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CHAPTER 4
Historic and Projected
Climate Change
S
ince 1990 scientists have clearly demonstrated the increasing evidence of
climatic impacts from increasing heat trapping greenhouse gases (GHG).
Scientists from the U.S. and around the globe have registered “abrupt and rapid”
changes that are occurring over decades including sustained
modifications in the hydrologic cycle, rapid decline of glaciers
and ice fields, shifts in major ocean currents, as well as signifi-
Scientists attribute observed global
cant increases in the rate of release of GHG and methane that
and regional temperature rises to
had been trapped in the permafrost of the northern latitudes.
This evidence strongly indicates that the earth’s climate is
the increase of greenhouse gas
changing (Bates et al. 2008, Clark et al. 2009, and Lawler et
concentrations in the atmosphere,
al. 2009).
The United Nations created the Intergovernmental Panel
on Climate Change (IPCC) in 1988. The IPCC recently released
its Fourth Assessment Report (2007) assessing current climatic
including CO2. A warming
atmosphere allows it to hold greater
changes and projecting future climatic changes. This IPCC
amounts of water vapor, which in
report is a culmination of decades of research and contribu-
turn influences both the increase in
tions from more than 1,200 authors and 2,500 scientific expert
reviewers from over 130 countries.
Recent research by Bates et al., Clark et al., and Lawler
average precipitation as well as the
associated increase in the frequency
et al. (2008, 2009, 2009, respectively) indicates widespread
consensus amongst the world’s scientists that there is a virtual
of large pre-cipitation events.
certainty that:
• Human activities are changing the composition of Earth’s
atmosphere. Since pre-industrial times, increasing atmospheric levels of heat
trapping gasses like carbon dioxide (CO2) are well-documented and understood.
• The atmospheric buildup of CO2 and other heat trapping gasses is largely the
result of human activities such as the burning of fossil fuels.
• An “unequivocal” warming trend of about 1.0 to 1.7°F occurred from 1906-2005.
Warming occurred in both the Northern and Southern Hemispheres, and over the
oceans.
F O R G I N G
T H E
L I N K 4-1
H I S T O R I C
A N D
P R O J E C T E D
• Major GHGs emitted by human activi-
C L I M A T E
C H A N G E
CO2 concentrations as far back as
ties remain in the atmosphere for
400,000 years can be explained by look-
time periods ranging from decades to
ing at historical concentrations of CO2
centuries. It is therefore virtually cer-
gas trapped in Greenland and Antarctic
tain that atmospheric concentrations
ice. While historically, CO2 levels very
of GHGs will continue to rise over the
seldom exceeded a concentration of
next few decades.
280 parts per million (ppm), since last
• Increasing GHG concentrations tend
mid-century, a dramatic increase has
occurred. A similar trend has been
to warm the planet.
recorded for other gases as well, including
LONG-TERM
CLIMATE RECORDS
methane (CH4) and nitrous oxide (N20)
The Pew Center on Global Climate
derived gases can persist for only a few
(Petit et al., 1999).
Change defines “greenhouse effect”
as the insulating effect of atmospheric
greenhouse gases that maintains the
Earth’s temperature. This effect is not
only related to the concentration of CO2
in the atmosphere, but also gases such as
nitrous oxide, ozone, methane and even
water vapor. These gases, in addition to
others, have the capability of trapping
heat within the atmosphere.
Once in the atmosphere, carbon
days or weeks, while others can remain
a long time, continuing their influence
on global warming. As an example,
methane can last for decades, while CO2
can persist for thousands of years (Archer,
2005). In the 1990s, global CO2 emissions
increased 1.3 percent per year, but since
2000 this rate has jumped to 3.3 percent
per year. The latest data from the Mauna
Loa observatory, located on the big
FIGURE 4-1
Concentrations of CO2
(IPCC, 2007)
4-2
F O R G I N G
T H E
L I N K
H I S T O R I C
A N D
P R O J E C T E D
C L I M A T E
C H A N G E
island of Hawaii, indicates that current
modeling results indicated that by remov-
CO2 atmospheric levels have risen to a
ing human influences, the atmosphere
yearly average of 385 ppm, an increase
would have experienced cooling, rather
of approximately 138 percent above the
than the observed rise in global tem-
long-term, pre-industrial high of 80 ppm
peratures due to anthropogenic sources
(Tans, 2010) (see Figure 4-1).
(Hegerl et al., 2007).
Over the last 1000 years, there has
been a paralleling of global temperature
fluctuations in concert with changes in
CO2. Examining oxygen isotopes and
GHGs found trapped in ice cores of the
Vostok Ice Sheet in the Antarctic, the
relationship between global temperature
and CO2 is visible as far back as 400,000
years (Petit et al., 1999).
Scientists attribute observed global
and regional temperature rises to the
increase of GHG concentrations in the
atmosphere, including CO2. A warming
atmosphere can hold greater amounts
of water vapor, which in turn influences
both the increase in average precipitation
as well as the associated increase in the
frequency of large precipitation events
(Solomon et al., 2009).
EVIDENCE OF A CHANGING
CLIMATE
The long record of climate evidence
found in ice cores, tree rings, and other
natural records show that Earth’s climate
patterns have undergone rapid shifts
from one stable state to another within
as short of a period as a decade. The
occurrence of abrupt changes in climate
becomes increasingly likely as human
disturbance of the climate system grows
(Meehl et al., 2007).
The NASA Goddard Institute for Space
recently released a report which considers the climate close to a “tipping point,”
which is defined as a concentration
of GHG in the atmosphere which can
have disastrous impacts worldwide due
NATURAL AND HUMAN
INFLUENCES
At both the national and regional scale,
yearly fluctuations in weather patterns
to abrupt and dramatic changes in the
climate (NASA, 2010).
Increases in Precipitation, Storm
Intensity and Temperature
occur that do not reflect the longer term
Paralleling the rise in global and regional
trends seen in temperature or precipita-
temperatures are increases in the asso-
tion. Such fluctuations can be influenced
ciated average precipitation and the
by cyclical changes in ocean current tem-
number of extreme storm events across
peratures or the eruption of volcanoes.
the U.S.’s northern latitudes. According to
Recently, scientists conducted a modeling
NOAA climatic records for the U.S., which
experiment simulating GHG concen-
has been collected from stations across
trations and the resulting impacts on
the 48 contiguous states, average pre-
temperature over the last century under a
cipitation has increased 6.1 percent since
scenario without human influences. The
the early 20th century. Figure 4-2, from
F O R G I N G
T H E
L I N K 4-3
H I S T O R I C
A N D
P R O J E C T E D
C L I M A T E
C H A N G E
FIGURE 4-2
Average Precipitation
Changes for the US
(NOAA Climatic
Data Center)
the NOAA Climatic Data Center, shows
trends over the last few decades that are
where the greatest increases in average
associated with rising global tempera-
precipitation have occurred across the
ture and precipitation changes. These
country. As depicted, the Midwest, North
include:
Central, South, and Northeast regions
• Warmer winters
have experienced increases in precipita-
• Decreased snowfall
tion of 10 to 20 percent since the early
• Fewer days with snow on the ground
20th century (Figure 4-2).
• Earlier spring runoff
In looking at a more recent time
frame, researchers from Antioch
University New England analyzed
weather records for specific locales in
New England from 1979 to 2000. Over
this time span, there was a 20 to 28
percent increase in the average amount
• Earlier lilac and honeysuckle bloom
dates
• Shifts in U.S. Department of
Agriculture plant Hardiness Zones
• More frequent summer drought
periods
of rainfall in a twenty-four hour period
(Hodgkins et al., 2002, 2006; Wolfe et
(Stack et al., 2005; Simpson et al., 2008).
al., 2005; Wake and Markham, 2005;
Additional localized data analyzed in
4-4
• Lake ice out 9-16 days earlier
Hayhoe, 2006; Frumhoff et al., 2008;
the northern states has shown similar
Backlund et al., 2008)
F O R G I N G
L I N K
T H E
H I S T O R I C
A N D
P R O J E C T E D
C L I M A T E
C H A N G E
FIGURE 4-3
Increase in the
Heavy Rainfall Events
1958-2007
(Karl 2009)
Steadily rising average and extreme
shows the percent increase of the largest
temperatures observed in the record of
one percent of all storm events in the
historical data, combined with increases
U.S. over the last 50 years.
in average precipitation and the number
Since 2005, researchers in New
of extreme storm events (especially rain
England have documented 6 major
storms in the Northeast and Midwest
storms crossing the states of New
regions), provide strong evidence of
Hampshire, Vermont and Maine that
measureable changes in climate. The
have all exceeded the amount of rain-
World Meteorological Organization
fall expected for the 100-Year Storms,
(WMO) states that no single storm can
based on historical precipitation records.
be attributed directly to the increase in
Two of those storms, one in the fall
overall global temperatures. However,
of 2005 and another in the spring of
in looking at recent trends in New
2006, caused more than $1,300,000 in
England data, there is a higher fre-
related property damage from associated
quency of storms with greater amounts
flooding. Since 2005, record breaking
of precipitation which parallels trends
storm events with associated flooding
over the same time period for increases
have also occurred in the Midwest, Great
in regional average temperatures and
Lakes, and Northeast regions (Simpson,
associated average rainfall. Figure 4-3
2008; Wake, 2009; Karl, 2009).
F O R G I N G
T H E
L I N K 4-5
H I S T O R I C
A N D
P R O J E C T E D
C L I M A T E
C H A N G E
PROJECTED CHANGES
IN CLIMATE
FIGURE 4-4
IPCC Future Scenarios
The IPCC considered a series of possible
(Nakicenovic
et al. 2000)
future outcomes in regards to energy,
technology and land use in concert
with various economic and population
growth scenarios. (Nakicenovic et al.
2000) The following graph shows how
these future scenarios would influence
the release of CO2 (Figure 4-4). A1Fi is
considered “business as usual” or the
FIGURE 4-5
Midwest Shift in
Seasonal Precipitation,
Late 21st century
(Kling et al., 2003)
4-6
F O R G I N G
T H E
L I N K
H I S T O R I C
P R O J E C T E D
C L I M A T E
C H A N G E
“fossil fuel-intensive” economic growth
24-hour and multi-day downpours, and
scenario, and projects CO2 concentra-
thus flooding, may continue to increase
tions reaching 940 ppm by the end of
(Kling et al., 2003).
this century – three times today’s levels.
Figure 4-6 depicts possible future
B1 is also a high economic growth sce-
scenarios developed by the IPCC in
nario but also includes economic shifts
relation to precipitation patterns for
to less intensive fossil fuel use as well
the northern tier of the U.S. through
as introductions of resource efficiency
the year 2099. As shown, this region
strategies and technologies. Under this
will experience significant increases in
scenario, CO2 atmospheric concentrations are projected to be at 550 ppm by
projected rainfall changes in the Great
Lakes states, under a highly fossil fuel
intensive scenario, is likely to bring
wetter winters with more precipita-
8%
6%
4%
2%
0%
shows that while Pthe
R E CI Ptotal
I TAT I Oannual
N I N T E N S I TaverY
INCREASE
RELATIVE TO 1961-1990 AVG
10%
rainfall amounts
will shift. The projec8%
tions include
increasing precipitation
as rainfall6%during winter seasons and
summer months
are forecasted to expe4%
rience decreasing
rainfall.
2%
1.5
1
0.5
0
2010-2039
2040-2059
2070-2099
may eventually
grow drier
because
(Bates, 2008)
1
0.5
2010-2039
> 2”
Lower Emissions
Higher Emissions
Overall,
the Great Lakes region
0%
1.5
2070-2099
2
ADDITIONAL EVENTS PER YEAR
RELATIVE TO 1961-1990 AVG
Higher Emissions
2040-2059
NUM B ER O F D AY S W I TH RAI N
14%
age precipitation
Lowerlevels
Emissions are unlikely to
Lower Emissions
0
2010-2039
century(Kling et al, 2003). Figure 4-5
MAXIMU M PR E C IPITAT IO
Lower Emissions
Higher Emissions
20%
15%
10%
5%
0%
2010-2039
> 2”
2040-2059
2070-2099
2010-2039
ADDITIONAL EVENTS PER YEAR
RELATIVE TO 1961-1990 AVG
Lower Emissionsand transpiraincreased evaporation
Higher Emissions
tion in a1.5
warmer climate. Under a high
CO2 emissions scenario, the Union
1
of Concerned
Scientists projects a 30
percent reduction in soil moisture as
0.5
well as lower
long-term average lev-
els of surface and ground water. The
M AX I M UM PREC I PI TATI O N I N 5 D AY S
INCREASE IN AMT OF PRECIPITATION
RELATIVE TO 1961-1990 AVG
N U MBE R O F DAYS WI T H R A I N
25%
Lower Emissions
Higher Emissions
20%
15%
10%
0
2070-2099
paradox is that
even in2040-2059
a considerably
2010-2039
2070-2099
5%
0%
2010-2039
2040-2059
2070-2099
drier summer climate, the frequency of
F O R G I N G
2040-2059
25%
increases in rain or snow are unlikely
to compensate
for the drying effects of
2
DAYS WIT H
Midwest US
Precipitation Higher
Scenarios
Emissions
10%
tion as rain by the second half of the
change, 12%
the seasonal distribution of
Lower Emissions
Higher Emissions
ADDITIONAL EVENTS PER YEAR
RELATIVE TO 1961-1990 AVG
Concerned Scientists determined the
12%
2
INCREASE IN AMT OF PRECIPITATION
RELATIVE TO 1961-1990 AVG
The Kling et al. and the Union of
FIGURE
N U MBE R4-6
OF
PREC I PI TATI O N I NTENS I TY
14%
INCREASE
RELATIVE TO 1961-1990 AVG
2100 (NECIA 2006).
N I NTEN SIT Y
2059
A N D
T H E
L I N K 4-7
2040-2059
H I S T O R I C
A N D
P R O J E C T E D
C L I M A T E
C H A N G E
FIGURE 4-7
Minnesota’s
Migrating Climate
(Kling, 2005)
the frequency and intensity of extreme
summer days exceeding 100 degrees F
precipitation events, especially under a
will increase.
higher emissions scenario.
• Winter precipitation will increase with
The possible effects of a changing
climate also include the potential
of rain as compared to snow, increas-
for climate migration. According
ing the likelihood of high flow events
to a study by Kling, et al. using the
in the winter months.
IPCC scenarios, summer weather
patterns characteristic of the North
Central region are anticipated to have
• Summer precipitation will remain
similar.
• Snow-pack will not last as long and
migrated south by the year 2095. As
will melt earlier in the spring, resulting
such, and illustrated in Figure 4-7,
in increasing spring-runoff.
summer temperature and precipita-
• Higher summer temperatures and
tion levels normally representative of
corresponding increases in evaporation
Michigan could eventually be found in
rates will result in extended low-flow
Arkansas (Kling et al, 2003).
conditions in streams.
• The frequency of intense storms and
CONCLUSIONS
storms with greater amounts of precipi-
Climate research provides evidence that,
by mid-century across the northern tier
tation will increase.
• Rising temperatures will cause evapo-
and other parts of the U.S., the following
ration rates to increase, reducing soil
can be expected to occur:
moisture in summer.
• Temperatures will rise, with winters
warming the fastest.
• The frequency of short-term summer
droughts will increase.
• The number of summer days exceed-
4-8
more precipitation falling in the form
• The combination of sea-level rise and
ing 90 degrees F will increase. In cities,
increasing storm intensities will result in
which are heat-sinks, the number of
a greater frequency of coastal flooding.
F O R G I N G
T H E
L I N K
H I S T O R I C
A N D
P R O J E C T E D
REFERENCES
C L I M A T E
Frumhoff, P.C., McCarthy, J.J., Melillo,
J.M., Moser, S.C., Wuebbles, D.J.,
Archer, D. (2005). Fate of fossil fuel CO2
Wake, C., & Spanger-Siegfried, E.
in geologic time. Journal of Geophysical
(2008). An integrated climate change
Research, 110 (C09S05), 6.
assessment for the Northeast United
Backlund, P., Janetos, A., & Schimel,
D. (2008, May). The Effects of
Climate Change on Agriculture,
Land Resources, Water Resources
States. Mitigation and Adaptation
Strategies for Global Change, 13 issue
5-6(5-6), p. 419-423.
Hayhoe, K., Wake, C., Anderson,
and Biodiversity in the United
B., Bradbury, J., DeGaetano, A.,
States. United States Department of
Huntington, T., Liang, X., et al. (2006).
Agriculture. Retrieved from www.glo-
Climate Change in the U.S. Northeast.
balchange.gov/publications/reports/
UCS Publications.
scientific-assessments/saps/304
Bates, B., Kundzewicz, Z., Wu, S. &
Hegerl, G. C., Crowley, T. J., Allen, M.,
Hyde, W. T., Pollack, H. N., Smerdon,
Palutikof, J. (2008). Climate Change
J., & Zorita, E. (2007). Detection
and Water, IPCC Technical Paper VI.
of Human Influence on a New,
Retrieved from www.ipcc.ch/pdf/techni-
Validated, 1500-Year Temperature
cal-papers/climate-change-water-en.pdf
Reconstruction. Journal of Climate,
Clark, P. U., Dyke, A. S., Shakun, J. D.,
Carlso, A. E., Clark, J., Wohlfarth, B.,
20(4), 650-666.
Hodgkins, G. A., & Dudley, R. W.
Mitrovica, J. X., Hostetler, S. W.
(2006). Changes in the timing of
& McCabe, A. M. (2009). The last
winter–spring streamflows in east-
glacial maximum. Science 325(5941),
ern North America, 1913–2002.
p. 710-714.
Geophysical Research Letters, 33(6).
Fischer. Hubertus., Wahlen, M., Smith,J.,
doi:10.1029/2005GL025593
Mastroianni, D., and Dec, B., (1999)
Hodgkins, G. A., James II, I. C., &
Ice Core Records of Atmospheric
Huntington, T. G. (2002). Historical
CO2 Around the Last Three Glacial
changes in lake ice-out dates as indica-
Terminations, Scripps Institution
tors of climate change in New England,
of Oceanography. Published by
1850- 2000. International Journal of
the American Association for the
Advancement of Science. Science, 283,
1712-1714
Climatology, 22(15), 1819-1827.
Intergovernmental Panel on Climate
Change. (2007). IPCC Fourth
Frumhoff, P.C., J.J. McCarthy, J.M.
Assessment Report: Working Group
Melillo, S.C. Moser, and D.J.
II Report “Impacts, Adaptation and
Wuebbles. 2007. Confronting Climate
Vulnerability”. Retrieved March 31,
Change in the U.S. Northeast:
2009, from www.ipcc.ch/ipccreports/
Science, Impacts, and Solutions.
ar4-wg2.htm
Synthesis report of the Northeast
C H A N G E
Karl, T. R., Melillo, J. M., & Peterson, T. C.
Climate Impacts Assessment (NECIA).
(2009). Global Climate Change Impacts
Cambridge, MA: Union of Concerned
in the United States (p. 188). US Global
Scientists (UCS)
Change Research Program. Retrieved
F O R G I N G
T H E
L I N K 4-9
H I S T O R I C
A N D
P R O J E C T E D
from http://downloads.globalchange.
C H A N G E
Simpson, M. H. (2006). Projected Impacts
gov/usimpacts/pdfs/climate-impacts-
from Climate Change on Low Order
report.pdf
Streams. PPT presented at the Society of
Kling, G., Hayhoe, K., Johnson, L.,
Lindroth, R., Magnuson, J., Moser, S.,
Polasky, S., Robinson, S., Shuter, B.,
Wetland Scientists National Meeting,
Holly Cross College, Worcester, MA.
Simpson, M. H. (2008). Water from the Hills:
Wander, M., Wilson, M., Wuebbles, D.,
The Need to Adapt is Now. PPT presented
Zak, D., (2003). Confronting Climate
at the Great Bay Estuary Guest Lecture
Change in the Great Lakes Region:
Series, Great Bay Estuary, NH.
Impacts on Our Communities and
Ecosystems. UCS/ESA: Cambridge, M
Lawler, J. J., Shafer, S. L.,White, D., Kareiva,
Stack L.J., Simpson M.H., Crosslin T.W.,
Spearing W.S., Hague E.P.M., (2005). A
point process model of drainage system
P., Maurer, E. P., Blaustein, A. R., &
capacity under climate change. Report
Bartlein, P. J. (2009). Projected climate-
presented to City of Keene (NH)
induced faunal change in the Western
Planning Department.
Hemisphere. Ecology, 90(3), 588-597.
Meehl, G. (2007). Contribution of Working
Solomon, S., Plattner, G., Knutti, R., &
Friedlingstein, P. (2009). Irreversible
Group I to the Fourth Assessment Report
climate change due to carbon dioxide
of the Intergovernmental Panel on
emissions. Proceedings of the National
Climate Change. In Climate Change: The
Physical Basis. Cambridge GB and New
York NY: Cambridge University Press.
NASA - Earth’s ‘Tipping Points’: How
Close Are We? (n.d.). Media Resources.
Retrieved August 10, 2010, from
Academy of Sciences, 106(6), 1704-1709.
Tans, P., 2010.NOAA/ESRL (www.esrl.
noaa.gov/gmd/ccgg/trends/) and Dr.
Ralph Keeling, Scripps Institution of
Oceanography (scrippsco2.ucsd.edu/).
Wake, C., & Markham, A. (2005).
www.nasa.gov/topics/earth/tipping_
Indicators of Climate Change in
points.html
the Northeast. Clean Air Cool Planet.
Nakicenovic, N. et al (2000). Special
Retrieved from www.cleanair-
Report on Emissions Scenarios: A Special
coolplanet.org/information/pdf/
Report of Working Group III of the
indicators.pdf
Intergovernmental Panel on Climate
Wake, C. (2009). Climate Change in the
Change, Cambridge University Press,
Northeast: Past, Present and Future.
Cambridge, U.K., 599 pp.
Presented at the New England
Petit J.R., J. Jouzel, D. Raynaud, N.I.
Barkov, J.M. Barnola, I. Basile, M.
Bender, J. Chappellaz, J. Davis,
G. Delaygue, M. Delmotte, V.M.
4-10
C L I M A T E
Federal Partners Interagency Meeting
on Climate Change Adaptation,
Boston, MA.
Wolfe, D., Schwartz, M., Lasko, A.,
Kotlyakov, M. Legrand, V. Lipenkov, C.
Otsuki, Y., Pool, R., & Shaulis, N.
Lorius, L. Pépin, C. Ritz, E. Saltzman,
(2005). Climate Change in Shifts
and M. Stievenard. 1999. Climate
in Spring Phenology of Three
and atmospheric history of the past
Horticultural Woody Perennials in
420,000 years from the Vostok Ice
Northeastern USA. International Journal
Core, Antarctica. Nature 399:429-436.
of Biometerology, 116, 303-309.
F O R G I N G
T H E
L I N K