Presentation on theme: "What Are Our Options? Mitigation – the act of decreasing or reducing something Taking actions aimed at reducing the extent of global warming by reducing."— Presentation transcript:
1 What Are Our Options?Mitigation – the act of decreasing or reducing somethingTaking actions aimed at reducing the extent of global warming by reducing the production of greenhouse gases or their emission into the atmosphereWe can improve energy efficiency, rely more on carbon-free renewable energy resources, and find ways to keep much of the CO2 we produce out of the troposphere.Adaptation – change along with the changing climateWe recognize that some warming is unavoidable and devise strategies to reduce its harmful effects, or live with the outcome.1
2 Solutions: Global Warming, Methods for Slowing Atmospheric Warming
3 Case Study: Is Capturing and Storing CO2 the Answer? Carbon sequestration - removing CO2 from the atmosphere and storing it
4 Ways to Prepare for the Possible Long-Term Harmful Effects of Climate Change
5 Governments Can Help Reduce the Threat of Climate Change A program to slow and adapt to global warming now is very likely to cost less than waiting and having to deal with its harmful effects later.Governments can tax greenhouse gas emissions and energy use, increase subsidies and tax breaks for saving energy, and decrease subsidies and tax breaks for fossil fuels.Getting countries to agree on reducing their greenhouse emissions is difficult.5
6 The Kyoto Protocol: International Climate Negotiations In 1997, delegates from 161 countries met in Kyoto, Japan to negotiate a treaty on global warming which went into effect January, 2005.It requires 38 participating developed countries to cut their emissions of CO2, CH4, and N2O to 5.2% below their 1990 levels by 2012.This represents a reduction of 2010 levels by 29%The protocol implements a “cap-and-trade” program that involves setting a cap or limit on emissions.If a country emits less than their allowed limit, they can sell the remaining allowances to another country.Many countries distribute their allowance to specific companies or power plants.Developing countries were excluded.6
7 The Kyoto Protocol: International Climate Negotiations 191 countries have signed and ratified the protocol.U.S. signed the protocol but has not ratified it.Developing countries such as China, India and Brazil were considered exemptBelief that it would hurt the U.S. economyThe U.S. did not sign, but 10 U.S. states and 740 U.S. Cities are participating.The Kyoto Protocol will have little effect on global warming without support and action by the U.S., China, and India.7
8 Some Are Reducing Their Carbon Footprints What is your carbon footprint?The impact you have of the Earth (in terms of CO2 emissions) through your actions, decisions, and purchases.Carbon neutral – a balance between the amount of carbon released into the atmosphere and the amount sequestered or removed from the atmosphereU.S. cities, states, businesses, and schools are taking initiatives to reduce carbon emissions
9 19-4 How Have We Depleted O3 in the Stratosphere and What Can We Do? Concept 19-4A Widespread use of certain chemicals has reduced ozone levels in the stratosphere, which allows for more harmful ultraviolet radiation to reach the earth’s surface.Concept 19-4B To reverse ozone depletion, we must stop producing ozone-depleting chemicals and adhere to the international treaties that ban such chemicals.
10 Our Use of Certain Chemicals Threatens the Ozone Layer The ozone layer that is concentrated in the stratosphere keeps about 95% of the sun’s harmful UV radiation from reaching the earth’s surface.UV rays damage skinSunburns, cancerLess ozone in the stratosphere allows for more harmful UV radiation to reach the earth’s surface.
11 Our Use of Certain Chemicals Threatens the Ozone Layer In the early 1980’s scientists noticed a seasonal depletion in the stratospheric ozone.This ozone thinning was occurring in most of the atmosphere but was most severe over Antarctica and the Arctic.The largest ozone depletions have occurred over Antarctica. The hole is the so-called ‘ozone hole’.
12 Our Use of Certain Chemicals Threatens the Ozone Layer It is the greatest over Antarctica in spring because of the presence of polar clouds and weak Antarctic sunlight, which provide efficient mechanisms for ozone depletion.During Oct./Nov. each year 40-50% of the ozone in the stratosphere over Antarctica and a smaller amount over the Arctic is depleted.
13 Our Use of Certain Chemicals Threatens the Ozone Layer Chlorofluorocarbons (CFCs) were deemed responsible for the depletion of stratospheric ozone.CFCs were used coolants in air conditioners and refrigerators, propellants in aerosol cans, etc.There are other, similar ozone-depleting chemicalsCFCs are harmful because:They are chemically stableIn the troposphere they acts as greenhouse gases and eventually find their way into the stratosphereIn the stratosphere they break down ozone moleculesEach CFC molecule can last years
14 Sun UV radiation Cl C F Cl Cl O Cl Cl O O O Cl O O Ultraviolet light hits a chlorofluorocarbon (CFC) molecule, such as CFCl3, breaking off a chlorine atom and leaving CFCl2.Once free, the chlorine atom is off to attack another ozone moleculeand begin the cycle again.UV radiationClCFClClOClA free oxygen atom pullsthe oxygen atom offthe chlorine monoxidemolecule to form O2.The chlorine atom attacks an ozone (O3) molecule, pulling an oxygen atom off it and leaving an oxygenmolecule (O2).ClOOOClOThe chlorine atom andthe oxygen atom join toform a chlorine monoxidemolecule (ClO).O
15 Summary of CFCs and Other Chlorine –Containing Compounds that Destroy Ozone
16 Natural Capital Degradation: Effects of Ozone Depletion
17 We Can Reverse Stratospheric Ozone Depletion Montreal Protocol – A 1987 international treaty that controls the production and consumption of chemical that destroy the ozone layer.Later strengthened and accelerated in 1992 by the Copenhagen Protocol.191 countries have ratified this treaty and many of them do not produce or consume any CFCs.Substitutes for CFCs are available.Some developing countries still use CFCs and other damaging chemicals.
18 Pollution Control Devices Human Impact (Positive)Pollution Control DevicesEmission Control Devices – filter particlesScrubbers – use water to filter particles and gasesCatalytic Converters – on cars; finish burning wastes to decrease carbon monoxide levelsSMOG
19 Law – Clean Air Act 1963 - first passage 1970, 1977 and 1990 - amended Involves EPASets standards for acceptable levels of sulfur oxides, nitrogen oxides, ozone, carbon monoxide, hydrocarbons, lead, & moreProvides pollution credits for industries that utilize pollution-control devices+Bush administration has relaxed rulesIt established NAAQS and AQI
20 National Ambient Air Quality Standards (NAAQS) Sets acceptable concentrations for 6 “criteria” pollutants that:Threaten public health/the environment over broad areas (non-point)Are emitted in large quantitiesCO, Pb, Nitrogen Oxides, Ozone, Particulate Matter and Sulfur Dioxides
21 Air Quality Index (AQI) Measures levels of 5 criteria pollutantsForecast of daily air pollution levelsPurpose to educate and protect public- focuses on health effectsCategories: green= good, yellow= moderate, orange= unhealthy for sensitive groups, red= unhealthy, purple= very unhealthy
22 National Emissions Standards for Hazardous Air Pollutants Regulates emissions (from point sources)For specific substances (air toxics w/ known or suspected serious health effects (mutagens, carcinogens, neurotoxins)Tend to be localized, from point sourcesExamples: Ammonia, chlorine, asbestos, arsenic, mercury, benzene