POINT | COUNTERPOINT
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POINT #1:
CO2 is a pollutant.
COUNTERPOINT
CO2 is essential to life on earth. It is the primary food necessary for plants to grow. These plants ultimately become a primary food source for many animals, humans included. Consequently, increased CO2 in the air causes many plants to grow more vigorously.CO2 has been vilified as a pollutant because it is one of the results of burning anything that contains carbon which includes hydrocarbons, biofuels, wood and all other organic matter. Burning carbon based material requires oxygen and results in CO2 and H2O. CO2 is no more a pollutant than water.
The Canadian Government has included CO2 in their List of toxic substances managed under Canadian Environmental Protection Act but it is not listed in Canada’s Air Pollutant Emissions Inventory Report 1990 - 2019 . This demonstrates that the government wants the EPA to control CO2 but it does not believe CO2 emissions should be inventoried – odd isn’t it?
Pollutants do not help plants grow but CO2 does just that.
This map presents the changes in vegetative cover caused by increased CO2 fertilization between 1982 and 2010 (GEOPHYSICAL RESEARCH LETTERS Donohue et al., 2013). A major study published in CO2 Science shows that CO2 fertilization will likely increase the value of crop production between 2013 and 2050 by an additional $11.7 trillion ($US 2014).
For further details see CO2 Increases Plant And Forest Growth.
POINT #2:
The "hockey stick" graph proves that temperatures gradually decreased for 1000 years then sharply increased 100 years ago.
COUNTERPOINT
The "hockey stick" is the creation of Mann, Bradley and Hughes in 1998 and it has become the poster child of the climate alarmism movement. The graph is a presentation of temperatures that includes corrections applied to the data that removed historic warming and cooling trends. The result is indeed a relatively flat temperature chart with a large increase starting in about 1900. Coincidentally 1900 happens to be defined as the beginning of the industrial revolution and the large temperature increase then gets blamed on human emissions. The hockey stick only proves how bad science can create any result you want.The manipulations used to achieve the hockey stick shape were discredited in 2003 by two Canadians, Ross McKitrick and Stephen McIntyre, who published that the Mann “hockey stick” contained many errors and omissions. They also discovered that the computer model used was faulty and it created hockey sticks no matter what the input data was.
In the graph above, the lower curve in blue is the Mann et al hockey stick graph and it is compared with the correct temperature data in red. (Source: page 766 in McIntyre & McKitrick, 2003)
RWP = Roman Warm Period AD 1-300 | DACP = Dark Age Cold Period 300-900 |
MWP = Medieval Warm Period 800-1300 | LIA = Little Ice Age 1300-1900 |
CWP = Current Warm Period 1900-present |
The above chart demonstrates that significant temperature changes have occurred in the past two thousand years. Most importantly is to note that the Medieval Warm Period (MWP) was warmer than the current warming (CWP). The MWP was when Vikings settled Greenland and discovered eastern Canada. The MWP was then followed by the Little Ice Age (LIA) which was a bitterly cold period between 1600 and 1800.
For further details see The IPCC Hockey Stick and Temperature Over Geological Time.
POINT #3:
Human produced CO2 has increased over the last 100 years adding to the Greenhouse effect and in turn fueling most of the warming of the last 100 years.
COUNTERPOINT
Over the past 100 years CO2 concentration in the atmosphere has indeed increased primarily due to the increased use of fossil fuels. However, inferring that the increase in CO2 concentration caused the earth’s warming is incorrect. The Vostok Antarctica ice core measurements have demonstrated that temperature changes precede CO2 concentration changes by about 800 years.(Source: Caillon pg.1730 Timing of Atmospheric CO2 and Antarctic Temperature Changes Across Termination III, 2003)
These findings confirm that increasing CO2 concentration is an effect of temperature increase. Increasing temperature causes the oceans to expel CO2 because CO2 is less soluble in warm water. The core data also shows that when temperature starts to drop, after reaching a high in each cycle, CO2 concentrations continue to increase for as much as another 800 years! This lag of CO2 to temperature is the opposite of what one would expect if CO2 were the primary driver of a warming climate.
For further details see Temperature Leads CO2 Changes.
POINT #4:
CO2 is the most common greenhouse gas.
COUNTERPOINT
In 2020, CO2 constitutes ~411 ppm (parts per million) which is ~0.04% of dry air. Water vapour is actually the most abundant greenhouse gas.Water vapour has a varying atmospheric concentration from 0 to 40,000 ppm (0 to 4%). In the cold, dry artic regions water vapour usually accounts for less than 1% of the atmosphere, while in humid, tropical regions water vapour can account for almost 4% of the atmosphere. The average value for water vapour is ~17,000 ppm (~1.7%) or more than 41 times that of CO2.
All greenhouse gases form approximately 1.74% of the near-surface global atmosphere by volume. They consist of 1.7% water vapour, 0.04% carbon dioxide (CO2), 0.00019% methane (CH4) and trace amounts of Ozone and nitrous oxide (N2O).
The remaining 98.26% of the atmosphere consists of 76.8% nitrogen, 20.6% oxygen and 0.9% argon.
The individual contributions to the "Greenhouse effect" are: water vapour and clouds at 75%, CO2 at 16%, remaining greenhouse gases at 9%. At current concentrations, a 1% increase of water vapour in the atmosphere would have a greenhouse effect 5.4 times that of a 1% change in CO2 concentration.
For further details see CO2 Versus Water and The Greenhouse Effect.
POINT #5:
Global temperatures are rising at a rapid, unprecedented rate.
COUNTERPOINT
Temperatures have varied over the centuries with many recorded warming and cooling trends. Specifically, since the 1860s global temperature has indeed risen as a whole. However the rate of change has not been unprecedented and demonstrates evidence of several positive and negative rate changes. These rate changes support that temperatures have not risen in an exceptional manner.Source: European Environment Agency: Chart - Rate of change of global average temperature
POINT #6:
Computer models prove that increasing CO2 causes significant global warming.
COUNTERPOINT
Computer models are constructed to test hypothesises. In the case of climate change they test the hypothesis that CO2 is the primary driver of warming. Using the output of a model created to prove that CO2 causes global warming to verify that CO2 drives climate is circular reasoning.The reason we need computer models is that we have no way to run controlled experiments of CO2 levels in our atmosphere and measuring the resulting temperatures. Computer models use formulas to calculate how energy flows through our land, water and atmosphere and they are used to make predictions about the fate of our planet. Problems arise because models have serious limitations that severely limit their predictions. Some of these limitations are that they disregard or do not properly take into account the effects of the sun, cosmic rays and clouds.
Then there is the question of how accurately models predict? This is simply answered by comparing their outputs to actual measurements, as McKitrick summarized in Climate Models vs Observations: 2019 Update.
This graph is from page 2 of McKitrick's work. It represents:
• the HadCRUT4 surface temperature average (black line)It is evident that the modelled mean CMIP5 (red line) temperatures are reasonably close to the actual measured temperatures (black line) prior to 2000. After 2000, the actual temperatures are considerably lower than the red mean line implying that models run hot and tend to overestimate forecasted temperatures.
• the CMIP5 mean (red line) is the average of 108 climate models
• the pink band shows the 1-sigma (67%) distribution
• the tan band extends out to the 2-sigma (95%) distribution
• the yellow shading is the outer envelope of all 108 climate model simulations • the temperature data are calculated to average zero over the interval 1961-1990
For further details see how Computer Models Fail and Computer Model Temperature Trends Versus Observations.
POINT #7:
The UN's IPCC has proven that man–made CO2 causes global warming.
COUNTERPOINT
No scientific proof that man-made CO2 causes significant global warming has been found by the IPCC even though they do their best to look for it.It is important to note that the IPCC was not created to evaluate the cause of climate change but to document that it is man-made. In their own words:
The role of the IPCC is to assess on a comprehensive, objective, open and transparent basis the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation.In 1996 they were caught blatantly corrupting the peer-review process for their “The Science of Climate Change 1995” report (Wall Street Journal A Major Deception On Global Warming). The article reports that the following passages were in the approved report but deleted from the supposedly peer-reviewed published version:
(2. in PRINCIPLES GOVERNING IPCC WORK)
• None of the studies cited above has shown clear evidence that we can attribute the observed [climate] changes to the specific cause of increases in greenhouse gases.Energy balance calculations, (Gregory, 2020) including urban and natural warming, demonstrate that the transient climate response of a gradual doubling of CO2 concentration yields a global temperature change of 0.83 ºC. Which is much less, in comparison, than the IPCC computer model estimated value of 1.8 ºC. The calculations show that CO2 caused 0.265 ºC of the 0.67 ºC of warming from 1901 to 2000, or just 40%.
• No study to date has positively attributed all or part [of the climate change observed to date] to anthropogenic [man-made] causes.
• Any claims of positive detection of significant climate change are likely to remain controversial until uncertainties in the total natural variability of the climate system are reduced.
POINT #8:
Global warming causes more storms and other weather extremes.
COUNTERPOINT
“A survey of official weather sites and the scientific literature provides strong evidence that the first half of the 20th century had more extreme weather than the second half, when anthropogenic global warming is claimed to have been mainly responsible for observed climate change.” (Journal of Geography & Natural Disasters Trends in Extreme Weather Events since 1900 – An Enduring Conundrum for Wise Policy Advice, 2016)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. Hurricane and major hurricane landfall counts exhibit no significant overall trend over 167 years of available data, nor did accumulated cyclone energy over the continental USA over 119 years of available data. The average number of strong tornadoes annually from 1986 to 2017 was 40% less than from 1954 to 1985 (GWPF pg.14 WEATHER EXTREMES Are they caused by global warming?, 2020).
For further details see Severe Weather.
POINT #9:
Receding glaciers and the calving of ice shelves are proof of man-made global warming.
COUNTERPOINT
Receding glaciers and ice shelves calving only prove that temperatures have warmed since the Little Ice Age and not that anything is man-made.Glaciers have been receding and growing cyclically for thousands of years (Glacier fluctuations during the past 2000 years, 2016) (How does present glacier extent and sea level compare to the extent of glaciers and global sea level during the Last Glacial Maximum (LGM)?). Recent glacier retreat is a consequence of warming since the bitter cold of the Little Ice Age.
It is actually natural to have some glaciers retreating while some grow (Surprise: Largest Glacier in Northern Hemisphere has started growing again, 2019) (Mount St. Helens, still steaming, holds the world’s newest glacier, 2015) (Climate science: Glacier growth consistent with man-made climate change, 2017).
Similarly, ice shelve calving has also been happening for centuries. It is also important to note that glacier extent is highly dependent on precipitation as much as on temperature (How Monsoons in Africa Drove Glacier Growth in Europe, 2018) (Global warming causing California glacier to grow, scientists say, 2008).
POINT #10:
The earth’s poles are warming causing the polar ice caps to break up and melt.
COUNTERPOINT
The northern hemisphere is warmingbut the southern is not
The graph above demonstrates that since 1979 Arctic sea ice has been declining and
this graph shows that Antarctic sea ice has been essentially constant for 40 years with minor growth. Temperature is an obvious cause and effect, a warming Northern Hemisphere causes ice to melt while a constantly cold Antarctica maintains the ice pack.
It is important to note that 40 years of data are not very representative. In fact “we live in the coldest period of the last 10,000 years” with temperatures in Greenland, which are a reasonable proxy for the Arctic, having been about 1.5 °C warmer 1,000 years ago. This in turn means that Arctic ice would have been much less extensive in the Medieval Warm Period than it is today.
More information:
National Snow and Ice Data Center (NSIDC) Sea Ice Index maps and graphs
Climate4you Global Arctic & Antarctic Sea Ice Area Compilationof NSIDC data
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