Download Global Environmental Change

Global Environmental Change:
Technology and the Future of Planet Earth
Where will all the heat go?
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Outline
• Evidence for
global climate
change
• Future
atmospheric
carbon dioxide
concentrations
• Simulations of
global climate
and future
climate change
• How much
change is “safe”?
• Summary
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resweb.llu.edu/.../VGD/L
UCC/background1.html
Source: Turner, B.L.
1989. The human
causes of global
environmental
change.
His Figure 11.1, p.91;
reprinted with permission from the
National Academy of
Sciences
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Types of Global Environmental Change
These yet-unanswered questions point to another set of
fundamental concepts in the study of global environmental
changes. We need to define what types of environmental
changes we ought to expect.
Here, we present two ways of identifying environmental
changes: the first aggregates changes in a genetic sense,
i.e., by asking "how do the changes come about?"; the
second views changes according to their occurrence, i.e.,
by asking "in which earth system do we find changes?".
Such typologies help us detect, analyze, and understand
global changes and thus ultimately to manage them.
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www.rri.wvu.edu/.../listoffigures.htm
Humanities-based theories
Contributions to the analysis of how people
relate to nature and the environment originate
mainly in the disciplines of history,
anthropology and psychology within the
broader academic terrain of the Humanities
Studies. The terms "environmental history",
"environmental (and/or cultural)
anthropology", and "environmental
psychology" usually denote the particular
subdisciplines specializing in the above
theme. The following discussion is a selective
presentation of characteristic approaches
from the broad collection of contributions in
each of the three sub-disciplines.
Environmental history is concerned with
recording, presenting, and analyzing the
socio-economic, political, institutional, and
cultural forces that have shaped and
transformed particular environments
spanning all spatial scales from the local to
the global (see, for example, the contributions
in Turner et al. 1990). A theory advanced to
provide a broad explanatory framework for the
historical changes in the uses of land under
the influence of the above-mentioned forces is
the frontier thesis (Richards 1990) which is
applicable to all scales but it seems more
suitable to the larger regional and global
scales.
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A Genetic Typology of Global Environmental
Change:
1. Systemic Change
2. Cumulative Change
An Occurrence-Oriented Typology of Global
Environmental Change
1. Changes in material and energy flows
2. Changes in biota
3. Changes in the physical structure of the biosphere
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Carbon Dioxide and Temperature
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Carbon Dioxide and Temperature
2005
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Carbon Dioxide and Temperature
2040
2005
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Carbon Dioxide and Temperature
Stabilization at 550 ppm
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Carbon Dioxide and Temperature
“Business as Usual” (fossil intensive)
2100
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Associated Climate Changes
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Global sea-level has increased 1-2 mm/yr
Duration of ice cover of rivers and lakes decreased by 2 weeks in N.
Hemisphere
Arctic ice has thinned substantially, decreased in extent by 10-15%
Reduced permafrost in polar, sub-polar, mountainous regions
Growing season lengthened by 1-4 days in N. Hemisphere
Retreat of continental glaciers on all continents
Poleward shift of animal and plant ranges
Snow cover decreased by 10%
Earlier flowering dates
Coral reef bleaching
Source: Intergovernmental Panel on Climate Change, 2001 Report
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Mann, M. E., R. S. Bailey, and M. K. Hughes, 1999: Geophysical Research Letters 26, 759.
www.boilermakers.org/resources/news/c
limate_c...
THE DISCOVERY OF global warming has
its roots in an unlikely source — the
search for an explanation of the ice ages.
In the 19th and early 20th centuries, the
idea of ice ages was new, and scientists
were clamoring for an explanation of
how they began. Weather fluctuations
are normal, but always within narrow
confines. What would cause
temperatures to drop so much that ice
sheets miles thick would cover vast
reaches of the northern hemisphere?
This question led to interesting
discoveries. In 1824 Joseph Fourier
explained the greenhouse effect, and in
1859 John Tyndall identified several
greenhouse gases — most notably
carbon dioxide (CO2) and water vapor.
Water vapor is the main cause of the
greenhouse effect, with CO2 a distant
second.
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Land Use and Land Cover Change
In the study of global change, human interactions with the environment are
tackled in one of three fundamental ways:
(1) the human causes of change, (2) the consequences for, or impacts of changes
in the environment on, society, and (3) the societal responses to change. We have
already seen that the ways in which humans use the earth's resources in their
sociocultural, technological, economic, political, and organizational context
provides the entry point to gaining a better understanding of global change. The
study of land use and land cover is central in this respect .
Land use is the observed immediate reason and/or manifestation of
environmental change. Consider the following examples: Agricultural and forestry
practices have changed entire landscapes; land-management practices more
generally alter plant and animal communities both at the species and habitat level,
or they affect nutrient cycling and distribution in the soil; creation or changes of
transportation routes dissect habitats, and alter water and energy flows; industrial
emissions affect environmental and human health and built structures (as for
example through acid deposition, or the destruction of the ozone layer). Similarly,
we must be interested in how humans adjust to a variable and changing
environment, which factors facilitate or impede such adjustments and
adaptations, and which factors augment or diminish societal vulnerability to, say,
climatic variability, and thus what might be the most effective avenues to take in
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response to global environmental changes.
Source: Ojima, Galvin, and Turner 1994; their
Figure 1, p.301; reprinted with permission from
the American Inst. of Biol. Sciences.
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Agung, 1963
El Chichon (1982)
Mt. Pinatubo (1991)
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Hansen, Scientific American, March 2004
Source: IPCC, 2001: Climate Change 2001: The Scientific Basis
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Source: IPCC, 2001: Climate Change 2001: The Scientific Basis
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Change in Downwelling Longwave Radiation vs.
Change in Surface Temperature
Normalized Change
Longwave Down
Surface (2m) Temperature
From GEWEX News, 14, 1 (November 2004); http://gewx.org/gewex_nwsltr.html
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NASA photographs show the minimm Arctic sea ice
concentration in 1979 at left and in 2003.Satellite passive
microwave data since 1970s indicate a 3% decrease per decade
in arctic sea ice extent.
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Since 1979, the size of the summer polar ice cap has shrunk more than 20 percent.
(Illustration from NASA) (http://www.nrdc.org/globalWarming/qthinice.asp)
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Source: Jerry Meehl, National Center for Atmospheric Research
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Source: National Center for Atmospheric Research
The planet is committed to
a warming over the next
50 years regardless of
political decisions
Source: National Center for Atmospheric Research
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Source: Intergovernmental Panel on Climate Change, 2001 Report
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40% Probability
5% Probability
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Source: Intergovernmental Panel on Climate Change, 2001 Report
Climate Change
Projected for 2100
Rapid Economic
Growth
Slower Economic
Growth
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Source:
Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact
Assessment (www.acia.uaf.edu) Cambridge University Press
(www.cambridge.org).
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Kennedy Space
Center
Impact of a 1-m
rise in sea level
on low-lying areas
Areas subjected to
Inundation with a 1 m
(~3 ft) rise in sea
level
Miami
Source:
Corell, R. W., 2004: Impacts of a
warming Arctic. Arctic Climate
Impact Assessment
(www.acia.uaf.edu) Cambridge
University Press
(www.cambridge.org).
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Climate Surprises
• Breakdown
of the ocean
thermohalin
e circulation
(Greenland
melt water)
• Breakoff of
the West
Antarctic Ice
Sheet
larvatusprodeo.net/.../
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www.aiaccproject.org/about/right_frame.html
Global environmental change vulnerabilities, risks, and responses: a framework for "second
generation" assessment.
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Kennedy Space
Center
Areas subjected to
Inundation with a 1 m
(~3 ft) rise in sea
level
Miami
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DROUGHT INCREASING
Climate change is intensifying the circulation of water on, above and
below the surface of the Earth — causing drought and floods to be more
frequent, severe and widespread.
Higher temperatures increase the amount of moisture that evaporates
from land and water, leading to drought in many areas. Lands affected by
drought are more vulnerable to flooding once rain falls.
As temperatures rise globally, droughts will become more frequent and
more severe, with potentially devastating consequences for agriculture,
water supply and human health. This phenomenon has already been
observed in some parts of Asia and Africa, where droughts have become
longer and more intense.
Hot temperatures and dry conditions also increase the likelihood of forest
fires. In the conifer forests of the western United States, earlier
snowmelts, longer summers and an increase in spring and summer
temperatures have increased fire frequency by 400 percent and have
increased the amount of land burned by 650 percent since 1970.
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Heat Absorption by Ice Masses
• Arctic ice
• Antarctic ice
• Mountain glaciers
– Mt. Kilimanjaro glacier will disappear within 20
years
– Chacaltaya glacier, Andes Mountains, will
disappear in 7-8 years (water supply for La Paz,
Bolivia)
– Italian Alps will lose its permanent ice in
20-30 years
– Glacier National Park is losing ice at an
accelerating rate
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Hansen, Scientific American, March 2004
As the Earth heats up, sea levels rise
because warmer water takes up more
room than colder water, a process
known as thermal expansion. Melting
glaciers compound the problem by
dumping even more fresh water into
the oceans.
Rising seas threaten to inundate lowlying areas and islands, threaten dense
coastal populations, erode shorelines,
damage property and destroy
ecosystems such as mangroves and
wetlands that protect coasts against
storms.
Sea levels have risen between four and
eight inches in the past 100 years.
Current projections suggest that sea
levels could continue to rise between 4
inches and 36 inches over the next 100
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years.
What Consitutes “Dangerous Anthropogenic
Interference with the Climate System”?
James Hansen,
Director of the
NASA Goddard
Institute for Space
Studies:
*
Radiative forcing limit:
1 Watt/ m2
*
1 oC additional rise in
global mean
temperature
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Summary
• Climate change is real and we need to be doing
something about it
• The longer we wait, the fewer our options
• Regional patterns of warming will be complicated
• Climate surprises can’t be
discounted
• We need dialog on what constitutes
“dangerous anthropogenic
interference with the climate
system”
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For More Information
• For peer-reviewed evidence supporting everything you
have seen in this presentation, see my online Global
Change course:
http://www.meteor.iastate.edu/gccourse
• Contact me directly:
[email protected]
• For a copy of this presentation:
http://www.meteor.iastate.edu/faculty/takle/
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Global Environmental Change:
Technology and the Future of Planet Earth
Where will all the heat go?
Eugene S. Takle
Agronomy Department
Geological and Atmospheric Science
Department
Iowa State University
Ames, Iowa 50011
[email protected]
Mechanical Engineering 484X, 8 February 2005
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