Questions and Answers about “Global Warming”
by John Stanley
(with the warning that I don't have all the answers)
- Is the earth warming up?
- Is this warming caused by human activity?
- Is human activity the major cause of the 1 degree rise?
- Are the oceans rising?
- Are humans increasing the CO2 in the atmosphere?
- Apart from the greenhouse effect, is CO2 bad?
- How does the greenhouse effect work?
- How sensitive is the temperature to CO2?
- How then can IPCC predict up to 6 degrees rise in this century?
- What will be the effects of a temperature rise of a few degrees?
- Will animals and plants be devastated?
- What about the Polar Bears?
- Won't many people die of heat strokes?
- Will tropical diseases spread due to global warming?
- Will super hurricanes get worse?
- Will the Gulf Stream shut down plunging Europe into an ice age?
- What can we do to prevent further global warming?
- If we can't stop it, what can we do?
- Could the “cure” be worse than the “problem”?
- What can an individual person do? (Here is where I start to meddle!)
Very likely. It is very difficult to measure the average temperature of the earth. It seems there isn't
even universal agreement as to what global temperature means. Is it the average of all the
thermometers in the world? Is it the temperature determined by satellite sensors? Do we include the
effects of rising temperatures in cities simply due to their energy use and population or exclude those?
For these reasons, there are news reports stating that, for example, 2007 was the hottest year on record
and other sources stating that it definitely was not.
The best answer seems to be yes, the earth is warming up, probably by about 1 degree in the last
century. It is too early to tell if that trend is getting worse, has leveled off or has reversed within the
last 10 years or so. All three opinions are held by some and they have “data” to prove it.
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Some of it is. For example, the temperature in large cities is several degrees, at least, higher than the
surrounding countryside. Since cities are the result of human activity, clearly warming is caused, in
part, by that activity. Since it is unlikely that any conceivable human activity has lowered the
temperature in the countryside and if the “global temperature” includes cities in its average, it is hard to
imagine that human activity has not made some contribution to the global temperature rise.
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There are several theories as to why the temperature is rising. 1 - Human production of “greenhouse
gases” of which carbon dioxide is the most often mentioned. 2 - Variations in the solar output which is
receiving quite a bit of attention lately. 3 - Other natural cyclical variations. Since the temperature
seems to have been rising for longer than man has been a major user of fossil fuels, clearly not all of
the rise can be blamed on CO2. The human percentage likely lies somewhere between 5% and 80%
of the total.
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Yes, on this we have pretty good data and agreement. There are many places in the coastal areas where
sea level is measured. These data can be averaged and the long term trend noted. The actual
measurement is compared to the land nearby, so it is not possible from these data alone to say if the sea
is rising or the land sinking. There are web sites that give the average change per year in many places.
These mainly show variations of a few inches per decade either rise or fall. Some of the most striking
places where the ocean level is “falling” are in Alaska. This is probably due to the “rebound” effect.
The earth is still rising after being covered with huge glaciers during the last ice age. In places where
the sea level is “rising” dramatically, it is mainly due to the land sinking not the ocean rising. For
example, there are islands in areas of tectonic activity that are sinking rather quickly into the ocean.
As to a global average that can be teased out of the data, it seems that overall, the ocean level may be
rising about .1 inch per year or 1 inch per decade. This would give a 10 inch rise in 100 years. Others
say increased rates may make this 18 inches by 2100. Predictions of dramatically greater rise than this
(3 feet to 20 feet) are based on effects which have yet to be noted, such as the nearly complete melting
of Greenland. If such changes are to take place any time soon, we should see a big increase in the
RATE of rise very soon. If happening, this is very slight. Like the temperature, the seas have been
rising slowly since long before humans began to put CO2 into the atmosphere. Ocean levels are
constantly being monitored and any surge in the levels will be noticed many years before they pose a
great threat to human life.
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Two things are clear and there is no disagreement. 1 - Humans are putting CO2 into the atmosphere at
seeming rather large and ever increasing amounts, and 2 - The actual measured CO2 concentration is
rising. However, it is also true that humans generate only a tiny fraction of the CO2 that is produced
each year and much of what is produced is recycled by natural processes. For example, the oceans
absorb a huge quantity of CO2 and plants also use CO2 in quantities that dwarf human production.
Plants grow faster as CO2 levels rise. There is some evidence that rising CO2 is driven by temperature
more than the other way around. It is clear that as oceans warm they give off CO2.
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CO2 is an essential gas without which there would be no plant life. It presently makes up about 1/20th
of 1% of our atmosphere whereas oxygen makes up about 20%. Thus, the plants, which breath CO2,
are in much worse shape than are animals who breath oxygen. During past periods of earth's history,
for example, the Carboniferous Era, CO2 levels were much higher. It is believed that during that time,
lush vegetation laid down the beds of plant material which became our coal beds of today. At very
high levels, CO2 becomes dangerous to animal life, but those levels are much higher than any levels
that could possibly be produced by any human activity even if extended for many thousands of years.
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Certain gases, the most important of which is water vapor, tend to trap the earth's heat by preventing it
from radiating back into space during the hours of darkness. They also prevent heat from arriving from
the sun, but due to complicated issues related to the wavelengths of various types of light and heat and
the tendency of various gases to absorb or pass certain wavelengths, the net result of these
“greenhouse” gases is to raise the average temperature. This is mainly by raising the night time
temperature with less effect on the daytime temperature which may even go down. For example, in the
desert where there is very little water vapor (the most powerful greenhouse gas), the daytime
temperature may reach 120 degrees and the night time temperature may fall nearly to freezing. In the
tropics on the other hand, where humidity is very high, the day time temperature may be only 90 and
the night time temperature 80 degrees. This shows how the water vapor acts like a blanket and keeps
out the daytime heat and holds in the night time heat. CO2 is a less effective green house gas, but it
adds to the total effect. Methane and other gases also contribute.
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If all other greenhouse gases stay unchanged, doubling the concentration of CO2 should raise the
global temperature about one degree. After that, it must double again (4 times the base value) to
produce a similar increase. For each doubling, a similar step in temperature is expected. This
illustrates that temperature sensitivity to CO2 is a logarithmic curve, not a linear one. Using the above
figures, a 4 degree increase in temperature would require 24 more CO2 or a 16 times increase. Since so
far we have seen much less than even a doubling of CO2 from the base line, it would seem likely there
is not enough fossil fuel in existence to produce such a temperature increase, even if we were so foolish
as to burn it all at once.
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The IPCC (a UN panel for climate change) models are based on “feedback” mechanisms. This means
that they do not expect the temperature to increase only from the CO2 itself, but from other
mechanisms which the CO2 or its associated temperature increase will trigger off. For example, one
scenario holds that as the arctic permafrost melts, it will release methane gas, which is a more powerful
greenhouse gas than CO2 itself. Water vapor, being the most important greenhouse gas, is also
implicated as a multiplying factor in that higher temperatures might cause more evaporation, thus
multiplying the effect. It should be noted that other models predict a “negative feedback” effect,
implying that the earth has built in mechanisms that tend to counteract the effect of CO2 or other heat
producing factors. Neither of these feedback mechanisms seems to have been observed conclusively in
nature. They are the result of computer simulations which may or may not reflect what is actually
happening.
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This will be considered under a number of aspects. There seems to be a presupposition on the part of
many that the present global temperature is some kind of “ideal” even though the earth has been much
hotter and much cooler in the past than it is at present. However, it should be noted that it is the rapid
rate of change, not the absolute temperature, that is of concern to many.
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If some climate models are correct, it is possible that the earth has never seen such a rapid change in
temperature as we are about to experience. This rapid change means that plants and animals will have
difficulty adapting and many species may go extinct. To put this in perspective, assuming a 6 degree
rise (worst case IPCC estimate) over 100 years, this corresponds to about 1 degree every 17 years. If
we note that in North America, the average temperature rises about 1 degree for every 70 miles of
latitude, it would mean that the distribution of a given animal species would have to move north at
about 4 miles a year to stay in a similar climate or it would have to adjust to a temperature change of
1/17 of a degree per year. Since the year to year variations in average climate vary much more that
this, one would think that at least some animals could adjust. Plants have a harder time migrating. The
most important plants from a human standpoint are the food crops and these could be adapted to the
slow changes in temperature. 100 years may be only a microsecond in geologic time, but in terms of
the time animals or plants live it is rather long. Nevertheless, specific species may require some
intervention.
It should be noted that as one goes nearer the equator both plant and animal diversity increases. There
is little life at the poles and abundant life in the tropics. That alone should indicate that overall a few
degrees of warming would probably help more than hurt in terms of plant and animal habitat, once the
flora and fauna have adjusted to the new climate. Both heat and increased CO2 are generally positive
as far as crop production, so it would seem overall food production need not suffer.
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We have assumed that some animals can migrate if needed to find a more optimum climate. Of course,
polar bears cannot go further north. However, there is evidence that they have survived much warmer
periods in the past than we are projecting due to global warming. Polar bear populations seem to have
increased in the past 50 years (mainly due to conservation efforts). However, we should monitor these
populations since it is relatively easy to do and important. Hopefully, we could take action as needed to
protect the bears and the animals they prey on. There is no reason for the species to go extinct. If
necessary we can breed them in captivity until such time as the earth cools off again.
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At least in the developed world where good records are available, many more people succumb to cold
related health problems than to heat. A few degrees increase should reduce mortality not increase it.
During a heat wave, many vulnerable people do die over a short period and this makes big headlines.
The effects of cold are less dramatic as otherwise healthy people die from flu and similar problems
over a period of weeks after the cold weather event. This is much less dramatic and goes under
reported, but the numbers are there. If more data were available from the tropics the picture might be
more balanced in terms of heat versus cold as a killer, but would not likely show any significant net
increase in mortality due to the heat. Both heat and cold related deaths have a strong poverty
component. It is obvious that air conditioning has done much to reduce heat stress in modern societies.
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Many “tropical” diseases are not very temperature sensitive. Malaria was once rampant in the U.S. and
Europe. It was conquered by modern medicine and hygiene. This and other diseases associated with
the tropics are more strongly related to underdevelopment and poverty than to temperature. For
example, malaria was eliminated from Singapore by the 1970s. Singapore lies on the equator. It
differs from malaria ravaged countries mainly in wealth and development. More on this later.
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The scientific community is divided on this. Some say yes, others say that higher temperatures will
lead to fewer or weaker hurricanes. After Katrina, some thought global warming would bring on more
of the same every year. Yet the 2006 and 2007 seasons were mild. In terms of total energy in the
storms, 2007 was exceptionally mild. There were several strong storms, but they were very short lived.
Hurricanes are highly variable from year to year so no one year can “prove” anything. Analysis over
the last 100 years, taking into account differences in reporting and monitoring ability, seem to suggest
that the 1 degree rise we have seen so far has had very little impact on hurricanes.
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The Gulf Stream, contrary to popular belief, for the last 300 years has had a very minor effect on
Europe's climate. Because of the westerly winds off the ocean, both England and the Pacific Northwest
of the U.S. have “maritime” climates. Ocean water heats the winds that carry moist, warm air over
land. In addition, the fear of major changes in the Gulf Stream due to warming is largely discredited.
After all, it is tropical warming that produces the Gulf Stream in the first place.
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Insofar as changes in the sun or other cosmic factors are producing it, basically nothing. Insofar as
human activities are part of the problem, we have some options. It is generally agreed that should ALL
burning of fossil fuels stop today, the present CO2 induced warming would continue for a number of
decades. It is only as an attempt to limit the worst extremes of global warming that carbon taxes or
voluntary cutbacks are suggested. So far there seems to be no generally accepted plan as to how
modern countries can make major cuts without serious damage to their economy and life style. Human
populations have shown themselves unwilling to make such sacrifices until the consequence of the
failure to do so are immediate, indisputable and severe. Thus, within a democratic framework, it is not
likely that much will be done. Totalitarian regimes have shown themselves to be even worse in
dealing with environmental dangers.
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There are many who are now turning attention to the ways to “mitigate” the effects of global warming
rather than trying to stop it, although the attempt to do both is often made. In my opinion, mitigation is
a much more fruitful avenue of approach. It would be much cheaper to relocate low lying communities
or to build levees or dikes rather than shutting down the power industry or applying some “heroic”
scheme of capturing carbon and putting it in the oceans.
While planning can be done now at a relative low cost, the actual implementation of some of the
mitigation schemes need not be done way in advance. For example, if the oceans continue to rise at an
ever quickening pace, we should still have several decades to plan and implement contingency plans.
If crops need to be moved further north or new varieties cultivated, this can be done with only a few
years' advance notice. Outbreaks of disease can be planned for and then bold plans put into action
when needed.
Dealing with existing problems in these areas can serve as pilot programs for more serious problems
that may (or may not) arise later. For example, if malaria is largely defeated in Africa NOW, we need
not fear it spreading to Europe or North America in 20 years due to global warming. If flooding in
Bangla Desh can be stopped NOW or, at least, life saving approaches adopted, then we will be ready
when Florida sees the same kind of devastating storms from which Bangla Desh now suffers. If
presently endangered species can be preserved by various innovative methods NOW, then we will be
ready to save the polar bear if and when that becomes necessary. If persons in presently temperate
latitudes face future death in heat waves, why not learn how to prevent those deaths by working in
India or the Saraha NOW. None of the projected catastrophes which the future MAY produce are
totally absent from our present world. Does it not make more sense to solve the ACTUAL PRESENT
problems before or, at least, along with trying to prepare for or prevent future uncertain ones?
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Yes, it could be. I have already mentioned the association of malaria and other premature deaths with
poverty and underdevelopment. Probably nothing would save more lives in the third world than
improvements in the infrastructure. These could include improved roads and vehicles to take the sick
and injured to the hospital. LP stoves could replace the use of animal dung cooking fires which cause
millions of deaths from respiratory distress, better diet could help bring many health benefits, etc. Yet
all of these things are the result of development and development seems to have as its price the burning
of fossil fuel, at least for the next few decades.
The worse case scenario is that in a futile attempt to “stop” global warming, we would hinder
development in the third world and, thus, condemn those folks to continue to experience the very same
devastating problems that we are trying to avoid. Neither climate scientists nor politicians can
intelligently deal with many aspects of this problem. Economists and non governmental organizations
active in disaster relief are much better suited to solve these problems.
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There is much that we can do that makes sense whether we believe that global warming is a problem or
not. It is good that grade school children come home and turn off unused lights. It is unfortunate that
they must be traumatized about polar bears in order to do it. Either from a personal financial point of
view or from an ecologically sensitive point of view, wasting energy is just stupid. Yet it is rampant.
I have never understood the opposition to CFLs (compact fluorescent lights) on the part of those who
are skeptical about global warming. Should we waste our money and the world's energy just because it
doesn't matter if we make CO2? Of course, if you have light dimmers, which don't work with CFLs,
lay in a few dozen regular bulbs just in case they are outlawed. But, otherwise, why not save many
dollars a year of your own money? When LEDs become cheaper they will be even better than CFLs.
Better yet, turn off all the lights you aren't using (automatic controls are available) and use outside light
as much as possible (skylights, etc). Why not sit by a window to read or sew?
Don't overcool or overheat your house. Most of the world knows about sweaters. They do wonders in
a 65 degree house. Long underwear is even better. Fans help in summer if you sit under them (in an
unoccupied room they make it hotter). Leave unoccupied rooms unheated or uncooled. Turn down
your water heater, take shorter showers. Drive less. Car pool. Walk or bike to work if you can. Buy a
fuel efficient car. Exercise by mowing with a push mower or have no yard. Exercise machines should
generate electric power, not use it. I have to admit, I do use a chain saw and hydraulic log splitter for
my firewood. Old age makes some luxuries into necessities. But you get the idea. Ask yourself , if I
just HAD to cut my fuel and electric bill in half, what would I do? Some day you may have to.
Most of the things that really make “green sense” cost less. If things cost more, it is a good reason to
question if they are really green. Organic food costs more because it takes more resources to produce
(more land, more work). If everyone ate organic, 20% of the world would starve because we simply
don't have enough land to grow all the needed food in the less efficient organic way. If organic food is
your chosen luxury, then eat it, but don't think you are “saving the planet”. At least in the first world, it
is a luxury only the rich can afford. But of course, if you do the work and use your own land, fresh
vegetables are wonderfully cheap and delicious, organic or not.
The same thing can be said about meat. There is not enough farmland to feed the world with the
typical U.S. meat heavy diet. Raising grain fed meat animals takes much more land than producing the
same number of calories from vegetables or grains. Only if meat is raised on otherwise unsuitable land
and the animals eat food unsuitable for humans can meat eating be efficient in a food limited world.
This explains the popularity of goats in poor countries. Of course, locally harvested wild game is a
“green “ meat source which satisfies the above criteria. Deer and wild turkeys are good examples. I
eat meat, but when in Africa, if times are hard, I can do without.
The “food miles” concept is a questionable “green” idea. I buy the cheapest food for a given quality
without regard to place of origin. If food is cheaper, it probably was produced more efficiently,
including transportation. Besides, imported food helps third world countries to develop which they
need to do to buy air conditioners so they can survive in the warmer world.
Recycling can be very good as in the case of aluminum cans or just about neutral as is often the case
with paper. If the recycled product costs more than the normal one, than you can be pretty sure it has
used more resources to produce, even if the raw material was free. Either that or someone is making a
extra buck to provide you a “feel good” recycled product which has no real environmental advantage.
The best recycling is to keep your old stuff longer. Most of us discard lots of perfectly usable “stuff”
just to buy more “stuff”.
Buying “carbon offsets” is of questionable value and, in some cases, an outright scam. If you think
trees are good, plant them yourself. Donations to NGOs working in the third world are vastly more
helpful than paying for carbon offsets.
Here is a good rule of thumb. If you pay a premium for anything, apart from it being a higher quality
product that will last longer or better meet your real needs, you are likely NOT making the “green”
choice. So, be a cheapskate and you will be both greener and richer for it.
Make it a point to live on less. Such a lifestyle has been around long before being “green” was in
vogue. The idea is to consume less so you can share more. The world is full of folks whose very
survival depends on our willingness to share some of what God has blessed us with. John Wesley's
motto was: “earn all you can, save all you can, give all you can.” Jesus said, “it is blessed to give”.
Another good rule is to “live simply so that others can simply live”.
Above all, enjoy life. The best things in life really are free and don't produce much CO2.
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This page was last modified on the 10th of April 2008.