The Greenhouse Effect.
Basic Components to what should be called the Enhanced
The earth has a natural greenhouse effect due to trace amounts of
H20 and CO2 that naturally occur. The
enhanced greenhouse effect refers to the augmentation of these
natural gases by human activities.
The net result is that we are depositing approximately 2 billion extra
tons of carbon in an out of equilibrium cycle. Eventually this will
be taken up by the land but the timescale for that process is unknown.
Hence, the extra carbon, in the form of C02 remains in the
The deposition of C02 and methane (CH4) continues
to exponentially increase.
Such that we are now at historical all time high concentration:
- In principle, CFCS are very bad and will dominate the
greenhouse gases in our atmosphere if their terrestrial usage
remains high. CFC worldwide production, however, has been
significantly reduced because of concern about
The Ozone Layer
- Methane is more directly related to food production and population
growth so it could also dominate in the near future
Methane is also found in the
Arctic Ice Caps and in ocean
hydrates and will
be released due to global warming thus excarerbating the problem
While the US is the worst offender, this is
truly a global problem. Are we going to tell China, for instance, not
Bare bones simulator
Manifestations and Predictions of the
- Popular Misconception --> Amazon Rain Forest Destruction greatly
contributes to the problem. It doesn't, its the total amount of biomass
on the planet that contributes to the Carbon
Cycle . The real problem with deforestation is the immediate
release of methane. However, detailed studies of gas exchange in
rain forest systems indicates that rain forests are net producers
of greenhouse gases (due to methane emissions) and not net sinks
(e.g. they remove CO2). This point is a bit controversial
still and in any event, is not one that the public believes.
- Evidence of increased hurricane strength is here: Hurricane Andrew ;
Emiliaa in the Pacific ;
Hurricane Linda in the Eastern Pacific
Simplest Prediction is increase in global mean temperature.
Role of clouds is crucial --> Net Cooling or Warming? -->
There is general consensus that cloud cover will increase as
the capacity for the atmosphere to retain water increases with
What does the actual data look like?
All the Data: Global
Warming NCDC Document
Long Term Temperature Trends:
Distribution of Temperature trends on the Earth. Where is it getting
warmest the fastest:
- Is the pre-1920 data reliable?
- Increasing number of recording stations since 1950 means
non-uniform data quality
- Southern Hemisphere is more ocean to land area than Northern
- But, there does appear to be an 0.5 degree Celsius increase per
century in the data
All the historical data
When positional data is combined with temperature data and timesliced
in this way - it seems clear the Global Warming is occurring.
This conclusion was reached by a National Academcy of Science panel
in Sept. 1995 and is accepted by most.