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Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Chapter 12: Climate and Glaciation
• Lonnie Thompson trekks to Himalaya, the Andes, and beyond to study ice.• Do you know why ? What is he studying ?
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Chapter 10: Climate and Glaciation• No scientist has taken bigger risks above 18000 ft, risking blood clots, temporary blindness, frostbite, and hurricane-force winds.
• Risks to gather measurements and help us understand current climate trends.
• Lonnie Thompson reconstructed a meticulous calendar of temperatures and dates from isotope measurements in ice.
• He found that the Earth's frozen ice stores a history of climate changes as far back as 750,000 yrs.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
The Earth's Climate
• What is climate ?
Climate is described by the average weather conditions at a point on the Earth's surface daily, yearly or longer.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
The Earth's Climate
• The climate includes many components of the Earth's system and interactions between them.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
The Earth's Climate
• The atmosphere is layered with different temperature values in each
• Temperatures in other Earth systems such as ocean water, biosphere, lithosphere, & crysophere all contribute to an average surface temp.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Glaciers
• The cryosphere comprises all of the ice on the Earth.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Glaciers
• Most of the Earth's ice is found in Antarctic continental glacier.• Where are some other continental glaciers ?
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
• Greenland is the second largest glacier on Earth and with Antarctica cover 10% of the Earth's land mass.
• These glaciers store 75% of the world's fresh water.
• While Greenland has 2.6 mill cubic km of ice, it is dwarfed by Antarctica which has 30 mill cubic km (90%) of the Earth's cryosphere.
• Antarctica's ice is ~4000 m thick!
Glaciers
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Glaciers
• Snow melt is the source of much of the fresh water in the hydrosphere.
• Snowfall is 60-70% of all annual precipitation which melts in spring into rivers and streams.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Glaciers
• The cryosphere includes sea ice which grows in volume in the winter and shrinks in the summer.
• This satellite picture (left) shows sea ice flowing through the Bering Strait in May 2002.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Solar energy input to Earth’s surface is342 W/m2.
Heat flowing out of Earth’sdeep interior is only 0.06 W/m2.
Therefore, heat radiating from Earth must balance solar input.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
• The Earth reflects radiation not absorbed by the atmosphere & surface• Strong greenhouse gases reflect this radiation back to the Earth and prevent it from leaving the atmosphere.
Heat and Radiation from the Sun
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
The Balance of Heat Flow into/out of the Earth
• Water vapor gives positive feedback, that is, it is a greenhouse gas and its presence prevents escape of the Earth's excess radiation.
• Albedo gives positive feedback. Albedo measures the Sun's reflected energy from the cryosphere. As the Earths' temp rises, and glaciers melt, the albedo decreases. This process reduces reflected radiation escape.
• Radiation damping can give negative feedback. Infrared energy escape is increased if temperatures rise. This process slows large temperature fluxuations and keeps the oceans from freezing or boiling off.
• Plant growth gives negative feedback. Conversion of CO2 into organic matter reduces greenhouse gasses in the atmosphere and allows for more escape of radiative energy.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
What Would our Planet be like Without Greenhouse Gases ?
• The Earth rotates (1 day) much faster than the Moon (30 days) which evens out its temperature
• The Moon's temp changes from 130 C in the day to -170 C at night! This would be very uncomfortable!• The Earth's glaciers increases its albedo to 31% where the Moon's albedo is only 7%.
• However without any greenhouse gases, the Earth's surface temp would be very cold, -19 C (-2 F) and would freeze all our oceans.
• Some greenhouse gases are necessary to moderate strong fluctuations in surface temperature from Solar radiation
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Local Climate Variations
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Antarctic Ice Sheet
• Today many scientists work to study ice cores in Anarctica
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
• Russian scientists at Vostok station carefully remove an ice core at 3500m altitude (T is about -55C !)
• Below inspection of the core is done in a cold lab.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Past Glaciationfrom Ice Cores
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Temperature relative to present climate
(°C)
Thousands of years before present
Relative carbon dioxide
and
methane concentrations
High
Low
Key:TemperatureCO2
Methane
There is a decline in both temperature and greenhouse gas concentrations during glacial periods… …and a rapid
rise duringdeglaciation.
Climate has been relatively warm andstable during the last 10,000 years.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Glacial and Temperature Cycles
• White shows evidence indicating the extent of the Wisconsin glacier in the Great Lakes during it's maximum about 18000 yrs ago and was ~3 km thick.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
GEOLOGIC RESERVOIRS
Fossilorganiccarbon
Rockcarbonates
Fossil-fuel
burning(5.3 Gt/yr)
OCEAN
Cement production (0.1 Gt/yr)
Land-use change:
deforestation,agriculture(1.7 Gt/yr)
Land uptakeBy new plantgrowth(1.9 Gt/yr)
Ocean uptake by air-sea gas
exchange(1.9 Gt/yr)
Terrestrial biosphere
LAND
ATMOSPHERE
Human activities releasea total of 7.1 Gt of carbon into the atmosphere each year.
New plant growth andair-sea gas exchangeremove 3.8 Gt/yr,…
…yielding a netatmosphericincrease of3.3 Gt/yr.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and CompanyYears
Temperature
CO2
concentration
Global temperature anomaly
(°C)
A recent warming trend correlateswith the increase in CO2.CO
2 concentration
(ppm)
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and CompanyYears
Temperature
CO2 concentration
The 20th-century is clearly anomalous when compared with the last millennium.
Northern Hemisphere
temperature
anomaly (°C)
CO
2 concentration
(ppm)
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Arctic sea ice 1995-2007
(National Snow and Ice Data Center, Boulder)
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Arctic sea ice 2005-2007
(National Snow and Ice Data Center, Boulder)
4.3 million sq km4.3 million sq km
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Receding Glacier
South Cascade Glacier, Washington
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Meteorites found in Arctic Glaciers• The easiest place to locate dark, rocky meteorites is in Antarctic Ice
Sheet• A small number of meteorites appear to have come from the Moon
and Mars• Several of these appear to have come from Mars
martian meteorite
lunar meteorite
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Global Warming
• Global warming is a physical measurement that the Earth's surface temperatures are rising beyond normal fluctuations.
• Global warming can have many effects on our environment:
- increase atmospheric temperature- melt glacial ice- prevent escape of the Sun's excess radiation- harm habitat environments like polar bears- create drastic changes in our climate (extreme hot and cold seasons)- and remove our only evidence of past climate history !
What can we do about this at home ?
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
The Global Energy ChallengeRoel Snieder
Photo: USFWS/Susanne Miller
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Developing countries
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
… and our energy use
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
How do Geologist Find Old Glaciers Boundaries ?
Glaciers leave clues ...
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
• Glacial striations on a rock from stones grinding at the base of a heavy ice sheet leave these shiny linear marks on the bedrock below.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Glacial Characteristics
• Glaciers flow downhill as a solid mass that creates channels, and walls made of ground up rock debris known as a merraine.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Erosional Landscapes
• Erosional landforms produced by valley glaciers include: – U-shaped valleys
– Hanging valleys
• Smaller tributary glacial valleys left stranded above more quickly eroded central valleys
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
U-shaped valleys
Hanging valleys
Erosional Landscapes
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Glacial Deposits• Sediment-laden streams emerging
from ends of glaciers have braided channel drainage patterns
• Outwash landforms include drumlins, eskers, kettles and kames
• Drumlins give can tell us what direction a glacier moved.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
The History of Energy Consumption in the US over past 150 yrs
How much oil is available in the world for our use ?Is it infinite ?
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Peak oilPeak oil
N.B. based on USGS estimates, these are among the most optimistic (Energy Information administration)
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Declining production (1)
resource depleted
Time
Production
supply
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Declining production (2)
production gap!
Time
Production
demand
supply
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Oil Peak, Oil Panic ?(Study by Amos Nur - Stanford)
U.S., Canada, Japan, Germany, France, Italy, UK, are the biggestconsumers of oil reserves worldwide.
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Oil ConsumptionWorld wide by country
The US uses more oil thanall other countries combined
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Countries with highest per capita income seeking oil from countries holding the oil wells/reservoirs (Saudi Arabia, Iraq, Venezuala).
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
New find in Gulf of Mexico(Jack No. 2 test well)
• up to 3-15 billion barrels of oil
• US consumption 20 million barrels/day
• 5 months - 2 years
• reservoir is 8 km under sea level
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Non-convenional reserves(excluding gas and coal)
Produced (gone)
Proved Reserves
Undiscovered(?)
EORExtra Heavy Oil& Tar Sands Shale Oil
0 1 2 3 4 5 6 7 8 9 10
Trillions of Barrels Recoverable
Years Supply at2005 Production
Unconventional petroleum resources:(more difficult & dirty, and therefore expen$ive)
Conventional(“easy”)
0 25 50
(Courtesy of Joe Stefani)
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Non-conventional oil
from National Geographic, June 2004
Tar Sand
HeavyOil
Oilshale
2 tons of tar sands produce 1 barrel of bitumen (~asphalt)
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Other Energy Resources• The metal uranium is used to power nuclear power
generators– Found with organic matter in sedimentary rocks
– Accounts for 10% of U.S. energy production
– Leaves radioactive waste as by-product
• Hydroelectric power provides about 4% of U.S. energy needs– Renewable and non-polluting
• Geothermal power provides about 0.2% of U.S. energy needs
• Other renewable, non-polluting energy sources are wave/current power, solar power, wind power, and hydrogen fuel cells– As fossil fuel supplies dwindle, these sources become more important
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Other Energy Resources• The metal uranium is used to power nuclear power
generators– Found with organic matter in sedimentary rocks
– Accounts for 10% of U.S. energy production
– Leaves radioactive waste as by-product
• Hydroelectric power provides about 4% of U.S. energy needs– Renewable and non-polluting
• Geothermal power provides about 0.2% of U.S. energy needs
• Other renewable, non-polluting energy sources are wave/current power, solar power, wind power, and hydrogen fuel cells– As fossil fuel supplies dwindle, these sources become more important
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
First solar 2 MW arrayFt. Carson, CO
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Research: efficient solar cells
1 mm
http://gcep.stanford.edu/research/solar.html
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
Alternative Energy Sources: Wind power
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
What can I do as consumer?
Lighting Transportation Appliances
Jordan, The Essential Earth 1e © 2008 by W. H. Freeman and Company
What can I do as citizen?
• Ask: what is our energy plan?
• Start a discussion in your community.
• Demand that the United States becomes a world-leader in responsible use of energy.
“That which we are, we shall teach, not voluntarily but involuntarily.” [Emerson]
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