* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Chp. 8: “Air and Air Pollution”
Climate engineering wikipedia , lookup
Public opinion on global warming wikipedia , lookup
Climate change and poverty wikipedia , lookup
Climate change mitigation wikipedia , lookup
General circulation model wikipedia , lookup
Climate-friendly gardening wikipedia , lookup
Low-carbon economy wikipedia , lookup
Attribution of recent climate change wikipedia , lookup
Mitigation of global warming in Australia wikipedia , lookup
Instrumental temperature record wikipedia , lookup
Global warming wikipedia , lookup
Global Energy and Water Cycle Experiment wikipedia , lookup
Politics of global warming wikipedia , lookup
Carbon Pollution Reduction Scheme wikipedia , lookup
IPCC Fourth Assessment Report wikipedia , lookup
Chapter 10 The Atmospheric Environment Air Pollution: Long Distance Traveler Winds distribute pollutants Developing countries lack regulations Global distillation effect Canadian Arctic accumulates high levels of toxins Inuit people High levels of PCBs Why? The Atmosphere Gaseous envelope surrounding Earth Mostly oxygen & nitrogen (99%) Four layers Troposphere Stratosphere Mesosphere Thermosphere The Atmosphere The Atmosphere What’s In Our Atmosphere Nitrogen Oxygen Argon Carbon dioxide Other Gases 78% 21% 0.93% 0.04% 0.03% The Atmosphere Ecosystem services Protects Earth from UV radiation Allows visible light and some infrared to penetrate We depend on the atmosphere Oxygen balance The sun makes life on Earth possible: Primary determinant of climate: amount of sunlight received Solar radiation powers Earth’s cycles Solar Radiation and Atmospheric Circulation Electromagnetic spectrum Entire range of electromagnetic radiation Includes gamma, x-ray, ultraviolet, visible, infrared, microwave, and radio 43% of incoming solar radiation peaks in visible light wavelengths Gamma, x-rays and most UV rays are absorbed by the stratosphere Plants use portions of visible light for photosynthesis Sun does not reach all places uniformly: why? Temperature varies locally Inclination on its axis determines Earth’s seasons N. and S. hemispheres are opposite The Atmosphere Temperature differences drive circulation Continuous circulation moderates surface temperature on the Earth Atmospheric Circulation Winds Small-scale, horizontal movements Result of atmospheric pressure and Earth’s rotation Prevailing winds Major surface winds; blow continuously Polar easterlies, westerlies, trade winds Atmospheric Circulation Coriolis effect Earth’s rotation from west to east Moving air or water is deflected N. hemisphere: deflected right S. hemisphere: deflected left Influences wind direction Oceanic Conveyor Belt Transfer of warm water from Pacific ocean to the Atlantic as a surface current Cold dense water sinks and slowly flows from Atlantic to the Pacific Ocean as a deep water current Weather Atmospheric conditions at a specific place and time Rapid changes Climate Average weather conditions Changes over hundreds/thousands of years Important factors: temperature and precipitation Air Quality & Air Pollution Various chemicals present in the atmosphere in levels high enough to cause harm Natural & human sources Seven important types Two categories Primary: enter directly into atmosphere Secondary: form in the atmosphere Primary and Secondary Air Pollution Carbon Oxides Gases Carbon monoxide Colorless, odorless, tasteless Reduces blood’s ability to transport oxygen Carbon dioxide Produced in very large quantities Major greenhouse gas Sulfer Oxides Gases Acid deposition Corrode metals, damage stone Damage plants, respiratory irritant Nitrogen Oxides Gases Inhibit plant growth Aggravate health problems Photochemical smog Nitrous oxide: greenhouse gas, depletes ozone Nitrogen oxides: corrode metals & textiles Particulate Matter Different solid and liquid particles Suspended in the atmosphere Soil particles, soot, lead, etc… Corrodes metal, erodes buildings, soils clothing Can be microscopic! Inhaling can be hazardous Hydrocarbons Contain only carbon and hydrogen Methane, benzene, paraffin Many different kinds! Varying effects Some have no effect Some cause respiratory damage Some cause cancer Sources of Sulphur and Nitrogen Oxide Emissions Volatile Organic Compounds VOC’s: unburned hydrocarbons and vapors that evaporate easily in the atmosphere VOC concentration may be 10 times higher indoors, why? Toxic effect on humans Ozone Essential component of stratosphere Filters out harmful UV radiation Pollutant in the troposphere Most harmful component of photochemical smog Reduces visibility, causes health problems Reduces plant vigor Sources of Air Pollutants Natural: Erupting volcanoes Forest fires (lightening) Ocean spray and salt particulates Volatile organic compounds from coniferous forests Natural process from other vegetation Air Pollution Human Activities: Fossil fuels (coal, natural gas) Transportation (mobile) Industrial (stationary) Human Health Effects Eye and respiratory tract problems Suppresses immune system Chronic respiratory disease Cancer Birth defects Neurological damage Effects of Air Pollution Injures organisms Reduces visibility Corrodes metals, plastics, textiles Harms respiratory tracts Reduces plant production Ozone depletion, climate change Managing Air Pollution Difficult due to long-range transport Nations have to work together Emissions trading – “cap and trade” EU ETS – one of the largest programs Kyoto Protocol uses emissions trading system for six major greenhouse gases Carbon credit trading – two types COC’s CRC’s Canada’s Response Clean Air Act Includes air pollutants and greenhouse gases Controversial Federal and provincial governments need to work together Incentive-based regulation Kyoto Protocol Signed in 1997 Conservative government dropped it in 2006 Second Clean Air Act introduced Urban Air Pollution Smog Industrial smog Sulphur oxides, particulate matter Worst in winter…why? More problematic in developing countries…why? Urban Air Pollution Photochemical smog Brownish-orange haze Chemical reactions Worst in summer…why? Sources? Urban Air Pollution Weather and Topography Temperature change air circulates pollutants dispersed Temperature inversion Cold air layer trapped near the ground by warm layer Traps pollutants close to ground Cities in valleys: more temperature inversions Temperature Inversion Commitments to Reduce Smog Smog has serious impacts on Canadian economy 1990, Canadian Council of Ministers of the Environment developed regulations, guidelines and education initiatives Targeted automobile emissions and commercial emission restrictions Los Angeles Very bad smog…why? 1969: California is first state to enforce vehicle emission standards Every pollutant regulated today Should meet federal standards by 2010 Sulphur and nitric acids in precipitation Dry acid particles in air Around since Industrial Revolution Causes much damage Kills fish, damages structures Affects forest ecosystems Sulphur dioxide and nitrogen oxides released Where do these pollutants come from? Wind carries these pollutants React with water in atmosphere Form dilute acids Sulphuric Nitric, nitrous How Acid Deposition Develops Ph Scale runs from zero (most acidic) to fourteen (most alkaline) A one unit change on the Ph scale represents a 10 fold unit change in acidity Corrodes metals and building materials Decline in some fish species Birds lay eggs with thinner shells Damaging to forests Research at ELA on lake 223 Reduction in Ph Reduction in biodiversity Ph lower than 4.0 may mean no fish at all Damage to forests Overall tree weakening Increase in UV radiation Insect infestation Changes in soil chemistry Difficult to control Who should pay for the pollution? Acids are released in one place Returned to Earth’s surface hundreds of miles from source Over past 15 years, Canada has committed to reducing sulphur dioxide 1985, Eastern Canadian Acid Rain Program 1991, Canada-United States Air Quality Agreement Canada Wide Acid Rain Strategy for Post-2000 Reduction achieved by: Scrubbers installed in smoke stacks Low sulphur coal (but other problems arise) Acid Neutralizing Capacity Ability of water or soil to neutralize acids Critical Loads Maximum amount of pollution an ecosystem can tolerate before it becomes damaged Indoor Air Pollution May be more pollution inside than out! We spend a lot of time indoors Radon, cigarette smoke, cleaners, etc… Viruses, bacteria, fungi, dust mites Sick building syndrome Eye irritations, nausea, headaches, fatigue Caused by indoor air pollution Lost work time Indoor Air Pollution Radon Most serious indoor air pollutant Radioactive gas produced by decay of radium in Earth’s crust Seeps into homes Dangerous when inhaled Can cause cancer Energy efficient homes, radon can’t disperse Test your home! Temperature is increasing Spring arriving earlier; autumn later more heat waves Radiative forcing – the imbalance in the Earth’s energy budget that results when the amount of energy radiated to outer space is changed through either natural or human influences Positive forcing results in warming Negative forcing leads to cooling Greenhouse gases absorb infrared radiation warms atmosphere We are increasing concentrations of these gases Two important factors: amount of gas emitted and properties of the gas Average residence time: length of time gas resides in the atmosphere Global warming potential: how much given mass of greenhouse gas contributes to global warming over a period of time compared to the same mass of carbon dioxide CO2, CH4, N2O, CFCs, O3 accumulate Where do these gases come from? Concentrations of these gases are increasing Carbon Footprint What is a Carbon footprint? Calculate your carbon footprint Think about what steps you can take to reduce your carbon footprint Some pollutants cool the atmosphere Atmospheric aerosols Natural human sources Reflect sunlight into space Cools atmosphere Sulphur haze, volcanic eruptions Most nations trying to reduce Precipitation patterns will change More droughts, floods Impact on freshwater supplies Agricultural changes Some areas will flood Pests could increase their ranges Polar amplification More extinctions Melting sea ice Rise in sea level, devastating impacts on coastal communities Increasing coastal erosion rates Changing salt levels in ocean Rise in sea level with flood some agricultural lands Agricultural pests and disease causing organisms will reduce crop yields Increased frequency of drought (occurrence and duration) – more drought resistant crops Changing length of growing season New areas suitable for agricultural production Every species on earth affects Some will expand and thrive – example Mountain Pine Beetle Inter-related ecosystem changes At greatest risks are polar seas coral reefs mountain ecosystems coastal wetlands tundra More extinctions Antarctica: less silverfish less Adélie penguins; more egg failures Bleaching of coral reefs ; increase 10-20 C Tree species may shift ranges More heat-related illness More malaria, dengue & yellow fever: why? More schistosomiasis, cholera CO2 must be the focus Two ways to manage Mitigation Moderate/postpone global climate change Buy us time Adaptation Response to changes Implies that climate change is unavoidable Mitigation of Global Climate Change Developing fuel alternatives Increasing energy efficiency Plant and maintain trees: Carbon management Separate and capture CO2 Sequester from atmosphere Coastal populations must move inland Build massive sea walls Plant different crops: why? Develop heat and drought-resistant trees Change coastal sewage systems to reduce flooding Pollutant in troposphere Essential in stratosphere: why? CFC’s, halons, industrial solvents First used in 1960’s These chemical were cheap and easy to produce Were eventually banned More UV radiation reaches Earth Damage to ecosystems Human health problems More cataracts More skin cancer Weakened immunity 1987 Montreal Protocol – 50% reduction By 2007, 191 countries participating Industry substitutes such as hydroflurocarbons do not attack ozone but are potent greenhouse gases Most countries have phased out HCFC’s Long residence time Eco Canada Career Focus Consider a career as a Climatologist Use long range data to study trends and make predictions about climate change Case Study: IDHP Management of the atmospheric environment on a global scale Promotes scientific and social research Initiated in 1990 Decision making, policy creation, raising awareness happens across many governmental levels Assists with linkages and multi-level decision making