Introduction
Greenhouse warming has existed for quite some time, arguably since Earth was
first formed. Greenhouse gases, or gases conducive to the greenhouse effect,
act like a blanket or the panes of glass in a greenhouse's walls; they reflect
the heat the earth would radiate into space back down towards the earth,
holding it in. You see, the balance of heat on earth is maintained by different
processes. Solar radiation approaches the earth, and clouds and the atmosphere
reflect some of it back into space. More radiation is absorbed by the
atmosphere, clouds, and the surface of the earth. Then the earth radiates the
heat back as infrared radiation. To maintain a certain, constant temperature,
the rate that Earth emits energy into space must equal the rate it absorbs the
sun's energy. The greenhouse effect's refusal to allow a certain amount of this
terrestrial radiation to pass keeps the Earth's average surface temperature at
about 60°F (15°C). If there were no greenhouse gases in the atmosphere, most of
the heat radiated by the Earth's surface would be lost directly to outer space,
and the planet's temperature would be 0°F (-18°C), too cold for most forms of life
(Greenhouse).
Background
There are several atmospheric gases that act as greenhouse gases (GHGs). The
most infamous is carbon dioxide, which is emitted through the respiration of
humans and animals, the burning of fossil fuel, deforestation, and other
changes in land use. Carbon dioxide is the main focus of many greenhouse gas
sanctions, since it is the greenhouse gas that has most been released into the
atmosphere. However, some other gases may have a greater effect upon climate
than CO2. If one examines research into the possible warming effect of other
GHGs relative to CO2, one finds that over a 100-year period, there are gases
present in far smaller amounts that have a much more concentrated effect.
Methane, a gas produced by livestock (flatulence), oil and gas production, coal
mining, solid waste, and wet rice agriculture, has 11 times more warming
potential per volume than CO2 (Science), or 25 times more per molecule
(Clarkson). Nitrous oxide, produced mainly in connection with current
agricultural practices, has 270 times more warming potential per volume over
this period than CO2 (Science). Chlorofluorocarbons (CFCs), the gases used as
refrigerants and in aerosol spray dispensers that were banned some time back
due to their ozone depletion potential, have 3400-7100 times more warming
potential per volume than CO2 (Science). Hydrochlorofluorocarbons (HCFCs) and
hydrofluorocarbons (HFCs), the CFC substitutes, have a slightly smaller warming
potential at 1200-1600 times larger per volume than CO2 (Science).
And so, as one might infer, studies are showing that additions of GHGs may
cause the earth to get warmer than it naturally would. This is what is referred
to as anthropogenic (human-caused) global warming. Many times, the terms global
warming and climate change are used interchangeably. (We will do the same, for
continuity's sake.) But, this is not correct and the concepts are different.
Climate change includes precipitation, wind patterns, and temperature. It also
refers to the whole climate, not just weather conditions of one place. Global
warming is an indication of climate change. It is an example of a climate
change that has the atmosphere's average temperature increase. Earth has
experienced much warming and much cooling throughout its history. There is a
great deal of debate as to whether or not the earth is experiencing a globally
warming climate change and, if it is, whether the underlying causes are
man-made or natural. Different research has given different results.
However,
even when greenhouse gases were arguably at a stable level, before the onset of
the Industrial Revolution, Earth's climate tended to fluctuate widely. A period
from 5,000 to 3,000 BC (when civilization began) is called the Climatic Optimum
and another period from 900 - 1200 AD is called the Little Climatic Optimum or
the Medieval Climatic Optimum, both so named for their unusually warm
temperatures. Likewise, a period from 1550 to 1850 is known as the Little Ice
Age for its unusually cold temperatures (Pidwirny). At this time, glaciers in
southern Norway
reached their greatest extent in 9000 years (Keigwin). With such large
variations possible, it is difficult to know where the next natural fluctuation
could take us. Perhaps those who find that global climate is warming are simply
measuring a natural fluctuation. Or perhaps a natural fluctuation is masking
the real effect of GHGs on the globe.
Global
Warming: Big Questions, Big Research
There is a great debate over whether or not humans are
causing global warming. Some activists and researchers have resorted to
name-calling or accusing the opposing side of having "sold out" to
one special interest or another. As mentioned previously, we have attempted to
cut away the personal attacks between the opposing sides, search for the kernel
of truth (or logic, where truth cannot be discerned), and get down to the heart
of the matter.
In order to properly read any of the reports or research on global climate
change, one must keep in mind that nothing (or almost nothing) is certain.
Everything has a certain degree of uncertainty, a certain flavor of the
unknown. There really is no conclusive evidence of global warming, and many
scientists in favor of the global warming hypothesis say that it will be a
decade or more before it is possible to develop any substantial evidence. As an
anonymous senior climate modeler has said about global warming, "The more
you learn, the more you understand that you don't understand very much". Global climate is by nature always
fluctuating, and that only adds to the confusion about anthropogenic global
warming. If there were an anthropogenic global warming, we couldn't be sure
what temperature we were supposed to be at, as climate shifts are a natural part
of life on Earth. Compounding that confusion is natural variability, which is
always working to confuse researchers just as they come close to attributing a
perceived change in average temperature to some external factor, such as
atmospheric composition (GHGs) or solar variation. One reason for this
variability is the long adjustment time of the oceans' heat storage and current
systems. It is estimated to take several hundred years for water to circulate
from the deepest portions of the oceans back to the surface. This means that
if, for example, a pool of extra cold water is singled out and stored in the
depths by some freak mechanism, it could stay there a century or two before
resurfacing and producing a local, cool climate change .
Since no one can create another Earth (let alone one that behaves exactly like
ours) and perform atmosphere-altering experiments on it, we are left with the
alternative of theorizing based on observations. In other words, the only way
we can purport to know anything about what might be changing in our climate is
by playing with data, such as records of temperature, borehole measurements,
etc., and seeing what scenarios the data will agree with.
Most of the body of global warming theory is based on computerized climate
models called global circulation models or GCMs, for they are almost the only
tools global warming researchers have. GCMs are difficult to make as making
them properly involves a deep-rooted understanding of the way the atmosphere
works and how its actions are interconnected with other planetary bodies, such
as the oceans or the terrestrial biosphere. But our understanding of the inner
workings of the atmosphere and the ways it relates to other planetary bodies is
not very good.
GCMs are made by formulating mathematical descriptions of the
interrelationships between the atmosphere/ocean/biosphere/cryosphere system and
conducting numerical experiments. They certainly are unable to form a
mathematical description based on the kind of interconnections, or feedbacks,
that the butterfly effect would suggest. Indeed, "in the climate
system, there are 14 orders of magnitude, from the planetary scale--which is 40
million meters--down to the scale of one of the little aerosol particles on
which water vapor can change phase to a liquid [cloud particle]--which is a
fraction of a millionth of a millimeter." Of these 14 orders of magnitude,
only the two largest (the planetary scale and the scale of weather
disturbances) can currently be included in models. to
include the third order of magnitude (the scale of thunderstorms, at about 50
km resolution) a computer a thousand times faster would be necessary, "a
teraflops machine that maybe we'll have in 5 years." Including all orders
of magnitude would require 1036-1037 times more computing power .
Lately, a model has been designed and tested at the National Center
for Atmospheric Research to eliminate the flux corrections. This model better
incorporates the effects of ocean eddies, not by shrinking the scale, but by
parameterization, passing the effects of these invisible eddies onto larger
model scales using a more realistic means of mixing hear through the ocean that
any earlier model did. This model doesn't drift off into chaos even after 300
years of running. This model gives a 2oC rise in temperature due to a CO2
doubling. (Some of the more popular GCMs assume that the concentration of CO2
will double in 70 years or quadruple in 140 years and use the assumption to try
to predict what the climate will be like in decades or even centuries based on
that doubling or quadrupling.) This figure is on the low side of estimates and
puts the model's sensitivity to greenhouse gases near the low end of current model
estimates .
GCMs are very sensitive to the representations of the effects of clouds and
oceans, as their effects are complex and not understood well. While some GCMs
are being specially made to simulate water behavior in clouds, limited vertical
resolution (i.e., they don't go up far enough) and coarse horizontal resolution
(i.e., the cloud activity of large areas of the Earth is averaged together and
this average is used for the entire area) prevent even these models from
accurately covering thin clouds and some cloud formation processes. Most early
simulations were run with fixed cloud distributions based on observed cloud
cover data, but these fixed levels didn't allow any feedback between cloud
distributions and changing atmospheric/oceanic temperatures and motions.
Problems in cloud feedback are seen as the Achilles heel of GCMs. Likewise,
ocean representations were initially crude; in some early models, a swamp
(stagnant, heat-absorbing, heat and water vapor-releasing body of water) was
used as the oceanic model. Later models had a 50 meter thick slab of ocean that
allowed summertime heat storage and wintertime heat release. While not
including ocean currents (caused by the movement of heat to colder areas of
ocean), these models attempted to represent seasonal responses to temperature
in the upper ocean, but the lack of currents resulted in tropical oceans being
too hot and polar regions too cold. Even today's most sophisticated,
computationally-intense climate models are still just numerically experimental
approximations of the exceedingly complex atmosphere/ocean/biosphere/cryosphere
system. And yet, these GCMs are the basis of global warming theory, if for no
other reason than the near-impossibility of conducting physical experiments at
the global level (Cotton & Pielke).
Even while the satellites may need adjustments in their data for changes in
orbit, this data is still more accurate than surface data. Satellites do not
have anything in their surroundings to skew the data. On the other hand, many
sources of error exist here on Earth. Things as seemingly minuscule as
variation in the color and type of paint used for the instrument shelters can
skew data slightly, for different types and colors of paint absorb small but
differing amounts of solar radiation. As another example, the urban heat island
effect is known to make cities warmer at night and milder during the day. If this bias exists in the global climate data set, its use to
represent a wider geographic record for climate change studies will be
misleading.
Another largely-ignored factor affecting temperature data is solar variation,
or periodic changes in the brightness of the sun based on sunspots and the
like. Some climate modelers say that the Sun only varies with an 11-year cycle,
and this period is too fast for the climate system to respond to. But poorly measured,
anthropogenic forcings, especally changes of atmospheric aerosols, clouds, and
other land-use patterns, cause a negative forcing that tends to offset
greenhouse warming. One consequence of this partial balance is that the natural
forcing due to solar irradiance changes may play a larger role in long-term
climate change than inferred from GHGs alone".
Effects
of Global Warming on Our Everyday Lives
Another area where uncertainty rears its head is in the realm of the "real
life" effects of global warming. The possible effects of global warming
have been played out in the media: hurricanes, plagues, a great increase in sea
level, etc. Some scientists refute these claims. But, again, since the climate
models can tell us little with much certainty, we can not know for certain if a
global warming would have these effects or not.
Some researchers claim that global
warming will lead to an increase in violent storms such as hurricanes and
typhoons. But, warming should
actually lead to a reduction in these storms as the equator-to-pole temperature
differences diminish, for it is this atmospheric temperature heterogeneity that
drives storms and makes them strong.
Some, do say that warming could cause the
mosquito carrying dengue fever and yellow fever to migrate northward, causing
epidemics.Cholera (which is
known to live in sea-borne plankton), could become epidemic in America as
changes in marine ecology favor the growth and transmission of the pathogen. Another group of researchers,
went a step further and blamed an El Niño warming of the Pacific at least
partially for a 1991 Latin American cholera epidemic affecting 500,000 and
killing almost 5,000. But cholera is known to spread from humans to other
humans through food, water, and feces; this is why cholera epidemics appear
when public health and sanitation break down. CDC medical epidemiologist Fred
Angulo stated that "We had a powder keg ready to explode, an entire
continent in which the sanitation and public water supplies and everything was
primed for transmission of this organism once it was introduced," possibly
by ships emptying bilge water near fishing areas. He adds that cholera has been
introduced into the US
several times in the past few years; it didn't spread "because we have a
public health and sanitation infrastructure that prevents it."
As for the mosquito-borne diseases, the
predictions suffer from many levels of uncertainty. No one disputes that
weather patterns have an impact: "There's reason to believe that if it's
an extremely rainy spring, summer mosquito populations will increase," but no one knows just how patterns of temperature
and rainfall will change in a warmer world, or how these changes will affect
the biology of diseases. Paul Epstein has attributed Latin American dengue
epidemics in 1994 and 1995 to El Niño and global warming, but experts on dengue
at the Pan American Health Organization and the Centers for Disease Control and
Prevention say these epidemics resulted from a breakdown in programs to
eradicate the specific species of mosquito responsible and its subsequent
return. The epidemics once caused by mosquitoes in the US have
vanished due to mosquito control, eradication programs, piped-water systems,
and lifestyle changes ( good housing, air conditioning, and television
to keep us inside, and screens to keep the mosquitoes outside).
Other areas of life global warming has an effect upon are those affected by
attempts to stop global warming. Some people suggest that small changes, such as using high-efficiency compact fluorescent
lights, using self-powered or public transportation more often, etc., could
make a big impact on the global warming problem (assuming it exists). This would
go along with the idea expressed by some scientists that the only actions that
should be taken until there is more certainty are those that would (or should)
be taken anyway . But will people do these things if they don't have to? Some
other scientists are more pessimistic.
Let's assume for a moment
that there is a global warming occurring. If this is anthropogenic global
warming and it will have a negative impact on climate and life, then we must
take action. If this is not anthropogenic global warming and warming will have
a negative effect on climate and life, nothing can be done. If there is no
anthropogenic global warming and the warming will not have a negative effect on
climate and life, nothing need be done. Likewise, if humans have caused the
global warming but it will not have a negative impact on climate and life, no
action is necessary.
But there is one other dimension to choosing what to do: assuming that
anthropogenic global warming is occurring and it will negatively impact climate
and life, one must weigh the costs and benefits of maintaining that risk
against the costs and benefits of action.
Fact and
Fiction:
FICTION: Even if the Earth is warming, we can’t be sure how much, if any, of
the warming is caused by human activities.
FACT: There is international scientific consensus that most of the warming over
the last 50 years is due to human activities, not natural causes. Over millions
of years, animals and plants lived, died and were compressed to form huge
deposits of oil, gas and coal. In little more than 300 years, however, we have
burned a large amount of this storehouse of carbon to supply energy.
Today, the by-products of fossil fuel use – billions of tons of carbon (in the
form of carbon dioxide), methane, and other greenhouse gases – form a blanket
around the Earth, trapping heat from the sun, unnaturally raising temperatures
on the ground, and steadily changing our climate.
The impacts associated with this deceptively small change in temperature are
evident in all corners of the globe. There is heavier rainfall in some areas,
and droughts in others. Glaciers are melting, Spring is arriving earlier,
oceans are warming, and coral reefs are dying.
FICTION: The Intergovernmental Panel on Climate Change predicts an increase in
the global average temperature of only 1.4°C to 5.8°C over the coming century.
This small change, less than the current daily temperature range for most major
cities, is hardly cause for concern.
FACT: Global average temperature is calculated from temperature readings around
the Earth. While temperature does vary considerably at a daily level in any one
place, global average temperature is remarkably constant. According to analyses
of ice cores, tree rings, pollen and other “climate proxies,” the average
temperature of the Northern Hemisphere had varied up or down by only a few
tenths of a degree Celsius between 1000 AD and about 1900, when a rapid warming
began.
A global average temperature change ranging from 1.4°C to 5.8°C would translate
into climate-related impacts that are much larger and faster than any that have
occurred during the 10 000-year history of civilization.
From scientific analyses of past ages, we know that even small global average
temperature changes can lead to large climate shifts. For example, the average
global temperature difference between the end of the last ice age (when much of
the Northern Hemisphere was buried under thousands of feet of ice) and today’s
interglacial climate is only about 5°C .
FICTION: Warming cannot be due to greenhouse gases, since changes in
temperature and changes in greenhouse gas emissions over the past century did
not occur simultaneously.
FACT: The slow heating of the oceans creates a significant time lag between
when carbon dioxide and other greenhouse gases are emitted into the atmosphere
and when changes in temperature occur.
This is one of the main reasons why we don’t see changes in temperature at the
same time as changes in greenhouse gas emissions. You can see the same process
occur in miniature when you heat up a pot of water on the stove: there is a
time lag between the time you turn on the flame and when the water starts to boil.
In addition, there are many other factors that affect year-to-year variation in
the Earth’s temperature. For example, volcanic eruptions, El Niсo, and small
changes in the output of the sun can all affect the global climate on a yearly
basis.
Therefore, you would not expect the build-up of greenhouse gases to exactly
match trends in global climate. Still, scientific evidence points clearly to
anthropogenic (or human-made) greenhouse gases as the main culprit for climate
change.
FICTION: Carbon dioxide is removed from the atmosphere fairly quickly, so if
global warming turns out to be a problem, we can wait to take action to reduce
greenhouse gas emissions until after we start to see the impacts of warming.
FACT: Carbon dioxide, a gas created by the burning of fossil fuels (like
gasoline and coal), is the most important human-made greenhouse gas.
Carbon dioxide from fossil fuel use is produced in huge quantities and can
persist in our atmosphere for as long as 200 years.
This means that if emissions of carbon dioxide were halted today, it would take
centuries for the amount of carbon dioxide now in the atmosphere to come down
to what it was in pre-industrial times. Thus we need to act now if we want to
avoid the increasingly dangerous consequences of climate change in the future.
FICTION: Human activities contribute only a small fraction of carbon dioxide
emissions, an amount too small to have a significant effect on climate,
particularly since the oceans absorb most of the extra carbon dioxide
emissions.
FACT: Before human activities began to dramatically increase carbon dioxide
levels in the atmosphere, the amount of carbon dioxide emitted from natural
sources closely matched the amount that was stored or absorbed through natural
processes.
For example, as forests grow, they absorb carbon dioxide from the atmosphere
through photosynthesis; this carbon is then sequestered in wood, leaves, roots
and soil. Some carbon is later released back to the atmosphere when leaves,
roots and wood die and decay.
Carbon dioxide also cycles through the ocean Plankton living at the ocean’s
surface absorb carbon dioxide through photosynthesis. The plankton and animals
that eat the plankton then die and fall to the bottom of the ocean. As they
decay, carbon dioxide is released into the water and returns to the surface via
ocean currents. As a result of these natural cycles, the amount of carbon
dioxide in the air had changed very little for 10,000 years. But that balance
has been upset by man.
Since the Industrial Revolution, the burning of fossil fuels such as coal and
oil has put about twice as much carbon dioxide into the atmosphere than is
naturally removed by the oceans and forests. This has resulted in carbon
dioxide levels building up in the atmosphere.
Today, carbon dioxide levels are 30% higher than pre-industrial levels, higher
than they have been in the last 420,000 years and are probably at the highest
levels in the past 20 million years. Studies of the Earth’s climate history
have shown that even small, natural changes in carbon dioxide levels were generally
accompanied by significant shifts in the global average temperature.
We have already experienced a 1°F increase in global temperature in the past
century, and we can expect significant warming in the next century if we fail
to act to decrease greenhouse gas emissions.
FICTION: The Earth has warmed rapidly in the past without dire consequences, so
society and ecosystems can adapt readily to any foreseeable warming.
FACT: The Earth experienced rapid warming in some places at the end of the last
glacial period, but for the last 10,000 years our global climate has been
relatively stable. During this period, as agriculture and civilization
developed, the world’s population has grown tremendously. Now, many heavily
populated areas, such as urban centers in low-lying coastal zones, are highly
vulnerable to climate shifts.
In addition, many ecosystems and species that are already threatened by
existing pressures (such as pollution, habitat conversion and degradation) may
be further pressured to the point of extinction by a changing climate.
FICTION: The buildup of carbon dioxide will lead to a “greening” of the Earth
because plants can utilize the extra carbon dioxide to speed their growth.
FACT: Carbon dioxide has been shown to act as a fertilizer for some plant
species under some conditions. In addition, a longer growing season (due to
warmer temperatures) could increase productivity in some regions.
However, there is also evidence that plants can acclimatize to higher carbon
dioxide levels – that means plants may grow faster for only a short time before
returning to previous levels of growth.
Another problem is that many of the studies in which plant growth increased due
to carbon dioxide fertilization were done in greenhouses where other nutrients,
which plants need to survive, were adequately supplied.
In nature, plant nutrients like nitrogen as well as water are often in short
supply. Thus, even if plants have extra carbon dioxide available, their growth
might be limited by a lack of water and nutrients. Finally, climate change
itself could lead to decreased plant growth in many areas because of increased
drought, flooding and heat waves.
Whatever benefit carbon dioxide fertilization may bring, it is unlikely to be
anywhere near enough to counteract the adverse impacts of a rapidly changing
climate.
FICTION: If Earth has warmed since pre-industrial times, it is because the
intensity of the sun has increased.
FACT: The sun’s intensity does vary. In the late 1970’s, sophisticated
technology was developed that can directly measure the sun’s intensity.
Measurements from these instruments show that in the past 20 years the sun’s
variations have been very small.
Indirect measures of changes in sun’s intensity since the beginning of the
industrial revolution in 1750 show that variations in the sun’s intensity do
not account for all the warming that occurred in the 20th century and that the
majority of the warming was caused by an increase in human-made greenhouse gas
emissions.
FICTION: It is hard enough to predict the weather a few days in advance. How
can we have any confidence in projections of climate a hundred years from now?
FACT: Climate and weather are different. Weather refers to temperatures,
precipitation and storms on a given day at a particular place. Climate reflects
a long-term average, sometimes over a very large area, such as a continent or
even the entire Earth.
Averages over large areas and periods of time are easier to estimate than the
specific characteristics of weather.
For example, although it is notoriously difficult to predict if it will rain or
the exact temperature of any particular day at a specific location, we can
predict with relative certainty that on average, in the Northeastern United
States, it will be colder in December than in July.
In addition, climate models are now sophisticated enough to be able to recreate
past climates, including climate change over the last hundred years. This adds
to our confidence that projections of future climates are accurate.
Finally, when we report climate projections, we use a range of results from
climate models that represent the boundaries of our projections (what’s the
least global average temperature could change to what’s the most global average
temperature could change) and our degree of certainty of the projections.
FICTION: The science of global climate change cannot tell us the amount by
which man-made emissions of greenhouse gases should be reduced in order to slow
global warming.
FACT: The U.N. Framework Convention on Climate Change states that emissions of
greenhouse gases should be reduced to avoid “dangerous interference with the
climate system.” Scientists have subsequently attempted to define what
constitutes “dangerous interference.”
One study (O’Neill and Oppenheimer, 2002) supplies three criteria that could be
used:
1) risk to threatened ecosystems such as coral reefs
2) large-scale disruptions caused by changes in the climate system, such as
sea-level rise caused by the break-up of the Antarctic Ice Sheet and
3) large-scale disruptions of the climate system itself, such as the shutdown
of the thermohaline circulation of the Atlantic Ocean (the Gulf stream), which
would result in a severe drop in temperature to Europe.
This study projects that if C02 concentrations are capped at 450 parts per
million (ppm), major disruptions to climate systems may be avoided, although
some damage (such as that to coral reefs) may be unavoidable.
Current estimates of atmospheric CO2 concentrations likely to be reached
without aggressive action to limit greenhouse gas emissions are far higher –
from 550 ppm to as much as 1000 ppm in the next hundred years.
FICTION: Because of the uncertainty of climate models, it is extremely
difficult to predict exactly what regional impacts will result from global
climate change.
FACT: According to the IPCC, certain climate trends are highly likely to occur
if greenhouse gas emissions continue at their current rate or increase: sea
level will rise; droughts will increase in some areas, flooding in others;
temperatures will rise, leading to heat waves becoming more common and glaciers
likely to melt at a more rapid rate.
Regional impacts are very likely to occur, but exactly when and what they will
be is harder to predict.
This is because:
1) regional climate models are more computer intensive than global climate
models – they take longer to run and are more difficult to calibrate, and
2) many non-climate factors contribute to impacts at regional levels. For
example, the risk of mosquito-borne illnesses like Dengue fever and malaria may
rise due to increased temperatures, but the actual likelihood of infection will
depend greatly on the effectiveness of public health measures in place.
A Better
World Climate: How Do We Get There From Here?
As has been stated previously, there are a great many unanswered questions
about global warming. We wonder whether or not there really is an anthropogenic
global warming or the threat of one because we don't have the perfect climate
model to tell us so. And we don't have this model because we don't understand
what is going on; we don't understand how the atmospheric system interacts with
the oceans, the terrestrial biosphere, the cryosphere, or any of its other
contributing factors. Therefore, the research that should be first and foremost
in our minds is that to better understand the rich interrelationships between
these bodies as well as the various features of each that may not be well
understood. The effect of clouds, for example, on warming and vice versa are not
understood very well. Do they simply cool by reflecting heat back to space, or
is their role more complex than that? What effect does each shape and size of
cloud have? What outside factors have an effect upon cloud formation? And, most
importantly, how can we best relate these effects into GCMs?
Likewise, aerosols are in need of study. Do they simply cause cooling by
reflecting solar radiation back out into space, or, as one researcher stated,
is that effect canceled out by heating through reflection of terrestrial
radiation back to earth and give their real cooling effect by fortifying clouds
with water droplets, giving them a higher albedo?
Are variations in solar radiation and sunspot cycles behind part or all of the
perceived global warming? Could there be changes in the sun's energy output
that would cause warming such as some have observed?
How does the tropical ocean interact with global atmospheric circulation, given
that tropical cyclones (hurricanes) form there? Are there any special processes
at work there that would affect the global warming theory? Likewise, how do the
atmosphere, the ocean, and sea ice interact at high latitudes?
What, exactly, is the terrestrial biosphere's place in the carbon cycle? How
much CO2 does different types of vegetation, soil, or rock absorb? If CO2 is
shown to be a substantial problem, would there be any way to make parts of the
terrestrial biosphere take on more CO2? What effect would that have on the
various ecosystems involved?
And on and on the potential questions go. As can be seen above, there are a lot
of different directions global warming research can go in and is going in. All
of these would be helpful in trying to better determine the climatic direction
we as a planet are headed in. But there is one other dimension to this attempt
to better understand global warming: the modeling. Currently, even the most
sophisticated and encompassing of the GCMs is incredibly crude and
oversimplified compared to the actual atmospheric system and its feedbacks. And
so, given new findings in research related to above topics and others, we must
continue to update the models. We must keep working on the models, improving
them, until flux corrections or "fudge factors," as they are called,
are unnecessary to make them properly predict today's conditions. As computer
technologies continually become smaller and faster and more capable of complex
systems, we must keep shrinking the scale of the models and bringing in more
variables to account for or better, more detailed understanding of the existing
variables. To have a perfect model, every variable, every ocean eddy and
sulfate particle would have to be accounted for. While this is improbable as a
state of modeling, we can continue to try to better explain what is going on
and how things are connected and interrelated by bringing bigger and better
understandings of atmospheric intricacies to the modeling table.
Concluding statements:
Unfortunately for these global climate change researchers, the computer
industry is not moving nearly fast enough for this research. In many ways,
climatologists are waiting on the computer industry to build more powerful
supercomputers so they can make more complex models to take advantage of that
computing power. And yet, there is at least a small advantage to waiting: many
valuable studies being conducted with innovative, legitimate methods simply
haven't been collecting data long enough to be as useful as possible. Satellite
data is a good example of this. If we wait, the data will be better.
And so, we can see that the science behind global warming is far from settled.
Much is not known and conflicting theories abound, as they often do in
scientific forums. New ideas and new studies keep the science of global climate
change going, keep it second guessing itself, keep it looking for newer, better
ways to explain what's going on. In the end, global climate change may be a way
for science to prove it can work well even under the most uncertain of
circumstances.
