intoduction

1. Definition of Global Warming: Gradual increase in the earth's surface temperature.
Popular usage definition: Warming caused by human activity.
Technical term for this: Anthropogenic global warming.
Definition of Greenhouse Gas: A gas, like CO2, which traps the sun's heat.
Human causes: Carbon dioxide (CO2), e.g. exhaust from cars and power plants.
Natural causes: Some claim the sun is getting hotter.
What Causes Global Warming, human activity or the sun? The final answer is not in,
but you can see the results so far. (1) Exhaust is clearly the source of CO2. (2) Everyone
now agrees the earth is warming. (3) Decide for yourself if warming is better explained
by CO2, or the sun's heat.

2. The Effects of Global Warming. We can see the long-term effects coming in the
melting of polar ice and glaciers. But a powerful trend in Atlantic hurricane data indicates
we can already see the impact. Katrina was partly the result of a normal weather cycle,
but that cannot explain away stronger hurricanes world wide.
Can we Stop Global Warming?
It's too late for that, but we can slow it down and lessen its effects. CO2 does not last as
long in the air as was once thought, so the big problem is slowing human use of fossil
energy, especially coal. (Especially since CO2 goes into the ocean and destroys coral
reefs.)
We don't need absolute scientific proof before we take precautions.
Quite a lot can be done rather cheaply. Here are the directions which look most promising
at present.
• Hybrid cars
• Nuclear power
• CO2 sequestration (pumping it back in the ground)
• Wind power
Why are these cheap?
First, energy is only about 5% of all costs.
Second, everyway of using less fossil fuel saves about $60/gallon.
Third, the market always leaves some low-hanging fruit.
HYBRID CARS. These still cost more than they save, but not too much, and lots of
people like the idea of polluting less. We will eventually switch over almost completely
and the sooner the better--there's lots of room for savings here.
NUCLEAR POWER. Nuclear power still has problems, but makes no C02. A high
priority needs to be placed on solving the nuclear-waste problem.
PUMPING C02 UNDERGROUND. It seems incredible, but they do it all the time to
force oil out of oil wells. US DOE has a big project to study this. It may turn out to be too
expensive, but it is considered to be one of the best options by those in the know.
WIND POWER. ZFacts will be studying this option soon. It is nearly break-even but
how much could be installed? Is 5% of total power realistic? Right now that seems very
far off.

3. Global warming is the increase in the average temperature of Earth's
near-surface air and oceans since the mid-20th century and its projected
continuation. Global surface temperature increased 0.74 ± 0.18 °C
(1.33 ± 0.32 °F) between the start and the end of the 20th century.[2][A]
The Intergovernmental Panel on Climate Change (IPCC) concludes that
most of the observed temperature increase since the middle of the 20th
century was very likely caused by increasing concentrations of
greenhouse gases resulting from human activity such as fossil fuel
burning and deforestation.[2] The IPCC also concludes that variations in
natural phenomena such as solar radiation and volcanic eruptions had a
small cooling effect after 1950.[3][4] These basic conclusions have been
endorsed by more than 40 scientific societies and academies of science,[B]
including all of the national academies of science of the major
industrialized countries.[5]
Climate model projections summarized in the latest IPCC report indicate
that the global surface temperature is likely to rise a further 1.1 to 6.4 °C
(2.0 to 11.5 °F) during the 21st century.[2] The uncertainty in this
estimate arises from the use of models with differing sensitivity to
greenhouse gas concentrations and the use of differing estimates of
future greenhouse gas emissions. Most studies focus on the period
leading up to the year 2100. However, warming is expected to continue
beyond 2100 even if emissions stop, because of the large heat capacity of
the oceans and the long lifetime of carbon dioxide in the atmosphere.[6][7]
An increase in global temperature will cause sea levels to rise and will
change the amount and pattern of precipitation, probably including
expansion of subtropical deserts.[8] Warming is expected to be strongest
in the Arctic and would be associated with continuing retreat of glaciers,
permafrost and sea ice. Other likely effects include changes in the

4. frequency and intensity of extreme weather events, species extinctions,
and changes in agricultural yields. Warming and related changes will
vary from region to region around the globe, though the nature of these
regional variations is uncertain.[9]
Political and public debate continues regarding global warming, its
causes and what actions to take in response. The available options are
mitigation to reduce further emissions; adaptation to reduce the damage
caused by warming; and, more speculatively, geoengineering to reverse
global warming. Most national governments have signed and ratified the
Kyoto Protocol aimed at reducing greenhouse gas emissions.