Climate Change and Ozone Loss - PowerPoint PPT Presentation

Loading...

PPT – Climate Change and Ozone Loss PowerPoint presentation | free to download - id: 3b7464-MGU2N



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Climate Change and Ozone Loss

Description:

Climate Change and Ozone Loss G. Tyler Miller s Living in the Environment 14th Edition Chapter 21 Key Concepts Section 21-1 and 21-2 Key Ideas How has the Earth s ... – PowerPoint PPT presentation

Number of Views:246
Avg rating:3.0/5.0
Slides: 96
Provided by: manskopfC
Category:
Tags: change | climate | loss | ozone

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Climate Change and Ozone Loss


1
Climate Change and Ozone Loss
G. Tyler Millers Living in the Environment 14th
Edition Chapter 21
2
Key Concepts
  • Changes in Earths climate over time
  • Factors affecting climate
  • Possible effects of global warming
  • Adapting to climate change
  • Human impacts on the ozone layer
  • Protecting and restoring the ozone layer

3
Section 21-1 and 21-2 Key Ideas
  • How has the Earths temperature changed in the
    past?
  • How do scientists study past climate changes?
  • What role do the natural greenhouse effect play
    in Earths temperature?
  • What are the major greenhouse gases?

4
Past Climate Changes
  • CLIMATE VERSUS WEATHER...what is the difference?
  • Temperature and climate have been changing
    throughout Earths history.
  • Earth 4.6 billion years

5
Past Climate Change
  • Over past 4.7 billion years climate has changed
    by
  • Volcanic eruptions
  • Changes in solar output
  • Continents moving
  • Meteorites
  • Natural variations in CO2
  • Some changes slow, some quickly

6
Past Climate Variations
  • Glacial and interglacial periods over last
    900,000 years
  • Last glacial period ended 12,000 years ago
  • With each temperature change were changes in sea
    level and precipitation patterns.

7
Past Climate Changes
  • Past global temperatures
  • Recent trends in global temperatures

Todays global average temp 59oF, 15oC
8
(No Transcript)
9
Studying Past Climates
  • Geologic records and atmospheric measurements
    provide a wealth of information about past
    temperature and climate.
  • Ice Cores
  • Lake Sediment
  • Past 200-300 records
  • CO2 levels since 1958

10
Studying Past Climates
11
(No Transcript)
12
Greenhouse Gases
  • Certain gases in the atmosphere absorb heat and
    warm the lower atmosphere.
  • Greenhouse effect
  • Energy from the sun warms the earth. Some of that
    energy is radiated as heat and trapped in the
    atmosphere by clouds, water vapor and other gases.

13
Greenhouse Gases
14
Greenhouse Gases
  • Water Vapor
  • Carbon Dioxide
  • Methane (CH4)
  • CFCs
  • CO2 levels gathered from ice data closely reflect
    changes in temperature.
  • 1764 --- 276 ppm
  • 1995 --- 360 ppm

15
(No Transcript)
16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
19
The Greenhouse Effect
  • Greenhouse effect
  • Greenhouse gases (Refer to Table 21-1 p. 464)

Fig. 6-14 p. 110
20
Section 1 and 2 Review
  • How has the Earths temperature changed in the
    past?
  • How do scientists study past climate changes?
  • What role do the natural greenhouse effect play
    in Earths temperature?
  • What are the major greenhouse gases?

21
(No Transcript)
22
Section 3 Climate Change and Human Activities
Key Ideas
  • How have human activities affected concentrations
    of greenhouse gases in the troposphere?
  • What role does the U.S. play in greenhouse gas
    emissions?
  • Is the troposphere warming?
  • What are some visible warning signals coming from
    glaciers?

23
Humans and Greenhouse Gases
  • Burning Fossil Fuels
  • Clearing and burning forests and grasslands
  • Raising large numbers of livestock
  • Large rice production
  • Using inorganic fertilizers
  • All these activities have greatly increased CO2,
    CH4 and nitrous oxide (N2O)

24
CO2 levels appear to be highest in last 160,000
years
25
Humans and Carbon Dioxide
  • 42 Coal powerplants
  • 24 transportation
  • 20 industrial processes
  • 14 residential and commercial usages
  • Exhale, drive, turn on light, burn log in fire
  • 1 gallon of gas burned equals 20 pounds of CO2

26
U.S. and Greenhouse Gases
  • 4.6 of the worlds population, yet 24 of
    emissions of CO2
  • From just U.S. coal burning exceeds 146 other
    nations with 3/4th of world population
  • Per capita yearly 500 tons
  • Also large CH4

27
Is the troposphere warming?
  • There is considerable and mounting evidence that
    the troposphere is warming quickly
  • Rate of change
  • IPCC found
  • 1) 20th Century warmest in past 1,000 years

28
Is the troposphere warming?
  • 2) Since 1861 global avg. temp increase 0.80C or
    1.40F (mostly post 1980)
  • 3) 16 of the warmest years on record occurred
    since 1980 (hottest 1998 followed by 2001 and
    2003)
  • 4) Glaciers around world melting quickly and
    poles warming more pronounced
  • 5) Global sea levels rose 4-8 inches during 20th
    Century and continue to rise.

29
Is the troposphere warming?
  • Few skeptics still exist, most just argue it is
    not human caused warming
  • Global warming versus Global climate change---
    what is the difference?
  • Do NOT confuse it with ozone depletion

30
Warning Signals From Glaciers
  • The worlds floating ice and land-based ice is
    slowly melting, reflecting less incoming solar
    energy and warming the troposphere further.
  • Largest Glaciers Greenland and Antarctica
  • Floating Ice Arctic Ocean

31
Warning Signals From Glaciers
  • Due to wind currents poles will warm more quickly
    than mid-latitudes.
  • Arctic Ocean free of ice summer 2050???
  • Albedo reflectivity of different surfaces

32
1979
2003 shrunk by 9
33
Albedo of different surfaces
34
Warning Signals From Glaciers
  • Positive Feedback more ice melting more
    warming more ice melting.
  • Melting floating ice has little impact on sea
    level rise (WHY?)
  • Fresher water in ocean, what are the
    consequences?

35
Warning Signals From Glaciers
  • Greenland melting
  • Sea level rise 7m or 23 feet
  • 3oC (5oF) would melt entire continent over next
    several centuries
  • Warming has become more evident in polar regions
    like Alaska
  • Permafrost melting (a positive feedback)

36
Warning Signals From Glaciers
  • Mount Kilimanjaro glacier free in 15 years?
  • 80 of South American glaciers gone also in 15
    years?
  • Less fresh water sources
  • Tourism loss
  • Any good impacts?

37
Riggs Glacier Alaska
Glacier National Park, Montana 1913 and 2005
38
(No Transcript)
39
Section 4 Climate Models Looking Into The Future
Key Ideas
  • How do scientists model changes in the earths
    temperature and climate?
  • IPCC consensus about future changes in earths
    temperature.
  • Why should we be concerned about a warmer earth?

40
Projecting Future Changes in Earths Climate
  • Climate models
  • Apparent influence of human activities
  • Could be natural changes

41
Climate models
  • Scientists have developed complex mathematical
    models of the earths climate system.
  • Inputs
  • Solar energy
  • Earths land
  • Ice
  • Greenhouse gases
  • Clouds, winds, water vapor

42
(No Transcript)
43
(No Transcript)
44
(No Transcript)
45
IPCC Reports Best Science
  • IPCC (Intergovernmental Panel on Climate Change)
  • 1990, 1995, 2001 and now 2007 reports
  • Three Major Finding From 2001
  • 1) Latest climate models closely match changes
    since 1850

46
IPCC Reports Best Science
  • 2) There is strong evidence that most of the
    warming observed over the last 50 years is
    attributable to human activities.
  • 3) It is likely that the world will warm 1.4oC to
    5.8oC (2.5oF to 10.4oF) between 2000 and 2100

47
(No Transcript)
48
Why Be Concerned?
  • RAPID changes give little time for humans and
    other species time to adapt to changes.
  • Fastest change during the last 1,000 years
  • Water resources and precipitation changes
  • Ocean currents
  • Agriculture

49
Why be concerned?
  • Flooding
  • Extreme Weather
  • Changes to world biomes
  • Diseases may spread
  • Displaced nations
  • A threat to the worlds economy and stability?

50
(No Transcript)
51
Section 5 Factors Affecting the Earths
Temperature
  • Can oceans store more carbon dioxide and heat?
  • How might changes in cloud cover affect the
    tropospheres temperature?
  • What impact does air pollution have on
    temperature?
  • Can photosynthesis be stimulated thus storing
    more carbon dioxide?

52
Factors Affecting the Earths Temperature
Positive (amplify) vs. Negative (dampen)
Feedbacks, Give example of both types
  • Changes in solar output
  • Changes in Earths albedo
  • Moderating effect of oceans
  • Clouds and water vapor
  • Air pollution

53
Ocean Storage of CO2 and Heat
  • Ocean currents act to redistribute heat arriving
    at equator moving it north.
  • Example Gulf Stream
  • Deep ocean currents not well understood.

54
Ocean Storage of CO2 and Heat
  • Evidence has shown that ocean currents have
    shifted and even stopped during times in the
    past.
  • Effect of salinity levels (cold, salty water more
    dense)
  • Day After Tomorrow movie effectmore Hollywood
    than science

55
Ocean Storage of CO2 and Heat
  • Oceans also act to trap about 29 of CO2 released
    into the atmosphere as part of global carbon
    cycle.

56
(No Transcript)
57
(No Transcript)
58
(No Transcript)
59
Cloud Cover
  • Warmer Troposphere
  • More Evaporation
  • More Clouds
  • WARMER OR COOLER?
  • Why might it be a
  • positive feedback?
  • Why might it be a
  • negative feedback?

60
Cloud Cover
  • Day versus Night Impacts
  • Thick clouds versus thin clouds
  • High clouds versus Low clouds
  • Latent heat release during cloud formation

61
Air Pollution
  • Soot and other pollutants can warm or cool the
    troposphere.
  • Complex interactions between air pollutants and
    their location in the atmosphere may warm or cool
    the troposphere.
  • Solar dimming effect

62
Photosynthesis
  • More CO2
  • More Plant Growth
  • Less CO2 in atmosphere
  • Right?
  • Or is this temporary?
  • Young vs. Old Plants
  • Once dead
  • Summer versus Winter

63
Methane Gas
  • Warmer air release more methane caught up in
  • Bogs and wetlands
  • Permafrost in tundra
  • CH4 is a more powerful greenhouse gas than CO2

64
Section 5 Review
  • Can oceans store more carbon dioxide and heat?
  • How might changes in cloud cover affect the
    tropospheres temperature?
  • What impact does air pollution have on
    temperature?
  • Can photosynthesis be stimulated thus storing
    more carbon dioxide?

65
Permafrost
66
Section 6 Some Possible Effects of a Warmer World
  • What are some possible effects of a warmer
    troposphere?
  • Ecosystem changes
  • Agricultural changes
  • Rising Sea Level
  • Project presentations1) Agriculture, water
    resources, forests, biodiversity, sea level,
    weather extremes, human population, human health.

67
Some Possible Effects of a Warmer World
68
(No Transcript)
69
(No Transcript)
70
(No Transcript)
71
(No Transcript)
72
Possible Benefits from a Warmer Atmosphere
  • Less severe winters
  • More precipitation in some dry areas
  • Less precipitation in some wet areas
  • Increased food production in some areas
  • Expanded population and ranges of some species

Refer to Fig. 21-13 p. 476
73
Section 7 Dealing with the Threat of Climate
Change
  • What are our best options?
  • What can be done to reduce the threat?
  • What about storing carbon dioxide (carbon
    sequestration)?
  • How can government play a role in reducing
    impacts?
  • What is carbon trading?
  • What are the costs of not acting?

74
Dealing with the Threat of Climate Change
  • There is little disagreement that our planet is
    warming, where most disagreement lies is in what
    to do about it.
  • 1) Are economic costs of reducing greenhouse
    gases higher than benefits?

75
Dealing with the Threat of Climate Change
  • 2) Developed or developing countries, how should
    take responsibility?
  • 3) Voluntary cuts or mandatory laws?
  • Arguments transcend politics, economics,
    scientific, cultural.

76
Solutions Dealing with the Threat of Climate
Change
Options
  • Do nothing
  • Do more research
  • Act now to reduce risks
  • Precautionary principle

Fig. 21-17 p. 479
77
What can be done?
  • Improve energy efficiency
  • Reduce fossil fuel use
  • Renewable energy sources
  • Reduce population growth
  • Reduce deforestation
  • Carbon sequestration

78
(No Transcript)
79
Removing CO2 from the Atmosphere
Fig. 21-18 p. 480
80
How can the government help
  • Tax emissions (carbon tax)
  • Increase subsidies for energy efficiency and
    renewable energy
  • Cut subsidies for fossil fuels
  • Help induce technology transfer

81
Emissions Trading
  • Buying and selling carbon credits on the open
    marketplace.
  • CAP and Trade System
  • Set a nationwide goal and allow markets to decide
    how to reach the goal.

82
Acting Later May Cost More
  • It is likely to cost us less to help slow and
    adapt to global climate change today than deal
    with effects later.
  • Costs versus Benefits

83
Section 8 What is being Done?
  • Kyoto Protocol What is it? What are the problems
    with it?
  • What are some other countries, states, businesses
    doing?
  • What can we do to prepare for warming?
  • Why is global warming such an Inconvenient
    Truth

84
Reducing Greenhouse Gas Emissions
  • Kyoto Treaty (1997)
  • U.S. withdraws from Kyoto Treaty (2001)
  • Other reductions in CO2

Refer to Fig. 21-18 p. 483
85
Kyoto Protocol
  • December 1997 2,200 delegates from 161 nations
  • 39 Developed countries cut greenhouse gas
    emissions 5.2 below 1990 by 2012
  • Developed countries no cuts until later

86
Kyoto Protocol
  • Kyoto would only be a first start (5.2 below
    1990 is not much)
  • Ratified by more than 120 nations.
  • Pres. Bush withdraws in 2001

87
Kyoto Protocol
  • Several ideas floated, but no real negotiations.
  • Next steps????

88
What some are already doing
  • Some countries, companies, U.S. states and cities
    are beginning to make voluntary cuts
  • Great Britain went below 1990 levels and aims to
    cut by 60 by 2050
  • BP has met goals of Kyoto

89
What some are already doing
Why are some states, cities, or even countries
acting alone a waste when it comes to global
warming?
90
(No Transcript)
91
How to prepare for warming
  • Humans need to adapt lifestyles to fit warming
    already built in.
  • Conservation of water
  • Moving from coastal zones
  • Expand wildlife preserves toward poles
  • Preparing for expanded disease areas
  • Recreational, agriculture shifts
  • Insurance industry beginning to prepare.

92
(No Transcript)
93
Why is climate change so difficult of a problem
  • An Inconvenient Truth
  • Long term issue (political system short term)
  • Consequences in future
  • Slow change on human time scale
  • Uncertainty built up by industries
  • Changing lifestyles
  • International issue
  • Hopelessness

94
Section 8 Review
  • Kyoto Protocol What is it? What are the problems
    with it?
  • What are some other countries, states, businesses
    doing?
  • What can we do to prepare for warming?
  • Why is global warming such an Inconvenient
    Truth

95
(No Transcript)
About PowerShow.com