Non Anthropogenic Causes of Climate Change

1. 1
Professor Hector R Rodriguez
School of Business
Mount Ida College

2. 2
•Weather: daily temperature and moisture conditions in a
place
•Climate: a description of the long-term weather pattern in
a particular area
•Global warming: the increase in Earth’s average surface
temperature due to rising levels of greenhouse gases.
•Climate change: a long-term change in the Earth’s
climate, or of a region on Earth. Climate change includes:
–Changes in temperature (Global Warming)
–Changes to precipitation patterns and sea levels
–Humidity, wind, and severe weather events.
First, Some Terms to Understand

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Climate Change Over the Years
There is a significant amount of historical evidence pointing to
episodes of climate change in both distant and recent past.
How do we know? Let’s review some geology first.

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Glaciation
Advancing GlaciersOriginal State

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Glaciation in Our Backyard – White Mountains, NH
•Glacial features in the White Mountains - Cirques
•Cirques are one of the most
common and most distinct glacial
landforms in glaciated mountains.
•Cirques are large bowl-like shaped
valleys with a large steep headwall
on one side.
•Cirques are commonly found on
the eastern slopes of the White
Mountains where the snow would
have been blown off of the
summits and collected.
Winter
Spring

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Glaciation in Our Backyard – White Mountains, NH
•Glacial features in the White Mountains - Glacial throughs
–The notches in the White Mountains were carved by the valley
glaciers. These glaciers followed V-shaped river valleys and as the
glacier passed through it widened and deepened the valley leaving
behind a U-shaped valley after the glaciers retreated.
Crawford Notch

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More Evidence of Glaciation
Cirques Glacial Through
Hanging Valley Horn

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•The Medieval Warm Period in the 11
th
century raised the
mean temperature in AK to 3-5
o
F warmer than it is today;
the snow line in the Rocky Mountains was about 300 yards
higher than today
Recent Changes in Climate
•Likewise in the middle
of the last millennium
saw a marked cooling,
named the Little Ice
Age. The Artic pack ice
extended so far south
that there are six
records of Eskimos
landing their kayaks in
Scotland.

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•Glaciers have been advancing and receding since the last
ice age; most glaciers in the Northern Hemisphere were
small or absent from 9,000 to 6,000 years ago.
Conclusion: Glaciers are Cyclical
•They reached a recent maximum
at the end of the Little Ice Age.
So it should not be surprising to
see them dwindling as we leave
the Little Ice Age; we are
comparing them with their
absolute maximum over the last
10,000 years
What causes this cyclicality?

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Some Causes of Climate Change
•Variations in the Earth's Orbit and Inclination to the Sun (see
Milankovitch Cycles on next slide)
•Changes in the Atmosphere (which can be caused by
volcanoes and sunspots)
These are not related to human activity…
•Changes in Circulation
of Sea Water
•Sliding of the West
Antarctic Ice Sheet
over the Ocean
June 1991 Mt Pinatubo eruption cooled temperatures
in some regions by as much as 0.5 degrees C*
*http://vulcan.wr.usgs.gov/Glossary/VolcWeather/description_volcanoes_and_weather.html

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Milankovitch CyclesClick Here
•Inclination (variation of tilt)
–The changes in the axial tilt (22
o
to 24.5
o
) of
the Earth
–The greater the tilt the greater the contrast
between summer and winter temperatures
–Cycle is about 41,000 years
•Precession
–The wobble of the Earth as it spins on its axis
–Cycle is about 26,000 years
•Earth’s orbital changes controls its climate
•Eccentricity
–Measure of the non-circularity of
Earth's orbit
–Cycle is about 100,000 years

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Please Note!
•What I said…
–Climate change has happened in the past
–There is evidence that proves so
–These effects were not driven by human activity
•What I will also say…
–Pace of climate change seems to be increasing
–Human activity is influencing GHG concentrations in the
atmosphere
–This is causing anthropogenic global warming and may cause
future catastrophic climate change
As future business leaders we cannot afford to be influenced by
unbalanced arguments, laced with hyperbole… our
stakeholders expect more of us… our credibility depends on it.

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•A comprehensive strategy to mitigate the risk associated
with GHG emissions must be implemented. It should
include the following steps:
–Developing renewable sources of energy
–Implementing comprehensive International Protocols
–Establishing emission trading markets (Cap & Trade)
–Increasing efficiency (in buildings, IT, transportation)
–Implementing engineering controls (geo-engineering, CCS)
A Balanced Conclusion (cont.)
We’ll discuss each one of these potential steps in future sessions…