Download Powerpoint

Introduction to Climate
Change – Science and
Impacts
Greenhouse Gases


Allow sunlight to pass through while
trapping heat- opposite of sulfites
(1970’s cooling)
4 types of anthropogenic gases
• Carbon dioxide (50%)
• Methane
• Nitrous Oxide
• CFC’s
Carbon Cycle
Effects of Industrialization



Unearthed and burned sedimentary
deposits of fossil fuels at an
unnatural rate
3 billion tons of CO2 a year
If states can reduce to 1994 levels
and maintain levels, CO2
concentration will still increase for at
least 2 centuries
Carbon connection


Avg. global
temperatures
already increased
.6 degrees C since
late 1800’s
International Panel
on Climate Change
(IPCC) predicts
1.4-5.8 degree C
increase by 2100
International Response
UNEP and WMO formed the IPCC in 1988
to gain consensus on climate change –
political will
- Working group I – science
- II – Impacts and policy
- III - Economic and social impacts
IPCC’s assessments lead to UNCED
framework and Kyoto targets and
timetables

Impacts of Climate Change



Most contentious part of debate – will they
happen, when will they happen, how
severe will they be
2001 WG II IPCC – Impacts from climate
change occurring by chance is negligible
Hard to attribute regional and specific
changes to particular causes (regional
differences – north warming faster than
south)
Types of Impacts

Sea level rise – 10
to 20 cm so far (9
to 88 by next
century)
• Greenland Ice
sheet- over 1000
years, could result
in 3-7 meter rise
• West Antarctic
sheet (maybeprecipitation)

Coastal and Marine
Ecosystems
• Erosion, increased
salinity of
freshwater, loss of
delta
• Low lying areas
flooded (New
Orleans)
• Increased salinity
affects organisms,
bleaching of coral
Impacts Cont’d



Weather impacts –
increased storms,
droughts, floods; very
uncertain
Public health – more
insect borne
disearses, water
borne; north v. south
Agriculture and Food –
regional – positive in
north worst around
equator – too hot to
grow




Forest loss – types of
forests will change –
increase in short term
production, worst in
high latitudes – beech,
sugar maple (Adr.)
Deserts – increase in
desertification
More precipitation –
increased runoff and
flooding
Loss of ice cover –
Glacial National Park
Biodiversity Loss and Discussion




Warm water fish will flourish, cold water may die out;
changing habitats for terrestrial animals – will have to
migrate – synergistic impacts with pre-existing habitat loss
All these impacts are speculative, and regional – how do
you make a country with no coastal resources, or who may
benefit try and reduce emissions
Public perception – Page 606 question 5 – media impact –
confusion of weather and climate – hot summer, a lot of
coverage; climate cannot be effected by man – volcano’s
Clinton’s meeting of weathermen – is that a good tactic to
gain support? Regional effects v. national trends