Presentation on theme: "Global Change Unit Chapter 9: Sustaining Biodiversity: The Species Approach Chapter 19: Climate Change and Ozone Completion."— Presentation transcript:
1 Global Change UnitChapter 9: Sustaining Biodiversity: The Species ApproachChapter 19: Climate Change and Ozone Completion
2 Chapter 9: Sustaining Biodiversity - The Species Approach
3 Extinction Background extinction - Continuous low level extinction Extinction rate - number of species that go extinct during a time period (%)Extinction is natural, but human activities are destroying and degrading biodiversity causing premature extinctions.
4 Endangered and Threatened Species Endangered species have so few survivors that the species could soon become extinct.Threatened species are abundant in their natural range but could become endangered because of declining numbers.
10 Invasive Species Accidentally or intentionally introduced Often have no natural predators or competitors.
11 Invasive SpeciesPrevention of new invasive species is important.
12 OverexploitationIllegal killing, capturing and selling of wild species.Demand for bushmeatExotic pets
13 Protecting SpeciesU.S. Endangered Species Act - Identify and protect endangered species in the U.S. and abroad. Based on biological factors alone, which makes it controversial.ESA forbids projects that could jeopardize and endangered species or threaten its habitat.
14 Protecting SpeciesEstablish wildlife refuges and other protected areas.Gene banks, botanical gardens, and wildlife farmsZoos and Aquariums
16 The History of Global Warming Over earth’s 4.5 billion year history its climate has been altered by volcanic eruptions, solar input, moving continents, meteors etc.Glacial and interglacial periods have marked the past 900,000 years.
18 The Greenhouse EffectThe greenhouse effect warms the lower atmosphere in the surface of the earth.How? Water vapor, carbon dioxide, methane and nitrous oxide (all make up 1%) molecules kinetic energy increases when energy is reflected by the earth into the atmosphere. The energy is then reflected back to the surface in the form of infrared energy.
19 Greenhouse GasesHumans emit A LOT of greenhouse gases into the atmosphere.AgricultureDeforestationBurning fossil fuels
20 In the past, increases in greenhouse gases have coincided with increased global temperature.
21 Greenhouse GasesCO2 levels have increased from 228 ppb to 384 ppb (59%) in the last 275 years from mostly burning fossil fuels.Methane emissions are caused by: dams, landfills, farm animals, extracting fossil fuels, melting permafrost.N2O levels have risen by 20% during the last 275 years mostly due to increased use of nitrogen fertilizers.
24 Predicting the Effects of Global Warming is Complicated
25 Understanding Global Warming Hotter Sun? Probably not, as the stratosphere has been cooling.Oceans absorb carbon dioxide, but as they warm, they cannot hold as much and release CO2 back into the atmosphere (oops).
26 Understanding Global Warming Increased Cloud Cover could reflect the sun and cool the earth or keep the energy near the surface (like a greenhouse gas). Depends on cloud type.Air pollution - aerosols (suspended microscopic droplets and particles) can hinder or increase cloud formation.
27 Effects of Global Warming Problem: The change in global temperature is occurring rapidly.
34 Slowing Climate Change Problems:Global IssueEffects are long lastingLong-term political issueImpacts of Climate Change are not spread evenlySolutions could disrupt economies
35 Slowing Climate Change Improve energy efficiencyShift from non-renewable fossil fuels to a mix of renewable sources.Stop cutting forests (especially tropical)Capture and store as much CO2 as possible.How can this be done?
37 Carbon Capture and Storage CCS involves removing CO2 from smokestacks and storing the elsewhere like abandoned coal beds or gas fields.Expensive power plantsHow can CO2 be capturedRequires a lot of energySupports continued use of coal
39 Governments and Climate Change The cost of damages from global warming and the cost to slow it down are debatable.Governments can regulate CO2 and CH4 pollutants, use carbon or energy taxes instead of property or income tax.
40 The Kyoto ProtocolIn 1997, 161 nations met in Japan to negotiate a treaty to slow climate change.174 of the worlds 194 nations ratified the treaty that required developed countries to reduce greenhouse gas emissions.Allows for trading of greenhouse gas emissions. (caps set high)
41 Some are Making a Change China and India are investing in sustainable development.U.S. Companies are reducing greenhouse emissions to save money.Wal-Mart saves $34 million a year by using cfl’s and auxiliary power units for shipping trucks.
42 Ozone Depletion Seasonal thinning of the ozone layer caused by: Chlorofluorocarbons - air conditioners, fridges, aerosol cans, cleaners, fumigantsHydrobromoflurocarbons - fire extinguishersMethyl bromide - fumigantHydrogen chloride - space shuttlesVarious chemicals from cleaning solvents
43 Ozone Depletion is BadMore UV-A and UV-B radiation will reach the earth’s surface resulting in more cataracts, sunburns and skin cancer.Increased radiation could impair or destroy phytoplankton.
44 Reversing Ozone Depletion Stop producing all ozone-depleting chemicals. (60 years to recover)Warming the troposphere makes the stratosphere cooler which slows down ozone repair.Copenhagen Protocol (1992) countries agreed to phase-out key ozone-depleting chemicals.