Air pollution, climate change, and ozone depletion

1. Air pollution, climate change, and ozone depletion

2. what is the nature of the atmosphere • We live at the bottom of a thin layer of gases surrounding the earth called the atmosphere, which is divided into smaller spherical layers • In the troposphere, the layer closest to earth, about 75-80% of the earths air mass is found here. • About 99% of the air you inhale everyday consists of two gases: nitrogen (78%) and oxygen (21%)

3. The second layer of the atmosphere is the stratosphere • The composition is the similar to that of the troposphere, but its concentration of ozone (O3) is much higher • Much of the atmosphere’s small amount of ozone is found in a concentrated portion of the stratosphere called the ozone layer • Thanks to the ozone layer, about 95% of the suns harmful UV radiation is kept from reaching the earths surface

4. What are the major air pollution problems? • Air pollution is the presence of chemicals in the atmosphere in concentrations high enough to harm organisms, ecosystems, or human made materials, or to alter climate. • Air pollutants can come from natural and human sources. • Natural sources include pollutants from wildfires and volcanic eruptions, dust blown by wind, and volatile organic chemicals released by some plants. • Most natural air pollutants and spread out, throughout the earth, or are removed by precipitation or gravity.

5. Human sources of air pollutants • Occur in industrialized and urban areas • Majority of these pollutants are caused by the burning of fossil fuels in power generation, industrialized plants, and automobiles • Primary pollutants - harmful chemicals emitted directly into the air from natural processes and human activities • Secondary pollutants - formed when primary pollutants react with one another and with other normal components of air in the atmosphere to form new harmful chemicals.

6. Major outdoor air pollutants • Carbon monoxide • Colorless, odorless, and highly toxic gas that forms during an incomplete combustion of carbon-containing materials. • Major sources - exhaust from vehicles, burning of forests, tobacco smoke, and open fires. • Carbon monoxide reacts with hemoglobin in red blood cells, which reduces the bloods ability to transport oxygen to body cells and tissue • At high levels, it can cause headache, nausea, drowsiness, mental impairment, collapse, coma and even death.

7. Carbon dioxide • Colorless, odorless gas • 93% of the CO2 in the atmosphere is from the natural carbon cycle. The other 7% comes from human activities, mainly the burning of fossil fuels and clearing forests • Suspended particulate matter (SPM) consists of a variety of solid particles and liquid droplets small and light enough to remain suspended in the air for long periods of time • 62% of SPM comes from natural sources such as dust and wildfires while the other 38% comes from human activities • These particles can irritate the nose and throat, damage the lungs, aggravate asthma and bronchitis, shorten life and cause cancer

8. Smog • Industrial smog consists mostly of an unhealthy mix of sulfur dioxide, suspended droplets of sulfuric acid, and a variety of other SPM’s. • Today in the US, industrial smog is no longer a big problem, but in urban areas of China, India and Eastern European Countries, still burn coal in houses, power plants and factories with bad pollution controls • This problem can be fixed by setting standards for coal burning industries. China and India are only just beginning to take such steps • Photochemical smog is a mixture of primary and secondary pollutants formed under the influence of UV radiation from the sun. • All modern cities have photochemical smog, but it is much more common in cities with sunny, warm, and dry climates and a massive number of automobiles

9. Present day china

10. Decreasing outdoor air pollution • Five natural factors help reduce outdoor air pollution • Particles heavier than air settle out as a result of gravitational attraction • Rain and snow help remove pollutants from the air • Salty sea spray from the oceans washes out many pollutants from the air that flows from land over the oceans • Winds sweep pollutants away and mix them with cleaner air • Some pollutants are removed by chemical reactions

11. Increasing outdoor air pollution • Six other factors can increase outdoor air pollution • Urban buildings slow wind speed and reduce dilution and removal of pollutants • Hills and mountains reduce the flow of air in valleys below them and allow pollutant levels to build up at ground level • High temperatures promote the chemical reactions leading to the formation of photochemical smog • Emissions of volatile organic compounds from certain trees and plants in heavily wooded urban areas can play a large role in the formation of PS • Grasshopper effect occurs when air pollutants are transported by evaporation and winds from tropical areas where they are deposited • Temperature inversions can cause pollutants to build to high levels

12. Acid deposition • Acidic substances from coal-burning power plants produce air pollutants such as Sulfur dioxide and Nitrogen oxides mix and form a mixture called Acid Deposition or Acid Rain • This is a major problem for places that lie downwind of these power plants that burn coal • Many acid-producing chemicals generated in one country are exported to other countries by prevailing winds • Acid Deposition is harmful to human respiratory diseases, harms aquatic ecosystems and can also affect forests by leaching essential plant nutrients and by releasing ions of aluminum, lead, cadmium, and mercury

13. Indoor air pollution • In developing countries, the indoor burning of wood, charcoal, dung, crop residues, coal, and other cooking and heating fuels exposes people to dangerous levels of particulate air pollution • Indoor air pollution is also a problem in developed countries due to chemicals used in building materials and products

14. EPA studies have revealed some alarming facts about indoor air pollution • Levels of 11 common pollutants generally are 2-5 times higher inside US homes than outside • Pollution levels inside cars in traffic-clogged urban areas can be up to 18 times higher than outside levels • The health risks from exposure to such chemicals are magnified because most people in developed urban areas spend 70-98% of their time indoors • Indoor air pollutants cause about 1.6 million deaths per year, or 1 every 20 seconds • The four most dangerous indoor pollutants are, tobacco smoke, formaldehyde, radioactive radon -222 gas, and very small (ultrafine) particles

15. Your body’s defense against air pollution • Your respiratory system has a number of ways to help protect you from air pollution. • Hair in your nose filter out large particles. Hundreds of thousands of tiny mucus-coated, hair like structures called cilia, line you upper respiratory tract. • The cilia transport mucus and the pollutants they trap to your throat where they are either swallowed or expelled • Fine and ultrafine particles get lodged deep in the lungs, resulting in lung cancer, asthma attacks, heart attacks, and stroke.

16. Air pollution is a big killer • At least 2.4 million people worldwide die prematurely each year from the effects of air pollution. • Most of these deaths occur in Asia, with China having 656,000 deaths per year • In the US, deaths range from 150,000 to 350,000 people, which is like 2-5 fully loaded, 200-passenger airliners crashing each day with no survivors • The EPA says that each year, more than 125,000 Americans get cancer from breathing soot-laden diesel fumes emitted by buses and trucks.

17. How should we deal with Air Pollution? - Laws/Regulations • Clean Air Acts (1970, 1977, 1990) Federal governments established air pollution regulations for key pollutants to be enforced by states and major cities. EPA was directed to establish air quality standards for six major pollutants: • Carbon monoxide (CO) • Nitrogen Dioxide (NO2) • Sulfur Dioxide (SO2) • Suspended particulate matter (SPM) • Ozone (O3) • Lead According to the 2009 EPA report, the combined emissions of these pollutants decreased significantly between 1980 and 2008, despite an increase in gross domestic product, population, transportation lengths and energy consumption.

18. How can we improve? • US relies heavily on cleanup rather than prevention in regards to air pollution • Improve fuel efficiency for vehicles • Machine such as lawn mowers and motorcycles are inadequate. The emissions from a gas powered lawn mower for an hour = 34 cars for an hour. • “ultra fine particles”, the main contributors to premature deaths as a result of air pollution are not adequately regulated • Airports are exempt from many air pollution laws

19. How can we improve? • Urban ozone levels are still far too high in many areas • Laws have not yet begun seriously dealing with indoor air pollution and quality • There is a general need for enforcement of our Clean Air Acts. • Many companies that are being urge to develop environmental policies are claiming that implementing new regulations would cost too much money and hinder economic growth. Supporters say that, historically, the estimates of costs are much higher than their actual numbers, and that new regulations would stimulate the economy by providing new jobs.

20. Using the Marketplace • Allow air pollutant producers to buy and sell government air pollution allotments in the marketplace. • (Act of 1990): emissions trading (cap-and-trade program) enables 110 of the most pollutant coal-burning power plants in 21 states to buy and sell Sulfur Dioxide pollution rights. Businesses are given pollution credit, which allows them to emit a certain amount of pollutants. A utility that falls below their given credits then has a surplus that can either be sold/traded or kept as a buffer for future pollution.

21. Using the Marketplace, cont’d • The problem with this idea is that it’s based on self-reporting and there is a constant risk of a company lying about it’s emissions. • This method also allows for certain power plants to buy themselves out of irresponsible pollution. • But, the strategy is deemed cheaper in the long run and between 1990 and 2006 was found to reduce pollutant emissions from electric power plants by 53%.

22. Reducing Outdoor Pollution • About 20,00 old coal-burning plants, industrial plants and oil refineries in the United States have not been required to meet the air pollution standards for new facilities under the Clean Air Acts. • Ways that industries are able to reduce environmental harm from pollutants are split between “prevention” and “dispersion/cleanup. The former prevents the pollution emission (obviously), while the latter attempts to reduce the harm of pollutants already sent into the atmosphere. • Prevention: • Burn Low-sulfur coal • Remove sulfur from coal before burning • Convert coal to a liquid or gaseous fuel • Just shift to a generally less harmful process of extracting energy (less pollutants)

23. Motor Vehicle Air Pollution • Prevention: • Use mass transit, ex: busses, trains, etc • Walk or bike • Use less polluting fuels • Get older cars off the road (more pollution) • Give large tax write-offs or rebates for buying low-polluting, energy efficient vehicles • Cleanup: • Require emission control devices • Inspect car exhaust systems twice a year • Set strict emissions standards

24. Reducing Indoor Pollution • Little has been done to reduce indoor pollution, which is bad seeing as indoor pollution poses a much greater threat to our health than does outdoor pollution. • Indoor pollutions comes as a result from leaky systems, inside burning fires and general mismanagement of materials within enclosed spaces. • Prevention: clean ceiling tiles and line AC ducts to prevent release of fibers, ban smoking or limit it to well-ventilated areas, set stricter formaldehyde emissions standards for carpets, furniture and building materials, prevent radon infiltration, use office machines in well-ventilated areas and use less harmful substitutes for cleaning materials. • Cleanup/dilution: Use adjustable fresh air vents for work spaces, increase intake of outside air, change air more frequently, circulate a building’s air through rooftop greenhouses, use efficient venting systems for wood-burning stoves and use exhaust hoods for stoves and appliances burning natural gas.

25. General Solutions Outdoor: • Improve energy efficiency to reduce fossil fuel use • Rely on low polluting gas • Rely more on renewable energy • Transfer energy efficiency, renewable energy and pollution prevention technology must be given to less developed countries. Indoor: • Reduce poverty • Distribute cheap and efficient cookstoves or solar cookers to poor families in developing countries • Develop simple and cheap tests for indoor pollutants such as particulates, radon and formaldehyde

26. How might the Earths Climate Change in the Future • Climate change is not new; the climate has been changing over the past 3.5 billion years due to volcanic emissions and changes in solar input as well as continents slowly moving atop shifting tectonic plates, along with changes made by the impact of meteors. • Over the past 900,000 years, the planet has been experiencing prolonged periods of global cooling as well as global warming. These periods of freezing and thawing are known as glacial and interglacial periods. We are lucky enough to be living within an interglacial period characterized by temperate weather that remained stable enough for the human population to thrive via advancements in agriculture that was made possible by the kind weather. But since about 1975, temperatures have begun to rise as they historically have during glacial/interglacial periods.

27. Human Contribution • Life on earth depends on the natural greenhouse effect thanks to the presence of four natural greenhouse gases: water vapor (H20), carbon dioxide (C02), methane (CH4), and nitrous oxide (N20), all of which help to warm the atmosphere and keep it hospitable. • Evidence of human impact on greenhouse gas emission/global warming: • Between 1906 and 2005, the average global surface temp has risen by about .74 ºC. Most of this has taken place since 1980. • Annual greenhouse gas emissions from human activities rose 70% between 1970 and 2008, which all correlate closely with the rising temperatures • In certain part of the world, glaciers are shattering and sea ice is drifting apart, as evidence of slowly warming waters and general temperatures. • During the last century, the sea level rose about 10-20 centimeters primarily due to run off from melting land based ice and the expansion of ocean water as its temperature increased. • The 10 warmest years have been occurred since 1997. • http://www.youtube.com/watch?v=hC3VTgIPoGU

28. C02 • CO2emissions are being produced at the exponential rate of 3.3% per years, with levels in the atmosphere likely to rise about 560 ppm by 2050 and get up to 1390 ppm by 2100. Carbon dioxide would be introduced to the environment faster than it would be taken out, resulting in extreme changes in the global temperature and climate. • The problems cause by this would change our sights on “climate change” to “climate disruption”. • We must keep carbon emission levels from reaching 450 ppm (an irreversible tipping point, at which our planet will begin to free fall into a mess of climate-induced destruction over the course of thousands of years) • In 2008, the largest C02 emitters were China, the United States, the European Union (27 countries) Indonesia, Russia, Japan and India. The US is responsible for 25% of world cumulative C02 emissions. • US: emits 5x more per person than China and 200x more than people in the “poorest countries”.

29. Oceans • Help to moderate the earths average temperature of the atmosphere and thus it’s climate by removing 25-30% of the C02pumped into the lower atmosphere by what we humans do. • The solubility of C02 in ocean water decreases with increasing temperature, thus the increasing temperature of the globe will result in an inability to efficiently absorb C02 into the oceans, which just becomes one big giant ugly cycle. • The higher levels of C02 in the ocean have increased the acidity of the ocean surface by 30% from preindustrial times and the ocean acidity could reach dangerous levels before 2050. • The water is becoming acidic because the C02 is reacting with the water to produce carbonic acid (H2C03). The increasing acid level is further weakening the oceans ability to absorb C02 and safely store it in bottom sediments.

30. Effects of Projected Climate Change • Increased chance of drought and flooding • Rising sea levels • Spreading Deserts • Larger Forest Fires • Decrease in crop yields • Fragmentation of ecosystems

31. Rising sea level • Dependent on the expansion of seawater as it warms and the melting of land-based ice. • Predicted rise of at least 1m by 2100 • Would erode coast lines, flood barrier islands, threaten coastal ecosystems and cause trillions of dollars of damage to costal cities.

32. Extreme weather • Projected climate change will increase the incidence of heat waves and severe drought in some regions, while the warmer atmosphere holding more water will cause flooding in other regions. • Debate over if the the size and strength of tropical storms will be increased or not.

33. Agriculture • Crop productivity could increase slightly in middle to high latitudes at 2o warming but worsen as a whole. Worst effect is projected to be in Africa and areas of South America. • Northward shift in the production of some agriculture. • Soil in these regions is not as suitable for large scale crop production. • IPCC scientists warn that by 2050, 200-600 million of the worlds poorest and most vulnerable people could face malnutrition and starvation due to the effects of climate change on agricultural systems.

34. Can we stop it? • A warming of 2o C and the effects that follow are inevitable according to the IPCC • Even if greenhouse gas emissions are completely stopped, some effects will be felt for at least the next 1,000 years. • Effects become much more severe with 3o and 4o C global climate warming.

35. What we can do to slow projected Climate Change? • 2 basic approaches • Drastically reduce greenhouse gas emissions and shift to a mix of noncarbon-based energy options • Recognize climate change is unavoidable and devise strategies to reduce its harmful effects • Most scientist agree we need a mix of both approaches.

37. Government’s Role • Government can regulate pollution by installing a carbon and methane tax • Currently emissions are free and this has led to a Tragedy of the commons. • Incentive for corporations to move towards cleaner practices • International Negotiations • Kyoto Protocol involving 161 nations agreeing to a multiple phase plan requiring participating nations to cut greenhouse gas emissions to 5.6% under their 1990 levels. • US Withdrew in 2001 because the agreement did not require rapidly developing countries like China to meet the 1st phase and it could hurt our economy

38. Ozone in the Stratosphere • Ozone layer keeps about 95% of harmful UV rays from reaching the earths surface • Chlorofluorocarbons (CFCs) are manufactured chemicals discovered in the 1930’s which were used in many products including aerosol spray cans and air conditioner because they were so cheap and versatile. • In 1974 Sherwood Rowland and Mario Molina discovered the harmful effects of these persistent chemicals on the ozone layer of our atmosphere.

39. Reversing Ozone Depletion • Experts recommend we should immediately stop producing all ozone depleting chemicals. • Even with immediate and sustained action it will take 60 years for ozone to recover to 1980’s levels and 100 years to recover to pre 1950’s levels.