Download Chapter 19 Home and classwork

Chapter 19 Home and classwork
Climate Disruption and Ozone Depletion
Summary
1.
The earth’s average surface temperature and climate has changed in the past. The changes include prolonged
periods of global cooling and global warming.
2.
There is a natural greenhouse effect in the earth’s atmosphere caused by the presence of gases that trap longwave radiation (water, CO2, and others). Human emissions of carbon dioxide, methane, and nitrogen oxide
increase the concentrations of greenhouse gases and cause additional warming of the earth’s surface.
3.
Factor’s influencing changes of earth’s average surface temperature include changes in the solar output, the
earth’s reflectivity, the ability of oceans and land ecosystems to store carbon dioxide, the ocean currents, the
average sea level, cloud cover, and air pollution.
4.
Possible effects from a warmer earth include shifts in plant-growing areas, crop yields and pests, extinction of
some species, loss of habitats, prolonged heat waves and droughts, increased flooding, changes in water
supplies, decreased water quality, changes in forest composition, increased fires, rising sea levels, beach
erosion, contamination of aquifers, spread of tropical diseases into temperate zones, increased respiratory
diseases and allergies, increased deaths, and migration.
5.
To prevent or slow global warming we can limit fossil fuel use, shift from coal to natural gas use, place energy
efficient technologies in developed and developing countries, improve energy efficiency, shift to renewable
resources, reduce deforestation, use sustainable agriculture, limit urban sprawl, reduce poverty, and slow
population growth.
6.
Human activities that cause ozone depletion include emissions of chlorofluorocarbons, methyl bromide,
hydrogen chloride, carbon tetrachloride, methyl chloroform, and others. The stratosphere contains high
concentrations of ozone that absorbs UV radiation as it enters the atmosphere. Ozone depletion can lead to
sunburns, cataracts, skin cancers, immune suppression, and reduced crop yields, particularly in the Southern
Hemisphere. Note that students often confuse tropospheric ozone (air pollution) and stratospheric ozone (UV
absorption), and confuse ozone depletion with global warming.
Please answer the following questions in your APES notebook. This is a big homework and we will be working on
this as a class and groups, but you are still responsible for the answers in your notebook to earn points.
1.
Explain why weather and climate are not the same. Describe atmospheric warming and cooling over the past
900,000 years and during the last century. How do scientists get information about past temperatures and
climates? What is the greenhouse effect and why is it so important to life on the earth? How have human
activities affected atmospheric greenhouse gas levels during the last 275 years and especially in the last 30
years? List the major human activities that add CO2, CH4, and N2O to the atmosphere.
2.
Explain why weather and climate are not the same. Describe atmospheric warming and cooling over the past
900,000 years and during the last century. How do scientists get information about past temperatures and
climates? What is the greenhouse effect and why is it so important to life on the earth? How have human
activities affected atmospheric greenhouse gas levels during the last 275 years and especially in the last 30
years? List the major human activities that add CO2, CH4, and N2O to the atmosphere.
3.
After studying past climate change and the nature of the earth’s climate system for almost three decades, what
two general conclusions did most of the world’s climate scientists agree on about atmospheric warming over the
past 30 years? How did scientists arrive at these two general conclusions, and why was this such a rare event?
How do scientists use models to make projections about future temperature changes? What do a number of
climate models project about temperature changes during this century? How can positive feedback loops affect
future temperature changes and thus global climate? Give two examples of such loops. Describe the role that
climate scientist James Hansen has played in improving our understanding of climate and projected climate
disruption. Describe the contribution of waste heat from energy conversion devises to projected climate
disruption.
4.
Describe how each of the following might contribute to projected atmospheric warming and resulting global
climate disruption: (a) CO2 emissions, (b) a hotter sun, (c) the oceans, (d) cloud cover and (e) air pollution.
What are three effects of increasing atmospheric CO2 levels on the oceans?
5.
Briefly describe how projected climate disruption is likely to affect: (a) drought, (b) ice cover, (c) permafrost,
(d) sea levels, (e) extreme weather, (f) biodiversity, (g) crop yields, and (e) human health during this century.
Pick three of these factors and describe how each can become part of a positive feedback loop leading to
climate disruption.
6.
List six steps that governments could take to help slow projected climate disruption. What is a pollutant and
why is CO2 being classified as a pollutant? What are the advantages and disadvantages of using taxes on
carbon emissions or energy use to help reduce greenhouse gas emissions? What is cap-and-trade and what are
the advantages and disadvantages of using it to help reduce greenhouse gas emissions? What are the pros and
cons of developing an international treaty to help deal with the threat of projected climate disruption? What is
the U. S. city of Portland, Oregon, doing to help reduce its greenhouse gas emissions? What is China doing to
help reduce its contribution to the climate disruption? What is the United States doing to help reduce its
contribution to this problem?
7.
Describe how human activities have depleted ozone in the stratosphere, and list five harmful effects of such
depletion. Describe how scientists Sherwood Roland and Mario Molina help to awaken the world to this threat.
What has the world done to help reduce the threat from ozone depletion in the stratosphere? How are the
problems of atmospheric warming and ozone depletion connected?
My overall goal is for you to be able to have an intelligent science backed conversation with someone about climate
change. We need to educate as many people we can to help make a positive difference for our world. Solutions are
out there!!