Green House Gases
Science and Changing Opinions Ice vs Hot
Natural Causes of Climate Change
Human or Anthropogenic Causes
Energy and Population
Southern Nevada Weather and Water
Anthropogenic Global Warming
Fossil Fuels and Greenhouse Gases
Green House Gases (GHSs), Methane (CH4)
and Carbon Dioxide (CO2) Water Vapor
Human Impacts on Biomes
Carbon dioxide levels are
Large part of the 2008 Presidential Election
Significant Media coverage CBS last
PBS Channel 10 Nova and Front Line
1970’s Major research-publications was on
Aerosols and particulate matter was thought
to be responsible for Global Cooling.
Oregon passes legislation banning the
products in consumer goods such as hair
spray, deodorants, and cleaning products.
Particulate material from fossil fuels, dust
and aerosols would reflect sunlight resulting
in Global Cooling.
This research was based on 1940
temperature data, which showed a cooling
In addition, orange groves in South Carolina
were subjected to freezing.
Decreasing global ice sheets and glaciers
Great Basin Park Nevada
Glacier National Park
Better long term climate measurements due
to oxygen isotope (delta 18)
Global Warming and the Greenhouse Effect
20th Century – 0.6ºC (1.0ºF) increase
Last quarter of 20th century – 0.2º to 0.3ºC (0.4ºF) increase
If Current Trends Continue
Earth’s Climate Change History
• Climate has changed
throughout Earth’s history.
• Greenhouse climates are
more common than icehouse
• Greenhouse = no glaciers.
• Icehouse = glaciers present.
• Earth is currently in an
Natural Climate Changes
Plates and continental movement
Changing Oceanic currents
Variations of the Earth’s Tilt
Results in increased solar radiation in the
Increased Solar radiation results in melting
of ice in the northern hemisphere and
cooling in the southern hemisphere (Very
Percessional- Wobble Like a Top
Northern Hemisphere v Southern Hemisphere Facing the Sun
Change in the direction of the Axis of rotation
relative to the Sun
25,800 Year Cycle
Current 365.4 day orbit around the Sun
100,000 Orbital variation eccentricity around the Sun
We are here today
This drawing is not to scale, its not even close
Temperature does not control CH4. what is
important is that temperature controlled the aerial
extent of wetlands, which releases methane.
Earth’s orbital variations such as 23,000 orbital
precession. The tilt varies and changes, thus in
10,500 years the Earth will have a summer tilt when
it is closer to the sun resulting in a net increase in
solar radiation (northern Hemisphere).
Earth orbital variations over time results in
normal climate change (Paleo Climatology).
Humans through the introduction of
agriculture changes and Greenhouse Gases
such as CO2 and CH4 have resulted in a
continuation of a warming period.
According to Ruddiman, we have delayed a
600,000 Year scale
Stable isotope analyses:
Show that Earth has experienced fluctuation
between glacial and interglacial periods on an
approximately 100,000 year cycle.
How do we know this?
Stable isotope analyses: (Using Isotopes of Oxygen and
Hydrogen (That’s How)
Stable isotopes of oxygen Delta 18, and 16 or hydrogen delta
2 and 1. can be used as a temperature proxy. Fractionation
of these isotopes within materials (e.g.,water and calcium
carbonate) is largely a temperature-dependent process.
Fractionation refers to the relative amounts of Oxygen
Delta 18 vs.
Delta 16 contained within a given material.
Analysis of the Oxygen18/ Oxygen16 ratio in materials
provides information about the temperatures those
materials formed at.
These temperature data can be used to infer global
temperatures throughout time.
Isotopes of Oxygen Hydrogen and
concentrations of Carbon and Methane
Sea Floor sediments
Past Climate 650,000 Years Ago
Interglacial periods (peaks) Glacial periods (troughs)
Caused Climate Change
8,000 years ago to present
Anthropocene: The term refers to the most
recent period of the Earth’s history starting
about 8,000 years ago when activities of the
human race first began to have a significant
global impact on ecosystems and climate.
The term Anthropocene was coined by Paul
Anthropogenic Global Warming
Describes an increase in the average temperatures
of the Earth’s atmosphere and oceans.
The terms global warming or anthropogenic global
warming are used to describe the theory that
increasing temperatures are the result of
strengthening greenhouse effect caused primarily
by human actions.
Importance of Green House Gases.
Explanations of pre-industrial Green
House Gases (GHGs).
Industrial Revolutions I and II.
Major Greenhouse Gases.
Population and Industrial Revolution III.
Industrial Revolution III.
Solar Radiation and Global Dimming.
Melting of the Permafrost.
The Colorado River
Good Referances (Andrew Ruddiman, 2006)
(Joos et al., 2004)
Humans discovered agriculture 12,000 years
Prior to religion, writing, and great cities
humans started alerting climate.
Ruddiman puts forth the hypothesis that
through the discovery of plant and animal
domestication the Anthropocene began
8,000 years ago.
CO2 and CH4 are the two most talked about
Green House Gases.
CH4 Cycles may be linked to monsoon
intensity (greater wetland extent) and
increases in CH4 concentrations in the
Vostock Ice cores (Greenland). They
measured monsoon maxima at ~10, 80, 105,
and 130 kyr BP, which corresponds to
Methane follows the normal climate cycles
until 8,000 years ago.
CO2 also varies with the orbital cycles
CO2 reaches a maximum at the height of the
Orbital variations result in a trade off between
the northern and southern hemispheres.
When the northern hemisphere cooled the
southern warmed and visa versa.
From Ice core evidence it is apparent that
the last 8,000 have been different than the
past 100,000 years
There is a seemingly anomalous trend in
which CO2 and CH4 levels start to increase
8,000 years ago when they should be
In addition, Both the northern and southern
hemispheres are warming.
Hypothesis of Human Cause
Humans have disrupted the Carbon Cycle
Land use changes through clear cutting of
Rain Forrest in Mesopotamia and China
Spread of agriculture throughout Europe,
Asia, South and Central Americas.
Deforestation of large parts of China and the
cultivation of rice 8,000 years ago.
Latter Methane is attributed to fossil fuel
Increased Incidence of Costal
Higher Tidal Surges
In the Year 2050. This has come under
Carbon Based Fuels
Industrial revolution I and II has caused an
increase in CO2
Industrial Revolution III India and China
will contribute additional CO2
Industrial Revolution III
China and India are in the process of
The catalyst for this industrialization is
western investment, inexpensive labor,
reduced regulations, innovations in
communication, and transportation.
World Population 2004
The Future of Human Populations
Melting of Ice
Since industrialization glaciers have
Great Basin glaciers
Glacier National Park
Sea level increase have impacted low lying
Global Warming and Water
Resources of Southern Nevada
Increased temperature without the
influences of melting ice equates to dryer
Warmer Dryer v. Cooler Wetter
1927 & 1944 Allocations
Odd Years 1961-1970 Glen Canyon Reservoir Filling
Gunnison River Tributary to
Southern Nevada allocation 300,000 MAF/year, Use 475,000 due to return credits
Humans have disrupted the carbon cycle?
Through deforestation and land use changes
Consumption of fossil fuels
Climate modeling to date is based on
End of Anthropogenic Climate Change
Punta Gaspareno Baja California, Sur. N22o47’22’’