Monday, August 4, 2014

Null Hypothesis

Christopher Keeting:
You say
"1. I will award $30,000 of my own money to anyone that
can prove, via the scientific method, that man-made global climate change is
not occurring;"
I write to claim the money and will inform how you can forward it to the charity of my choice when you announce that my scientific conclusion is the winner.
The 'proof' is as follows.
The Null Hypothesis says it must be assumed a system
has not experienced a change unless there is evidence of a change.

The Null Hypothesis is a fundamental scientific principle and
forms the basis of all scientific understanding, investigation and interpretation.
Indeed, it is the basic principle of experimental procedure where an input to a system is altered to discern a change: if the system is not observed to respond to the alteration then it has to be assumed the system did not respond to the alteration.
In the case of climate science there is a hypothesis that increased
greenhouse gases (GHGs, notably CO2) in the air will increase global temperature.
There are good reasons to suppose this hypothesis may be true, but the Null Hypothesis says it must be assumed the GHG changes have no effect unless and until increased GHGs are observed to increase global temperature. That is what the scientific method decrees. It does not matter how certain some people may be that the hypothesis is right because observation of reality (i.e. empiricism) trumps all opinions.
Please note that the Null Hypothesis is a hypothesis which exists to be refuted by empirical observation. It is a rejection of the scientific method to assert that one can “choose” any subjective Null Hypothesis one likes. There is only one Null Hypothesis: i.e. it has to be assumed a system
has not changed unless it is observed that the system has changed.
However, deciding a method which would discern a change may require
a detailed statistical specification.
In the case of global climate no unprecedented climate behaviours are observed so the Null Hypothesis decrees that the climate system has not changed.
Importantly, an effect may be real but not overcome the Null Hypothesis because it is too trivial for the effect to be observable. Human activities
have some effect on global temperature for several reasons. An example of an anthropogenic effect on global temperature is the urban heat island (UHI). Cities are warmer than the land around them, so cities cause some warming. But the temperature rise from cities is too small to be detected when averaged over the entire surface of the planet, although this global warming from cities can be estimated by measuring the warming of all cities and their areas.
Clearly, the Null Hypothesis decrees that UHI is not affecting global temperature although there are good reasons to think UHI has some
effect. Similarly, it is very probable that AGW from GHG emissions are too trivial to have observable effects.
The feedbacks in the climate system are negative and, therefore,
any effect of increased CO2 will be probably too small to discern because
natural climate variability is much, much larger. This concurs with the empirically determined values of low climate sensitivity.
Empirical – n.b. not model-derived – determinations indicate
climate sensitivity is less than 1.0°C for a doubling of atmospheric CO2 equivalent.
This is indicated by the studies of
Idso from surface measurements
and Lindzen & Choi from ERBE satellite data
and Gregory from balloon radiosonde data
Indeed, because climate sensitivity is less than 1.0°C for a doubling of CO2 equivalent, it is physically impossible for the man-made global warming to be large enough to be detected (just as the global warming from UHI is too small to be detected). If something exists but is too small to be detected
then it only has an abstract existence; it does not have a discernible existence that has effects (observation of the effects would be its detection).
To date there are no discernible effects of AGW. Hence, the Null Hypothesis decrees that AGW does not affect global climate to a discernible degree. That is the ONLY scientific conclusion possible at present.
That being the only valid scientific conclusion concerning AGW which accords to the scientific method is sufficient for you to pay the
$30,000 to the charity of my choice.

Richard S Courtney


Is there some kind of psychosis that makes people making submissions claim the money before their submission is even reviewed? That would be like a sports team ordering the championship rings before the season even starts.

The author of this submission should at least be congratulated for trying something new. But, I'm not sure he really got off to a good start.

The null hypothesis is the thing that is to be disproved, rejected or nullified in any scientific experiment (where are all of those people claiming you can't disprove something?). It is a basic tenet of all scientific experimentation, even if indirectly. I wish the people making submissions to this challenge would employ the null hypothesis in their submissions instead of just assuming they are right because they want to be.

But, what makes Mr. Courtney think the null hypothesis has not been employed in climate science? In fact, it is not only used, it has been used continuously and extensively all along, even long before the issue of AGW was ever raised.

But, a good start goes way south very quickly with the statement,
In the case of global climate no unprecedented climate behaviours are observed so the Null Hypothesis decrees that the climate system has not changed. 
Did he just say there has been no unprecedented behavior? Take a look at just a few figures:
Source: SIO Keeling Curve

This is a plot of the CO2 levels for the last 800,000 years with the unprecedented rise that has occurred in recent years on the right-hand side.

Source: Wikipedia

This is a plot of the global average temperature over the last 800,000 years. The rise in temperature in recent years is that spike on the right-hand side, unprecedented in the last 100,000+ years.

Source: Skeptical Science

This is the sea level over the last 150,000 years with the unprecedented levels of today on the left-hand side. (The gap in the data is due to missing foraminifera during the last ice age because of very salty water).

Global Ocean Heat Content 1955-present 0-2000 m
Source:  NOAA

This graph shows the global heat content, the amount of energy stored in the entire planet (not just the surface), showing the unprecedented heat content of today on the right-hand side.

So, Mr. Courtney made a null hypothesis of his own that had to be accepted unless disproved. His null hypothesis was that there have been no unprecedented changes to the climate in recent years.

Very quickly and easily, I was able to show that there actually are quite a few unprecedented changes occurring in the climate of today. There are more, but this is sufficient.

Let this be a lesson for you, Mr. Courtney - never, NEVER, NEVER believe one word from the Idso family or from Lindzen. These are professional, paid deniers and all of them have been caught providing false research.

Based on your null hypothesis and how it was disproved, rejected and nullified, I have to conclude that you did not prove man made global warming is not real.

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