EVS CH-1 PDF

EVS CH- 1 Major Environmental Issues o Ozone Layer Depletion o Resource Depletion o Pollution o Extinction o Global Warming Ozone Layer Depletion Ozone is a gas in the stratosphere which converts the incoming UV radiation fro...

EVS CH- 1 Major Environmental Issues o Ozone Layer Depletion o Resource Depletion o Pollution o Extinction o Global Warming Ozone Layer Depletion Ozone is a gas in the stratosphere which converts the incoming UV radiation from the sun into infrared rays by what is known as the ozone-oxygen cycle. The ozone–oxygen cycle is the process by which ozone is continually regenerated in Earth's stratosphere, converting ultraviolet radiation (UV) into heat. Also called Chapman cycle. In the above diagram, the blue part is the “ozone hole” over the Antarctic. It is the part of the stratosphere where the concentration of Ozone is very low. Most of the ozone production occurs in the tropical upper stratosphere and mesosphere. The global mass of ozone is relatively constant at about 3 billion metric tons. The total mass of ozone produced per day over the globe is about 400 million metric tons. Sun produces about 12% of the ozone layer each day. Ozone hole is no longer a prevailing issue. The ban imposed on the worldwide use of the CFCs and other Ozone Depleting substances via the Montreal Protocol (1987) has solved the problem. Since then, the concentration of such substances in the atmosphere have stabilized or are decreasing and are soon expected to disappear. The “Ozone hole” is expected to close by 2040.  Only a few gases like HCFCs are on the rise but are expected to be phased out by 2030. Other slight rises are due to weak regulation in East Asian countries and are expected to go down as well as those countries become more developed and impose regulations more stringently Resource Depletion “Tragedy of the commons” is a term that was first used to explain how the exploitation of common grazing lands by farmers in Great Britain and Ireland. The individuals acting on their self-interest will benefit by shifting the burden of maintenance of the commons on the other parties, but eventually everyone will suffer from the degradation of that resource. Hence the word tragedy is used. Resource like grazing land, river, air, roads etc. were exploited. - Ground water is a tragedy of the commons issue because underground water is a commons property. Individuals extract water from their borewells but the underground aquifer is common to all. If one extracts heavily, it affects the supply of others. - Overfishing is commons problem because though fish stocks are a renewable resource, they are common to all fisherman and are renewable only if they can breed in the same numbers as they are being extracted. If some fishermen over extract fish, the other fishermen have a lesser fish stock to fish, straining the overall population of fish. As a result, each subsequent population of fish will be smaller than the previous causing a “tragedy” for all. It was discovered government intervention and privatization can not be a solution to this problem however later on: - Elinor Ostrom is the first woman to win the Nobel Prize in Economics. She won it for her work that showed for the first time that the local commons can be successfully managed by locals without any regulation by government or privatization. Till her work was seen, it was assumed that only the latter two options existed for solving this problem. - Small, local communities were able to manage shared natural resources such as fishing water or forests, and that, over time, rules for managing the common were established to maintain the resources' long-term sustainability. Pollution WHO guidelines which says that up to 10 ug/m3 is safe, after which it is can be detrimental. The scale in the US map reflects this with 10 ug/m3 designated as green. The highest that scale goes to is 20ug/m3. If the PM2.5 goes to this level, they usually announce health advisory and generally discourage people from going out of their houses. US follows WHO. India follows the NAAQS (National Ambient Air Quality Standards) which is a standard it formed itself. NAAQS limit is 4 times above WHO limits. India has one of the highest death rates related to chronic respiratory issues. 1.5 million Indians die every year because of this. And of the 20 most polluted cities in the world, we are home to 13. Extinction Rate of extinction is so fast that scientists now think that the 6th mass extinction has begun. In many instances, we are losing species faster than we are discovering them. Global Warming Charles David Keeling - He was a geochemist who built the first instrument to take precise measurements of CO2 in the atmosphere and took preliminary readings from Mauna Loa in Hawaii. - Mauna Loa was chosen as the first test site because it is away from the mainland US and as winds come from the ocean to the mainland, the readings he would get would not contaminate by local influence such as cars and industries. He would truly get the average conc. of CO2 in the atmosphere. He took readings from 1957 to 1960. The graph is the result of his measurements. It has three major breakthroughs. First, that the CO2 conc. in the atmosphere is not a constant. It varies according to season. (Spring and summer have low while fall and winter has high conc.) Second breakthrough was that if you were drawing a trend line through this graph, you would see a slight uptick. He roughly calculated this uptick is at the same rate of fossil fuel emissions in the world. Third, though the rate is the same, the total estimated quantity of CO2 increase in the atmosphere is not the same as the amount emitted in the atmosphere by fossil fuels. He conjectured that some of it was being absorbed by natural systems like forests and oceans THE KEELING CURVE The graph is the result of his effort. Though somewhat vaguely present in his 1960 graph, This one shows a clear uptick in the CO2 conc. and an increase of roughly 100ppm of CO2 in the atmosphere since 1957. Mauna Loa is now the worlds longest continuous CO2 measuring station. ICE CORES They are cylindrical blocks of ice dug out of from permafrost (Permanent frost). In certain places in the world, like the poles, when snow forms in the winter, it never melts. When this snow forms, it traps small air pockets within itself, and as snow forms every winter every year, each year forms a layer of ice over the last years ice deposit. If we dig vertically into these layers and extract the air pockets from each layer of ice, we would get a temporal scale of atmospheric composition of the planet. This can be used to measure the composition to decipher the amount of CO2 in the atmosphere and also the ambient temperature of the planet in that year. - Scientists have been able to reconstruct earth’s CO2 and avg. Antarctic temperature history for the past 800,000 years through ice cores data. In this graph, each trough represents an ice age. In the last 800,000 years, we have seen 7 ice ages. Temperature and CO2 are strongly correlated (the relationship between them though, is not linear). If CO2 and temp are correlated, and if every time CO2 has increased in the atmosphere, the Earth has warmed enough to come out of an ice age. Earth has never seen so much CO2 in the atmosphere in its past 800,000-year history. This excess CO2 is clearly a cause of major concern and is entirely due to man-made reasons. There is nothing natural about this CO2 conc. in the atmosphere. - This problem is further made worse by the fact that the rate of change of CO2, has accelerated despite our efforts to curtail it in the last couple of decades. SOME EVIDENCES: - The Greenland and Antarctic ice sheets have decreased in mass. Greenland lost an average of 286 billion tons of ice per year between 1993 and 2016, while Antarctica lost about 127 billion tons of ice per year during the same time period. - Both the extent and thickness of Arctic Sea ice has declined rapidly over the last several decades. - The number of record high temperature events in the United States has been increasing, while the number of record low temperature events has been decreasing, since 1950. The U.S. has also witnessed increasing numbers of intense rainfall events. - Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30%. The amount of carbon dioxide absorbed by the upper layer of the oceans is increasing by about 2 billion tons per year.  GRAPHS: Temperature change under different scenarios This is a graph of temperature change in the year 2100 under different scenarios. Each line represents a different model which takes into different, but equally valid assumptions about how the temperature of planet will rise. It ranges from about 1.5 C to about 6 C which, is quiet a large difference. 6 C change will mean evacuation of many coastal areas and islands around the world. 1.5 C change will mean slight but manageable sea level rise. COP21 or otherwise known as the Paris Climate Agreement, signed in 2015, has the ambitious goal of keeping global temperature rise by 2100 to below 2 C with aspirations to keep it below 1.5 C. This graph highlights this issue. Even with the current policies, we are realistically looking at about 4 C rise, which is catastrophic. Some new proposed environmental policies are expected to bring this down to 2.5-2.7 C but nothing close to the 2 C or 1.5 C COP21 goals. SUSTAINABLE DEVELOPMENT Development that meets the needs of the present without compromising the ability of future generation to meet their own needs. GROSS DOMESTIC PRODUCT (GDP) In our world, development is primarily defined by GDP. Lesser developed economies have lower GDP. Developed economies have higher GDP. Therefore, for development to happen GDP must rise. But GDP is actually a measure of how much natural resources are consumed. So, resource consumption must increase for development to happen. For the case of development- Sustainable growth - for development to happen at a regular pace, we need a “sustainable” GDP growth. But this means that we are increasing our resource consumption at a regular pace. For the case of the environment- Environmental sustainability - we don’t consume non-renewable resources since any consumption of such resources will reduce the environment as an entity. Therefore, sustainable growth and environmental sustainability necessarily cannot be the same thing.  KUZNETS CURVE Simon Kuznets was the first person to introduce the concept of GDP to understand year on year development rate of a country and quantify it. Earlier it was only measured in indirect terms and was very vague. This led to serious issues in framing proper economic policies. The great US depression of 1929 is a good example of the problems caused by this vague understanding He observed that as the income per capita increases, so does the income inequality of the country, but only up to a certain point. Any subsequent increase in the income per capita then decreases Inequality. The policy for removing income inequality was now simple. Just focus on GDP (Income per capita as an aggregate will be GDP). As long as the GDP rose, inequality would rise but at some point, come down on its own. Take the case of the western economies. They are on the right hand side of this curve and their income inequality is low. India is somewhere near the top left side of the curve and our inequality is high. Environmental Kuznets Curve (EKC) As a country is developing, it will consume resources at a rate which will cause environmental decay, but after a certain point, environmental decay will come to a halt and will start to improve. Europe is rich enough to spend some of its income on protection of their environment. India is not quite there yet and is seeing destruction of its environment. Many developing countries are doing worse. This and the previous graph combined, what it means for them is that if they focus just on growing the GDP, though in the short-term inequality and environmental destruction will rise, in the long run both of those major issues will be resolved automatically. The EKC is right if you take countries in isolation but very wrong when taken for the whole world. There is therefore a need to move to better policies to reduce environmental degradation and actually develop sustainably.