Why I'm an skeptic and you should be too.
Edit: My position seems have been consistantly misinterpereted so I have rephrased the opening sentence and Bolded the conclusion
Conventional wisdom states that the Earth's atmospheric temprature is rising and that man-made Carbon Dioxide (CO2) is to blame.
Conventional wisdom states that man-made Carbon Dioxide (CO2) is to blame for an observed increase in the Earth's atmospheric temprature.
To question this assertation is to face ridicule and be labled a "denier", "afterall..." the crowd will shout, "the science is settled!"
The problem with this attitude from a scientific/engineering perspective is that very little of what we consider to be common knowledge is actually settled. One of the first things your professor will be tell you upon embarking on a math or science degree is "much of what you think you know is at best conjecture and at worst outright wrong". It is not enough to simply look out the window and observe the color of the sky, you must be able to prove that it is blue and explain why. This inherent skeptism is the basis of the scientific method.
So with this in mind let's review the evidence...
Because accurate thermometers have only existed the last 300 years scientists must use "proxies" (things that react to temperature) to derive past Climatological data. Ice cores are a proxy just as tree rings and the price of grain are. The problem is that people tend to forget that Proxies are not thermometers. Atmospheric temprature is not the only variable in play, precipitation, sunlight, and blind stupid luck all have a hand in determining how much a tree grows or how much ice sloughs off a glacier in a given season.
Now we've all seen the following graph...
Al Gore saw to that. The colored lines represent global temprature as estimated using various proxies, the black line towards the end represents direct measurement (thermometers).
Note that the infamous "hockey stick" is not reflected in the proxies. Given perfect data we should have perfect correlation. This mismatch would seem to imply that one set of data or the other is flawed.
For the sake of argument let us assume that the IPCC is correct and that the Earth’s atmospheric temperature has increased by about a 0.6 degree Celsius. Likewise let us assume that this 0.6C increase is due to man-made greenhouse gasses.
It has been widely reported that since the beginning of the industrial revolution, mankind has increased the atmospheric concentration of CO2 from 0.028% to 0.038%, an increase of approximatly 36%.
http://www.theregister.co.uk/2011/06/14/ice_age/
Using simple math, we may guess that if temperatures have risen 0.6C due to a 36% increase, we might expect that if the amount of CO2 in the atmosphere were to double (to 0.056% of the atmosphere) tempratures would rise by 1.67C. The problem is that this assumes the relationship is linear. It is not.
As greenhouse gasses go CO2 is a lightwheight Water Vapor (Gasseous H2O) and Methane (CH4) are actually far more potent greenhouse gasses than CO2. If CO2 is the prime motivator for global warming the change in temprature should be even lower than the 1.67C cited above. If this is the case where did the IPCC get idea that the temperature would increase by 4-8 degrees C in the next century?
I have suspicions but precious little evidence.
Now the above issues alone would be enough to make a naturally skeptical and individual take a step back and go "Hmmmmmmm..." but then there was "Climate-Gate"
It seems that the IPCC's data is in dispute, not only that but the atmospheric tepratures may in fact be trending downwards. Who could have possibly seen that coming?!
Errrr... NASA
It seems th sun has decided to throw a monkey wrench into the whole equation.
Sadly the question of climate change has become sufficiently politicized that there is more money (and political advantage) to be gained in perpetuating the controversy than there is in objective research.
Likewise please understand that none of this actually disproves the theory of anthropological global warming. The problem is that the IPCC is engaged in shoddy science and if enviromentalism wishes to remain credible they should be called to task.
The data does show a correlation between atmospheric CO2 and temprature but correlation is not causation.
Then again what the fuck do I know? I listen to talk radio and thus cannot be trusted.
Further Reading
IPCC AR4 full text
http://www.geocraft.com/WVFossils/greenhouse_data.html
http://neptune.gsfc.nasa.gov/bsb/publications/index.php?year=2010
http://europa.agu.org/?uri=/journals/gl/gl1023/2010GL045338/2010GL045338.xml&view=article
http://www.skepticalscience.com/co2-lags-temperature.htm (read the comments)
http://www.nso.edu/press/SolarActivityDrop.html
http://www.realclimate.org/index.php/archives/2011/06/what-if-the-sun-went-into-a-new-grand-minimum/
http://journals.ametsoc.org/doi/abs/10.1175/1520-0442%282004%29017%3C0906%3ATRIOSA%3E2.0.CO%3B2
http://www.sciencemag.org/content/294/5549/2149.short (note that while while the authors dismiss changes of 0.4 as "quite small" the total change observed thus far is only 0.6
http://www.realclimate.org/index.php/archives/2011/06/what-if-the-sun-went-into-a-new-grand-minimum/
http://borepatch.blogspot.com/2009/12/should-you-be-global-warming-skeptic.html
In the end it seems to me that very little is "settled".
Conventional wisdom states that the Earth's atmospheric temprature is rising and that man-made Carbon Dioxide (CO2) is to blame.
Conventional wisdom states that man-made Carbon Dioxide (CO2) is to blame for an observed increase in the Earth's atmospheric temprature.
To question this assertation is to face ridicule and be labled a "denier", "afterall..." the crowd will shout, "the science is settled!"
The problem with this attitude from a scientific/engineering perspective is that very little of what we consider to be common knowledge is actually settled. One of the first things your professor will be tell you upon embarking on a math or science degree is "much of what you think you know is at best conjecture and at worst outright wrong". It is not enough to simply look out the window and observe the color of the sky, you must be able to prove that it is blue and explain why. This inherent skeptism is the basis of the scientific method.
So with this in mind let's review the evidence...
Because accurate thermometers have only existed the last 300 years scientists must use "proxies" (things that react to temperature) to derive past Climatological data. Ice cores are a proxy just as tree rings and the price of grain are. The problem is that people tend to forget that Proxies are not thermometers. Atmospheric temprature is not the only variable in play, precipitation, sunlight, and blind stupid luck all have a hand in determining how much a tree grows or how much ice sloughs off a glacier in a given season.
Now we've all seen the following graph...
Al Gore saw to that. The colored lines represent global temprature as estimated using various proxies, the black line towards the end represents direct measurement (thermometers).
Note that the infamous "hockey stick" is not reflected in the proxies. Given perfect data we should have perfect correlation. This mismatch would seem to imply that one set of data or the other is flawed.
For the sake of argument let us assume that the IPCC is correct and that the Earth’s atmospheric temperature has increased by about a 0.6 degree Celsius. Likewise let us assume that this 0.6C increase is due to man-made greenhouse gasses.
It has been widely reported that since the beginning of the industrial revolution, mankind has increased the atmospheric concentration of CO2 from 0.028% to 0.038%, an increase of approximatly 36%.
http://www.theregister.co.uk/2011/06/14/ice_age/
Using simple math, we may guess that if temperatures have risen 0.6C due to a 36% increase, we might expect that if the amount of CO2 in the atmosphere were to double (to 0.056% of the atmosphere) tempratures would rise by 1.67C. The problem is that this assumes the relationship is linear. It is not.
As greenhouse gasses go CO2 is a lightwheight Water Vapor (Gasseous H2O) and Methane (CH4) are actually far more potent greenhouse gasses than CO2. If CO2 is the prime motivator for global warming the change in temprature should be even lower than the 1.67C cited above. If this is the case where did the IPCC get idea that the temperature would increase by 4-8 degrees C in the next century?
I have suspicions but precious little evidence.
Now the above issues alone would be enough to make a naturally skeptical and individual take a step back and go "Hmmmmmmm..." but then there was "Climate-Gate"
Click to viewIt seems that the IPCC's data is in dispute, not only that but the atmospheric tepratures may in fact be trending downwards. Who could have possibly seen that coming?!
Errrr... NASA
It seems th sun has decided to throw a monkey wrench into the whole equation.
Sadly the question of climate change has become sufficiently politicized that there is more money (and political advantage) to be gained in perpetuating the controversy than there is in objective research.
Likewise please understand that none of this actually disproves the theory of anthropological global warming. The problem is that the IPCC is engaged in shoddy science and if enviromentalism wishes to remain credible they should be called to task.
The data does show a correlation between atmospheric CO2 and temprature but correlation is not causation.
Then again what the fuck do I know? I listen to talk radio and thus cannot be trusted.
Further Reading
IPCC AR4 full text
http://www.geocraft.com/WVFossils/greenhouse_data.html
http://neptune.gsfc.nasa.gov/bsb/publications/index.php?year=2010
http://europa.agu.org/?uri=/journals/gl/gl1023/2010GL045338/2010GL045338.xml&view=article
http://www.skepticalscience.com/co2-lags-temperature.htm (read the comments)
http://www.nso.edu/press/SolarActivityDrop.html
http://www.realclimate.org/index.php/archives/2011/06/what-if-the-sun-went-into-a-new-grand-minimum/
http://journals.ametsoc.org/doi/abs/10.1175/1520-0442%282004%29017%3C0906%3ATRIOSA%3E2.0.CO%3B2
http://www.sciencemag.org/content/294/5549/2149.short (note that while while the authors dismiss changes of 0.4 as "quite small" the total change observed thus far is only 0.6
http://www.realclimate.org/index.php/archives/2011/06/what-if-the-sun-went-into-a-new-grand-minimum/
http://borepatch.blogspot.com/2009/12/should-you-be-global-warming-skeptic.html
In the end it seems to me that very little is "settled".