From www.friendsofscience.org comes this section:

MYTH 1:  Global temperatures are rising at a rapid, unprecedented rate.

FACT:  Accurate satellite, balloon and mountain top observations made over the last three decades have not shown any significant change in the long term rate of increase in global temperatures. Average ground station readings do show a mild warming of 0.6 to 0.8C over the last 100 years, which is well within the natural variations recorded in the last millennium. The ground station network suffers from an uneven distribution across the globe; the stations are preferentially located in growing urban and industrial areas (“heat islands”), which show substantially higher readings than adjacent rural areas (“land use effects”).

There has been no catastrophic warming recorded.

MYTH 2:  The “hockey stick” graph proves that the earth has experienced a steady, very gradual temperature increase for 1000 years, then recently began a sudden increase.

FACT:  Significant changes in climate have continually occurred throughout geologic time. For instance, the Medieval Warm Period, from around 1000 to1200 AD (when the Vikings farmed on Greenland) was followed by a period known as the Little Ice Age. Since the end of the 17^th Century the “average global temperature” has been rising at the low steady rate mentioned above; although from 1940 – 1970 temperatures actually dropped, leading to a Global Cooling scare.

The “hockey stick”, a poster boy of both the UN’s IPCC and Canada’s Environment Department, ignores historical recorded climatic swings, and has now also been proven to be flawed and statistically unreliable as well. It is a computer construct and a faulty one at that.

MYTH 3:  Human produced carbon dioxide has increased over the last 100 years, adding to the Greenhouse effect, thus warming the earth.

FACT:  Carbon dioxide levels have indeed changed for various reasons, human and otherwise, just as they have throughout geologic time. Since the beginning of the industrial revolution, the CO₂ content of the atmosphere has increased. The RATE of growth during this period has also increased from about 0.2% per year to the present rate of about 0.4% per year,which growth rate has now been constant for the past 25 years. However, there is no proof that CO₂ is the main driver of global warming. As measured in ice cores dated over many thousands of years, CO₂ levels move up and down AFTER the temperature has done so, and thus are the RESULT OF, NOT THE CAUSE of warming. Geological field work in recent sediments confirms this causal relationship. There is solid evidence that, as temperatures move up and down naturally and cyclically through solar radiation, orbital and galactic influences, the warming surface layers of the earth’s oceans expel more CO₂ as a result.

MYTH 4:  CO2 is the most common greenhouse gas.

FACT:  Greenhouse gases form about 3 % of the atmosphere by volume. They consist of varying amounts, (about 97%) of water vapour and clouds, with the remainder being gases like CO₂, CH₄, Ozone and N₂O, of which carbon dioxide is the largest amount. Hence, CO₂ constitutes about 0.037% of the atmosphere. While the minor gases are more effective as “greenhouse agents” than water vapour and clouds, the latter are overwhelming the effect by their sheer volume and – in the end – are thought to be responsible for 60% of the “Greenhouse effect”.

Those attributing climate change to CO₂ rarely mention this important fact.
MYTH 5:  Computer models verify that CO2 increases will cause significant global warming.

FACT:  Computer models can be made to “verify” anything by changing some of the 5 million input parameters or any of a multitude of negative and positive feedbacks in the program used.. They do not “prove” anything. Also, computer models predicting global warming are incapable of properly including the effects of the sun, cosmic rays and the clouds. The sun is a major cause of temperature variation on the earth surface as its received radiation changes all the time, This happens largely in cyclical fashion. The number and the lengths in time of sunspots can be correlated very closely with average temperatures on earth, e.g. the Little Ice Age and the Medieval Warm Period. Varying intensity of solar heat radiation affects the surface temperature of the oceans and the currents. Warmer ocean water expels gases, some of which are CO2. Solar radiation interferes with the cosmic ray flux, thus influencing the amount ionized nuclei which control cloud cover.

MYTH 6:  The UN proved that man–made CO2 causes global warming.

FACT:  In a 1996 report by the UN on global warming, two statements were deleted from the final draft. Here they are:
1)     “None of the studies cited above has shown clear evidence that we can attribute  the observed climate changes to increases in greenhouse gases.”
2)     “No study to date has positively attributed all or part of the climate change to man–made causes”

To the present day there is still no scientific proof that man-made CO2 causes significant global warming. 

MYTH 7:  CO2 is a pollutant.

FACT:  This is absolutely not true. Nitrogen forms 80% of our atmosphere. We could not live in 100% nitrogen either. Carbon dioxide is no more a pollutant than nitrogen is.  CO2 is essential to life on earth. It is necessary for plant growth since increased CO2 intake as a result of increased atmospheric concentration causes many trees and other plants to grow more vigorously. Unfortunately, the Canadian Government has included  CO2 with a number of truly toxic and noxious substances listed by the Environmental Protection Act, only as their means to politically control it.

MYTH 8: Global warming will cause more storms and other weather extremes.

FACT:   There is no scientific or statistical evidence whatsoever that supports such claims on a global scale.  Regional variations may occur. Growing insurance and infrastructure repair costs, particularly in coastal areas, are sometimes claimed to be the result of increasing frequency and severity of storms, whereas in reality they are a function of increasing population density, escalating development value, and ever more media reporting.

MYTH 9:  Receding glaciers and the calving of ice shelves are proof of global warming.

FACT:  Glaciers have been  receding and growing cyclically for hundreds of years. Recent glacier melting is a consequence of coming out of the very cool period of the Little Ice Age. Ice shelves have been breaking off for centuries. Scientists know of at least 33 periods of glaciers growing and then retreating. It’s normal. Besides, glacier’s health is dependent as much on precipitation as on temperature.

MYTH 10:  The earth’s poles are warming; polar ice caps are breaking up and melting and the sea level rising.

FACT:  The earth is variable. The western Arctic may be getting somewhat warmer, due to unrelated cyclic events in the Pacific Ocean, but the Eastern Arctic and Greenland are getting colder. The small Palmer Peninsula of Antarctica is getting warmer, while the main Antarctic continent is actually cooling. Ice thicknesses are increasing both on Greenland and in Antarctica. 

Sea level monitoring in the Pacific (Tuvalu) and Indian Oceans (Maldives) has shown no sign of any sea level rise.

The fact that most people in the world today believe that air pollution causes Global Warming drives me absolutely crazy. The fact that these people embrace the Kyoto accord to deal with these problems makes even less sense: Kyoto deals almost exclusively with the reduction of CO2 gas in the atmosphere.  CO2 is neither a pollutant, nor the cause of Global Warming. CO2 is a colourless, ordourless gas that is the ‘oxygen’ to all the plants and trees in the world. Remember your grade 9 biology class? Photosynthesis? It is the lifeblood of the tropical rainforests we all tried so hard to save during the late seventies and early eighties.

Let’s play with some numbers shall we?

CO2 (a greenhouse gas) makes up about 3% of the world’s greenhouse gases. About 95% is water vapour, the other 2% a mixture of various gases. Of this 3%, humans are responsible for generating about 6%. Through agriculture, and reforestation, humans are also responsible for REDUCING CO2 by about 3%, making the net human contribution 3%. That makes human source CO2 3% of 3% of all greenhouse gases. Canada is responsible for less than 3% of all human generated CO2, making our share less than 3% of 3% of 3%, or 0.000027%. Kyoto requires us to scale back our emissions by 6%, or 6% of less than 3% of 3% of 3%, or 0.00000167%. We are going to spend billions of dollars to reduce the total concentration of CO2 in the global greenhouse gas concentrations by less than 0.00000167%.

Even if we all stopped driving our cars, stopped heating our houses, and stopped breathing, since exhaling puts CO2 in our atmosphere, and we achieved a 100% reduction in CO2 emissions, we’d only reduce the global CO2 levels in the total greenhouse gases by less than 0.000027%.

Hardly seems worth it, does it?

More reading:
http://www.friendsofscience.org
http://www.junkscience.com/Greenhouse/