INTRODUCTION TO GLOBAL CLIMATE CHANGE “Everybody talks about the weather, but nobody does anything about it.” This comment, attributed to Mark Twain in 1897, is no longer valid. Today, human activities influence climate, long- term trends in weather, on both local and global scales. Aver- age temperatures are rising. Storms and forest fires seem to be increasing in severity (Figure 1.1). The vagaries of weather may obscure specific cause and effect relationships, but humans are definitely part of the problem. Humans are also part of the solution. To diminish the potential damage from climate change and the extreme weather events that result, governments have implemented policies that range from limiting carbon emissions to reinforcing levees. As the public has become more aware about this issue, their behaviors in matters ranging from recycling of materials to the purchase of refrigerators, vehicles, and windows, increasingly reflects their concerns. On contentious issues such as global climate change, a broad understanding of the subject generally contributes to the quality of debate. This book considers the factors respon- sible for climate change; the geophysical, biological, eco- nomic, legal, and cultural consequences of such change; and 1 1
Transcript
INTRODUCTION TO GLOBALCLIMATE CHANGE
“Everybody talks about the weather, but nobody does anything about it.” This comment, attributed to Mark Twain in 1897, is no longer valid. Today, human activities infl uence climate, long-term trends in weather, on both local and global scales. Aver-age temperatures are rising. Storms and forest fi res seem to be increasing in severity (Figure 1.1). The vagaries of weather may obscure specifi c cause and effect relationships, but humans are defi nitely part of the problem.
Humans are also part of the solution. To diminish the potential damage from climate change and the extreme weather events that result, governments have implemented policies that range from limiting carbon emissions to reinforcing levees. As the public has become more aware about this issue, their behaviors in matters ranging from recycling of materials to the purchase of refrigerators, vehicles, and windows, increasingly refl ects their concerns.
On contentious issues such as global climate change, a broad understanding of the subject generally contributes to the quality of debate. This book considers the factors respon-sible for climate change; the geophysical, biological, eco-nomic, legal, and cultural consequences of such change; and
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2 CHAPTER 1
various strategies to diminish some of the undesirable consequences. It compares methods that researchers in different disciplines employ to evaluate past and future conditions, and it highlights the complexity of devel-
oping effective policies when the information available may be sparse and vague.
Most textbooks concentrate on a single discipline (e.g., geophysics, biology, or economics) or subdisci-
pline (e.g., glaciology, plant physiology, or mac-roeconomics); they introduce the major con-cepts and then apply them to several examples involving a variety of issues. This book, by con-trast, focuses on a single issue—global climate change—and relates concepts from a number of natural and social sciences to it. Nearly every-one will fi nd certain topics from this wide spec-trum to be challenging; nonetheless, stretching to maintain flexibility becomes critical as one matures.
Articles on environmental issues frequently evoke fear, uncertainty, and doubt (FUD) that fur-ther exploitation of natural resources might cause irrevocable damage. Excessive exposure to FUD, however, desensitizes the public to such issues (“crying wolf”) or, worse, elicits fatalistic despair. This book strives to present a more balanced per-spective and occasionally unbridled optimism, but will deserve the subtitle Doom and Gloom with Bloom (Figure 1.2) if this attempt fails.
FIGURE 1.1 Extreme weather Hurricane Katrina extends across the Gulf of Mexico as it approaches New Orleans
on August 28, 2005. (Imagery from the GOES-12 weather satellite.)
FIGURE 1.2 “Doom and Gloom with Bloom” The author, Arnold J. Bloom, is shown marching in Times Square, New York City in this manipulated image.
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INTRODUCTION TO GLOBAL CLIMATE CHANGE 3
This chapter recalls the last 70 years of research on global climate change. The next three chapters constitute a geophysical section that examines the past, present, and future of Earth’s climate: Chap-ter 2 presents historical reconstructions of temper-ature and a few other indicators of climate, Chap-ter 3 details factors that influence climate, and Chapter 4 describes global climate models and the changes they predict during the next century. Sub-sequent sections of the book introduce additional aspects about climate change: direct and indirect effects on organisms, mitigation strategies and the economics thereof, international cooperation and accords, and, fi nally, the interplay of culture and public opinion. The book strives to support every statement with data in graphical or tabular form. The number of graphs and tables that results from such an effort disrupts the continuity of the text and may overwhelm readers who are less quanti-tative in orientation. For this reason, some of this documentation is presented on the book’s web site, www.sinauer.com/bloom, for readers who are more inquisitive and quantitatively inclined.
ClimateLong-term weather patterns, as mentioned in the previ-ous section, characterize the climate. The weather page in your local newspaper includes information on daily maximum and minimum temperatures; humidity; pre-cipitation; and wind speed and direction. Long-term averages of these measures defi ne the climate in your area. For example, a Mediterranean climate is charac-terized by relatively hot, dry summers and cool, wet winters. In Davis, California, more than 80% of the rain-fall occurs during the winter months (Figure 1.3), thus Davis is considered to have a Mediterranean climate.
“Climate is what we expect; weather is what we get,” is another statement attributed to Mark Twain. In other words, weather conditions are highly variable from day to day or year to year. Over an 11-year period, total precipitation during the month of December in Davis ranged from 0 to 250 millimeters (see Figure 1.3). Con-sequently, predicting daily weather based on climatic trends over time is seldom worthwhile. Subtle changes in climate over a few decades are sometimes diffi cult to discern from normal fl uctuations in weather.
The fi rst person to note the recent warming trend in Earth’s climate and associate it with fossil-fuel emis-sions was Guy Stewart Callendar (1898–1964). Callen-dar’s father, Hugh Longbourne Callendar, a professor of physics at the Imperial College of Science, London, had developed the platinum resistance thermometer, an
instrument that permitted precise, continuous record-ing of temperatures. Guy Stewart Callendar worked as a steam engineer for the British Electrical and Allied Industries Research Association, but he had inherited his father’s interest in temperature measurement and, as a hobby, scrutinized weather records from around the world.
Callendar examined historical trends in global aver-age temperatures by grouping temperature data from the most reliable weather stations in given regions of the world and weighting the importance of each group according to the geographic area represented by its sta-tions (Callendar 1938). He calculated 10-year moving averages (the average of the values 5 years before and 5 years after a given date) to smooth out year-to-year fluctuations (Figure 1.4). Callendar’s analysis sug-gested that world temperatures had increased by more than 0.2°C between 1890 and 1935. Based on crude measurements of carbon dioxide (CO2) concentrations in the atmosphere and a simplistic model, Callendar proposed that rising CO2 levels were responsible for over half of this warming.
The ideas of Callendar, an amateur encroaching on the domain of climatologists, licensed profession-als who focused on climate, were not well received (Weart 2003). Most climatologists of the day believed that temperature data, because they were so variable, could be statistically manipulated to support nearly any conclusion. For example, Helmut E. Landsberg (1906–1985), perhaps the most renowned climatologist of the twentieth century (Baer 1992), did not acknowl-edge any signifi cant historical changes in global aver-age temperatures and declared, “There is no scientifi c
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FIGURE 1.3 Precipitation (millimeters) in Davis, California Plotted are data for each month of every other year during the last decade and typical precipitation values (long-term averages).
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4 CHAPTER 1
reason to believe that our climate will change radically in the next few decades, hence we can safely accept the past performance as an adequate guide for the future” (Landsberg 1946).
The larger scientific establishment also doubted whether atmospheric CO2 concentrations had changed signifi cantly (Weart 2003). Readings of CO2 concentra-tions would fluctuate with the winds because local sources that released CO2, such as nearby factories, and sinks that absorbed CO2, such as nearby forests, infl u-enced every sample. The consensus of the scientifi c community was that nearly all the CO2 released from fossil-fuel burning would dissolve in the immense vol-ume of Earth’s oceans, and thus atmospheric changes would be negligible.
With the dawn of the nuclear age at the end of World War II, atmospheric and oceanic scientists became preoccupied with other products of human ingenu-ity, namely radioactive wastes. In 1954, fallout from an American nuclear bomb test injured the crew of a Japanese fi shing vessel. Later that year came the release of Gojira, the fi rst in a long series of horror movies to feature Godzilla, a fictional monster created by an American nuclear bomb test. Anxiety was escalating. Would radioactive carbon dioxide (14CO2), which was generated in the atmosphere during nuclear explo-sions, dissolve in the oceans and widely contaminate sea life and seafood?
Roger Revelle (1909–1991) and Hans Suess (1909–1993) of the Scripps Institution of Oceanography in San Diego, California, analyzed the exchange of 14CO2 between the atmosphere and the oceans. They published a seminal work in 1957 showing that only a thin, upper layer of seawater rapidly exchanged materials with the atmosphere (Revelle and Suess 1957). These results had broad implications. On the positive side, contamination of sea life from nuclear testing would be highly local-ized; but on the negative side, the oceans would remove only a small portion of the 14CO2 being released into the atmosphere; most of the radioactive gas would remain airborne. By analogy, these results indicated that only a
small portion of the CO2 released from fossil-fuel burn-ing would dissolve in the oceans: the bulk would remain in the atmosphere, and atmospheric CO2 concentrations would increase substantially.
By the mid-1950s, technological advances had increased the precision of CO2 measurements ten-fold. C. D. (Dave) Keeling (1928–2005), also of Scripps, obtained funds suffi cient to equip two weather stations with instruments that monitored atmospheric CO2 with unprecedented accuracy. To minimize the infl uence of local disturbances, he chose sites that were remote from industrial and biological sources of CO2 and were sub-ject to strong prevailing winds (Figure 1.5A). One site was at the South Pole and the other was on the Island of Hawaii, at the Mauna Loa Observatory atop the northern fl ank of the Mauna Loa volcano, at an eleva-tion of 3,397 meters (Figures 1.5B and C).
Monitoring at the South Pole began in September 1957 and at Mauna Loa 6 months later. Concentrations of CO2 at the South Pole rose slowly, but steadily. The CO2 measurements at Mauna Loa, however, oscillated from month to month (Figure 1.6), raising doubts about whether this instrument was performing properly (Keel-ing 1978). Fortunately, with more observations, Keeling realized that the oscillations at Mauna Loa refl ected the annual cycle on nearby continents of relatively rapid plant photosynthesis in summer, which removes CO2 from the atmosphere, and relatively rapid biological respiration in winter, which releases CO2 to the atmo-sphere. Funding for the South Pole station ran out after about 2 years, during which time data showed a rise in CO2 concentrations from 311 ppm to 314 ppm (parts per million; 311 ppm = 0.0311%). The Mauna Loa station has provided a nearly continuous record of rising atmo-spheric CO2 concentrations from about 315 ppm in 1957 to about 386 ppm in 2009, an increase of about 20%. This record has become known as the Keeling curve.
As evidence accumulated, the scientifi c establish-ment became more receptive to the idea of global warm-ing and its relationship to atmospheric CO2 concentra-tions (Figure 1.7). Even Landsberg, who by 1958 had
FIGURE 1.4 A graph from Callendar’s 1938 publicationThis graph shows temperature patterns (°C) for various climatic zones and of Earth. Plotted here are 10-year running averages (the average of 5 years before the date and 5 years after) with respect to the average temperatures from 1901–1930. (From Callendar 1938).
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INTRODUCTION TO GLOBAL CLIMATE CHANGE 5
become the director of the Offi ce of Climatology in the U.S. Weather Bureau, shifted his stance on the subject:
For nearly a half century, a general warming trend has been noted…For the moderate latitudes, 30° to 50°N in the area around the Atlantic, the natural rise can be estimated at about 2°F (1.1°C) per century …For the latest temperature change, there is an important contender as cause: atmospheric carbon dioxide. There are some interpretations of historical and current observations pointing toward a gradual increase of this atmospheric constituent…Carbon dioxide is an absorber of outgoing long-wave radiation, and hence has an infl uence…often referred to as the ‘greenhouse effect’ (Landsberg 1958).
Current State of AffairsDisagreements still remain about the extent to which the recent warming in global temperatures deviates from normal climatic cycles. Direct measurements of
FIGURE 1.5 Sites to monitor atmospheric CO2 concentration (A) Average wind speeds (meters per second) at ground level around the globe. The black dotted oval on the left demarcates the Hawaiian Islands. (B) Satellite photo of Hawaii showing the location of the Mauna Loa Observatory. (C) The observatory in 1982 shown against the backdrop of the neighboring peak Mauna Kea.
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FIGURE 1.6 Monthly average CO2 concen-tration (parts per million: 1 ppm means 1 microliter of CO2 is dissolved in each liter of total air; 1ppm = 0.001%) in the atmosphere at the South Pole and near the summit of Mauna Loa in Hawaii. The inset in the upper left shows data from the fi rst few years on an expanded scale.
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6 CHAPTER 1
temperature have been available from weather sta-tions around the world only since 1861. To reconstruct temperature patterns before 1861 requires the use of proxy measures, measurements such as the width of tree rings that are strongly dependent on temperature and can be dated with accuracy. Chapter 2 considers different types of proxy measures.
In 1999, Michael Mann of Pennsylvania State Uni-versity and his coworkers reconstructed the average annual temperatures in the Northern Hemisphere over the last 1000 years from a variety of direct measurements and proxy measures (Mann et al. 1999). The resulting graph (Figure 1.8) became affectionately known as the “hockey stick” because the “shaft” (representing tem-
peratures from A.D. 1000 to 1900) was relatively straight, whereas the “blade” (representing temperatures during the current century) was abruptly bent upward about 0.6°C (1.1°F). Mann and his colleagues proposed, as had Callendar and Landsberg several decades earlier, that emissions of CO2 and other greenhouse gases from the burning of fossil fuels were responsible for the dramatic warming trend (Mann et al. 1998).
By 2002, the political climate of the United States had changed, and fossil-fuel companies assumed a larger role in governmental policies on energy. ExxonMobil, the larg-est supplier of fossil fuels, distributed over $2 million per year from 2000 through 2003 to organizations promoting the message that the scientific evidence linking global warming and fossil-fuel burning was unsound (McKib-ben et al. 2005; The Royal Society 2006). The “hockey stick” data became even more contentious, and the U.S. Con-gress requested that the National Academy of Sciences, a body of prestigious scientists, verify Mann’s research.
Eight years after Mann and his coworkers published their 10-page article, the committee appointed by the National Academy released a 196-page report (National Research Council 2006). This report upheld the major premise of the hockey stick: Global temperatures have warmed more than 0.6°C during the last century, and such changes are without precedent during the preced-ing 4 centuries and probably much longer. In particu-lar, the year 2005 was the hottest on record, followed in descending order by 2007, 1998, 2002, 2003, 2006, 2004, 2001, and 2008 (Goddard Institute for Space Studies 2009). All indications are that this warming trend will continue and perhaps even accelerate.
About 130 stations around the world now monitor atmospheric CO2 concentrations and have affi rmed the trends fi rst observed in Keeling’s data from the South Pole and Mauna Loa. Atmospheric concentrations of CO2 have increased worldwide (Figure 1.9). Concen-
FIGURE 1.7 Rising temperatures A graph from Landsberg’s 1958 publication shows temperature patterns over nearly 50 years (°F and °C) for the summer (June–August) and winter (December–February) at Winthrup College, South Carolina. Dashed lines show the general temperature trend for the region. (From Landsberg 1958).
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FIGURE 1.8 Temperature variation This data from the 1999 publication of Mann et al. is dubbed the “hockey stick.” It shows deviations of average annual temperatures (°C) in the Northern Hemisphere from the long-term average from 1902–1980 (temperature change). It is a composite estimate that the authors reconstructed from a variety of sources. Gray shading indicates the extent of variation in the estimate, and the red line in the middle of the data represents the long-term trends. (After Mann et al. 1999).
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trations are lower in the summer, when plants incorpo-rate CO2 from the atmosphere into their organic carbon compounds via photosynthesis, and higher in the win-ter, when biological respiration exceeds photosynthesis and releases CO2 from organic carbon compounds. Sea-sonal variation is greater in the Northern Hemisphere than the Southern Hemisphere because the Northern Hemisphere has substantially more landmass (see Fig-
ure 3.13) and thus more terrestrial organisms that con-duct rapid photosynthesis and respiration.
Global temperatures and atmospheric CO2 concen-trations have tended to change in conjunction with one another (i.e., show a positive correlation) both in the current century and during the last 650,000 years (see Chapter 2). Admittedly, correlation does not imply causality (Box 1.1), but most in the scientifi c commu-
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FIGURE 1.9 Global distribution of atmospheric CO2 This is a three-dimensional representation of the latitudinal distribution of atmospheric CO2 based on data from the Global Monitoring Division (GMD) cooperative air-sampling network. Notice that the overall global trend is that CO2 concentrations are rising. CO2 concentration varies more during a year at higher latitudes because seasonal variation is greater there. This concentration also varies more in the northern hemisphere because it has more land area than the southern hemisphere. Moreover, the seasonal peak in concentration shifts with date from the northern hemisphere to southern hemisphere because photosynthesis, which absorbs CO2, is faster during the summertime of each hemisphere. (From Dr. Pieter Tans and Thomas Conway, NOAA ESRL GMD Global Carbon Cycle, Boulder, CO.)
The following examples about global warming dem-
onstrate that correlation does not imply causality. In a
parody of scientifi c method, Bobby Henderson—self-
described as an unemployed, amateur pirate with a
physics degree—found a negative correlation between
the number of pirates and global average temperature
(Figure A) and advocates that people become pirates
to stop global warming (Henderson 2006). In another
spoof, Connie M. Meskimen, a bankruptcy lawyer from
Arkansas, suggested that daylight savings time exacer-
bates global warming by setting sunrise at an earlier hour
(Figure B). Only a few scientists, however, have turned
to piracy or turned back their clocks prematurely.
BOX 1.1 Alternative explanations for global warming
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You may have noticed that March of this year was particularly hot. As a matter of fact, I understand that it was the hottest March since the beginning of the last century. All of the trees were fully leafed out and legions of bugs and snakes were crawling around during a time in Arkansas when, on a normal year, we might see a snowflake or two. This should come as no surprise to any reasonable person. As you know, Daylight Saving Time started almost a month early this year. You would think that members of Congress would have considered the warming effect that an extra hour of daylight would have on our climate. Or did they? Perhaps this is another plot by a liberal Congress to make us believe that global warming is a real threat. Perhaps next time there should be serious studies performed before Congress passes laws with such far-reaching effects.
CONNIE M. MESKIMEN
Figure B A tongue-in-cheek letter to an Arkan-sas newspaper.
Figure A Global average temperatures as a function of the number of pirates. This parodies standard presenta-tions of scientifi c data. Notice that the labels on the x axis are not consistent. (After Henderson 2006).
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8 CHAPTER 1
nity agree that global temperatures are rising and that human-generated emissions of CO2 and other green-house gases are contributing to this rise. Alternative explanations for the current temperature trends con-fl ict with a growing body of evidence. Even organiza-tions with strong vested interests in fossil fuels have modifi ed their message.
For instance, in 2005, ExxonMobil’s “Corporate Citi-zenship Report” acknowledged that “the accumulation of greenhouse gases in the Earth’s atmosphere poses risks that may prove signifi cant for society and ecosys-tems. We believe that these risks justify actions now, but the selection of actions must consider the uncertain-ties that remain” (ExxonMobil 2005). The report pres-ents ExxonMobil’s view of the uncertainties regarding the causes of global warming but then touts the $200 million that ExxonMobil had just bequeathed to the Global Climate and Energy Project at Stanford Univer-sity in California as “the largest-ever privately funded research effort in low-greenhouse-gas energy.”
Other fossil-fuel companies have taken similar approaches. In 2006, BP (formerly British Petroleum) and Chevron announced plans to allocate $500 mil-lion and $400 million, respectively, for research on bio-fuels. All these companies now advertise their efforts in developing energy resources while minimizing envi-ronmental degradation.
Telltale SignsGlobal warming has altered a broad range of geophys-ical and biological phenomena. These phenomena are the focus of several chapters in this book. Recent changes in ice cover, however, are so visually striking as to warrant a place in this fi rst chapter.
Mount Kilimanjaro reaches 5,895 meters above sea level in equatorial Tanzania. Not only is it the highest peak in Africa, it is also the only place on the conti-nent covered with snow year-round; hence its name, which translates as “Shining Mountain.” Satellite pho-tographs show the mountain in 1993 and 2000 (Figure 1.10A). A compilation of maps outlining the ice fi elds near the summit documents the changes over the last century (Figure 1.10B). If the current rate of decline continues, the snows of Kilimanjaro will disappear during the next few decades (Thompson et al. 2002).
The far end of Earth provides another visual example of changes in ice cover over time. Since 1950, the Arctic has experienced an increase in average temperatures of about 2°C, more than twice that observed at lower latitudes (ACIA 2005). In response, the polar ice cap is receding at a rate of around 10% per decade (Figure
1.11). Sometime in the not-too-distant future, the Arc-tic Ocean will have an ice-free season and realize the long-sought Northwest Passage, a sea route between the Atlantic Ocean and the Pacifi c Ocean through the Canadian archipelago (see Chapter 4). This might prove to be a fi nancial windfall for Pat Broe, a Denver entre-preneur who bought the port of Churchill on Hudson Bay at auction for $10 Canadian in 1997: An ice-free Northwest Passage could bring up to $100 million of shipping business to Churchill each year.
In the Course of Human EventsThe effects of climate have determined the outcome of many human endeavors. An appropriate ending to this introduction is the famous fi gure drawn by Charles Joseph Minard (Figure 1.12), a testament to climate and the fate of empires (Tufte 2001). On June 24, 1812, Napoleon invaded Russia, crossing the Niemen River from Poland into Russia with 422,000 men. Six months later, after experiencing temperatures as low as –38°C, Napoleon’s Grande Armeé departed Russia with a mere 10,000 men.
Climate again played a pivotal role in the disastrous German invasion of the Soviet Union in 1941. German forces were trapped outside Moscow during the Rus-sian winter with inadequate shelter, clothing, fuel, and food. All in all, more than 4 million German and 8 mil-lion Soviet troops lost their lives on the Eastern Front.
As these examples illustrate, insuffi cient consider-ation of climate can have dire consequences. In 2007, military and spy agencies in the United States warned that anticipated changes in the world’s climate pose a serious threat to the security of nations because of sub-stantial shifts in the availability of natural resources and the forced migration of millions of people (Mazzetti 2007). In their fourth assessment, the Intergovernmen-tal Panel on Climate Change (IPCC), an organization established by the World Meteorological Organization and United Nations, agreed that further global warming is already unavoidable due to past human activities and a major international effort is required to mitigate the impacts (IPCC 2007a, 2000b,c).
▲▲FIGURE 1.10 Dramatic changes in ice cover (A) Mt. Kilimanjaro on February 17, 1993 (top) and February 21, 2000 (bottom). Satellite images of the summit indicate the minimum amount of snow cover. (B) Outlines of the ice fi elds near the summit of Mt. Kilimanjaro in 1912, 1953, 1976, 1989, and 2000. The inset illustrates the near-linear decrease in ice area over time. (B after Thompson et al. 2002.)
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INTRODUCTION TO GLOBAL CLIMATE CHANGE 9
This book outlines the causes and possible conse-quences of global climate change and then presents various strategies for addressing these possible con-sequences. Climate change is a complex problem, probably one without a simple solution. This book
cannot provide definitive answers to many of the questions raised while considering the issue of global climate change, but it can provide a broad context from which readers may draw their own insights and conclusions.
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FIGURE 1.11 Minimum amount of Arctic sea ice in 1979 (left) and 2007 (right). This is based on data collected
by NASA satellites at the end of the Arctic summer.
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10 CHAPTER 1
SummaryClimate refers to the general weather patterns in a par-ticular location. Long-term changes in such patterns are often diffi cult to differentiate from the large fl uctuations in weather that normally occur. Nonetheless, long-term measurements of temperatures from around the world indicate that Earth is warmer today than it has been for several centuries. This warming has been associated with human activities, especially the release of carbon dioxide from the burning of fossil fuels. Although a small portion of this carbon dioxide dissolves into the oceans, the vast majority remains airborne and increases atmospheric carbon dioxide concentrations.
Global warming has produced noticeable changes in a broad range of phenomena including the disappear-ing snows of Kilimanjaro and a decrease in the extent of the polar ice caps. Such changes are likely to infl u-ence the fate of human civilizations.
Review Questions1. Over the last century, global average temperatures have
(a) cooled about 0.1°C.
(b) not changed signifi cantly.
(c) warmed about 0.1°C.
(d) warmed about 0.6°C.
(e) warmed about 6.0°C.
2. Atmospheric CO2 concentrations were about _____ ppm in 1957 and about _____ ppm in 2009.
(a) 200
(b) 270
(c) 315
(d) 386
(e) 550
KovnoVilna
Gloubokoe
Smorgoni
Vitebsk
OrschaSmolensk
Dorogobongr
Chjat
Mojaisk Tarutino
Moscow
Malojaroslavetz
Botr
Berizina R.
Mohilow
Wirma
Moscowa R.
MolodecznoMinsk
Polotsk
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000
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000
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000
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00
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Niemen R.
–26° Nov. 14
–11° Nov. 14
–25° Nov. 28–30° Dec. 1
–38° Dec. 6
–14° Nov. 20
0° Oct. 24 0° Oct. 18
–40°
–20°
0°Temp. (°C)
Studianka
–33° Dec. 7
FIGURE 1.12 A map of Napoleon’s invasion of Russia in 1812 The tan band depicts the French army’s crossing the Niemen River into Russia and advancing east toward Moscow; the black band depicts the army’s westward retreat from Moscow. The thickness of the bands
refl ects the size of the French army at various locations. The branch points indicate where some troops separated during the advance and later rejoined the retreat. Temperatures (°C) in red are linked to the path of retreat.
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INTRODUCTION TO GLOBAL CLIMATE CHANGE 11
3. Which of the following researchers made major contributions to our understanding about climate trends? (Select one or several.)
(a) Guy Stewart Callendar
(b) C. D. Keeling
(c) Roger Revelle
(d) Pat Broe
(e) Charles Joseph Minard
4. Most of the carbon dioxide released from the burning of fossil fuels
(a) dissolves in the oceans.
(b) remains in the atmosphere.
(c) is consumed by animals via respiration.
(d) becomes radioactive.
(e) freezes and becomes dry ice.
5. Evidence of current global temperature trends include (select one or several)
(a) the disappearance of year-round snow in
Africa.
(b) Napoleon’s successful invasion of Russia.
(c) the Northwest Passage through the Canadian
archipelago.
(d) the proliferation of movies featuring Godzilla.
(e) the extension of daylight savings time.
Suggested ReadingsNational Research Council. 2006. Surface Temperature
Reconstructions for the Last 2,000 Years. The National
Academies Press, Washington, D.C., http://www.nap.edu/catalog/11676.html. The National Academy of Sciences has a mandate from the U.S. Congress to advise the federal govern-ment on scientifi c and technical matters. The Acad-emy appointed a committee of twelve distinguished scholars to prepare this report on global temperature changes over the past two millennia.
Weart, S. R. 2003. The Discovery of Global Warming. Harvard University Press, Cambridge, Mass.
A fascinating account about the history of research on climate change. Dr. Weart regularly updates the version available for free at http://www.aip.org/history/climate/.
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