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Pollution of Lakes and Rivers
Chapter 14:
Greenhouse gas emissions and a
chnaging atmosphere: tracking the
effects of climatic change on water
resources
Copyright © 2008 by DBS
Contents
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Climate change, pollution, and paleolimnology
The need for paleoclimatic data
Human-influenced climatic change: our greatest environmental problem
Paleolimnological methods to track climate change
Climate change and pollution
Greenhouse Gas Emissions
Climatic Change, Pollution, and Paleolimnology
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Climate changes have myriad effects on water quality
Greenhouse Gas Emissions
The Need for Paleoclimatic Data
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Only 200 yrs of direct temperature measurements
Variable observational standards
Most from major Western European cities – ‘urban heat island effect’
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Longer term measurements needed to answer the following questions:
– What are the types and ranges of natural variability at different
time-scales?
– How have human influences affected climate?
– Has the frequency and intensity of extreme climate events
increased?
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Also useful for modeling future changes
Greenhouse Gas Emissions
Human-Influenced Climatic Change
NATURAL:
Younger Dryas (12,800 yr BP):
Earth returned very quickly into near
glacial conditions
Ended extremely abruptly
(after 1,200 yrs),
temperature increased by as
much as 10°C in 10 years
Glacial termination:
15,000 years ago, the Earth started warming
after ~ 100,000 of "ice age"
Greenhouse Gas Emissions
Human-Influenced Climatic Change
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Natural forcing mechanisms:
– Earth’s orbit (eccentricity, obliquity, precession)
– Solar activity
– Ocean circulation patterns
– Volcanic activity
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How do we know climate has changed?
– Landscape features
– Dinosaur bones
– Plant and animal remains
Greenhouse Gas Emissions
Human-Influenced Climatic Change
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Man-made influences: burning fossil fuels, deforestation
Greenhouse Gas Emissions
Human-Influenced Climatic Change
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Keeling Curve
What could be
responsible for
this seasonal
up-down
fluctuation?
Since 1958
atmospheric
carbon dioxide has
risen by more than
15%
http://www.cmdl.noaa.gov/ccgg/index.html
Greenhouse Gas Emissions
Human-Influenced Climatic Change
Animation
http://news.bbc.co.uk/2/shared/spl/hi/sci_nat/04/climate_change/html/greenhouse.stm
Greenhouse Gas Emissions
Paleolimnological Methods to Track Climate Change: Biological
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Direct inferences
– Early work by palnologists and entomologists
– Paleolimnology since 1990s – species distributions, transfer functions
– Chironomids - Walker et al (1991)
– Diatoms - Pienitz et al (1995)
– Cladocera - Lotter et al (1997)
– Ostracods - Curry & Delorme (2003)
From Walker et al. (1991)
Greenhouse Gas Emissions
Paleolimnological Methods to Track Climate Change: Biological
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Indirect inferences
– Tracking past lake and pond ice cover
– Tracking past river discharge
– Trees, water chemistry, and shifting ecosystem boundaries
– Links between lake water pH and climate
– Shifts in precipitation-evaporation (P/E) ratios
Greenhouse Gas Emissions
Paleolimnological Methods to Track Climate Change
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Greenhouse Gas Emissions
Paleolimnological Methods to Track Climate Change
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Greenhouse Gas Emissions
Paleolimnological Methods: Isotopes
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Stable isotopes (McCrea, 1950; Ito, 2001; Talbot, 2001; Leng and
Marshall, 2001; Leng et al, 2006)
Fractionation of oxygen-16 and oxygen-18 isotopes (16O/18O ratio)
16O more easily evaporated, water is enriched with 18O
Signatures from lipids (Huang et al 2004), ostracod shells (Donovan et al,
2002) or diatom frustules (Jones et al, 2004; Rosqvist et al, 2004)
Greenhouse Gas Emissions
Paleolimnological Methods: Geological Techniques
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Chivas & Holmes (2002)
Francus et al (2002)
Lamoureux et al (2006)
Last and Ginn (2005)
Smith et al (2004)
Greenhouse Gas Emissions
Climate Change and Pollution
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Climate influences every water-quality issue addressed so far:
Higher temperatures:
• speed up chemical and biological reactions
e.g. P loading (Blenckner et al, 2006)
• Stronger and more prolonged thermal stratification
• Enhanced periods of deepwater anoxia
• Concentration of pollutants through evaporation of water
(Schindler and Donahue, 2006)
• Changes in biodiversity
Greenhouse Gas Emissions
Climate Change and Pollution
Alteration of atmospheric transport patterns:
• Transport of acidic deposition
• Grasshopper effect of cycling POPs
• Melting of mountain glaciers (Blais et al, 2001) mobilizes local pollution
• Cumulative and synergestic effects of higher loads in aquatic ecosystems
(Wrona et al, 2006)
Wind and precipitation:
• Erosion changes (Kelley et al, 2006)
Drought:
• Decline in pH, DOC and increased UV penetration (Yan et al, 1996)
Greenhouse Gas Emissions
Summary
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Reconstructing climate is not simple
Several proxy methods are available
References
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Alverson et al (1999)
Battarbee (2000)
Blais et al (2001)
Blenckner et al (2006)
Bradley (1999)
Brooks (2006)
Chivas and Holmes (2003)
Cohen (2003)
Curry and Delorme (2003)
DeDekker et al (1988)
Donovan et al (2002)
Flannery, T. (2005)
Goose et al (2005)
Goose et al (2006)
Huang et al (2004)
Ito (2001)
Jones et al (2004)
Kelley et al (2006)
Leng et al (2006)