Matakuliah Tahun : S0782 - Teknik Lingkungan : 2009 GLOBAL WARMING CHAPTER 4 www.duke.edu/~eac23/NonHTMLDocs/EcologyWaterAir.ppt Bina Nusantara Objectives: • Ozone Depletion • Global Warming and Global Climate Change • Acid Rain • Biological Magnification • Human Impacts on Water, Air, Fisheries • What we can do Bina Nusantara Bina Nusantara Ozone Depletion • Ozone layer (20-50km up) protects the Earth from UV radiation • Gases (CFCs) used in aerosols break down ozone causing the “holes” over the Arctic and Antarctica • Montreal Protocol stopped production of CFC’s on January 1, 1996 • Holes are not growing but will not recover until . . . . . . . 2065! Bina Nusantara Excess UV radiation: • • • • Bina Nusantara Skin cancer Cataracts Immune System Problems Other unknown effects on plant/animal life Global Warming • Caused by gases (mostly CO2) that trap heat • Burning of fossil fuels, cutting/burning of forests releases CO2 faster than Carbon cycle can remove it • Temperatures have risen 0.6oC. since industrial age • Since 1980, average temp risen 0.3OC. Bina Nusantara Global Warming Global Climate Change Melting of permafrost, increasing release of greenhouse gases Melting of poles Rising sea level Flooding, Drought Loss of habitat, species extinction Loss of coral reef ecosystems (fisheries, tourist revenue, natural storm barriers) All the above have economic impacts Bina Nusantara Acid Rain Burning of fossil fuels release nitrogen and sulfur gases Combined with H2O vapor = nitric and sulfuric acids Fall as acid rain Plants damaged Soil chemistry altered, potentially hazardous compounds released and flow into water system BIOMAGNIFICATION (mercury) Bina Nusantara Eastern U.S: average pH of 3.6, with some values as low as pH 2.6 Los Angeles: pH of fog has been measured at 2.0 Bina Nusantara Biomagnification Pesticides and heavy metals work their way into rivers or lakes and move up the food chain becoming more concentrated at each level “Silent Spring” by Rachel Carson Bina Nusantara FOR EXAMPLE: If in one day a small fish eats 1,000 plankton and a larger fish eats 1,000 small fish, the human who catches the larger fish is ingesting all the toxins that were in a 1,000,000 plankton! (1,000 x 1,000 = 1,000,000) Add that up over a lifetime and you’re in trouble! Bina Nusantara Clean Water • Renewable but not unlimited! same water is recycled (the water cycle!) BUT if contaminated during that cycle, may not be reusable Two issues: Pollution and loss of water filtration! Bina Nusantara Some water pollutant sources: Sewage Runoff: agricultural fertilizers, factory farms Factory outfall Bina Nusantara Some Effects of Water Pollution •Contaminated drinking water • Contaminated food animals (biological magnification of toxins from the environment over their life spans) •Unbalanced river and lake ecosystems that can no longer support full biological diversity • Deforestation from acid rain •Loss of natural beauty Bina Nusantara For water use to be sustainable we need to protect the natural systems of the water cycle. Preserve wetland areas = water filtration Think before you pave it = less filtration Think before you cut it = less transpiration Bina Nusantara Fisheries Overfishing - harvesting fish faster than they reproduce An example of “tragedy of the commons” •Everyone uses the resource but no one maintains it • If properly managed, can be a renewable resource Bina Nusantara Air Air Quality Issues (caused by burning of fossil fuels): •Smog •Particulates - microscopic particles of ash and dust •Acid Rain Their Effects: Human health Deforestation Bina Nusantara Things we can do Don’t litter Turn off lights, all electronic equipment Recycle - don’t fill up our landfills Conservative or little use of fertilizers Walk or bike when possible Drive more fuel efficient vehicles Support wetlands preservation Develop sustainable energy sources: Wind, solar, fuel cells Think before you pave it Use sustainable building practices - green space and gravel, porous paving Design pedestrian friendly cities Bina Nusantara