Myth #1: 'They' predicted an ice age in the 1970s
This myth is based upon stories in TIME and Newsweek in the 1970s regarding global cooling. It was even quoted by Republican Sen. James Inhofe, chair of the Environment and Public Works Committee, on the floor of the Senate. This myth appeals to some people because these 'predictions' have turned out to be so wrong. If 'they' were wrong in the 1970s on predicting global cooling, then 'they' could easily be just as wrong on recent global warming. Some people therefore conclude that the science of global warming remains unsettled.
A better conclusion, however, would be that one should not rely on the mass media for scientific information if better sources are available (i.e. scientific studies themselves).
Recent studies of the scientific literature at the time have concluded that the supposed "global cooling" consensus among scientists during the 1970s is indeed a myth.
"Thomas Peterson of the National Climatic Data Center surveyed dozens of peer-reviewed scientific articles from 1965 to 1979 and found that only seven supported global cooling, while 44 predicted warming. Peterson says 20 others were neutral in their assessments of climate trends."
Among those scientists who predicted continued global cooling, some based their conclusions on the assumption that human aerosol emissions would continue to increase rapidly. Up until 1970, aerosol emissions (primarily sulfur dioxide) were increasing rapidly. Aerosols block sunlight, causing global dimming and thus global cooling, and were primarily responsible for the very slight global cooling from 1940-1970.
Some scientists were concerned that if these emissions continued to accelerate, they would overwhelm the warming associated with carbon dioxide emissions and continue to cool the planet. However, many countries began to pass Clean Air Acts in response to the various problems associated with these emissions (acid rain, for example), and worldwide sulfur dioxide emissions have actually decreased since 1980. In short, the scenario which was predicted as the possible cause of global cooling did not come to pass.
The lesson to be learned from this myth is that it's important to get our scientific information directly from scientists, rather than filtered through the media. Media bias is one of the most common causes of misinformation with regards to global warming even today. Some articles are too sensationalist, and others provide misinformation stemming from a political agenda. This is why the Intergovernmental Panel on Climate Change (IPCC) is such a critical organization, and why it won a Nobel Prize.
Myth #2: There is no scientific consensus on man-made global warming
This myth often stems from a misunderstanding of the term 'consensus'. In this context, 'consensus' does not mean 'unanimity'. The term generally means 'majority', but in the context of man-made global warming, it means 'vast majority' of agreement among scientists.
A nice compilation of the various groups which are in agreement about man-made global warming is available at Logicalscience.com. Every so often, certain parties will attempt to compile lists of scientists who disagree with some aspect of the theory in an attempt to disprove the consensus. The two most oft-cited lists are the Oregon Petition and Senator James Inhofe's list of 400.
In both cases, the lists were not limited to people with expertise in climate science, but essentially allowed anybody with any college degree (in the case of the Oregon Petition) or any scientific degree (in the case of Inhofe's list) to sign. In the example of Inhofe's list, it included botanists, chemists, mathematicians, economists, and political scientists, to name a few.
When considering how many scientists work in these fields, 400 is a fraction of a percent and certainly does not disprove a scientific consensus on the subject. Particularly since many on the list have no expertise or experience in climate science research. The Oregon Petition has been found to be fraudulent, and a new version was recently circulated.
In short, it is quite apparent that there is indeed a scientific consensus on man-made global warming. A nice description of what the consensus is can be found at RealClimate.
Myth #3: One volcanic eruption emits more CO2 than humans have in [insert length of time here]
Because volcanic eruptions look so massive, some people assume they emit vast amounts of carbon dioxide. However, studies have shown that on average, annual human CO2 emissions are at least 100 times greater than volcanic CO2 emissions.
As one example, the Mount Pinatubo eruption emitted 42 to 234 million tons of CO2. Humans emit 30 billion tons of CO2 per year, or approximately 80 million tons of CO2 per day. In other words, humans emit approximately as much CO2 every day as the entire Mount Pinatubo eruption.
This particular
Myth #4: Mars and/or all the planets in our solar system are warming, so the Sun is causing global warming
There is a nugget of truth to this myth. Our observations of Mars appear to indicate that the planet is warming. However, we don't have a lot of data regarding the climate of Mars, and while some regions of the planet are warming, we aren't certain that the planet is warming as a whole. If Mars is experiencing global warming, scientists believe it's due to dust storms darkening its surface, causing the planet to absorb more sunlight (a.k.a. decreased albedo).
A sub-myth is that both ice caps on Mars are melting. In reality, while the southern polar cap is vaporizing, the northern cap is expanding.
A few other planets in our solar system appear to be warming. For example, Pluto appears to be warming at a rate much faster than Earth (the opposite of what you would expect from a planet further from the Sun if the warming were due to solar effects), most likely because of
its orbital cycles (seasonal changes). However, of the many planets and moons in our solar system, the vast majority appear to be experiencing no significant temperature change.
Moreover, we don't need to look at other planets to measure changes in the Sun - we have satellites which have directly measured solar output for the past 30 years. The satellite data shows that solar irradiance has not changed on average over that period, so it cannot be causing global warming on Earth or any other planet.
http://greenhome.huddler.com/wiki/global-warming-myths
This myth is based upon stories in TIME and Newsweek in the 1970s regarding global cooling. It was even quoted by Republican Sen. James Inhofe, chair of the Environment and Public Works Committee, on the floor of the Senate. This myth appeals to some people because these 'predictions' have turned out to be so wrong. If 'they' were wrong in the 1970s on predicting global cooling, then 'they' could easily be just as wrong on recent global warming. Some people therefore conclude that the science of global warming remains unsettled.
A better conclusion, however, would be that one should not rely on the mass media for scientific information if better sources are available (i.e. scientific studies themselves).
Recent studies of the scientific literature at the time have concluded that the supposed "global cooling" consensus among scientists during the 1970s is indeed a myth.
"Thomas Peterson of the National Climatic Data Center surveyed dozens of peer-reviewed scientific articles from 1965 to 1979 and found that only seven supported global cooling, while 44 predicted warming. Peterson says 20 others were neutral in their assessments of climate trends."
Among those scientists who predicted continued global cooling, some based their conclusions on the assumption that human aerosol emissions would continue to increase rapidly. Up until 1970, aerosol emissions (primarily sulfur dioxide) were increasing rapidly. Aerosols block sunlight, causing global dimming and thus global cooling, and were primarily responsible for the very slight global cooling from 1940-1970.
Some scientists were concerned that if these emissions continued to accelerate, they would overwhelm the warming associated with carbon dioxide emissions and continue to cool the planet. However, many countries began to pass Clean Air Acts in response to the various problems associated with these emissions (acid rain, for example), and worldwide sulfur dioxide emissions have actually decreased since 1980. In short, the scenario which was predicted as the possible cause of global cooling did not come to pass.
The lesson to be learned from this myth is that it's important to get our scientific information directly from scientists, rather than filtered through the media. Media bias is one of the most common causes of misinformation with regards to global warming even today. Some articles are too sensationalist, and others provide misinformation stemming from a political agenda. This is why the Intergovernmental Panel on Climate Change (IPCC) is such a critical organization, and why it won a Nobel Prize.
Myth #2: There is no scientific consensus on man-made global warming
This myth often stems from a misunderstanding of the term 'consensus'. In this context, 'consensus' does not mean 'unanimity'. The term generally means 'majority', but in the context of man-made global warming, it means 'vast majority' of agreement among scientists.
A nice compilation of the various groups which are in agreement about man-made global warming is available at Logicalscience.com. Every so often, certain parties will attempt to compile lists of scientists who disagree with some aspect of the theory in an attempt to disprove the consensus. The two most oft-cited lists are the Oregon Petition and Senator James Inhofe's list of 400.
In both cases, the lists were not limited to people with expertise in climate science, but essentially allowed anybody with any college degree (in the case of the Oregon Petition) or any scientific degree (in the case of Inhofe's list) to sign. In the example of Inhofe's list, it included botanists, chemists, mathematicians, economists, and political scientists, to name a few.
When considering how many scientists work in these fields, 400 is a fraction of a percent and certainly does not disprove a scientific consensus on the subject. Particularly since many on the list have no expertise or experience in climate science research. The Oregon Petition has been found to be fraudulent, and a new version was recently circulated.
In short, it is quite apparent that there is indeed a scientific consensus on man-made global warming. A nice description of what the consensus is can be found at RealClimate.
Myth #3: One volcanic eruption emits more CO2 than humans have in [insert length of time here]
Because volcanic eruptions look so massive, some people assume they emit vast amounts of carbon dioxide. However, studies have shown that on average, annual human CO2 emissions are at least 100 times greater than volcanic CO2 emissions.
As one example, the Mount Pinatubo eruption emitted 42 to 234 million tons of CO2. Humans emit 30 billion tons of CO2 per year, or approximately 80 million tons of CO2 per day. In other words, humans emit approximately as much CO2 every day as the entire Mount Pinatubo eruption.
This particular
Myth #4: Mars and/or all the planets in our solar system are warming, so the Sun is causing global warming
There is a nugget of truth to this myth. Our observations of Mars appear to indicate that the planet is warming. However, we don't have a lot of data regarding the climate of Mars, and while some regions of the planet are warming, we aren't certain that the planet is warming as a whole. If Mars is experiencing global warming, scientists believe it's due to dust storms darkening its surface, causing the planet to absorb more sunlight (a.k.a. decreased albedo).
A sub-myth is that both ice caps on Mars are melting. In reality, while the southern polar cap is vaporizing, the northern cap is expanding.
A few other planets in our solar system appear to be warming. For example, Pluto appears to be warming at a rate much faster than Earth (the opposite of what you would expect from a planet further from the Sun if the warming were due to solar effects), most likely because of
its orbital cycles (seasonal changes). However, of the many planets and moons in our solar system, the vast majority appear to be experiencing no significant temperature change.
Moreover, we don't need to look at other planets to measure changes in the Sun - we have satellites which have directly measured solar output for the past 30 years. The satellite data shows that solar irradiance has not changed on average over that period, so it cannot be causing global warming on Earth or any other planet.
http://greenhome.huddler.com/wiki/global-warming-myths