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In 1988 Jim Hansen published a study that modeled global temperatures as a function of carbon emissions. The graph, shown here, and cleaned up from the original journal scan, shows Hansen’s computer models for temperature as a function of carbon emissions. The white solid line indicates observed temperatures through 1988, when the study was published. The orange dotted line is a computer model of temperatures assuming carbon emissions continued to be produced exponentially The blue dashed line assumed carbon emissions would be moderately curtailed, And the yellow dotted line assumed carbon emissions would be drastically curtailed. What does the actual data look like? It almost exactly follows the drastic reduction projection, even though carbon emiisions have basically gone unchecked since 1988. So, past predictions have tended to overestimate the increase in global temperatures.
Global Warming For more detail visit: http://bit.ly/b6Lotq http://www.jorbit.com/
Introduction Is the world getting warmer? If so, are the actions of mankind to blame for earth’s temperature increases? What can/should be done about these issues? Are the potential resolutions worth the cost to implement them?
History of Earth’s Climate Earth formed ~4.6 billion years ago Originally very hot Sun’s energy output only 70% of present Liquid water present ~4.3 billion years ago (zircon dating) Much of earth’s early history erased during late heavy bombardment (~3.9 billion years ago)
History of Earth’s Climate Life appeared ~3.8 billion years ago Photosynthesis began 3.5-2.5 billion years ago Produced oxygen and removed carbon dioxide and methane (greenhouse gases) Earth went through periods of cooling (“Snowball Earth”) and warming Earth began cycles of glacial and interglacial periods ~3 million years ago
Earth’s Temperature
Earth’s Temperature
Earth’s Temperature
Earth’s Temperature
Greenhouse Effect Sun
Earth’s Atmospheric Gases >99% <1% Non- Greenhouse Gases Greenhouse Gases
Sun Runaway Greenhouse Effect 97% carbon dioxide 3% nitrogen Water & sulfuric acid clouds Temperature: 860°F
Carbon Dioxide
170 220 270 320 370 420 200000 400000 600000 Time (YBP) CO2 (ppm) Vostok Ice Core Dome Concordia Carbon Dioxide Levels 0
Worldwide Carbon Emissions Carbon (109 metric tons) 0 1 2 3 4 5 6 7 8 1750 1800 1850 1900 1950 2000 Year
Annual Carbon Emissions 1955 1965 1975 1985 1995 2005 0 4 6 8 2 Year Carbon (109 metric tons)
Future Carbon Dioxide Levels Increasing CO2 emissions, especially in China and developing countries Likely to double within 150 years: Increased coal usage Increased natural gas usage Decreased petroleum usage (increased cost and decreasing supply)
Kyoto Protocol Adopted in 1997 Cut CO2 emissions by 5% from 1990 levels for 2008-2012 Symbolic only, since cuts will not significantly impact global warming
Past Temperatures
-0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1880 1900 1920 1940 1960 1980 2000 Year D Mean Temperature (°C) Recorded Worldwide Temperatures
Historic Los Angeles Temperatures
2009 Temperature Changes Compared to 1951-1980 2009 Temperature Changes Compared to 1951-1980
Past Temperatures Measurement Proxy – a method that approximates a particular measurement (e.g., temperature) Tree rings Ice cores Pollen records Plant macrofossils Sr/Ca isotope data Oxygen isotopes from speleothem calcite (stalactites and stalagmites)
Temperature History of the Earth Little ice age (1400-1840) – 1°C cooler Medieval warm period (800-1300) – 1°C warmer than today Cool/warm cycles occur ~1,500 years Affect mostly Northeastern U.S. and North Atlantic Mostly due to changes in thermohaline circulation Dramatic shutdown of thermohaline circulation occurred 8,200 years ago as a large lake in Canada flooded the North Atlantic
Main Ocean Currents Adapted from IPCC SYR Figure 4-2
Temperature History of the Earth For the past 3 million years, the earth has been experiencing ~100,000 year long cycles of glaciation followed by ~10,000 year long interglacial periods These climate periods are largely the result of cycles in the earth’s orbit – precession, obliquity, and eccentricity
Orbital Parameters: Precession Perihelion Apehelion
Orbital Parameters: Obliquity
Orbital Parameters: Eccentricity Minimum: 0.005 Maximum: 0.061 Not to scale! To Scale!
Orbital Parameters & Earth’s Climate Age (kya) 1000 900 800 700 600 500 400 300 200 100 0
Temperature History of the Earth For the past 3 million years, the earth has been experiencing ~100,000 year long cycles of glaciation followed by ~10,000 year long interglacial periods Last ice age began to thaw 15,000 years ago, but was interrupted by the “Younger Dryas” event 12,900 years ago
Younger Dryas Event -55 -50 -45 -40 -35 -30 -25 0 5 10 15 20 Age (kya) Temperature (°C) 0.05 0.10 0.15 0.20 0.25 0.30 0.35 Snow Accumulation (m/yr)
Younger Dryas Event -44 -43 -42 -41 -40 -39 -38 -37 -36 -35 -34 d18O (Greenland) -8.0 -7.5 -7.0 -6.5 -6.0 -5.5 -5.0 -4.5 -4.0 10 11 12 13 14 15 16 d18O (China) Younger Dryas Age (kya)
Temperature History of the Earth Middle Pliocene (3.15 to 2.85 million ya) Temperatures: 2°C higher than today. 20°C higher at high latitudes 1°C higher at the Equator Sea levels were 100 ft higher Causes CO2 levels that were 100 ppm higher Increased thermohaline circulation
Temperature History of the Earth Eocene (41 million years ago) Opening of the Drake Passage (between South America and Antarctica). Increased ocean current exchange Strong global cooling First permanent glaciation of Antarctica ~34 million years ago
Temperature History of the Earth Paleocene Thermal Maximum (55 mya) Sea surface temperatures rose 5-8°C Causes Increased volcanism Rapid release of methane from the oceans
Temperature History of the Earth Mid-Cretaceous (120-90 mya) Much warmer Breadfruit trees grew in Greenland Causes Different ocean currents (continental arrangement) higher CO2 levels (at least 2 to 4 times higher than today, up to 1200 ppm)
Breecker D O et al. PNAS 2010;107:576-580 6000 5000 4000 3000 2000 1000 0 30 60 90 Atmospheric CO2 Concentration (ppmV) Continental Glaciation (Paleolatitude) 400 300 200 100 0 Paleozoic Mesozoic Cenozoic S D Carb P Tr J K Pg Ng A Compilation of Phanerozoic Atmospheric CO2 Records
Recent Temperature Changes
“Hockey Stick” Controversy 1000 1200 1400 1600 1800 2000 -0.8 Year -0.6 -0.4 -0.2 0 0.2 0.4 0.6 Temperature Change (°C) Direct temperature measurements Mann et al. 1999
The Problem with Tree Rings 1000 1200 1400 1600 1800 2000 -0.6 Year -0.5 -0.4 -0.3 0 0.1 0.2 0.3 Temperature Change (°C) -0.2 -0.1 Jones et al. 1998 Briffa et al. 1999 Mann et al. 1999
What Influences Tree Rings? Temperature Rainfall Carbon dioxide concentration
Mann et al. 1999 Esper et al. 2002 800 1000 1200 1400 1600 1800 -2 -1 0 1 2 Temperature Change (°C) 2000 Year Is the Hockey Stick Correct?
Is the Hockey Stick Correct? -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0 400 800 1200 1600 2000 Year Temperature Change (°C)
U.S. National Academy of Sciences: June 2006 1000 1200 1400 1600 1800 2000 -0.8 Year -0.6 -0.4 -0.2 0 0.2 0.4 0.6 Temperature Change (°C)
-1.0 -0.5 0.0 0.5 1.0 1.5 1980 1990 2000 Year -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1980 1990 2000 Year Temperature Cgange (°C) Atmospheric Temperatures Troposphere Stratosphere
170 220 270 320 370 0 200000 400000 600000 Time (YBP) CO2 (ppm) Antarctica 25 26 27 28 29 30 31 SST (°C) Tropical Pacific CO2 Concentration Vs. Temperature
Consequences of Global Warming
Global Warming Primarily Impacts the Northern Hemisphere -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 1920 1960 2000 Year Temperature Change (°C) 1920 1960 2000 Year Northern vs. Southern Latitude Land vs. Ocean Northern Hemisphere Southern Hemisphere Land Ocean
2009 Temperature Changes Compared to 1951-1980
Ice Sheets Melting? GRACE (gravity measured by satellite) found melting of Antarctica equivalent to sea level rise of 0.4 mm/year (2 in/century) Zwally, 2005 (satellite radar altimetry) confirmed Antarctica melting Greenland ice melting on exterior, accumulating inland (higher precipitation)
Melting Glaciers – Mt. Kilimanjaro
1000 800 600 400 200 0 -200 -400 -600 2003 2004 2005 Ice Mass (km3) Year Changes in Antarctica Ice Mass
Rise in Sea Levels? Present rate is 1.8 ± 0.3 mm/yr (7.4 in/century) Accelerating at a rate of 0.013 ± 0.006 mm/yr2 If acceleration continues, could result in 12 in/century sea level rise Scenarios claiming 1 meter or more rise are unrealistic
Changing Sea Levels 1700 1750 1800 1850 1900 1950 2000 -20 -10 0 10 20 Relative Sea Level (cm) Adapted from IPCC SYR Figure 2-5 Amsterdam, Netherlands Brest, France Swinoujscie, Poland
Time (KYBP) Sea Level (m) 20 0 -20 -40 -60 -80 -100 -120 Sea Levels for 450,000 Years 450 400 350 300 250 200 150 100 50 0 25 26 27 28 29 30 31 SST (°C) Tropical Pacific
Increase in Hurricanes? Two studies showed the total number of hurricanes has not changed However, the intensity of hurricanes has increased (more category 4 and 5 hurricanes and cyclones) Probably due to higher sea surface temperatures (more energy) Difficult to know if this trend will continue
How Much Temperature Increase? Some models propose up to 9°C increase this century Two studies put the minimum at 1.5°C and maximum at 4.5°C or 6.2°C Another study puts the minimum at 2.5°C
Wildlife Effects Polar Bears Require pack ice to live Might eventually go extinct in the wild Sea turtles Breed on the same islands as their birth Could go extinct on some islands as beaches are flooded Other species may go extinct as rainfall patterns change throughout the world
Effect on Humans Fewer deaths from cold, more from heat Decreased thermohaline circulation Cooler temperatures in North Atlantic CO2 fertilization effect Precipitation changes Droughts and famine (some areas) Expanded arable land in Canada, Soviet Union
Potential Worldwide Precipitation Changes
Drought in Africa Lake Faguibine Lake Chad
Cost to Stabilize CO2 Concentrations 450 550 650 750 1800 1600 1400 1200 1000 800 600 400 200 0 Carbon Dioxide (ppm) Cost (Trillons U.S. Dollars)
Possible Solutions to Global Warming
Mitigation of Global Warming Conservation Reduce energy needs Recycling Alternate energy sources Nuclear Wind Geothermal Hydroelectric Solar Fusion?
Storage of CO2 in Geological Formations Depleted oil and gas reservoirs CO2 in enhanced oil and gas recovery Deep saline formations – (a) offshore (b) onshore CO2 in enhanced coal bed methane recovery Adapted from IPCC SRCCS Figure TS-7 3a 2 3b 1 4
Global Warming Myths
Global Warming Has Stopped? -0.2 0.0 0.2 0.4 0.6 0.8 1975 1980 1985 1990 1995 2000 2005 Year D Mean Temperature (°C) 2010
Volcanoes Put Out More CO2 Than Fossil Fuel Burning 0 2 4 6 8 10 Carbon (109 metric tons)
Global Warming is Caused by Sunspots -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1880 1900 1920 1940 1960 1980 2000 Year D Mean Temperature (°C) 0 50 100 150 200 250 Sunspots
Hadley Temperatures Vs. Sunspots -2.0 -1.5 -1.0 -0.5 0.0 1.0 1.5 1750 1800 1850 1900 1950 2000 Year D Mean Temperature (°C) 0 50 100 150 200 250 Sunspots
Global Warming is Caused by GCR -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 1950 1960 1970 1980 1990 2000 2010 Year D Mean Temperature (°C)
CO2 Vs. Sea Level CO2 Vs. Temperature 0 100000 200000 300000 400000 500000 Time (ybp) Rohling et al. 2009. Antarctic temperature and global sea level closely coupled over the last five glacial cycles. Nature Geoscience 2:500.
Global Warming is Due to Urban Heat Islands 2009 Temperature Changes Compared to 1951-1980
Mt. Kilimanjaro’ Glaciers are Melting Because of Global Warming
Global Warming Primarily Impacts the Northern Hemisphere -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 1920 1960 2000 Year Temperature Change (°C) Northern vs. Southern Latitude Northern Hemisphere Southern Hemisphere
Sea Levels Will Rise 5-6 ft? Present rate is 1.8 ± 0.3 mm/yr (7.4 in/century) Accelerating at a rate of 0.013 ± 0.006 mm/yr2 If acceleration continues, could result in 12 in/century sea level rise Scenarios claiming 1 meter or more rise are unrealistic Recently, the California State Lands Commission said that sea levels could rise 55 inches this century, inundating ports
Changing Sea Levels 1700 1750 1800 1850 1900 1950 2000 -20 -10 0 10 20 Relative Sea Level (cm) Adapted from IPCC SYR Figure 2-5 Amsterdam, Netherlands Brest, France Swinoujscie, Poland
How Much Temperature Increase? Global warming alarmists propose up to 9°C increase this century Two studies put the minimum at 1.5°C and maximum at 4.5°C or 6.2°C Another study puts the minimum at 2.5°C
Predictions Vs. Reality Hansen, J. 1988. Journal Of Geophysical Research 93:9241. Exponential Increase in carbon emissions Moderate reduction in carbon emissions Drastic reduction in carbon emissions Observed temps through 1988
Temperature Extrapolation DT (°C) 1.5 1.0 0.5 0 -0.4 Date 1980 2000 2020 2040 2060 2080 2100 2.5 2.0 1960
Conclusions Global warming is happening Most warming is probably the result of human activities There will be positive and negative (mostly) repercussions from global warming The costs to mitigate global warming will be high – better spent elsewhere?
For more detail visit: http://bit.ly/b6Lotq http://www.jorbit.com/ Thank you
Summary: global warming
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