final review - Lecture01 :howarewedoingthis?ViaLUC,increaseinC02 ,

final review - Lecture01...

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Unformatted text preview: Environmental pollution Lecture 01 Humans are massively changing the earth​ : how are we doing this? Via LUC, increase in C02 concentrations thanks to the industrial revolution, we use most of the available freshwater for irrigation instead of what it should be used for­and we drive other species to extinction (we decrease biodiversity)­the pops are growing at an alarming rate and the rate of change is happening faster, and at larger scales than we can understand. 1. ​ Biosphere 2 (the experiment):​ ​ A closed system ecological experiment that was conducted in 1991 by researchers to provide valuable insight into our complex and evolving world (it also consisted of the 7 ecological biomes). The data collected included such things as (CO2 and 02 cycles, soil composition, coral reef health and vitality, agricultural pest management, waste and water recycling...) a. ​ Purpose:​ to assist in the ecological improvement of the human impacts on the earth’s biosphere­to determine how self­regulating a biosphere system is­to determine if people could work and live in a confined space­to explore possible use of biospheres in space colonization. b. ​ What went wrong?​ ­ 02 levels dropped significantly, C02 levels increased, H20 became polluted and several species went extinct c. ​ Pessimistic conclusion:​ Earth, like B2 is a closed system but, B2 is less forgiving then our planet­in addition or planet is far more complex, and is at a larger scale d. ​ Lessons learned:​ 10 in total (know for T/F) i. ​ Ecology can be a science​ ­test tube ecology, now we can experiment and not merely observe ii. ​ Coral reefs are salvageable​ ­ construction of the artificial reef=learned lessons in the management of ecologically stressed reefs in nature. iii. ​ Complexity is no obstacle​ ­some obstacles were faced but the system balanced itself remarkably well especially given the fact that it was a closed system iv. ​ Massive spacecrafts will hold their air­ ​ this sealed structure has <10% air leakage/yr can be used in space missions­but don’t use concrete as it absorbs C02 v. ​ Long space flights won’t drive you nuts­​ First time people confined to one area for long period of time­went mad­but no real battles vi. ​ Human beings can eat less­​ with less chow intake but more nutrition=improvement in overall health (BP, cholesterol) vii. ​ Waste can be recycled­​ natural, low tech waste management system developed in B2 now used in water treatment systems in Mexico and other developing countries. viii. ​ Watch out for stowaways­​ even with strict biological controls, some microbes thrive due to lack of predators ix. ​ Sealed ecosystems have a future­​ B2 allowed for the creation of imitator biospheres seen in zoos and which can help build simulated habitats on mars x. ​ Be ready to improvise­​ ants and roach overpopulation­unforeseeable outcomes. 2. ​ Pollution­​ what is it?­​ any substance introduced into the environment that adversely affects the usefulness of a resource­A chemical out of place ​ –oil in a tanker not pollutant­once its leaked into envi=pollutant. a. ​ Terms used to describe pollution­ ppm​ (largest amount),​ ppb(​ 1 thousand x smaller), ppt ​ (1 mil smaller), ​ ppq​ (one billion times smaller) b. ​ Why does it happen? ​ Usually due to non­natural or human processes such as technological inefficiencies, more plant management, or poor design processes. c. ​ What substances pollute?​ ​ Organic chemicals​ (PCB’s, oils, pesticides), ​ inorganic (metals, salts, nitrates), ​ acids​ (sulfuric, nitric), physical (trash), ​ radioactive ​ (radon), or biological​ compounds (microbes, pollens) d. ​ Pollutants move:​ either via the ​ air ​ or ​ water (​ urban runoffs due to pavement, leeching from surface to ground water, farm runoff)​ ​ AND pollution is usually greatest near the source, but some effects can occur far from the source (grasshoppering to the arctic) e. ​ Pollutants change form:​ can be degraded or can accumulate i. ​ Microbial degradation­ ​ important b/c they break down waste (that would otherwise build up) ii. ​ Physical contributors­ ​ degradation by sunlight, heat, O2, wave motion iii. ​ When natural systems not enough­​ natural systems become overwhelmed and pollutants build up and remain persistent f. When pollution becomes extreme:​ it can become devastating and deadly i. ​ Bhopal accident​ ­​ the site of one of the greatest industrialized disasters which occurred between 1977 and 1984. The plant was licensed to manufacture MIC and the pesticide sevin. The accident occurred due to a combination of legal, technological, organizational, and human errors. In addition, the safety standards and maintained procedures at the plant had been deteriorating and ignored for months. What was wrong with the MIC unit that led to the accident? Temperature and pressure gauges were unreliable, fridge for keeping MIC at low temps was shut off, water to neutralize remaining gas did not reach flare tower, MIC tank was filled beyond capacity.­as a result the MIC tank was blown out of its concrete base and it spewed a cloud of toxic MIC (pollutant at this point), cyanide. Prevailing wind then carried the toxic cloud of pollutants over Bhopal where it settled­many people died and many others were injured. 3. Pollution that is less obvious:​ some pollutants are present in barely detectable amounts in the environment­is this risky? Two views exist to answer this question. a. Pessimistic view­​ even though these pollutants/chemicals are present at minute levels they may have similar mechanisms of action and thus may act synergistically. This could pose a potential problem­in addition not all species will respond the same to the same level of pollutants (fly vs human, the dose will differ). b. Optimistic view:​ some chemicals inhibit the toxic effects of others (antidote)­in addition our bodies have dealt with contaminants for over millions of years (we are highly evolved and use specialized systems to detoxify). Furthermore, we are now able to detect these low level pollutants using sophisticated analytic software. 4. Global pollution/environmental health:​ In 1992, the ​ Earth Summit​ was held in Rio de Janeiro by the UN and it involved ~172 governments and other organizations such as the NGO. The purpose of this summit was to address the issues surrounding global pollution and envi health a. Systematic scrutiny of toxic compound production­​ lead, gasoline b. Alternative sources of energy­ ​ to replace the use of fossil fuels­slow CC c. New reliance on public transport­​ reduce car emissions, reduce congestion/smog/pollution in cities d. Address the growing scarcity of water e. s​ummit also led to the agreement of the ​ Kyoto protocol ​ which stemmed from the climate change convention­another was the agreement not to carry out activities on lands of indigenous people that would cause environmental degradation/culturally inappropriate.­both KYOTO and RIO failed as we continued to consume resources, pollute and spread poverty at unprecedented rates. f. pollution in less developed nations: ​ Lack of waste management practices in impoverished nations have led to a lot of pollution(especially in slums=lack basic municipal services­water sanitation schools or clinics), especially pollution of rivers­mostly children die from contaminated drinking water or from infections of untreated human waste­in addition the air is heavily polluted and breathing in this air is equivalent to smoking 2 packs of cigarettes each day.­the rest of the air pollution occurs due to indoor odors (burning straw wood/dried manure for cooking, or for heating their homes which have very poor ventilation). i. Root causes­​ the rate at which the population is growing in addition to the fact that we are not changing our practices is the biggest contribution to environmental degradation and poverty in the world. g. ​ Environmental Impact Equation= ​ I=P*A*T. where I=impact resulting from consumption, P= population, A=consumption per capita (affluence $$), T=technology factor (aka the inefficiency factor) We can also use the ​ Human impact equation=​ I=P*A*T​ , ​ where P= human population size and growth, A=human consumption­ecological footprint, H20 and energy consumption, T=inefficiency indicators (tech). i. ​ P=Population growth rate­​ The rate at which the number of individuals in a population increases.­usually refers to the change in a population over a specific time period and is expressed as a percentage­most of this growth is occurring in less developed countries (Africa, India, south America and Mexico as well as the middle east). 1. ​ Predictions:​ By 2025 half the world’s population will live in cities, and each of these cities will have a population that is >million, these are called megacities​ because they will populations >10 million ( Tokyo, Mexico city, Seoul, NY, Sao Paulo, Mumbai, Delhi, Shanghai, LA, Osaka) h. ​ Pollution in developed countries: ​ cities in these countries consume a lot of resources and thus become ‘black holes” that soak up ecological outputs i. ​ A=Affluence­ ​ this is a term related to consumption­ecological footprint?­to get this, need to calculate the aggregate land and water areas of each ecosystem (used to produce all the resources it consumes) for each nation. This will tell you about the ecological demand of each country on the biosphere­how much land is required for farming, how much water is used for irrigation, production of electricity etc­how is this effecting the worlds biospheres­that all equals the ecological footprint of a nation­this high level of consumption in wealthy nations is more responsible for envi degradation and resource depletion then is the pollution caused by poor countries. ii. ​ T=Technological inefficiencies­​ out of most of the technologies produced by wealthy nations only ~ 2.5% of it is useable and the rest is waste (lead and gold for example) 5. The tyranny of small decisions (1966 kahn): ​ the idea that our actions have consequences.­when we buy a product for example, we are accepting the impact caused by producing that product even though we often do not know the environmental impact of recovering the resources that go into it. a. Odum article­​ examines the cumulative effects of small decisions­shows are a series of small decisions made by individuals or small groups at the lower level eventually cause bug decisions to be made by the higher ups without even considering the problem at hand directly.­this process of reaching important decisions often does not produce optimal solutions for society i. Example­ ​ the eutrophication of lakes: resulted from the addition of domestic sewage and industrial dumping as well as agricultural runoffs. Lecture 02 Global Climate change We know that CC is nothing new­it’s just that now our actions are accelerating the process. About 18 thousand years ago we have had many ice ages­the earth’s climate constantly cycles between glacial and interglacial periods. 1. Global warming​ : the observed increase in the average temperature of the earth`s atmosphere and oceans th​ over the past several decades.­​ ​ ST​ ­​ ​ have risen by 0.6 +­ 0.2 degrees Celsius in the 20​ century ALONE! Ocean temperatures​ ­​ ​ have risen 0.6 degrees Celsius as well and at a depth of 3000m (because sea levels are rising) ­​ How is GW showing itself? a. ​ Snow and ice melt­ ​ increases in temperatures have cause a –ve glacier balance (ice thickness is changing and has been since 1970) which has led to glacier retreat around the world. (Though there is a worry that the Himalayan glaciers will not melt sooner enough­they are a reliable source of fresh water for China, India, and much of Asia during the dry season).­​ increase downward trend​ in glacial mass­continuous retreat b. ​ Sea level rise­ ​ post glacial melt­ sea levels had been constantly rising at a rate of 0.1­0.2 mm/yr (back then) which adds up to~ 120m since the last ice age. Now it rises at 3mm/yr 2. The greenhouse effect:​ the process by which the suns radiation is absorbed by the atmospheres greenhouse gases and is reradiated all over the earth­leading to an increase in surface temperatures­It is the mechanism that produces the difference between actual surface temps of (15 Celsius) and what it would have been without it (­19 Celsius)­makes the earth 34 degrees warmer than it would have been­Natural greenhouse­ suns radiation­Out of that 343, 103W of it is reflected back into space (ice, cloud cover, man­made structures, the rest 240W is trapped and re­radiated as heat by greenhouse gases (CO2,CH4,NO2,H20)..Which gases are doing the absorption (trapping)? CO2, CH4, NO2, H20­water vapor (65%) and carbon dioxide (25%) are actually the primary contributors to the natural greenhouse effect. Most gases though only. 1. CC is nothing new:​ the earth’s climate has always been changing­cycling between glacial and interglacial periods­we have had many ice ages 18000 years ago, a little ice age (1430­1850) 3. Greenhouse gases and their sources: ​ again, solar radiation passes through the film that is our atmosphere, some of this energy is reflected by earth’s surfaces back into space and some is re­emitted in all directions by greenhouse gases­the net effect of warming of the earth's surface (oceans included)­the ability of the atmosphere to capture and recycle this energy in this matter is the defining characteristic of the GHE 1. Anthropogenic GHE gases: ​ CO2 (55%,387 ppm)​ , CH4(5%,1791 ppb), N20 (5%,321 ppb­nitrous oxide), CFCs (15%,539 ppt­chlorofluorocarbons), O3(not quantified)­of all these GHGs­(​ power stations>industrial processes>transportation fuels>agricultural byproducts>FF mining>LUC> ​ in addition, all the GHGs are on a rise except for CFCs­and C02 is rising at the steepest curve a. ​ CO2:​ the single most important and most potent is as it contributes to about 55% to the intensity of the warming­the concentration of CO2 in the atmosphere only used to be 280 ppm prior to the 1700s (industrial revolution)­its increase is largely anthropogenic­​ CO2 major sources: ​ FF combustion via industrial processes, transportation and heating, electricity generation and cooking, and changes in vegetation LUC i. CC and marine phytoplankton: ​ oceans sequester­suck up the CO2 in the atmosphere via the ​ biological pump:​ this is the process by which single celled plants or phytoplankton at the surface uptake the dissolved C02 (the C02 is dissolved in the first place via the ​ solubility pump​ (chemical and physical processes) as they photosynthesize­they then convert this C02 into cellular matter­as they are the primary producers in the ocean they are consumed by higher trophic levels­when the plankton die they sink and decompose, their matter made up of carbon is the redissolved back into the ocean (​ marine snow)​ ­this is the mechanism by which carbon is pumped from the ocean surface to the floor­at the floor used by deep sea dwellers, and this is how C02 is effectively sequestered from the atmosphere by the ocean. ii. increase in ocean pH​ : C02+H20<­­>H2CO3,makes the oceans acidic, bad for corals­pH decreased by 0.12 units and is now 8.2 b. CFCs: ​ the strongest GHG/molecule but b/c they exists in low concentrations, this reduces their overall importance in the warming effect­due to the ​ Montreal Protocols 1987​ , their levels are on the decline thanks to an agreement between 46 nations c. CH4: ​ ​ concentrations in atmosphere have increased more than 150%­source: ​ rice cultivation, domestic grazing of animals (herbaceous digestion)/manure, termites,landfills, coal mining, oil./gas extraction d. N20: ​ ​ increasing at a rate of 0.2­0.3% a year sources: ​ FF combustion, biomass burning, soil fertilization Government action to reduce emission 1. Kyoto Protocol: ​ goal is to stabilize GHG concentrations at a level that would prevent dangerous climate interference­countries(more than ​ 160​ ) who rectify it promise to reduce C02 emission ­ IPCC predicted temp rise of 1.4­5.8 between 1990 and 2100­even if kyoto is a go which it isnt, it would reduce temperatures 0.02­0.28 degrees a. Annex 1: ​ have accepted GHG reduction obligation (developed nations who emit the most NA>EU>eastern EU>SA>Asia>Africa​ )­have cheated. did not meet the requirements (15% below expected, and some have increased emission)­bought their way to reduction. b. Annex 2: ​ no GHG reduction obligation (developing countries who still need the resources) c. Canada’s position: ​ 2002, we ratified (signed) the treaty­70% support opposition by those with vested interests in the creation of pollution­we declined to continue the protocol beyond 2012 (36 others) GW controversy:​ an ongoing dispute about the effects on humans on cc­what policies to implement­some politicians and businessmen deny human involvement in cc. ​ scientific position:​ GW is real and we are the problem that accelerates it­and at this rate serious damage will arise­opposition occurs b/c of claims actions against CC could cause enormous expense and disruption to the current geopolitical/economic situation­because their is no obvious short term benefit (sigh so nearsighted) 1. anthropogenic GW hypothesis: ​ isotopic carbon trapped in ice bubbles has given us a clear picture of the relationship between rise in C02 levels and rise in temperature­these records date back thousands of years. however, the recent rise in CO2 in recent years far exceeds any levels of C02 in the past­this one is human caused­burning of fossil fuels­thus this hypothesis indicates that the recent warming is caused by human activities and solar/other geological variations alone cannot explain the recent changes (past 50yrs) 2. opposition to GW theory: ​ some people except that warming at the global scale is happening but they say that there is a big difference between correlation and causation (temps have been rising since the beginning of the industrial revolution but it does not mean it was the cause)­also models of climate change use “consensus” evidence which appeals to the majority argument­having some climatologists in agreement in fear of losing their funds­also, UHI effect skews the temp measurements to indicate recent warming. 3. some thoughts: ​ Global models will only be able to predict climate if they can predict solar and volcanic variation­they also do not take into consideration any feedback models Solar Variation: ​ the intensity and the amount of sun we get cycles and changes every 11 years. the shorter the sunspot (black dots on the earth­give us that intense heat) cycle, the hotter the temperatures­hypothesized that solar variation has caused some changes in climate (maunder minimum)­coldest years were there were few sun spots UHI effects: ​ cities are filled with high rise buildings that blocks the circulation of the country breeze which would usually have a cooling effect. they also have a lot of pavement that absorbs a lots of UV radiation and has very low albedo contributing to the warming­in general cities are warmer than their suburban counterparts. El nino­southern oscillation and climate change: ​ el nino​ and ​ el nina​ are major temperature fluctuation in surface water in the eastern pacific ocean due to the ​ thermocline layer​ which is an area of transition between the warmer surface waters and the colder water of the bottom 1. el nino conditions: ​ results from weakened trade winds in the western pacific ocean near indonesia allowing piled up warm water to flow towards SA­this change in water temperature can cause a change in weather in that region­tropical thunderstorms can also occur because the sea surface temperatures are hot enough=results in rain falling over the deserts of peru instead of the rain forest of indonesia=forest fires and drought in western pacific and flooding in SA. ​ la nina​ characterized by cold ocean temps in pacific. note ​ el nino does not equate to GW​ it is only a speculation ...
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