Transcript Background Climate PPT

More than you wanted to know
about Climate change…
…in less than 20 minutes!
Bruce Larson
Stratham Memorial School
Stratham, NH 03885
In February 2007, an international panel of experts
(the Inter-Governmental Panel on Climate Change)
concluded:
-Global warming is occurring.
-Increase in global temperature is a result of human
activities.
-Given current trends, temperature extremes, heat waves,
and heavy rains will continue to escalate in frequency.
-The Earth’s temperature and seas will continue to rise
into the next millennium.
Understanding climate change
Involves understanding A
budget more complex
than Secretary Geithner’s…
Energy budget basics: more coming in than
going out.
The budget is out of balance
for two reasons directly related
to humans:
We are heating from below the
atmosphere with the energy
stored in fossil and nuclear fuel
and
human activity gives off gases which
act as a heat trapping blanket.
Climate is generally defined as average weather, and as such,
climate change and weather are intertwined. Observations
can show that there have been changes in weather, and it is
the statistics of changes in weather over time that identify
climate change.
Instrumental observations over the past 157 years show
that temperatures at the surface have risen globally, with
important regional variations.
Did the sun do it?
This diagram shows the
three ways the Earth
can ‘jiggle’ in its trip
around the Sun.
This graph spans
a million years.
Each color is a
wiggle, and the
bottom is a pretty
regular glacial
period.
On Mauna Loa, something was
making the CO2 graph rise in a
steady sawtoothed graph - rising in
the spring, and dropping in the fall.
Human activities contribute to climate change by causing
changes in Earth’s atmosphere in the amounts of greenhouse
gases, aerosols (small particles), and cloudiness.
Glaciers and ice caps are melting…
These maps are compiled monthly and are excellent to look at
during hurricane season to see the extent of surface warming.
February 2009 (average surface temperature)
“The Earth’s climate is tracking into uncharted territory.” Andrew Glikson Canberra,
Australia (Andrew Glikson undertakes earth and paleo-climate research at the Research
School of Earth Science, Australian National University.)
The IPCC has an excellent
FAQ about the science of climate
at the following location:
http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-faqs.pdf
Or you can Google ‘IPCC’ and see the entire package!
Cloud cover
Comet impacts
Ocean currents
Cows, horses, pigs
Fluorocarbons
Volcanoes
Plant transpiration
Solar cycles
Orbit variations
Burning fossil fuels
Glaciers and ice caps store/release fresh water