NPTEL Environmental Science Lecture 1 PDF

EL PT N Week 1: Environmental Concerns, Population Growth and Resource Consumption Lecture 1 – Major Environmental Concerns and Pollution  Major environmental concerns  The concept of sustainable development EL  Population growth models: arithmetic, geome...

EL PT N Week 1: Environmental Concerns, Population Growth and Resource Consumption Lecture 1 – Major Environmental Concerns and Pollution  Major environmental concerns  The concept of sustainable development EL  Population growth models: arithmetic, geometric and exponential  Resource consumption and pollution PT  Measures of Environmental impacts – pollution and the IPAT Model  Ecological Footprint N  Earth Overshoot Day  Energy Performance Index  Lifecycle Assessment  Course Objectives Learning objectives Environment EL Air Water Wastewater PT Solid waste Urban Heat Island Effect Pollutant versus contaminant N  Course objective is to ensure that students incorporate the concept of ‘sustainable development’ in their daily lives and decision‐making processes and are sensitive to diverse environmental issues and the impacts of pollution# Learning objectives 1. To understand the relationship between humans and their environment EL 2. To quantify the relationship between population growth, resource consumption and pollution 3. To identify sources of pollution in the environment, their impacts and remedial PT measures 4. To apply the laws of conservation of mass and energy in understanding and solving environmental problems N # A Supreme Court directive (M C Mehta vs. Union of India, 1991) requires that all students have an environmental subject at all levels of education. There should be growth in environmental awareness as students mature in their understanding of science, technology and other fields. Weeks Lecture Names Faculty Environmental Concerns, Population Growth, and Resource Week 1 S Goel Consumption Week 2 Principles of Sustainable Development S Chowdhury Week 3 Understanding Air Pollution S Chowdhury Week 4 Climate Change: Scientific Basis, Mitigation & Adaption S Chowdhury Course content EL Week 5 Renewable Energy – I (Solar Energy & Wind Energy) S Chowdhury Renewable Energy – II (Geothermal Energy, Ocean Energy, Week 6 S Chowdhury Hydroelectricity, Bioenergy) PT Week 7 Industrial Ecology & Circular Economy S Chowdhury Week 8 Water Quality, Reuse and Recycling S Goel N Week 9 Solid Waste Management (including E‐waste Management) S Goel Week 10 Noise Pollution S Goel Week 11 Ecology and Soil Pollution S Goel Week 12 Environmental Policies and Legislation S Goel  The Environment and its domains Solid and Air Pollution and Hazardous Waste Control; Climate Management; soil Change, noise pollution pollution EL PT Atmosphere Lithosphere N Water quality, Hydrosphere Biosphere water and wastewater Public Health treatment and Ecology  Major environmental concerns Air quality Poor air quality due to industries and vehicular emissions Stubble and solid waste burning Urban Heat Island Effect Climate change Water quantity and quality EL Lack of adequate drinking water Poor water quality PT Wastewater discharges and their impact on aquatic ecosystems Soil quality N Salinization Erosion Nutrient depletion and presence of synthetic organic compounds Biodiversity and stability of ecosystems Extinction of species Bioaccumulation of toxic compounds  Major environmental concerns – air quality Poor Air Quality Of the 30 most polluted cities in the world, 21 are in India Primary pollutants and Secondary pollutants EL Sources of air pollution: natural and anthropogenic Natural sources – forest fires, eruptions from PT volcanoes (dust, ash and gases) Anthropogenic sources ‐ biomass burning, waste N burning (municipal and agricultural), industries, thermal power plants, vehicles (air, road, rail, sea) Air Pollution Vectors by Vecteezy  Major environmental concerns – air quality Delhi’s AQI – before and during the COVID lockdown in EL 2020 PT N https://www.indiatimes.com/technology/science‐and‐future/not‐a‐single‐indian‐city‐in‐worlds‐top‐20‐polluted‐ ones‐thanks‐to‐coronavirus‐lockdown‐511180.html 9  Major environmental concerns – air quality Crop stubble burning in Northern India EL PT N Satellite image on 11 Nov 2021 using Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite https://eoimages.gsfc.nasa.gov/images/imagerecords/149000/149086/indiafire_vir_2021315_lrg.jpg 10  Major environmental concerns – air quality Urban Heat Island Effect Temperature difference between urban areas and suburban or rural areas in the same region EL Micro‐climatic effects on temperature and humidity PT N City Skyline Vectors by Vecteezy 11  Major environmental concerns – water quality Water quantity and quality Lack of adequate drinking water; lack of availability and diversion for irrigation Poor water quality EL Wastewater discharges and their impact on aquatic ecosystems PT https://www.telegraphindia.com/india/how‐india‐s‐ biggest‐sewage‐treatment‐plant‐in‐delhi‐is‐different‐ N from‐others/cid/1694191 https://www.livemint.com/Politics/gOHoaq0n5wa2qpjLx4yh5K/ Govt‐issues‐draft‐of‐new‐standards‐on‐water‐quality.html https://www.pexels.com/photo/a‐women‐carrying‐water‐on‐their‐heads‐4511301/  Major environmental concerns – soil quality Soil quality Soil degradation Erosion – deforestation and overgrazing Nutrient depletion – poor agricultural practices Soil pollution EL Salinization Contamination by chemicals: heavy metals and synthetic organic compounds PT Regulate water, nutrient availability N Support medium for Engineering SOILS plants, agricultural resource productivity Habitat for organisms  Major environmental concerns – biodiversity and stability of ecosystems Loss of biodiversity International Union for Conservation of Nature (IUCN) is dedicated to the conservation of nature Publishes a Red List of Threatened Species with various qualifiers shown in the adjoining figure EL India’s Red List of 2021 contained 199 species of plants and animals considered endangered PT Factors resulting in species extinction and/or endangered species Loss of habitat and poaching N Loss of food source or change in population dynamics Bioaccumulation of toxic chemicals in the environment Climate change  What is a pollutant or contaminant? A pollutant is a chemical species in the environment that causes undesirable effects on the environment or any of its components. Can be natural or anthropogenic Undesirable effects EL Endangers health of humans and other organisms Endangers safety PT Causes financial and aesthetic losses N Contamination is simply the presence of a substance where it should not be or at concentrations above background. Pollution results in or can result in adverse biological effects to resident communities.  Masters G and Ela WP (2012). Introduction to Environmental Engineering and Science. Prentice Hall, NJ, US. Miller GT (2004) Living in the Environment, Thomson/Brooks Cole. Khoiyangbam RS and Gupta N (2015) Introduction to Environmental EL Sciences, TERI Press, Delhi Davis ML and Masten SJ (2009) Principles of Environmental Engineering and Science, McGraw Hill Education, Indian edition. PT N N PT EL  EL PT N Week 1: Environmental Concerns, Population Growth and Resource Consumption Lecture 2 – Population Growth Models  Major environmental concerns  The concept of sustainable development  Population growth models: arithmetic, geometric and exponential EL  Resource consumption and pollution  Measures of Environmental impacts – pollution and the IPAT Model PT  Ecological Footprint N  Earth Overshoot Day  Energy Performance Index  Lifecycle Assessment  Commons Models Census data EL Curve-fitting Linear or arithmetic PT Geometric Exponential N  Sustainable development Development that meets the needs of the present without compromising the ability of future generations to meet their own needs (Brundtland Report – Our Common Future, 1987) Implications: Societal emphasis has to shift from a destructive, exploitative EL philosophy (The Tragedy of the Commons*) to one that fosters PT long-term protection of the environment and its inhabitants Two conflicting objectives have to be reconciled N improving quality of life vs. protecting the environment *Hardin, Garrett The Tragedy of the Commons, Science, 162:1243-1248.  Driving forces for sustainability Health and safety: human and other organisms Financial: property values, profits, taxes Aesthetics Civic pride and values EL THE LAW All the good intentions in the world are not equal to the arm of law PT N Our biggest challenge in this new century is to take an abstract idea like sustainable development and turn it into reality for all the world’s people – Kofi Annan, 2001  Why is pollution increasing? Population Growth EL PT Resource Consumption N Increase in population Higher standard of living Pollution More resources consumed More waste generated  World Population = 8.0 billion (as on 15 Nov 2022, UNPF) India’s population = 1.21 billion (Census, 2011) World Population - top 20 countries, UNPF, 2023 1500.00 17.82 20.00 17.78 Population % of total population Population, millions 15.00 EL 1000.00 https://www.unfpa.org/data/world- population-dashboard PT 10.00 500.00 4.24 3.46 2.79 2.16 1.60 N 1.54 1.41 1.23 1.07 0.90 5.00 3.00 2.70 1.80 1.58 1.46 1.28 1.11 1.04 0.00 0.00 Democratic… Russian… USA Iran India Brazil Mexico China Nigeria Philippines Egypt Türkiye Indonesia Pakistan Bangladesh Japan Thailand Ethiopia Germany Viet Nam  Population growth Population of the world and its regions (in millions). Data from https://population.un.org/wpp/ EL PT N By Conscious - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2562456  Population growth – arithmetic growth  This method is used when the population is growing by a fixed amount each year such as in areas where growth is planned or controlled.  This model is also called the linear growth model  If Pn = Population at the end of n increments (can be months, years, decades, etc.)  Pn = P0 + nX Where P0 = population at time t = 0 EL X = fixed increment in population, usually annual or decadal PT Problem If a college has a capacity for 1000 students now, and an additional 100 students N are to be taken every year, what will the student intake capacity be at the end of 10, 20 or 50 years? Solution As P0 = 1000, n = number of years and X = 100 P10 = 1000 + 10*100 = 2000 P20 = 1000 + 20*100 = 3000 P50 = 1000 + 50*100 = 6000 Goel, 2019 9  Population growth – geometric growth  This method is used when the population is growing at a constant rate each year. Unlike the exponential function which is a continuous function, this is a discrete function.  If Pn = Population at the end of n increments (can be months, years, decades, etc.)  Pn = P0 [1 + r/100]n Where P0 = population at time t = 0 r = constant rate of growth, usually annual or decadal EL Problem PT If a college has a capacity for 1000 students now, and the capacity for students is to be increased by 10% every year, what will the student intake capacity be at the end N of 10, 20 or 50 years? Solution As P0 = 1000, n = number of years and r = 10% or 0.1 P10 = 1000[1+0.1]10 = 2594 P20 = 1000[1+0.1]20 = 6727 P50 = 1000[1+0.1]50 = 117391 Goel, 2019 10  This method is used when the population is growing at a constant rate each year. However, it is a continuous function rather than a discrete function like geometric growth.  If Pn = Population at the end of n increments (can be months, years, decades, etc.)  Pn = P0 exp(rn) or P0 ern Where P0 = population at time t = 0 Population growth – r = constant rate of growth, usually annual or decadal exponential growth EL Problem PT If a college has a capacity for 1000 students now, and the capacity for students is to be increased by 10% every year, what will the student intake capacity be at the end N of 10, 20 or 50 years? Solution As P0 = 1000, n = number of years and r = 10% or 0.1 P10 = 1000exp(0.1*10) = 2718 P20 = 1000exp(0.1*20) = 7389 P50 = 1000exp(0.1*50) = 148413 Goel, 2019 11  160000 140000 Linear Geometric Exponential 120000 Comparing the three 100000 population growth Population models EL 80000 PT 60000 N 40000 20000 0 0 10 20 30 40 50 60 Time, years  Population growth EL PT N If Census data for India from 1911 to 2011 are used, we can assume exponential growth (good assumption since R2 >0.95) Average annual total population growth rate = 1.75% Average annual urban population growth rate = 2.85% 1. Fit the data to any equation - can be linear, exponential, polynomial, logistic growth or any other equation. 2. In Excel, use the trendline option and choose to get R2 and equation. Do NOT force the curve to go through zero or origin. 3. Coefficient of determination, R2 is used to test goodness-of-fit. Curve-fitting 4. Coefficient of determination, R2 = 1 – RSS/TSS where RSS = sum of exercise EL squared residuals (residual = predicted – observed values) and TSS = sum of squared residuals with respect to the mean of observed values PT (observed value – mean value). 5. R2 values can range from 0 to 1; closer to 1 implies best-fit. N 6. Thumbrule: if R2 >0.9, it is a reasonably good fit and >0.95 is a very good fit. Values of R2