures on land and oceans Melting ice and more extreme weather. So here the solar radiation passes through the atmosphere to the earth About half of the solar radiation is absorbed By the earth mostly by the ocean most of the radiation radiated heat is absorbed by greenhouse gases molecules Warming Earth's surface and the lower atmosphere So carbon dioxide and other greenhouse gases released by the burning of fossil fuels thicken the atmosphere heat Blanket trapping more heat on earth. Okay, that's what happened now the effects one is natural and one is human induced natural is due to water vapor and carbon dioxide two evaporation transpiration evapotranspiration the water vapor so then carbon dioxide then human induced is global warming okay due to increasing carbon dioxide level and other greenhouse gases like methane nitrous oxide and all trapping of by certain gases in lower atmosphere is a natural process. Similarly greenhouse or green glass house used to make in horticulture for warming effect of plants. So as we see the greenhouse around the atmosphere traps all the heat. The same model is applied for horticulture vegetable cultivation. Here from a green glass house is made so the heat, the temperature will sustain inside which will help in the growth of crops. So this happens when greenhouse gases like carbon dioxide, water vapor, nitrous oxide and methane trap heat and light from the sun in the earth's atmosphere which increases the temperature. The amount of heat trapping or greenhouse gases and the length of time they stay in atmosphere, that is the average global temperature is 15 degrees Celsius in the absence of these gases. this temperature would be minus 18 degree celsius warming or cooling more than 2 degree celsius over the past few decades may prove to be disastrous for various ecosystem on the earth some areas will become inhabitable because of drought or floods following a rise in average sea level not this diagram take a screenshot okay then greenhouse gases about greenhouse gases with this pie chart you can get the amount of green the portion of greenhouse in the atmosphere so first carbon dioxide industrial countries account for more about 76 percent of annual emission main source are fossil fuel burning uh 67 percent from that and deforestation carbon dioxide concentration in the atmosphere was 355 ppm and um 1990 that is increasing at a rate of 1.5 ppm every year okay so this is a chart that you need to analyze okay so here we can see 411.91 part per million or parts per million carbon dioxide right so next is chlorofluorocarbons main source of ozone depletion is cfc okay So main source of CFC include leaking air conditioners, refrigerators, evaporation of industrial solvents, production of plastic forms, aerosols, propellants. So this is 1500 to 7000 times more efficient than carbon dioxide molecule. Then methane, 16% contribution of the increased greenhouse gases. Methane is produced when bacteria break down dead organic matter in moist places that lack oxygen. suggests swamps natural wetland paddy field landfill and digestive tracts of cattle sheep and termites each methane molecule traps about 25 times as much heat as carbon dioxide molecule you can expect a essay question from this different types of greenhouse gases okay next is nitrous oxide it is responsible for six percent of the human input of greenhouse gases it is released from nylon projects from burning of biomass and nitrogen-rich fuels, especially coal, and from the breakdown of nitrogen fertilizers in soil, livestock waste, and nitrate-contaminated groundwater. We studied on this in Natural Resources chapter. So, its lifespan in the troposphere is 140 to 190 years, and it traps about 230 times as much heat per molecule as carbon dioxide. Refer to the pie charts, take a screenshot. And the stirrers also, take a screenshot or not them. Greenhouse gas, atmospheric lifetime, global warming potential, then primary current source. So carbon dioxide from fossil fuel use, land use, cement, methane from fossil fuel use, agriculture, nitrous oxide mostly from agriculture, anthropogenic also. then hydrofluorocarbons alternative to also depletion depleting substances perfluorocarbons primary aluminum production semiconductor manufacturing sulfur hexafluorite used in the electric power transmission magnesium semiconductor redistributes and all so these will be also helpful when you prepare for the essays on greenhouse gases okay next is impact of enhanced greenhouse effect Global temperature increase, sea level rise, submergence of areas, effect of human health, change to agricultural production, change in wind current patterns, ocean currents will change, hydrological cycle will intensify, cases of flood, drought, cyclones will rise. We studied this, I mean in this chapter itself, in this unit itself, in the first 15 slides I guess. This was the one. this is a good meme good news the sharks are saying like at the current rate the global warming oh we should be able to just swim over there and eat him in under five years okay these are also some memes you can read out them next is measure to check global warming, cut down the current rates of use of CFCA, chlorofluorocarbons, fossil fuels, use energy more efficiently, shift to renewable energy resources, increase nuclear power plants for electricity production, shift from coal to natural gas, adopt sustainable agriculture, stabilize population growth, efficiently remove carbon dioxide from smokestacks, biofuels, afforestation, and... Then reduce the current rate of CO2, CO3, OCR. We have already said that. Trap methane for fuel potential of algae. in carbon dioxide utilization than sustainable agriculture. Next is acid rain. We had discussed this, so I'm not gonna discuss it again. In the first year syllabus we have discussed it. This will affect the pH scale, reduce the pH scale. Right, the gaseous pollutants in the atmosphere, then the particulate pollutants in the atmosphere, both will collide with the precipitation and yeah this happens so again the definition acid rain is a broad term referring to a mixture of wet and dry deposition from the atmosphere containing higher than normal amounts of nitric and sulfuric acid it occurs when these gases react in the atmosphere with water oxygen and other chemicals to form various acidic compounds the result is a mild solution of sulfuric acid and nitric acid When sulfur dioxide and nitrogen oxides are released from power plants, other resources, other sources, prevailing winds blow these compounds across state and national borders, sometimes over hundreds of miles. pH will be less than 5.6, that is why it is acidic. If the acid chemicals in the air are blown into areas where the weather is wet, the acids can fall to the ground in the form of rain, snow, fog or mist. As the acidic water flows over and through the ground it affects a variety of plants and animals. In areas where the weather is dry, the acid chemicals may become incorporated into dust or smoke and fall to the ground through dry deposition, sticking to ground buildings, homes, cars and trees. Examples are given here. Khore canal. So, most of you will be familiar with the film Manumel. Manumel boys, so this is that Khore canal. 5.18 then minicoi 5.52 then mohanbari 5.50 effects of acid rain ph below 5.1 causes a harmful effect this effect is visible on the aquatic system even at ph less than 5.5 percent sorry 5.5 excel like the deterioration of buildings taj mahal because it was built of marbles then damage to stone structures then damage metals and car finishes. Aquatic life, especially fish, are badly affected by lake acidification. Due to acid rain, a lot of leaching of toxic materials like aluminium, mercury, manganese, zinc and lead into the water bodies which affect the aquatic animals. Many lakes of Sweden, Norway, Canada have become fishless due to acid rain. It damages foliage and weaken the trees and also make trees more prone for diseases. We studied how this affects the trees, the plant bodies in very detail in the last year. Here we have reduced the definition to one sentence. I hope that's enough. Now control of acid rain. Emission of sulfur dioxide and nitrogen dioxide from industries and power plants should be reduced by using pollution control equipments. Then liming of lakes and soils, then coating a protective level of inert polymer to the interior of water pipes. Next is ozone layer depletion. So ozone layer is a natural sunscreen. For the last 450 million years, the earth has a natural sunscreen in stratosphere. That is called ozone layer. This layer filters out the harmful ultraviolet radiations. UV rays from the sunlight and thus protects various life forms on the earth. So layers of atmosphere, we have covered the topic, we have covered the ozone everything. Formation of ozone layer, we have discussed it but again O2 plus HV gives. That is HV is the ultraviolet radiation which is less than 242 nanometer which decomposes molecular oxygen into atomic oxygen. So O2 is a molecule. When it is combined with the UV ray, it becomes atomic. It splits. And when that atomic oxygen, O, is combined with the molecular oxygen and a third body, M, which is necessary to carry away the energy released in the reaction, Ozone plus the same energy in result is produced. Oxon absorbs harmful ultraviolet radiation that is 200 to 320 nm and is continuously being converted back to molecular oxygen You know why this? Because O3 plus HV again gives you O2 plus O. It splits. Then O2 plus HV gives O plus O. Okay, thinning of ozone layer or ozone hole or ozone layer depletion. In 1984, ozone layer hole was discovered over Antarctica. The British Antarctica Survey Team led by Joe Farman in 1985 reported that ozone layer of Antarctica had shrunk each year since 1970. CFC are mainly responsible for ozone depletion in the stratosphere. Nitrous oxide emitted by supersonic aircraft during combustion of fossil fuels and use of nitrogen fertilizers break ozone molecules. CFC-11 and CFC-12 are the CFCs most commonly used. It's used... school and in refrigerators and air conditioners as propellants cleaning solvents etc CFC released in the troposphere reach into the stratosphere and remain for 65 to 110 years destroying all three molecules during winter season minus 90 degrees Celsius the winds form ice crystals CFC get collected on the surface of these ice crystals and destroy also much faster the cfc in the stratosphere uh therefore the chlorine atom is removed from cfc and attracts one of the three oxygen atoms in the ozone molecule the process continues and a single chlorine atom can destroy over one lakh molecules of ozone now effects of ozone hole due to also depletion that is also not also whole the ubb reaches to earth surface and affect DNA and photosynthetic chemicals any changes in DNA can result in mutation and cancer we know nowadays when we buy the sunscreens you can see that protect from UVB rays blue light and all okay that's it so easy absorption of UV rays by the lens and cornea of eyes will result in increase in incidence of cataract Melanin producing cells of the epidermis will be destroyed by UV rays that cause immunosuppression. Phytoplankton are sensitive to UV exposure. Phytoplankton produces in aquatic ecosystem. Then yield of vital crops like corn, rice, wheat will decrease. Degradation of paints, plastic and other polymer material happens. Now Vienna Convention for the Protection of Ozone Layer. In 1981, The UNEP acted on a proposal to develop a global convention on the ozone layer. There was a lack of understanding about the true extent of the environmental risk from depletion made early negotiations very... Depletions, okay. So, it said the negotiations were difficult because they didn't know the extent, the depth of this problem. There was a lot of questions of validity of the science on this. As a result, 1985, the Vienna Convention on the Protection of the Ozone Layer, a multilateral environmental agreement came into existence. Within two years that followed the creation of the Vienna Convention, there was incredible progress in reaching a global scientific consciousness on the nature and the threat from ozone loss. So by 1987, the disagreements and lack of understandings had given way to substantial trust among the international community. On September 16th, specifically, Montreal Protocol on Substances that Deplete the Ocean Layer was negotiated and signed by Canada along with 23 other countries. As of September 16, 2009, it has been signed and ratified by 196 countries achieving universal participation. The Montreal Protocol on Substances substances that deplete the ozone layer is one of the first international environmental agreements that includes trade sanctions to achieve the stated goals of a treaty. India became parity to the Vienna Convention and Montreal Protocol on 8th March 1991 and 19th June 1992 respectively. Main goal of Montreal Protocol was to phase out ozone depleting substances. Under the Montreal Protocol 95% of the production and consumption of ozone depleting substances substances has been phased out uh the grouped i mean the hundred chemicals that are grouped in the following categories okay cfc halone carbon tetro chloride hydro chlorofluorocarbons methyl chloroform either bromide and all now environmental ethics so the human centric thinking and earth centric thing in human centric thinking we think like human As all-powerful supreme creature, master of nature can harness it at his will. But like if we think nature has provided all the resources for leading a beautiful life, nourishes us like a mother, we should respect our nurture here, the world would have been a better place. The first view, we know, the humans are thinking because of the economic growth and development with much, without care on the planet. But we need to, we need to have that in our mind that Mother nature is everything, right? So, some important ethical guidelines. These all are like something that you can write by yourself. Love and honour, sacred to earth. No right to drive them to extinction, other creatures. Should be grateful to the plants and animals. We must not limit our offsprings and overburden them. Then, should not in the very... We should not waste your resources on destructive weapons. And also, we should not run after gains and take cost of nature. Then we should not steal from the future generations as we say in the Brundtland Commission. Then we should not consume the material goods in moderate, I mean above moderate amounts. Okay, so that's it. So, let's continue in the next part. Thank you.

In the first year you had four units, so this is a continuation in the second year. So we are starting with Unit 5, Global Environmental Issues and Policies. So the first quarter portion of this unit is same as what you have studied in the first unit.

That is in first year, you have studied the same thing. And majority of this unit is somewhat almost same as you have covered in your other units as well. So this won't be a Herculean task.

So we live in a natural as well as social world. Development cannot be of only the rich nor it means only high living standards and also not just economic development. Millions of people of developing countries are still lying at extreme poverty condition.

In developing countries extreme poverty still afflicts the lives of millions of people. 47 least developed countries exist on less than 0.5% of world's income. More than 2 billion people do not have access to adequate sanitation.

1 billion people do not have access to clean water. 1.3 billion people are breathing air below the air quality set by World Health Organization. Poverty and socio-economic inequality raise serious issue of sustainability. High rates of poverty are associated with various social evils like disease, family breakdown, endemic crime and use of narcotic drugs.

Therefore, there is an urgent need to interlink the social aspects with development and environment. It has to be a holistic approach. So let's see some intended and unintended results of human activities.

First let's check the intended results. So the human activities that we are referring here are land clearing, agriculture, fisheries, grazing, water diversion, mineral extraction, fuel consumption, industrialization, urbanization and recreation. So in intended results we have food production which helps in fiber production so it is an improved quality of life. Then we have shelter from land clearing and all we are having more shelter, house construction of buildings, flats and all. It also helps in water supply.

Then consumer goods from agriculture. It helps in enjoyment. Then culture which improves the quality of our life by providing knowledge.

Then we speak of unintended results and their environmental cost. You know with food production or shelter, let's say, the unintended result is habitat destruction of the wild animals. It leads to social degradation.

Then deforestation for grazing, for industrialization, urbanization, recreation. We cut down trees. which leads to pollution then desertification which leads to eutrophication so all these terms we have studied in the first year what eutrophication is bio magnification bioaccumulation everything we have covered all these topics in first year so i won't be repeating them the video gets more and more lengthy then that's why next is acid precipitation loss of biodiversity we studied what precipitation is and all the what to say ph level change everything then climate change There is no more environmental cost.

It itself is the issue. Next, nearly two-thirds of the services provided by nature to humankind are found to be on decline worldwide. Let's see what are they.

I'll minimize the slide so you can see the whole. Sorry, I'm unable to minimize the slide. Global environmental challenges. First we can go through the declining resources. Overfishing, food system stress, fresh water scarcity, loss of forests, loss of biodiversity.

The declining resources what to say also leads to altered biogeochemistry. In both ways they are affected. Altered biogeochemistry, also on depletion, elevated carbon dioxide, global warming, nitrogen loading, eutrophication.

Then when we come to the social impacts, one is social disintegration, unemployment, health crisis, family breakdown, regional armed conflicts. Then human population, 9 billion by 2025, refugees. We studied what the absorbing capacity and the non-renewable resources, renewable resources, everything in the last year. So you can connect those concepts here.

Refugees, urbanization, income inequality and poverty. Now the unemployment is because of 9 billion population by 2025. As the people increase, jobs are less. Then health crisis, refugees, then family breakdown due to urbanization, regional armed conflicts leading to income inequality and income inequity and poverty.

Okay, so you can note down them. Next is the same thing that we have covered in the first unit. Okay, introduction to environmental science. I'm repeating that again, but not explaining.

I'm just reading out them. From unsustainable to sustainable. The natural resources which require our existence are getting badly. which require for our existence are getting badly polluted and it is dwindling due to our exploitation. Therefore, a fear of unsustainable growth and development started in 1970s.

The UN conference on human environment or Stockholm conference held in Stockholm, Sweden from June 5th to 16th 1972 was the first UN major conference on international environmental issues and marked a turning point in the development of international environment politics the development was inclined toward more use of earth resources and continued as economic development the u.n established a commission called world commission on environment and development in 1983 it is called the bruntland commission it was headed by the norwegian prime minister gro harlem bruntland The Commission proposed a global agenda to address the world's environmental problem and people's concern relating to living conditions, resources, population, pressures, international trade, education and health. The Brundtland Commission report, Our Common Future, defined sustainable development as development that meets the needs of the present without compromising the ability of future generations to meet their own needs. The concept of sustainable development in Brundtland report was the landmark for UN conference on environment and development, later known as, I mean popularly known as Earth Summit in Rio de Janeiro, Brazil in 1992. Following five are the, what to say, just give me a second, I'll come now.

So the five significant agreement was the result of Earth Summit. Which are they? We studied the same thing, same topic, same definitions in the first unit.

So, Agenda 21, Rio Declaration on Environment and Development, Statement of Forest Principles, UNFCC, the United Nations Convention on Biological Diversity. So out of these five significant agreements, Agenda 21 proposes a global program of action on sustainable development in social, economic, political context for the 21st century. Refer to this diagram. I won't be explaining them.

Just refer to this diagram. We have already gone through all these in the first, I mean, last syllabus, I mean, first year, yeah. The definition of sustainable development can also be stated as development that meets the needs of the present while safeguarding Earth's life support system on which the welfare of current and future generation depends. Concept of sustainable development has three pillars, economic, social and environment, which this diagram depicts.

So, note them, okay? Take a screenshot or print screen. Now, the key aspects of sustainable development are Intergenerational equity, that is stop overuse, reduce impacts, maintain ecological balance, handover a safe, healthy and resourceful environment to our future generation.

Intergenerational, that is generation to generation. Then intragenerational equity, that is between the nations. Here we need to minimize gap between and within nations, the global south, global north, everything. Then...

support economic growth of poorer countries, provide technological help that will support economic growth of poor countries and help in narrowing the wealth gap. Next is measure of sustainable development. So this we had studied in the second unit or land resources, third unit. I am not remembering it exactly but we have covered this.

So, For sustainable development we need to use the technology appropriately. For that we need to adopt eco-friendly, locally adoptable, resource efficient and culturally suitable technology. Indigeneous technologies are most useful, cost effective and sustainable. Then three are approach to minimize waste generation, reduce, reuse, recycle. Then prompting environmental education and awareness.

that what we are having that's the only reason why we are studying environmental science in your undergraduate levels then resource utilization as per carrying capacity we know what supporting capacity is capacity to regenerate then assimilating assimilative capacity the capacity to tolerate different stresses both combines to carrying capacity okay that is any system can sustain a limited number of organisms on a long-term basis Now in order to attain sustainability it is very important to utilize the resources based upon the above two properties of system. As Gandhiji said, nature can provide all your needs but not your greed. So the Indian scenario, we have covered this also. Emphasis on framing a well-planned strategy, tremendous population, tremendous natural diversity, hence makes planning sustainably all the more important but complex. Ministry of Environment and Forests set up in 1985 has formulated guidelines for various developmental activities keeping in view the sustainability principles.

Now, climate change. So, climate change. New topic.

So, till this, all over what we have already studied. But now, it's something new we are going to study. Okay. So, climate change. We know what climate change is. average weather of climate is an average weather of an area okay climate is the average uh weather of an area it is the general weather conditions seasonal variation and extremes of weather in a region okay i'm stressing this here because and the last um question paper that will say quest the question was like this differentiate between climate and weather okay um that was a three or four marks question i guess four marks question yeah so it's important so climate is the average weather of an area it is the general weather condition seasonal variation and extremes of weather in a region such condition which average over a long period at least 30 years is called climate you Okay, the long term long period thing is climate and the short period one is weather.

The change in weather condition is I mean the change average weather of an area all this comes under climate. Okay, the global surface temperature has increased by 0.6 plus or minus 0.2 degree Celsius that is in the poles it will be decreased and I mean it varies right. equatorial region and also it is the data is by indoor uh ipcc okay in the governmental panel on climate change 1998 was the warmest year and 1990s was the warmest decade on record many countries have experienced increases in rainfall particularly in the countries situated in the mid to high latitudes It was observed that the earth temperature has changed considerably during the geological times. It has experienced several glacial and interglacial period. You can check the change in temperature with respect to the years.

So the anthropogenic that is man-made activities are the major driver of present climate which are upsetting the established balance between various components of the environment. We know now in... In winter also sometimes we experience a high temperature. There are no rains but in sudden sometimes there a flood happens. So these all are the indications.

The greenhouse gases are increasing enormously into the atmosphere and as a result the average global temperature of earth is increasing. This may disturb the hydrological cycle. We study the cycles in the second unit I guess.

Water cycle, the evaporation, condensation, precipitation and everything. So the water cycle result in floods and droughts in different region in the world. Because sea level rise changes in agricultural productivity that leads to famines and death of humans as well as livestock. Okay, got that change.

Sea level rise, change in agricultural productivity leads to famine, leads to death of Next is impact of climate change. The global change in temperature will not be uniform everywhere and will fluctuate in different regions. The places at higher latitudes will be warmed up more during late autumn and winter than the places in tropics.

The increased warming at poles will reduce the thermal gradient between the equator and high latitude regions. that will disturb the global pattern of winds and oceans, currents as well as timing and distribution of rainfall. That will lead to shifting the ocean current that can change the climate of Ireland and Britain.

Then, that is when the temperature is increased by 1.5 degree Celsius to 4.5 degree Celsius, the global water cycle is expected to intensify by 5 to 10 percent. It will lead to disturbed rainfall that will result in some areas becoming more wet or dry. Although rainfall may increase, higher temperature will result in the evapotranspiration.

We studied what that is, a combination of evaporation and transpiration leading to annual water deficit in crop fields. Now, potential climate change impacts. The climate changes that we are referring here that is the temperature variation in temperature precipitation sea level rise so that will lead to health impacts weather related mortality we know with tsunami flood and all there is a high death occurrence okay then infectious diseases air quality respiratory illness then agricultural impacts crop yield irrigation demand Forest impacts, change in forest composition, shift in geographic range of forest. Forest health and productivity Water resources impacts changes in water supply water quality increased competition for water impacts on coastal areas erosion of beaches inundate coastal lands caused to defend coastal communities Then species and natural areas. Okay cause to defend coastal communities means if the coastal areas are Many erosion of beaches and everything happened We need to protect the people who are living in the coastal region.

Rehabilitation and everything, their livelihood, all have to be cared for. Then species and natural areas shift in ecological zones, loss of habitat and species. So in 1989, the World Conference on Changing Atmosphere in Toronto led to formation of Intergovernmental Panel on Climate Change. From here on, I'll be referring to...

to this as IPCC only okay so this was jointly established by UN environmental program and the world meteorological organization expect a one word from here okay UNEP plus world meteorological organization led to the formation of IPCC the initial report of IPCC was focused on basics of climate change the work of IPCC continued through the 1990s with the supplementary assessment in 1992 and a major reassessment in 1995. The third and fourth assessment reports of the IPCC that is in 2001 and 2007 respectively give most comprehensive information about on the atmospheric abundance of greenhouse gases and its possible impacts on climate, ecological systems, global carbon cycle and other related issues. Okay, so next is global warming. We know what it is the increase in greenhouse gases mainly from the burning of fossil fuels it Traps more heat in Earth's system So that is global warming this extra heat has resulted in higher temperatures on land and oceans Melting ice and more extreme weather. So here the solar radiation passes through the atmosphere to the earth About half of the solar radiation is absorbed By the earth mostly by the ocean most of the radiation radiated heat is absorbed by greenhouse gases molecules Warming Earth's surface and the lower atmosphere So carbon dioxide and other greenhouse gases released by the burning of fossil fuels thicken the atmosphere heat Blanket trapping more heat on earth.

Okay, that's what happened now the effects one is natural and one is human induced natural is due to water vapor and carbon dioxide two evaporation transpiration evapotranspiration the water vapor so then carbon dioxide then human induced is global warming okay due to increasing carbon dioxide level and other greenhouse gases like methane nitrous oxide and all trapping of by certain gases in lower atmosphere is a natural process. Similarly greenhouse or green glass house used to make in horticulture for warming effect of plants. So as we see the greenhouse around the atmosphere traps all the heat. The same model is applied for horticulture vegetable cultivation. Here from a green glass house is made so the heat, the temperature will sustain inside which will help in the growth of crops.

So this happens when greenhouse gases like carbon dioxide, water vapor, nitrous oxide and methane trap heat and light from the sun in the earth's atmosphere which increases the temperature. The amount of heat trapping or greenhouse gases and the length of time they stay in atmosphere, that is the average global temperature is 15 degrees Celsius in the absence of these gases. this temperature would be minus 18 degree celsius warming or cooling more than 2 degree celsius over the past few decades may prove to be disastrous for various ecosystem on the earth some areas will become inhabitable because of drought or floods following a rise in average sea level not this diagram take a screenshot okay then greenhouse gases about greenhouse gases with this pie chart you can get the amount of green the portion of greenhouse in the atmosphere so first carbon dioxide industrial countries account for more about 76 percent of annual emission main source are fossil fuel burning uh 67 percent from that and deforestation carbon dioxide concentration in the atmosphere was 355 ppm and um 1990 that is increasing at a rate of 1.5 ppm every year okay so this is a chart that you need to analyze okay so here we can see 411.91 part per million or parts per million carbon dioxide right so next is chlorofluorocarbons main source of ozone depletion is cfc okay So main source of CFC include leaking air conditioners, refrigerators, evaporation of industrial solvents, production of plastic forms, aerosols, propellants. So this is 1500 to 7000 times more efficient than carbon dioxide molecule.

Then methane, 16% contribution of the increased greenhouse gases. Methane is produced when bacteria break down dead organic matter in moist places that lack oxygen. suggests swamps natural wetland paddy field landfill and digestive tracts of cattle sheep and termites each methane molecule traps about 25 times as much heat as carbon dioxide molecule you can expect a essay question from this different types of greenhouse gases okay next is nitrous oxide it is responsible for six percent of the human input of greenhouse gases it is released from nylon projects from burning of biomass and nitrogen-rich fuels, especially coal, and from the breakdown of nitrogen fertilizers in soil, livestock waste, and nitrate-contaminated groundwater. We studied on this in Natural Resources chapter. So, its lifespan in the troposphere is 140 to 190 years, and it traps about 230 times as much heat per molecule as carbon dioxide.

Refer to the pie charts, take a screenshot. And the stirrers also, take a screenshot or not them. Greenhouse gas, atmospheric lifetime, global warming potential, then primary current source. So carbon dioxide from fossil fuel use, land use, cement, methane from fossil fuel use, agriculture, nitrous oxide mostly from agriculture, anthropogenic also. then hydrofluorocarbons alternative to also depletion depleting substances perfluorocarbons primary aluminum production semiconductor manufacturing sulfur hexafluorite used in the electric power transmission magnesium semiconductor redistributes and all so these will be also helpful when you prepare for the essays on greenhouse gases okay next is impact of enhanced greenhouse effect Global temperature increase, sea level rise, submergence of areas, effect of human health, change to agricultural production, change in wind current patterns, ocean currents will change, hydrological cycle will intensify, cases of flood, drought, cyclones will rise.

We studied this, I mean in this chapter itself, in this unit itself, in the first 15 slides I guess. This was the one. this is a good meme good news the sharks are saying like at the current rate the global warming oh we should be able to just swim over there and eat him in under five years okay these are also some memes you can read out them next is measure to check global warming, cut down the current rates of use of CFCA, chlorofluorocarbons, fossil fuels, use energy more efficiently, shift to renewable energy resources, increase nuclear power plants for electricity production, shift from coal to natural gas, adopt sustainable agriculture, stabilize population growth, efficiently remove carbon dioxide from smokestacks, biofuels, afforestation, and... Then reduce the current rate of CO2, CO3, OCR. We have already said that.

Trap methane for fuel potential of algae. in carbon dioxide utilization than sustainable agriculture. Next is acid rain. We had discussed this, so I'm not gonna discuss it again. In the first year syllabus we have discussed it.

This will affect the pH scale, reduce the pH scale. Right, the gaseous pollutants in the atmosphere, then the particulate pollutants in the atmosphere, both will collide with the precipitation and yeah this happens so again the definition acid rain is a broad term referring to a mixture of wet and dry deposition from the atmosphere containing higher than normal amounts of nitric and sulfuric acid it occurs when these gases react in the atmosphere with water oxygen and other chemicals to form various acidic compounds the result is a mild solution of sulfuric acid and nitric acid When sulfur dioxide and nitrogen oxides are released from power plants, other resources, other sources, prevailing winds blow these compounds across state and national borders, sometimes over hundreds of miles. pH will be less than 5.6, that is why it is acidic.

If the acid chemicals in the air are blown into areas where the weather is wet, the acids can fall to the ground in the form of rain, snow, fog or mist. As the acidic water flows over and through the ground it affects a variety of plants and animals. In areas where the weather is dry, the acid chemicals may become incorporated into dust or smoke and fall to the ground through dry deposition, sticking to ground buildings, homes, cars and trees.

Examples are given here. Khore canal. So, most of you will be familiar with the film Manumel. Manumel boys, so this is that Khore canal. 5.18 then minicoi 5.52 then mohanbari 5.50 effects of acid rain ph below 5.1 causes a harmful effect this effect is visible on the aquatic system even at ph less than 5.5 percent sorry 5.5 excel like the deterioration of buildings taj mahal because it was built of marbles then damage to stone structures then damage metals and car finishes.

Aquatic life, especially fish, are badly affected by lake acidification. Due to acid rain, a lot of leaching of toxic materials like aluminium, mercury, manganese, zinc and lead into the water bodies which affect the aquatic animals. Many lakes of Sweden, Norway, Canada have become fishless due to acid rain.

It damages foliage and weaken the trees and also make trees more prone for diseases. We studied how this affects the trees, the plant bodies in very detail in the last year. Here we have reduced the definition to one sentence.

I hope that's enough. Now control of acid rain. Emission of sulfur dioxide and nitrogen dioxide from industries and power plants should be reduced by using pollution control equipments.

Then liming of lakes and soils, then coating a protective level of inert polymer to the interior of water pipes. Next is ozone layer depletion. So ozone layer is a natural sunscreen.

For the last 450 million years, the earth has a natural sunscreen in stratosphere. That is called ozone layer. This layer filters out the harmful ultraviolet radiations. UV rays from the sunlight and thus protects various life forms on the earth. So layers of atmosphere, we have covered the topic, we have covered the ozone everything.

Formation of ozone layer, we have discussed it but again O2 plus HV gives. That is HV is the ultraviolet radiation which is less than 242 nanometer which decomposes molecular oxygen into atomic oxygen. So O2 is a molecule. When it is combined with the UV ray, it becomes atomic.

It splits. And when that atomic oxygen, O, is combined with the molecular oxygen and a third body, M, which is necessary to carry away the energy released in the reaction, Ozone plus the same energy in result is produced. Oxon absorbs harmful ultraviolet radiation that is 200 to 320 nm and is continuously being converted back to molecular oxygen You know why this?

Because O3 plus HV again gives you O2 plus O. It splits. Then O2 plus HV gives O plus O.

Okay, thinning of ozone layer or ozone hole or ozone layer depletion. In 1984, ozone layer hole was discovered over Antarctica. The British Antarctica Survey Team led by Joe Farman in 1985 reported that ozone layer of Antarctica had shrunk each year since 1970. CFC are mainly responsible for ozone depletion in the stratosphere.

Nitrous oxide emitted by supersonic aircraft during combustion of fossil fuels and use of nitrogen fertilizers break ozone molecules. CFC-11 and CFC-12 are the CFCs most commonly used. It's used...

school and in refrigerators and air conditioners as propellants cleaning solvents etc CFC released in the troposphere reach into the stratosphere and remain for 65 to 110 years destroying all three molecules during winter season minus 90 degrees Celsius the winds form ice crystals CFC get collected on the surface of these ice crystals and destroy also much faster the cfc in the stratosphere uh therefore the chlorine atom is removed from cfc and attracts one of the three oxygen atoms in the ozone molecule the process continues and a single chlorine atom can destroy over one lakh molecules of ozone now effects of ozone hole due to also depletion that is also not also whole the ubb reaches to earth surface and affect DNA and photosynthetic chemicals any changes in DNA can result in mutation and cancer we know nowadays when we buy the sunscreens you can see that protect from UVB rays blue light and all okay that's it so easy absorption of UV rays by the lens and cornea of eyes will result in increase in incidence of cataract Melanin producing cells of the epidermis will be destroyed by UV rays that cause immunosuppression. Phytoplankton are sensitive to UV exposure. Phytoplankton produces in aquatic ecosystem.

Then yield of vital crops like corn, rice, wheat will decrease. Degradation of paints, plastic and other polymer material happens. Now Vienna Convention for the Protection of Ozone Layer. In 1981, The UNEP acted on a proposal to develop a global convention on the ozone layer. There was a lack of understanding about the true extent of the environmental risk from depletion made early negotiations very...

Depletions, okay. So, it said the negotiations were difficult because they didn't know the extent, the depth of this problem. There was a lot of questions of validity of the science on this.

As a result, 1985, the Vienna Convention on the Protection of the Ozone Layer, a multilateral environmental agreement came into existence. Within two years that followed the creation of the Vienna Convention, there was incredible progress in reaching a global scientific consciousness on the nature and the threat from ozone loss. So by 1987, the disagreements and lack of understandings had given way to substantial trust among the international community.

On September 16th, specifically, Montreal Protocol on Substances that Deplete the Ocean Layer was negotiated and signed by Canada along with 23 other countries. As of September 16, 2009, it has been signed and ratified by 196 countries achieving universal participation. The Montreal Protocol on Substances substances that deplete the ozone layer is one of the first international environmental agreements that includes trade sanctions to achieve the stated goals of a treaty.

India became parity to the Vienna Convention and Montreal Protocol on 8th March 1991 and 19th June 1992 respectively. Main goal of Montreal Protocol was to phase out ozone depleting substances. Under the Montreal Protocol 95% of the production and consumption of ozone depleting substances substances has been phased out uh the grouped i mean the hundred chemicals that are grouped in the following categories okay cfc halone carbon tetro chloride hydro chlorofluorocarbons methyl chloroform either bromide and all now environmental ethics so the human centric thinking and earth centric thing in human centric thinking we think like human As all-powerful supreme creature, master of nature can harness it at his will. But like if we think nature has provided all the resources for leading a beautiful life, nourishes us like a mother, we should respect our nurture here, the world would have been a better place. The first view, we know, the humans are thinking because of the economic growth and development with much, without care on the planet.

But we need to, we need to have that in our mind that Mother nature is everything, right? So, some important ethical guidelines. These all are like something that you can write by yourself. Love and honour, sacred to earth. No right to drive them to extinction, other creatures.

Should be grateful to the plants and animals. We must not limit our offsprings and overburden them. Then, should not in the very...

We should not waste your resources on destructive weapons. And also, we should not run after gains and take cost of nature. Then we should not steal from the future generations as we say in the Brundtland Commission. Then we should not consume the material goods in moderate, I mean above moderate amounts.

Okay, so that's it. So, let's continue in the next part. Thank you.

Transcript for:Global Environmental Issues and Sustainable Solutions

Transcript for:
Global Environmental Issues and Sustainable Solutions