Earth Science: Geology, the Environment, and the Universe
Resources and the Environment
WebQuest Projects 1
Is Global Warming Beyond Our Control?Introduction
The Earth's atmosphere is a
complex, dynamic system. Weather conditions affect everything from how we travel
on a daily basis to the food that can be produced worldwide each year. For millions
of years of Earth history, natural cycles of warming and cooling affected Earth
organisms in important ways, about which scientists can only speculate. But what
about human impact on the atmosphere? Do humans play a role in climate change?
Natural atmospheric cycles have occurred for millions of years. Is it possible
that human activities over the last 250 years could significantly impact such
an established, large, and complicated system?Task
The Industrial Revolution, which
began in Great Britain in the mid-1700s was a watershed event in human interaction
with the atmosphere. As fossil fuels were burned in increasingly greater amounts,
the amount of carbon dioxide released into the atmosphere rose significantly.
Industrialization and population growth continue today. At what cost? While the
topic is hotly debated in the scientific community, scientists agree on several
points. Atmospheric concentration of carbon dioxide and other greenhouse gases
is increasing at an unprecedented rate, there is a direct connection between the
concentration of carbon dioxide in Earth's atmosphere and the average surface
temperature, and the average temperature at the Earth's surface currently is increasing.
However, there is great debate on how much is a result of human activity. Throughout
Earth's history, climate change has been driven by natural processes and events
rather than by human activity. Is that still the case?
As you complete this
WebQuest, you will investigate the nature of the connection between the combustion
of fossil fuels, the production of greenhouse gases, and the global warming trend
the Earth currently is experiencing. You will conduct internet research to answer
questions about the greenhouse effect and changes in Earth's atmosphere and climate.
You will review and analyze graphed data at specific Web sites showing how carbon
dioxide, global surface mean temperature, and Arctic sea ice have changed throughout
Earth's recent and extended history. Finally, based on your evaluation of the
information gathered, you will form and write an opinion about the extent of the
role humans play in global climate change.Resources
The Web sites given here
will help you answer questions about global climate change and how it is measured.
The information you gather will help you form an opinion about the level of importance
of human activities to the current global warming trend.
The article at this site describes how the level of atmospheric carbon dioxide
is changing over time. A forecast from the Intergovernmental Panel on Climate
Change is given for atmospheric CO2 level and average global temperature change
by the year 2100. Be sure to visit the interactive global warming features at
this site, which give graphed data regarding CO2 emissions worldwide, a description
of the greenhouse effect, and a history of global warming over the last 20,000
Visit this site
to find answers to frequently asked questions about global warming. Questions
include "Is the climate warming?" and "Can observed changes be explained by natural
variability?" Links within the answers provide graphed data and additional related
at this site explains the process of global warming, and describes specific human
activities that are altering the composition of Earth's atmosphere.
The paleoclimate record shows that rapid and dramatic climate changes have occurred
throughout Earth's history. Visit this site to learn what scientists know and
don't know about what caused these changes, as well as how Earth's climate was
affected by them.
This site is based on a
timeline which describes Earth's climate history for periods ranging from current
to more than 100,000 years ago. Visit this site to learn about natural cycles
of climate change over time, and the factors that may cause these cycles to occur.
Visit this site to learn about abrupt climate change through answers to a series
of frequently asked questions. Questions include "Have humans contributed to global
warming?" and "Can global warming cause an Ice Age?"
The article at this site explains how scientists use a wide variety of information
to understand past climate change and predict future trends. Graphs showing estimates
of mean surface air temperature, as recently as the last 1000 years and as distant
as the last 100 million years, are provided.
This site explains how Earth's climate changed abruptly during a period in Earth's
history known as the Younger Dryas. The article found here relates long-term global
warming to possible rapid cooling of the climate.
The article at this Web site explains how scientists use ice cores to learn how
Earth's climate has changed over the last 200,000 years.
This site gives a chronology that outlines the history of weather data collection
in the United States.
The article at this site addresses changes in global climate that began 8000 years
ago. Visit this site to learn about a new theory connecting the development of
farmlands in Asia and Europe to increases in atmospheric CO2 and methane thousands
of years ago.
1 week to answer the questions, analyze the graphs, and write
Read the following series of questions before beginning your
research. As you explore each Web site, look for answers to the questions.
Questions about Global Climate Change
Next, visit the Web sites listed below. Use information from your research to
answer the questions. As you study the sites, remember that you will use the
information you gather to write your opinion about the extent to which human
activities affect global climate change. Your written opinion should include
specific information that supports your view.
- The greenhouse effect is a natural atmospheric process
that has a tremendous impact on Earth. Describe this process, including what
causes it, the factors that influence it, and how it affects Earth.
the major greenhouse gases found in Earth's atmosphere.
the term greenhouse effect often has a negative connotation when used in the
media, the process is crucial to life on Earth. Explain why.
- Compare the
levels of atmospheric carbon dioxide just prior to the beginning of the industrial
age in the mid-1700s and in 2004.
- Changes in the concentration of greenhouse
gases can cause changes in Earth's average surface temperature. What other natural
factors or events also can cause long-term changes in surface temperature?
- How long have consistent weather measurements been collected and recorded throughout
the United States?
- Atmospheric composition and conditions are different today
than at other times in Earth's history. What types of things do scientists examine
to learn what the atmosphere was like hundreds, thousands, or even hundreds
of thousands of years in the past? Specifically, explain how a history of climate
can be reconstructed from an ice core.
- Analysis of air pockets in glacial
ice show that an abrupt climate change took place about 12,000 years ago. The
discovery of this period, named Younger Dryas, has changed scientific thinking
about the length of time required for global climate change. Describe the Younger
Dryas period, including how it could be related to a past global warming trend.
Scientists collect data about
global change through both direct and indirect measurements. Graphed data often
shows trends and patterns that can help researchers evaluate past changes in
climate and make predictions about future climate changes. Study each of the
six graphs shown at the Web sites listed below, then write a brief analysis
of the data shown by each graph. Your analysis should include a description
of the variables shown on the graph and a summary of any trends or patterns
you observe. Consider copying and printing each graph, then making notes and
writing your analysis directly on the page that shows the graphed data.
Graphs to analyze
dioxide concentration, as measured at Mauna Loa, Hawaii, from 1955 to the present
of carbon dioxide and methane and Antarctic temperature, from 420,000 years
ago until prior to the Industrial Revolution
Global surface mean temperature anomalies from 1880 to the present
Reconstructed annual northern hemisphere mean temperature from 1400 to 2000
Estimate of Earth's
mean surface temperature for the last 800,000 years
Arctic sea ice extent anomalies from 1973 to 2000
Finally, write your opinion
which answers the following question: "Is human activity responsible for the
current global warming trend affecting the Earth?" Your written opinion does
not need to be lengthy, but should include details from your research that support
your point of view. Be prepared to defend your opinion during discussion with
your classmates and teacher.Conclusion
While completing this WebQuest, you
have learned about the greenhouse effect and its importance to life on Earth.
You have examined various factors that can cause changes in Earth's surface
temperature, including changes in atmospheric concentration of greenhouse gases.
You have analyzed graphs showing how surface temperature and atmospheric carbon
dioxide concentration have changed during Earth's recent and extended past,
and have learned how scientists estimate these measurements when they cannot
be made directly. Based on your research, you have written an opinion about
the dominant cause of the recent global warming trend. In developing your view,
you have recognized that while scientists agree that the Earth's mean surface
temperature is increasing, they do not all agree on the extent of the role played
by the burning of fossil fuels in global warming. Forming an opinion supported
by data, and recognizing the validity of differing opinions, also supported
by data, are crucial skills in science and in many real-world tasks.