Global Warming
INTRODUCTION
The greenhouse effect, which is causing global warming, is a natural phenomenon that helps regulate
the temperature of our planet. Sun heats the Earth, and some of the heat, rather than escaping back
into space is trapped in the atmosphere by clouds and greenhouse gases. The most important of these
gases are water vapor, carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons,
sulfur hexafluoride and ozone. If all of these gases were to suddenly disappear our planet would be
33°C colder and uninhabitable. Therefore the problem isn't actually the greenhouse effect in itself;
rather, it is maintaining the influence of the greenhouse effect at a relatively stable level.
Human actions are causing the release of additional greenhouse gases into the atmosphere; these gas
emissions are believed to remain in the atmosphere because the planet can't process surplus amounts.
Increased amounts of greenhouse gases trap more heat than usual, causing the planet to warm up. The
primary sources of emissions are fossil fuel burning, industrial production and changes in land use,
with especially motor vehicles counting for most of the increases in the critical CO2 emissions.
The direct results of global warming are thought to be increased median temperatures and heat waves,
rising sea level, flooding and droughts, and the melting of glaciers and polar ice caps. These will
then cause the spreading of tropical diseases, plant and animal range shifts or population declines,
earlier spring arrival, coral reef bleaching, heavier rain and snowfall, forest fires, worsened air
pollution, damaged crops, depleted water resources, more intense storms and cyclones, and so on.
However, the entire theory is still somewhat in doubt, and under constant debate. It is the purpose
of this article to list the main arguments both for and against this theory, and to point out flaws
in them if logically evident. I am not a scientist myself so I try to avoid getting involved in the
argument, and simply provide links for more information. One thing seems certain however: there are
loads of misinformation floating around. This article tries to set the facts straight for once.
One of the biggest misconceptions is that global warming can only be a bad thing; this is certainly
not true, considering that even the IPCC report openly admits that benefits are likely to be gained
at least in the form of lenghtened growing season, reduced energy needs and a more hospitable world
in general. At the same time they admit that many of the negative issues related to this phenomenon
are still very much in doubt. Eventhough global warming is likely to demand some adjustments in the
short term, we must note that it is generally better to live in a warmer world than a colder one.
STATISTICS
The most authorative publication on global warming is IPCC's climate change synthesis report, which
is published annually (see Sources). The statistics in this article are based on the 2001 synthesis
report. The amusing thing is that even much of the information in the synthesis report itself is so
contradictory to what the media and people in general seem to believe, that it makes an interesting
read on its own. The most important statistics are summarised here, for the reader's convenience.
The temperature record for the last 1000 years shows a cooling trend of some 0.1°C during the years
1000-1900, then a steady rise of 0.4°C during 1910-1940, leveling during 1940-1980 and then again a
continuing rise of 0.4°C during 1980-2000. World mean surface temperatures have risen between 0.4°C
and 0.8°C over the 20th century, although it might be noted that land areas warmed more than oceans.
Surface temperature ranges decreased; minimum night time temperatures rose twice as much as maximum
day time temperatures, with the former about 0.2°C per decade during 1950-2000. Cold and frost days
decreased while hot days increased. The warmest year in the entire instrumental record was 1998.
The amounts of greenhouse gases in the atmosphere were relatively stable before 1750, but have been
increasing rapidly since then. CO2 remained at a steady 280 ppm during 1000-1750 but was 368 ppm by
the year 2000. Methane remained at 700 ppb during 1000-1750, but climbed up to 1750 ppb by the year
2000, with the truly sharp climb starting at the start of the 20th century. Nitrous oxide (which is
less important in terms of radiative properties than the other two gases) also shows a pattern that
precisely matches that of methane. Overall, it is estimated that although the concentrations of CO2
and methane have varied widely during the Earth's history, their concentrations are now much higher
than at any time during the previous 420,000 years; this is a very noticeable increase indeed.
About 75% of the CO2 increase in the 1990s was caused by the burning of fossil fuels, with land use
change such as deforestation counting for the rest. Methane is emitted due to energy use, livestock,
rice agriculture, and landfills. Ozone and other gases come from burning fossil fuels, agricultural
and industrial emissions; no actual figures regarding the relative importance were given, but these
gases are considerably less important than CO2 and methane in terms of the overall effect anyway.
Precipitation has increased 5-10% in the northern hemisphere over the 20th century for the mid- and
high latitudes, but decreased in Africa and parts of South America. In general, small or no changes
have been noted in the global trends of droughts and heavy rainfall during the 20th century. The El
Niños (disruption of the ocean-atmosphere in the tropical Pacific that causes flooding, drought and
other severe weather events in a global scale; occurs about once per decade) have apparently become
more frequent, persistent and intense during the last 20-30 years when compared to the previous 100
years, but the computer models do not actually give any reason to believe that El Niño events would
become more frequent in a warmer world. It is not possible to measure the changes in frequencies of
tornadoes, storms, hails or cyclones; insufficient data and conflicting analyses prevent making any
conclusions. Coral reef bleaching has increased in frequency, especially during El Niño events.
Duration of river- and lake ice cover has decreased about 2 weeks over the 20th century in mid- and
high latitudes in the northern hemisphere. Arctic sea ice extent and thickness has fallen by 40% in
the last 3 decades, from late summer to early autumn; extent is thought to have decreased by 10-15%
since the 1950s, in the spring and summer. Non-polar glaciers have shown wide-spread retreat during
the 20th century. Snow cover has decreased in total area by 10% since the 1960s. Permafrost appears
to have become degraded in parts of polar, sub-polar and mountainous regions. Global mean sea level
has risen about 1-2 mm per year during the 20th century, at least based on measurements in Europe.
Growing season has been lenghtened by 1-4 days each decade during the last 40 years in the northern
hemisphere, especially in higher latitudes. Plant and animal ranges have shifted poleward and up in
elevation for plants, insects, birds and fish. Plant flowering, animal arrival and breeding seasons
have become earlier. Pest insect frequensies are also (although obscurely) noted to have changed.
UNCERTAINTIES
The IPCC report leaves much room for a debate; some of the data is not sufficient for making global
conclusions, while on the other hand many data sets show important deviations that are very hard to
explain and account for. Sometimes important information is totally missing or simply left out, and
at other times some factors are exaggerated. This is not to say that the report would be incomplete
of course, but there is room for improvement. This section is dedicated to discussing such issues.
First of all, the warming is not evenly distributed. IPCC states that global warming is supposed to
have much more influence on cold rather than warm areas. The temperature charts reveal most warming
within the horizontal "belt" which wraps around the planet, covering North America, Europe and Asia.
It is mirrored, although to a much lesser degree, in the southern hemisphere. Areas surrounding the
equator are not affected very much, and in some places they are actually even showing some regional
cooling. North pole appears to be almost as heavily affected as the rest of the northern hemisphere,
but the real problem is that except for a few isolated areas, Antarctica as a whole does NOT appear
to have been affected at all. In fact, even IPCC agrees that it may actually be getting colder.
This poses a serious problem because the theory states that warming should occur first and foremost
in the coldest regions of Earth. Antarctica is also vital in terms of sea level rise, because about
90% of the ice on this planet is deposited there. The situation actually looks like if somebody had
placed a huge lamp above the north pole; the northern hemisphere would get warmer, but the southern
hemisphere might actually become colder because it would be in the shade. Nobody seems to have paid
much attention to the possibility of the Earth's orbital alignment going through oscillations which
could, over long periods of time, switch the hemisphere that spends the most time facing the Sun.
Weather balloons and satellites generally show an identical temperature record but in the tropics a
very noticeable discrepancy appears. Weather balloons show much greater warming than satellites for
these areas, indicating that either the surface has warmed more than the lower atmosphere, or there
is something wrong with the measurements. Weather balloons are noted to suffer from the "urban heat
island effect", meaning that cities trap heat and would therefore throw off the results from nearby
measurement areas when they expand over time. On the other hand, satellites could be suffering from
orbital decay, which means that the measurements are thrown off because the satellites drift slowly
downward toward the surface. Based on the theory itself not much warming should be happening in the
tropics anyway, but it is worth noting that the lower atmosphere is supposed to warm up first.
There are considerable uncertainties regarding the indirect effects of aerosols, hydrological cycle,
organic carbon, black carbon (soot), biomass aerosols, and land use changes. Aerosols in particular
are troublesome because they are believed to counter some of the greenhouse effect, but the precise
amount is very difficult to calculate. The estimated range reaches from zero to such levels that it
could potentially even counter the entire global warming phenomenon by itself. This becomes amusing
when one considers how much effort has been spent on getting rid of products which release aerosols
into the atmosphere to avoid making the ozone hole bigger; it is like shooting at one's own foot.
The sea level measurements are unreliable because they only cover Europe; there are some reports of
dropping sea levels in other parts of the world, such as Australia. Overall, 1-2 mm per year is not
a significant number by any standards; it is so small that regional or measurement deviations could
easily count for it. Not much sea level rise should be occuring anyway; as noted earlier, there has
been no real cooling in Antarctica and the north pole actually has relatively little ice in it. Not
to mention that northern polar ice is already floating in the ocean, so it could have little effect.
We can therefore call this a non-issue. Even if all ice on the planet melted, sea levels would rise
only about 65 meters; disastrous for sure, but certainly not something we couldn't survive.
ECONOMICAL ISSUES
There is much concern over the economical costs of reducing emissions, and for a good reason; Kyoto
protocol, for example, requires emissions to come down by 43% for the 2008-2012 average. The impact
of this reduction is estimated to be between 0.04°C and 0.07°C, which of course means that it makes
absolutely no difference. At the same time, the financial losses caused by such drastics reductions
could collapse economies, and ultimately bring about exactly the sort of destruction these treaties
are meant to prevent. Reducing emissions so much that it would have practical impact to our world's
climate is therefore unthinkable; the direct consequence would literally be the end of the world.
Should there still be some effort to reduce emissions, at least it could be done in a more sensible
way. The basic rule of optimisation states, that one should only optimise where it actually matters.
This means that we should ignore the emissions of lesser greenhouse gases, and concentrate fully on
the few that really count, meaning CO2 and methane. This would result in much more efficient use of
the available resources and legislative mechanisms. The reductions should also be directed at those
countries with the highest levels of emission, like the United States. The Russian Federation comes
second with only about half of United States emissions, and Japan and Germany share the third place
with amounts that are roughly half of Russia's emissions. This is where such reductions could count;
getting other countries to reduce their tiny emissions matters only in the diplomatic sense.
Economic losses due to environmental disasters have increased by a factor of 6 over the previous 40
years, but this is in part due to the expanding human population and modern living habits; we are a
bigger target now than at any time in the past. The media is also paying much more attention to all
kinds of environmental disasters, which coupled with an increased saturation of monitoring stations
around the world explains the general but faulty perception that these events have become much more
frequent. Considering the history of our planet, the last 9000 years have been unusually quiet.
DEBATE ISSUES
The IPCC temperature record for the last 1000 years is apparently flawed, caused by its reliance on
tree ring data. It totally misses two historically documented climate anomalies, the "Medieval Warm
Period" and "Little Ice Age". These can be readily measured from various other sources. Temperature
fluctuated up to 3°C during these episodes, which is a lot more than what we are seeing now. In the
scale of hundreds of thousands of years we discover that temperatures fluctuate widely in a roughly
predictable manner; we are currently on the rising edge of a warming peak, still well below the top
levels of previous peaks, so being unable to detect any warming at all would be very surprising.
It is a historical fact that increases in CO2 and methane are linked to global warming; the problem
is that it is far from certain whether these increases are causing the warming, or if they are just
a result of it. Paleo-climate research suggests that increased levels of methane and CO2 come after
warming, not the other way around. A warming world would provide more room for swamps which produce
methane; similar explanations can also be given for increases in CO2. In some cases it's discovered
that the two phenomena don't correspond to each other at all; high levels of CO2 have been detected
even during ice age conditions, as well as relatively low levels during extremely warm periods.
IPCC states that not all of the warming is caused by human influence; indeed, it's possible to read
from the diagrams that natural forcings could be used to explain most warming prior to 1980s, which
is when the sharp rise begins. This gets interesting when one notices that many scientists, who are
otherwise supporting the theory, state that little or no warming has been detected since 1986. Some
scientists also question how the Earth could have cooled during 1940-1976, which was the most rapid
post world war re-building era; lots of greenhouse gases should have been released at this time. In
any case, it is strange that global warming seems to take place in short bursts while the increases
in greenhouse gases are mostly linear (actually more like an exponential curve, but predictable).
As a point of trivia, for much of this planet's history, CO2 levels have been much higher than they
are today. During the last 300 million years, there were only two periods of less than 1,000 ppm of
CO2. In the Mesozoic, which lasted several hundred million years, the levels of CO2 hovered between
1,000 and 2,000 ppm, with occasional peaks even above 2,000 ppm. Temperature changes have also been
much greater than what global warming is feared to cause. Large temperature changes in the order of
over a dozen degrees are known to have taken place rapidly within just a few years or decades.
Some critics note that solar activity can provide a fairly plausible explanation for global warming,
as well as many other climate issues. Increases in Sun's radiation correspond closely with the past
temperature record. Earth's orbit around the Sun is also slightly elliptical, which can have impact
on climate because it means that Earth's distance from the Sun varies over time. Proponents counter
by saying that the impact is minimal, but the research is far from complete. Other researchers have
discovered close correlations between climate trends and the orbits of Moon, Venus and Jupiter. The
periodic changes in the alignment of the Earth's axis are also found to have climate impacts.
The effects of sulfate aerosols appear questionable; since the southern hemisphere is almost devoid
of sulfate aerosols, and it is mostly the sulfates which IPCC uses to explain why its previous very
high predictions of warming have not come true, this is where most warming should have occured. The
estimated ranges of impact from other uncertainties don't come even close to sulfate aerosols.
It is questionable whether Earth could actually be as sensitive to sudden forcings as we are led to
believe; in order to have stayed habitable this far it would have needed strong recovery mechanisms.
Sudden and massive volcanic eruptions could otherwise throw the entire system off-balance instantly.
Man is responsible for only 2% of greenhouse gas emissions; natural variations can be a lot greater.
Increases in CO2 levels would increase vegetation which would then absorb and convert more CO2 into
oxygen; some research data suggests that this is already happening. Additionally, in a warmer world
more water vapor would reside in the atmosphere, forming much more clouds to cool the planet.
Unlike the greens would have us believe, global warming critics aren't actually a marginal group of
industry-lobbyists; many of IPCC's chief scientists have switched sides, and are now quite publicly
criticising the global warming theory, as well as the process used in drafting those reports. There
are currently over 17000 signatories in what is known as "The Oregon Petition" which is saying that
there is no man-made global warming; all of the signatories are verified, respected scientists, and
specialists in climate sciences or other fields that are closely related to global warming.
CONCLUSIONS
While few people are actually questioning whether the Earth has really warmed over the past century,
there are still many holes in the theory. We also don't have effective means to prevent it so until
we do, throwing bucketloads of money at the problem is not justified. Media and government pressure
are certainly not helping; the entire issue has become loaded and political, which degrades science.
In order to tackle the problem it should be removed from the public domain entirely, and given back
to scientists, where it belongs. Otherwise the results are doomed to be biased and thus useless.
SOURCES
Climate Change 2001: Synthesis Report
Intergovernmental Panel on Climate Change (IPCC)
http://www.ipcc.ch/pub/SYRtechsum.pdf
The Oregon Petition
Petition of Scientists Against Global Warming
http://www.oism.org/pproject/
The "Hockey Stick": A New Low In Climate Science
by John L. Daly
http://www.john-daly.com/hockey/hockey.htm
Global Warming: The Big Picture
by James J. Besemer, September 2001
http://www.ocs.orst.edu/forum/BigPicture.htm
Kyoto Protocol: A Useless Appendage To An Irrelevant Treaty
Patrick J. Michaels, Professor of Environmental Sciences, Cato Institute
http://www.cato.org/testimony/ct-pm072998.html
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