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Anthropogenic Global Warming

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1 Anthropogenic Global Warming
Is Earth at the tipping point? By: Geoffrey Pohanka

2 Objectives Examine in a thorough, yet understandable way, the theory of man made global warming Analyze plausibility Discuss what the primary driver of climate change is Give a prediction of the global climate for the next 20 years

3 Observation Temperatures on earth have been rising moderately….
So there is some “ warming” ….from whatever cause.

4 But recent warming is not global The warming is only in the Northern Hemisphere (Source: David Archibald)

5 Atmospheric temperatures have increased about
Atmospheric temperatures have increased about .2 degrees C since 1979 (using satellite data)

6 Despite this what do the supporters of the man made global warming theory (AGW) predict for the remaining years of the 21st Century?

7 Supporters of AGW predict temperatures will rise as much as 11
Supporters of AGW predict temperatures will rise as much as 11.5 degrees Fahrenheit by 2100

8 Polar ice and glaciers will melt
Polar ice and glaciers will melt. The Arctic sea ice could disappear completely within five years

9 Sea level will rise up to 20 feet by 2100

10 Hurricanes and their intensity will increase.

11 The rapidly changing climate will threaten species with extinction

12 Resulting in millions of climate refugees

13 But will this happen?

14 Words of wisdom/Rules of the road
Scientific Method…… Consists of theories and concepts that must be proven through observation. “Principles and procedures for the systematic pursuit of knowledge involving the recognition and formulation of a problem, the collection of data through observation and experiment, and the formulation and testing of hypotheses.” (Wikipedia)

15 “No amount of experimentation can prove me right, but a single experiment can prove me wrong.” Einstein

16 President Dwight D. Eisenhower gave two warnings in his farewell address to the nation, regarding:
“The military industrial complex” (and also…..) The “ domination of the nation’s scholars by Federal employment, project allocations, and the power of money is ever present – and is to be greatly regarded”… “…we must be alert to….the danger that public policy itself become captive of the scientific-technological elite”

17 Question: Is it warmer than it has ever been
Question: Is it warmer than it has ever been? With the exception of the recent Ice Ages the Earth’s temperature today is cooler than most of the last sixty-five million years (source: James Zachos)

18 The earth has been in an ice age much of the last 400,000 years
The earth has been in an ice age much of the last 400,000 years. The earth’s temperature in each of the last four interglacial periods was several degrees warmer than today (source: Vostok Ice Core, Law Ice Dome, Mauna Loa air sample)

19 We are in an 11,000 year interglacial period called the Holocene
We are in an 11,000 year interglacial period called the Holocene. It has been warmer than today quite a few times in this period. This warming is from natural causes and not man.

20 Temperatures were several degrees warmer than today in the Bronze Age, the Roman Age, and the Medieval Period. The earth cooled several degrees from 1400 to 1800, this period is called “The Little Ice Age”. The Earth’s warming started in the early 1700s, long before CO2 was a factor.

21 U. S. has tracked continental temperatures since 1895 U. S
U.S. has tracked continental temperatures since U.S. temperatures have been cooler in five of the last seven decades even though CO2 levels increased in this period. The forty year cooling period from the late 30’s to 70’s caused some to fear the return of an ice age.

22 The 1970s cooling scare

23 Headline: January 1977

24 The ten warmest years in the U.S.
1934 1998 1921 1906 1931 1999 1953 1990 1938 1939 Five of the ten warmest years in the USA were before 1940 The warmest decade in the USA was the 1930s (Source: NASA GISS)

25 The year that the record high temperature was recorded in each of the continents
1920 South America 1977 Europe 1960 Australia 1913 North America 1922 Africa 1933 Asia 1974 Antarctica 1960 Oceana (Source: Wikipedia)

26 U.S. 50-State Record High Temperatures Many were before (source:

27 The U.S. has the longest and most comprehensive record of temperature data from ground weather stations (source:

28 Most parts of the globe do not keep consistent track of the climate
Most parts of the globe do not keep consistent track of the climate. This map shows weather stations reporting data at least 67% of the time from (Source: GHCN)

29 In the early 1990s climate data stopped being collected from thousands of global weather stations. Many of these stations were in cooler rural areas such as Siberia. Temperatures appeared to rise as the stations were dropped. How temperature is collected impacts the data. (source: Joe D’Aleo)

30 One way the U.S. tracks temperature is from 1,221 ground weather stations. These stations are supposed to be kept at a distance from buildings, roadways, and trees (Source: Anthony Watts) (

31 Observation shows that many stations are poorly located next to buildings and gravel roadways

32 Adjacent to buildings, cars, parking lots, satellite dishes, and air conditioners

33 On hot rooftops

34 Next to trash burn barrels and tennis courts

35 Temperatures rose at this station when the nearby tennis court was built

36 Adjacent to transformers, buildings, and dumpsters

37 Next to A/C condensors

38 Many weather stations are located at airports

39 In sewage treatment plants. This one is next to a smoker’s urn

40 Some are in backyards and people’s “stuff” Changes within close proximity to climate stations impacts the temperatures that are recorded.

41 Some weather stations are near barbeque grills. Burgers anyone?

42 In junkyards

43 These two stations are forty miles apart and show different results due to the proximity of development. This demonstrates the impact of land use changes on ‘local’ temperatures.

44 Of the 1,221 U.S. ground weather stations over 82% have been independently surveyed.
Anthony Watts has found that 89% of the stations checked have a heat bias from 1 degree C to 5 degrees C Many ground weather stations have been encroached by development and thus show higher temperatures due to the “urban heat island effect” Attempts are made to correct temperature readings as a result of land use changes but…….by whom? And how?

45 Results of the 1,221 USCHN surface weather station quality ratings (Source: Anthony Watts)
Location of U.S. climate stations and their ratings Bias rating factor

46 URBAN HEAT ISLAND EFFECT The world’s population has increased six-fold in the last 100 years. The growing urbanization has caused “local” temperatures to rise. (heat from the day is slower to dissipate at night in urban areas) The chart below shows how the city of Reno Nevada retains the heat of the day (source: Anthony Watts)

47 Heat Island Effect The term "heat island" describes built up areas that are hotter than nearby rural areas. The annual mean air temperature of a city with 1 million people or more can be 1.8–5.4°F (1–3°C) warmer than its surroundings. In the evening, the difference can be as high as 22°F (12°C). (Source: )

48 As atmospheric CO2 levels increase how are temperatures reacting. U. S
As atmospheric CO2 levels increase how are temperatures reacting? U.S. temperatures in 2008 were below the 115 year average U.S Summer temperatures were the 34th coldest in 115 years. U.S. October 2009 temperatures were the 3rd coldest ever for that month, 4 degrees below normal (Source: U.S. National Climate Data Center)

49 Atmospheric temperatures do not have a bias from land use changes
Atmospheric temperatures do not have a bias from land use changes. They show cooling since 2002 (satellite measurement of atmospheric temps began in 1979)

50 70% of the earth is ocean. Argo (part of the inter global observation strategy) measures the earth’s ocean temperature with over 3,000 buoys (Source: ARGO)

51 Argo buoys dive 700 meters deep, surface, and then send their temperature data to satellites

52 Argo has discovered that ocean temperatures have not been warming but are somewhat cooler (source: Dr. Craig Loehle, PhD)

53 This ocean cooling is contrary to climate model predictions (source: John Willis, NASA, Craig Loehle, PhD)

54 Ocean surface temperatures are influenced by winds (El Nino-La Nina)
Ocean surface temperatures are influenced by winds (El Nino-La Nina). They also show a cooling trend. No heat sinks have been discovered.

55 Let’s explore Carbon Dioxide Atmospheric CO2 today is near the lowest level in the last 540 million years (Source: the Resilient Earth)

56 Three ice ages had more atmospheric CO2 than today’s level.
Ordovician-Silurian Ice Age - fifteen times more CO2 than today. Cretaceous Ice Age - five times more. Permian-Jurassic Ice Age - more CO2 than today as well. Either CO2 does not cause much warming……natural forces are much stronger…..or both. (source: Ian Plimer)

57 CO2 is less than 4/10,000ths of the atmosphere
CO2 is a trace gas, there is not much of it. There are 100,000 molecules in front of your face and only 38 of them are CO2, (388 parts per million) CO2 has grown 100ppm since the mid 1700s (+35%) CO2 as a percent of the atmosphere has grown only 1/10,000th since the mid 1700s (if you had ten cents in your pocket and it increases by 40%, the increase as a percentage is large, but there is still not much of an overall impact caused by it)

58 Global temperatures are cooling even though atmospheric CO2 concentrations are growing (source: Univ of Alabama Huntsville, NOAA)

59 Greenhouse gases slow the release of heat from the atmosphere
Greenhouse gases slow the release of heat from the atmosphere. This is one reason why the earth’s temperature is different from the Moon. Water vapor comprises 95% of greenhouse gases (source:

60 CO2 makes up 3. 62% of greenhouse gases. But only 3
CO2 makes up 3.62% of greenhouse gases. But only 3.4% of atmospheric CO2 comes from human sources, the rest is from the oceans, decomposing vegetation and volcanoes. Thus man made sources of CO2 are only responsible for 0.15% of all greenhouse gases in the atmosphere (source: Heritage Foundation)

61 Question: How much warming can CO2 cause?
Higher levels of CO2 do cause some warming. However, CO2s ability to absorb heat is logarithmic, meaning the more CO2 there is, the less heat it can absorb. If CO2 levels double or triple, CO2 can not cause temperatures to rise more than 0.5 to 1.5 degrees C For CO2 to cause warming above 1.5 degrees Centigrade rising levels of CO2 must cause positive feedbacks *more water vapor and heat trapping cirrus clouds or a reduction in clouds *observation shows this does not happen *warming causes more low level clouds to form, it rains and temperatures cool. Low level clouds are negative feedbacks, they moderate temperature.

62 Cirrus Clouds slow the release of heat from the atmosphere
Cirrus Clouds slow the release of heat from the atmosphere. Observation shows that fewer of these clouds form when air temperatures warm.

63 C02’s absorption of heat is logarithmic, the more there is the less heat it can absorb (source: David Archibald)

64 The first 20ppm of CO2 absorbs more heat than the next 580ppm (source: David Archibald)

65 Rising levels of CO2 have not had much impact on temperature by themselves (source: Richard Lindzen)

66 Rapid temperature change is a daily, seasonal occurrence
The difference between the daily low and high temperature is about 20 degrees F Difference between record low and high Virginia state temperatures is 140 degrees F Mankind and nature survived these radical temperature changes, (they adapted)

67 Effect of CO2 on temperatures at two locations, each at the same latitude
Dry desert Humid jungle

68 The impact of humidity, H2O, and CO2 on high/low temperatures
The slight impact of warming from CO2 can be demonstrated from the temperature changes between the low and high temperature in humid tropical and dry desert areas Tropical areas are cooler in the day than the desert and are also warmer at night, due to the stabilizing effect of humidity. In desert areas temperatures are both warmer in the day and cooler in night than tropical areas. CO2 levels are about the same in both areas, yet the CO2 in the desert does not trap/retain the heat of the day. This demonstrates that CO2 by itself does not cause much warming and how important water vapor is in stabilizing temperature.

69 The theory of AGW The theory of man made global warming states that increases in atmospheric CO2 from man will absorb heat and cause temperatures to rise. This warming from additional concentrations of CO2 is said to cause increasing levels of humidity which in turn absorbs even more heat, creating a vicious cycle with rising temperatures spinning out of control. If this theory is correct, why has runaway global warming not occurred in earlier times, when atmospheric CO2 concentrations were much higher than today’s? Temperatures and humidity also rise substantially in summer. This has not triggered runaway temperatures, either. Observation shows the theory of AGW to be false.

70 CO2 is essential for life on Earth
CO2 levels were 270ppm in the mid 1700s (they are 380ppm today). If CO2 levels fall below 200ppm, plants stop growing. Photosynthesis stops. Most life on Earth was thus close to extinction due to a lack of atmospheric CO2

71 Plants today grow 15% more quickly due to the higher level of CO2
Plants today grow 15% more quickly due to the higher level of CO2. Greenhouses raise CO2 levels to 1,000ppm to increase the growth rate of plants. Average growth enhancement due to a 300 PPM increase in atmospheric CO2. Higher levels of CO2 can help feed a growing global population. (source David Archibald) +49% C3 cereals +20% C4 cereals +24% Fruits and melons +44% Legumes +48 % Roots and tubers +37% vegetables

72 With rising levels of atmospheric CO2:
Plants require less water to grow. Arid areas of earth become more productive agriculturally

73 Question: Is storm intensity increasing due to AGW. U. S
Question: Is storm intensity increasing due to AGW? U.S. tornado activity is in decline (source:

74 Global hurricane intensity is at 50 year lows 2009 US Hurricane activity is at 12 year lows (source: Florida State University)

75 Global deaths due to extreme events is in decline

76 Question: Is the polar ice melting due to AGW?
The earth is in an interglacial period. There is an imbalance with the ice that remains at the poles from the last Ice Age and the warmer temperature of the Holocene. Slow melting has been going on for thousands of years and will continue. At the Poles, 20,000,000 square kilometers of sea ice melt and then refreeze every year. As one pole melts the other freezes, thus there is an offsetting balance Massive ice melt is natural and happens every single year

77 Both poles lose substantial amount of sea ice every year in the polar Summer

78 Question: If the entire North Pole, all the Arctic ice melts, along with all the sea ice on earth at both Poles…… How high would the seas rise?

79 Answer: None at All Floating ice is already in the ocean, displacing water. Melting sea ice cannot raise the sea level.

80 For the seas to rise, ice on land must melt.
Greenland has 10% of the land ice Antarctica has 90%. Question: In what year did Antarctica, with 90% of the globe’s ice on land have the most sea ice ever recorded?

81 Answer: Antarctica had the most sea ice ever recorded in 2008

82 Antarctic sea ice has been growing continuously for the last 30 years (source: The Air Vent)

83 There has been above average melting of the Arctic Summer sea ice but an almost equal growth in the Antarctic sea ice, a net 1.6% reduction according to Nasateam since 1979

84 The National Snow and Ice Data center bootstrap method shows a 177,000km increase in average global sea ice since 1979

85 In September 2009 the Arctic ice had grown 24% larger than two years prior. The Antarctic ice was also one million sq kilometers larger than the prior year. The Ice at both Poles is growing. Wind and currents have large impacts on the ice. Unusual winds and sea currents were responsible for much of the extra melting of the Arctic sea ice. As these reversed the ice has begun to grow again.

86 Antarctica is the key to sea level rise
Sea ice is greatly influenced by temperature, especially water temperature Sea ice has been growing in Antarctica for 30 years. Temperatures have been cooling in 96% of Antarctica for 50 years (but not the Peninsula) The average temperature in Antarctic interior is -58 degrees F. It is also the highest Continent on earth with an average altitude of 8,200 feet. Antarctic glaciers/ice sheets melt from the bottom up, not the top down Antarctica is classified as a desert. It is the driest place on earth. There is little snow. If the man made global warming theory is true, sea ice will melt, but the higher humidity will cause much more snow in the interior and overall ice volumes will grow. This is also true of Greenland. Mankind has little impact on the climate in Antarctica

87 Scientific name for the Polar Bear is “Ursus Maritimus”, sea bear
Scientific name for the Polar Bear is “Ursus Maritimus”, sea bear. Polar Bears are excellent swimmers and can easily swim 100 miles or more. The longest documented swim is 320 km. Polar Bear populations are today the largest ever recorded, an increase of 300%+ since the 1960s Polar Bears have survived previous periods when the Arctic ice melted completely (source of polar bear population, US Senate)

88 The sea level has been rising for 20,000 years and the end of the last Ice Age. The rate of increase has slowed. There has been no sea level rise in the last four years (source: Wikipedia)

89 Some say rising CO2 will cause ocean acidification, killing corals
If all the fossil fuels on earth were burned there would not be enough CO2 to cause the oceans to acidify. CO2 in the ocean is converted to carbonate. It becomes fixed in insoluble form, sinking to the ocean bottom. Coral reefs thrived when atmospheric CO2 was ten times higher and temperatures ten degrees warmer than today. Corals have adapted to changes in CO2 levels. (Source: Ian Plimmer)

90 Why has the earth been warming if not from rising CO2 levels
Why has the earth been warming if not from rising CO2 levels? The Sun may be the answer.

91 (source: Wiki Answers)
Unless one lives in a geothermal or volcanic area the source for the warm temperatures we have and need to sustain life comes entirely from the Sun. The Sun and earth’s greenhouse gases are the reason earth’s temperatures are not like those of the Moon, (-247 degrees F at night to +212 degrees F in day). Many climate scientists fail to look to the heavens and take a closer look at the Sun. (source: Wiki Answers)

92 Galileo was the first to observe Sunspots

93 Galileo’s drawing of sunspots in 1613

94 An active Sun on the left and inactive Sun on the right
An active Sun on the left and inactive Sun on the right. Sunspots are used to track solar activity. Solar activity is not constant, the Sun has cycles that last an average of 11 years. We are now in cycle 24.

95 Changing solar activity is measured by observing and counting Sunspots
Changing solar activity is measured by observing and counting Sunspots. Note the variation of solar activity.

96 The observatory at Armagh Ireland has one of the longest continuous temperature records on earth. This chart tracks the close relationship between temperature (dots) from 1796 and 11 year solar cycles (solid line) (source: Armagh Observatory)

97 The length of Sunspot cycles appears to be more closely linked with temperatures than changing levels of CO (source: Friis-Christensen & Lassen . Dr. Tim Patterson)

98 The solar activity in the last years of the 20th Century was the strongest in the last 8,000 years. This may explain why global temperatures were warming in this period (Source: Joe D’Aleo)

99 Solar cycles average 11 years in length, half are shorter and half are longer. When cycles are longer global temperatures cool and when they are shorter, temperatures warm. There is no deviation over 400 years of observation

100 This shows how solar cycles are charted
This shows how solar cycles are charted. A very active cycle was predicted starting in 2008 but solar activity abruptly changed. Solar activity today is at century lows.

101 Solar activity is driven by the Sun’s internal magnetic field
Solar activity is driven by the Sun’s internal magnetic field. It is measured using the AP Index. The AP index is today at the lowest level ever recorded. Note that the low AP index in mid chart was during the 1970s cooling scare (Source: David Archibald)

102 Solar cycle lengths from 1762
Solar cycle lengths from Today’s cycle 23 is the longest since 1788, a cycle that predated a several decade long very cold period called the Dalton minimum (Source:

103 Using temperature and solar records at De Bilt Netherlands , demonstrates the close relationship between solar cycle length and temperatures. With each additional year of cycle length above 11 years temperatures cool an average of 0.7 degrees C (source: David Archibald)

104 Using the record of temperature and solar cycle length at Hanover New Hampshire since 1835 one can see that short cycle 22 of the 1990s was during a warming period and today’s 13 year long cycle 23 should result in at least a 2.2 degree C. drop in global temperatures (source : David Archibald)

105 The years 2007, 2008, and 2009 have some of the lowest solar activity since This might explain why global temperatures have been cooling (Source: Anthony Watts)

106 Solar winds today are at the lowest level every recorded
Solar winds today are at the lowest level every recorded. Changes in solar activity have impact on the atmosphere that surrounds Earth.

107 Solar Impact on cloud formation
The impact on the earth’s climate from the Sun goes beyond irradiance (heat). Solar winds have declined over 30% . Ultra violet radiation is down 6% to 8%. Cosmic rays reaching earth’s surface have also increased substantially. Some scientists believe that changing solar activity affect global temperatures by causing changes within the atmosphere and especially the clouds. With today’s century low solar activity and record low solar winds it is thought that the increase in cosmic rays that reach our atmosphere from deep in space cause more clouds to form. Clouds reflect up to 65% of solar radiation back into space and when there are more clouds temperatures cool. Conversely, increasing solar activity and the resulting increase in solar winds reduces the amount of cosmic rays that reach the atmosphere, fewer clouds form, more solar rays reach the earth’s surface, and this leads to higher temperatures. If the past is a predictor of the future the changes we now see in solar activity will cause the temperatures to cool for the next 20 years or longer. The Thames River at London should regularly freeze once again as it often did during the Little Ice Age.

108 The relationship between cosmic rays and cloud formation
The relationship between cosmic rays and cloud formation. Changing solar cycles have long term impact on future global temperatures that can last for decades (source: David Archibald)

109 The frozen Thames River at London in 1814
The frozen Thames River at London in We should see this once again in the coming years.

110 Frozen canals of the Netherlands, in stories by Hans Christian Anderson

111 Londoners held Frost Fairs on the Thames during the Little Ice Age

112 Conclusions The earth’s current warming trend started in the mid 1700s with the end of the Little Ice Age Until we understand the natural forces that impact climate, models cannot be relied upon to predict future temperatures with accuracy CO2 does not have much direct impact on temperature Positive feedbacks caused by rising levels of CO2 have not been observed Rising CO2 levels have a beneficial impact on plant growth There is little loss of overall global polar ice, though some slow melting is normal. The melting of Arctic ice has no impact on sea level Sea levels have been rising for thousands of years, and some rise is normal Global hurricane intensity is at fifty year lows.

113 Conclusions Global temperatures have been cooling for eight years or more. Polar bear populations are growing Solar activity and temperature are closely linked. Today’s century low solar activity is causing temperatures to drop. Temperatures could fall as quickly as the 70’s cooling scare but they could become colder and last longer. This could cause the loss of two weeks in the growing season on both ends (*) and result in severe food shortages. Cold periods are much worse for humanity than warm ones. Cold periods in the past have been ones of famine, disease and political instability Man has little impact on global temperatures (* David Archibald)

114 For more information

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