Global Warming FAQ
What is Global Warming?
Global Warming is the increase of Earth's average surface
temperature due to effect of greenhouse gases, such as carbon
dioxide emissions from burning fossil fuels or from deforestation,
which trap heat that would otherwise escape from Earth. This is a
type of greenhouse effect.
Is global warming, caused by human activity, even remotely
Earth's climate is mostly influenced by the first 6 miles or so of the
atmosphere which contains most of the matter making up the
atmosphere. This is really a very thin layer if you think about it. In
the book The End of Nature, author Bill McKibbin tells of walking
three miles to from his cabin in the Adirondack's to buy food.
Afterwards, he realized that on this short journey he had travelled
a distance equal to that of the layer of the atmosphere where
almost all the action of our climate is contained. In fact, if you were
to view Earth from space, the principle part of the atmosphere
would only be about as thick as the skin on an onion! Realizing this
makes it more plausible to suppose that human beings can change
the climate. A look at the amount of greenhouse gases we are
spewing into the atmosphere (see below), makes it even more
What are the Greenhouse Gases?
The most significant greenhouse gas is actually water vapour, not
something produced directly by humankind in significant amounts.
However, even slight increases in atmospheric levels of carbon
dioxide (CO2) can cause a substantial increase in temperature.
Why is this? There are two reasons: First, although the
concentrations of these gases are not nearly as large as that of
oxygen and nitrogen (the main constituents of the atmosphere),
neither oxygen or nitrogen are greenhouse gases. This is because
neither has more than two atoms per molecule (i.e. their molecular
forms are O2 and N2, respectively), and so they lack the internal
vibrational modes that molecules with more than two atoms have.
Both water and CO2, for example, have these "internal vibrational
modes", and these vibrational modes can absorb and reradiate
infrared radiation, which causes the greenhouse effect.
Secondly, CO2 tends to remain in the atmosphere for a very long
time (time scales in the hundreds of years). Water vapour, on the
other hand, can easily condense or evaporate, depending on local
conditions. Water vapour levels therefore tend to adjust quickly to
the prevailing conditions, such that the energy flows from the Sun
and re-radiation from the Earth achieve a balance. CO2 tends to
remain fairly constant and therefore behave as a controlling factor,
rather than a reacting factor. More CO2 means that the balance
occurs at higher temperatures and water vapour levels.
How much have we increased the Atmosphere's CO2 Concentration?
Human beings have increased the CO2 concentration in the
atmosphere by about thirty percent, which is an extremely
significant increase, even on inter-glacial timescales. It is believed
that human beings are responsible for this because the increase is
almost perfectly correlated with increases in fossil fuel combustion,
and also due other evidence, such as changes in the ratios of
different carbon isotopes in atmospheric CO2 that are consistent
with "anthropogenic" (human caused) emissions. The simple fact is
that under "business as usual" conditions, we'll soon reach carbon
dioxide concentrations that haven't been seen on Earth in the last
50 million years.
Combustion of Fossil Fuels, for electricity generation,
transportation, and heating, and also the manufacture of cement,
all result in the total worldwide emission of about 22 billion tons of
carbon dioxide to the atmosphere each year. About a third of this
comes from electricity generation, and another third from
transportation, and a third from all other sources.
This enormous input of CO2 is causing the atmospheric levels of CO2
to rise dramatically. The following graph shows the CO2 levels over
the past 160 thousand years (the upper curve, with units indicated
on the right hand side of the graph). The current level, and
projected increase over the next hundred years if we do not curb
emissions, are also shown (the part of the curve which goes way up
high, to the right of the current level, is the projected CO2 rise).
The projected increase in CO2 is very startling and disturbing.
Changes in the Earth's average surface temperature are also shown
(the lower curve, with units on the left). Note that it parallels the
CO2 level curve very well.
Is the Temperature Really Changing?
Yes! As everyone has heard from the media, recent years have
consistently been the warmest in hundreds and possibly thousands
of years. But that might be a temporary fluctuation, right? To see
that it probably isn't, the next graph shows the average
temperature in the Northern Hemisphere as determined from many
sources, carefully combined, such as tree rings, corals, human
These graphs show a very discernable warming trend, starting in
about 1900. It might seem a bit surprising that warming started as
early as 1900. How is this possible? The reason is that the increase
in carbon dioxide actually began in 1800, following the
deforestation of much of North-eastern American and other
forested parts of the world. The sharp upswing in emissions during
the industrial revolution further added to this, leading to a
significantly increased carbon dioxide level even by 1900.
Thus, we see that Global Warming is not something far off in the
future - in fact it predates almost every living human being today.
How do we know if the temperature increase is caused by
Computer models strongly suggest that this is the case. The
following graphs show that 1) If only natural fluctuations are
included in the models (such as the slight increase in solar output
that occurred in the first half of the 20th century), then the large
warming in the 20th century is not reproduced. 2) If only
anthropogenic carbon emissions are included, then the large
warming is reproduced, but some of the variations, such as the
cooling period in the 1950s, is not reproduced (this cooling trend
was thought to be caused by sulphur dioxide emissions from dirty
power plants). 3) When both natural and anthropogenic emissions of
all types are included, then the temperature evolution of the 20th
century is well reproduced.
Is there a connection between the recent drought and climate
Yes. A recent study by the National Oceanic and Atmospheric
Administration gives strong evidence that global warming was a
Who studies global warming, and who believes in it?
Most of the scientific community, represented especially by the
Intergovernmental Panel on Climate Change (IPCC - www.ipcc.ch),
now believes that the global warming effect is real, and many
corporations, even including Ford Motor Company, also
acknowledge its likelihood.
Who are the IPCC?
In 1998, the Intergovernmental Panel on Climate Change (IPCC) was
established by the World Meteorological Organization (WMO) and
the United Nations Environment Programme (UNEP), in recognition
of the threat that global warming presents to the world.
The IPCC is open to all members of the UNEP and WMO and consists
of several thousand of the most authoritative scientists in the world
on climate change. The role of the IPCC is to assess the scientific,
technical and socio-economic information relevant for the
understanding of the risk of human-induced climate change. It does
not carry out new research nor does it monitor climate related
data. It bases its assessment mainly on published and peer reviewed
scientific technical literature.
The IPCC has completed two assessment reports, developed
methodology guidelines for national greenhouse gas inventories,
special reports and technical papers. Results of the first assessment
(1990--1994): confirmed scientific basis for global warming but
concluded that ``nothing to be said for certain yet''. The second
assessment (1995), concluded that `` ...the balance suggests a
discernable human influence on global climate'', and concluded
that, as predicted by climate models, global temperature will likely
rise by about 1-3.5 Celsius by the year 2100. The next report, in
2000, suggested, that the climate might warm by as much as 10
degrees Fahrenheit over the next 100 years, which would bring us
back to a climate not seen since the age of the dinosaurs. The most
recent report, in 2001, concluded that "There is new and stronger
evidence that most of the warming observed over the last 50 years
is attributable to human activities".
Due to these assessments, debate has now shifted away from
whether or not global warming is going to occur to, instead, how
much, how soon, and with what impacts.
Global Warming Impacts
Many of the following "harbingers" and "fingerprints" are now well
1. Rising Seas--- inundation of fresh water marshlands (the
everglades), low-lying cities, and islands with seawater.
2. Changes in rainfall patterns --- droughts and fires in some
areas, flooding in other areas. See the section above on the
recent droughts, for example!
3. Increased likelihood of extreme events--- such as flooding,
4. Melting of the ice caps --- loss of habitat near the poles. Polar
bears are now thought to be greatly endangered by the
shortening of their feeding season due to dwindling ice packs.
5. Melting glaciers - significant melting of old glaciers is already
6. Widespread vanishing of animal populations --- following
widespread habitat loss.
7. Spread of disease --- migration of diseases such as malaria to
new, now warmer, regions.
8. Bleaching of Coral Reefs due to warming seas and acidification
due to carbonic acid formation --- One third of coral reefs now
appear to have been severely damaged by warming seas.
9. Loss of Plankton due to warming seas --- The enormous (900
mile long) Aleution island ecosystems of orcas (killer whales),
sea lions, sea otters, sea urchins, kelp beds, and fish
populations, appears to have collapsed due to loss of plankton,
leading to loss of sea lions, leading orcas to eat too many sea
otters, leading to urchin explosions, leading to loss of kelp
beds and their associated fish populations.
Where do we need to reduce emissions?
In reality, we will need to work on all fronts - 10% here, 5% here,
etc, and work to phase in new technologies, such as hydrogen
technology, as quickly as possible. To satisfy the Kyoto protocol,
developed countries would be required to cut back their emissions
by a total of 5.2 % between 2008 and 2012 from 1990 levels.
Specifically, the US would have to reduce its presently projected
2010 annual emissions by 400 million tons of CO2 . One should keep
in mind though, that even Kyoto would only go a little ways towards
solving the problem. In reality, much more needs to be done.
The most promising sector for near term reductions is widely
thought to be coal-fired electricity. Wind power, for example, can
make substantial cuts in these emissions in the near term, as can
energy efficiency, and also the increased use of high efficiency
natural gas generation.
The potential impact of efficiency should not be underestimated: A
1991 report to Congress by the U.S. National Academy of Sciences,
Policy Implications of Greenhouse Warming, found that the U.S.
could reduce current emissions by 50 percent at zero cost to the
economy as a result of full use of cost-effective efficiency
Discussing Global Climate Change:
Here is a useful list of facts and ideas:
1. Given the strong scientific consensus, the onus should now be
on the producers of CO2 emissions to show that there is not a
problem, if they still even attempt to make that claim. It’s
time to acknowledge that we are, at very least, conducting a
very dangerous experiment with Earth's climate.
2. A direct look at the data itself is very convincing and hard to
argue with. Ask a skeptical person to look at the data above.
The implications are obvious. The best source of data is
probably the IPCC reports themselves.
3. The recent, record-breaking warm years are unprecedented
and statistically significant. It is a fact that they are very
statistically unlikely to be a fluctuation (and now we can point
to specific side effects from those warm temperatures that
appear to have induced recent worldwide drought).
4. Lastly, but perhaps most importantly, whether or not you
believe in global warming per se, the fact remains that the
carbon dioxide levels are rising dramatically --- there is no
debate about this. If we continue to use fossil fuels in the way
we presently do, then the amount of carbon we will release
will soon exceed the amount of carbon in the living biosphere.
This is bound to have very serious, very negative effects, some
of which, such as lowering the pH of the ocean such that coral
cannot grow, are already well known.
Response of Government: Develop "Carbon Sequestration"
Many government agencies around the world are very interested in
maintaining fossil fuel use, especially coal. It should be noted that
US energy use, which is enormous, is increasing, not decreasing.
Furthermore, we are not going to run out of coal in the near term
(oil may begin to run low sometime after 2010). Methods for
reducing carbon emission levels while still burning coal are now
investigation by government and industry, as we now discuss.
We believe that a major increase in renewable energy use should be
achieved to help offset global warming. While there are some US
government programs aimed in this direction, there is simply not
enough money being spent yet to achieve this goal in a timely
manner. A primary goal of many new programs is not to increase
renewables, but rather, is to find ways to capture the extra CO2
from electricity generation plants and "sequester" it in the ground,
the ocean, or by having plants and soil organisms absorb more of it
from the air.
Possible Problems with Carbon "Sequestration"
One of the Carbon sequestration approaches under investigation is
the possibility of depositing CO2 extracted from emission streams in
large pools on the Ocean bottom. It is possible that such pools will
not be stable, and may either erupt to the surface, or diffuse into
the ocean and alter the oceans pH.
Another scheme under investigation is the idea of stimulating
phytoplankton growth on the ocean surface by dusting the surface
with iron (the limiting nutrient). This will cause an increased uptake
of carbon by the plankton, part of which will find its way to the
ocean bottom. Fishing companies are considering using this to
increase fish harvests while simultaneously getting credit for carbon
sequestration. Serious ecological disruptions could occur, however,
especially if this approach is conducted on a sufficiently large scale.
Another idea is to stimulate Earth's terrestrial ecosystems to take
up more carbon dioxide. While the impacts here are more difficult
to ascertain, an important point to note is that these systems are
not thought to be able to completely absorb all the extra CO2 . At
best, they may be sufficient to help the US stabilize carbon emission
rates for a few decades, but even if this is achieved, stabilization of
rates are not likely to return the Earth to pre-industrial carbon
levels. Worse, biological feedbacks to global warming, such as forest
fires, drying soils, rotting permafrost, etc, may actually greatly
accelerate carbon emissions, i.e. we may experience massive
Another major approach under consideration is to pump CO2 into
old oil and gas wells. While seemingly attractive, it must be kept in
mind that for this to be truly effective, it would have to be done on
a world wide scale, include many sources of CO2 , including many
sources which are presently small and widely distributed (such as
car emissions, and not just coal plant emissions). All of this CO2
would need to be captured, transported, injected into old wells,
and then the wells would need to be sealed and monitored. It is not
clear that this would be affordable at all, and that there would be
adequate capacity or assurance that CO2 would not leak out in
In the worst case scenario, carbon sequestration efforts may simply
fail, but also end up being a political tool that is used to seriously
delay a transition to renewable energy sources, and also possibly
create many new environmental problems while prolonging old
In the best case scenario, given the truly enormous amount of CO2
we are presently emitting, some sequestration approaches may
serve as a useful bridge to curbing emissions while the transition to
renewables is being made.