COMMON MISCONCEPTIONS ABOUT GLOBAL WARMING
MYTH 1: Global temperatures are rising at a rapid, unprecedented rate.
FACT: The HadCRUT3 surface temperature index, produced by the Hadley Centre of the UK Met Office and the Climate Research Unit of the University of East Anglia, shows warming to 1878, cooling to 1911, warming to 1941, cooling to 1964, warming to 1998 and cooling through 2011. The warming rate from 1964 to 1998 was the same as the previous warming from 1911 to 1941. Satellites, weather balloons and ground stations all show cooling since 2001. The mild warming of 0.6 to 0.8 C over the 20th century 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"). Two science teams have shown that correcting the surface temperature record for the effects of urban development would reduce the reported warming trend over land from 1980 by half. See here.
There has been no catastrophic warming recorded.
MYTH 2: The "hockey stick" graph proves that the earth has experienced a steady, very gradual temperature decrease 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 17th 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. See here for more information.
MYTH 3: Human produced carbon dioxide has increased over the last 100 years, adding to the Greenhouse effect, thus causing most of the earth's warming of the last 100 years.
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 by about 120 part per million (ppm), most of which is likely due to human-caused CO2 emissions. The RATE of growth during this century has been about 0.55%/year. 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 0.04% 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 75% of the "Greenhouse effect". (See here) At current concentrations, a 3% change of water vapour in the atmosphere would have the same effect as a 100% change in CO2.
Those attributing climate change to CO2 rarely mention these important facts.
MYTH 5: Computer models verify that CO2 increases will cause significant global warming.
FACT: The computer models assume that CO2 is the primary climate driver, and that the Sun has an insignificant effect on climate. Using the output of a model to verify its initial assumption is committing the logical fallacy of circular reasoning. Computer models can be made to roughly match the 20th century temperature rise by adjusting many input parameters and using strong positive feedbacks. 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 United Nations' Intergovernmental Panel on Climate Change (IPCC) has proven 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 approved and accepted by a panel of scientists. 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.
See a Wall Street Journal article here.
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. The graph here shows changes in vegetative cover due to CO2 fertilization between 1982 and 2010 (Donohue et al., 2013 GRL). A major study here shows that CO2 fertilization will likely increase the value of crop production between now and 2050 by an additional $11.7 trillion ($US 2014). See here for more discussion.
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. See here for graphs and discussion of extreme weather.
MYTH 9: Receding glaciers and the calving of ice shelves are proof of man-made 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, changes to glacier's extent is dependent as much on precipitation as on temperature.
MYTH 10: The earth’s poles are warming and the polar ice caps are breaking up and melting.
FACT: The earth is variable. The Arctic Region had warmed from 1966 to 2005, due to cyclic events in the Pacific Ocean and soot from Asia darkening the ice, but there has been no warming since 2005. Current temperatures are the same as in 1943. The small Palmer Peninsula of Antarctica is getting warmer, while the main Antarctic continent is actually cooling. Ice cap thicknesses in both Greenland and Antarctica are increasing. North polar temperature graph here. South polar temperature graph here. See here for sea ice extent.
More FACTS and MYTHS? See what Professor deFreitas has to say. Click here.