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Environmental Problems
• Pollution
• Climate Change
Marine Pollution
• The introduction into the ocean by humans, substances that changes the physical, chemical or biological environment
Plastic Pollution
Video on the Problem: http://vimeo.com/21786927 One solution:: http://www.youtube.com/watch?v=cxV-NhiBqGU&feature=related
Fig. 15-27, p. 367
Fig. 15-28, p. 368
Each year 240 million gallons of used motor oil are dumped in storm drains…22x the amount spilled by Exxon Valdez
Marine Pollution
• Bioamplification – even small amounts of pollutants can have large effects
• DDT example
DDT in water 0.000003 ppm
DDT in fish-eating birds (pelicans) 25
ppm
Concentration has increased 10 million times
DDT in small fish (minnows) 0.5 ppm
DDT in small zooplankton 0.04 ppm
DDT in large fish
(needlefish) 2 ppm
Stepped Art
Fig. 15-32, p. 371
Marine Pollution
• Eutrophication– Excess nutrients in water also lead to problems
• HABs
• Oxygen depletion
© 2011 Pearson Education, Inc.
Determining Causes of Earth’s Climate Change
• Paleoclimatology • Proxy data – indirect
evidence using natural recorders of climate variability– Sea floor sediments– Coral deposits– Glacial ice rings– Tree rings– Pollen – Historical documents
© 2011 Pearson Education, Inc.
Natural Causes of Climate Change
• Solar energy changes, Variations in Earth’s Orbit, Volcanic eruptions, Movement of Earth’s Plates
• Linked to Pleistocene Ice Age, Little Ice Age, Medieval Warm Period
• Recent change unprecedented– More likely result of human activity than
natural causes
Global Warming: Causes
• “Green house effect”
Fig. 15-40, p. 378
Global Warming: Causes
• Green house gases (chloroflourocarbons =CFCs, methane, CO2, water vapor)
• Increasing CO2
– Deforestation & burning fossil fuels
Table 16.01
Fig. 15-31, p. 326
Today – CO2 highest it has been in 10 million years
© 2011 Pearson Education, Inc.
Ice Core Data
© 2011 Pearson Education, Inc.
Global Warming• The 8 warmest years have occurred since 1998• Earth’s surface temperature has risen 0.8°C (1.4°F) in last
140 years.
Fig. 15-43, p. 380
http://www.nsf.gov/news/special_reports/degree/how_do_we_know.jsp
Series of videos from National Science Foundation
© 2011 Pearson Education, Inc.
Changes in the OceansChanges in deep-water circulation • North Atlantic especially sensitive• Melting glaciers• Warmer surface waters
© 2011 Pearson Education, Inc.
Changes in the OceansPolar Ice Melting• Arctic amplification • Loss of more than
2 million square kilometers (800,000 square miles) of Arctic sea ice in last decade
• Loss of ice = enhanced warming due to lower albedo
Fig. 15-33, p. 327The North Pole 1996
© 2011 Pearson Education, Inc.
Changes in the OceansPolar Ice Melting• Arctic ice melting
affects polar bear survival.
• Food sources are dwindling for human Arctic dwellers.– Marine species migration
© 2011 Pearson Education, Inc.
Changes in the Oceans• Rising Sea Level –
already occurring • Main contributors:
– Melting of Antarctic and Greenland ice sheets
– Thermal expansion of ocean surface waters
– Melting of land glaciers and ice caps
– Thermal expansion of deep-ocean waters
© 2011 Pearson Education, Inc.
Global Sea Level Rise
The Maldives in the Indian Ocean – 80% pop. live only 1m above sea level
© 2011 Pearson Education, Inc.
Rising Sea Level
• Severely affect areas with gently sloping coastlines– U.S. Atlantic and Gulf Coasts
• Models predict rise between 0.5 and 1.4 meters (1.6 and 4.6 feet) by year 2100
• Affects coastal ecosystems like corals
Fig. 14-15, p. 340
Coral Bleaching Linked to Increased Temperatures
© 2011 Pearson Education, Inc.
Changes in the OceansOcean acidity increase• Some atmospheric
carbon dioxide dissolves in ocean water.– Acidifies ocean
• Threatens calcifying organisms– Coccolithophores– Foraminifers– Sea urchins– Corals
© 2011 Pearson Education, Inc.
Organisms Threatened by Increased Marine Acidity
Global Climate Change:Solutions?
• Alternative energy
Fig. 15-9, p. 355
Fig. 15-10a, p. 355
Fig. 15-10b, p. 355
