Modernidealist “Eminient scientists have reached consensus that this warming PROBABLY IS due to human activity.”

I ignore anything claimed as “probably”, unless accompanied by a qualifier of “probability”.

I could Claim Pluto is probably made of Green Cheese.

However, most folk would consider such a claim as having a very low statistical “probability”.

These days, with so much grant money hanging out there for grabs, many eminent scientists are prepared to “sell their souls for a sound bite” and the trappings of instant recognition.

Anne07 “So many strange responses and so little time...

Sorry! I would love to respond, but am too busy to keep up with everything.”

So tending lettuce is more important than defending your opinion?

If your opinion is, for yourself, so discardable, what credence should someone else ever bother to place in it?
,

I see Q&A is back making his/her own “Short, sharp snarky snippets with nothing to contribute.”

Ah I see Anne is back… defending her view …. No

Just lecturing us on how “I think many of you have been totally disgusting - and discredit your own lame causes.”

Yes Ann.. but I am not a third grade primary school student… so lift your game before you try to admonish me… maybe interject some logic and reason into your comments instead of a piffling stream of self-righteous indignation.

Modernidealist “I'm curious to know which of the following the climate sceptics disagree with or consider questionable:”

I am curious to understand how scientists can discount the history of the planet and explain the cycle of ice-ages which occurred before humans populations grew to any significance?

Ultimately we have two things to consider
1 is global warming actually happening… when the models claing so have discounted as complete frauds
2 Even if global warming is happening… is it due to human activity or natural cycles.

When some real probability of occurance has been established, we should respond.

We should not react like children because some feint hearted greenies supposedly see a boogey man to be frightened of.

I'm curious to know which of the following the climate sceptics disagree with or consider questionable asks modernidealist (Wednesday, 3 June 2009 1:45:46 AM). Modernidealist, I will answer your questions. Anne07, you may wish to take note.

* there is a greenhouse effect
Yes, natural atmospheric gases, including CO2, raise the Earth’s temperature to an estimated global average during the current epoch to something like 14 degrees Celsius. Whether the term Greenhouse is the best description for this process is debateable.
* carbon dioxide is a greenhouse gas
Yes, it is an important one too: from 0ppm to around 50ppm it raises atmospheric temperatures by around 20 degrees; between 50ppm and 200ppm it contributes about 4 degrees; between about 200ppm and 800ppm it contributes less than one degree. IOW its effect declines logarithmically with increasing atmospheric temperature.
* adding more carbon dioxide to the atmosphere can be expected to cause a warming
Again yes, but only by an extremely small amount; a doubling from the current 380ppm to 760ppm would be barely half a degree and anything from 60% to 90% of this increase is due to natural CO2 outgassing from, primarily, the oceans – that is up to 90% of the increase we humans can do nothing about, which begs the question: what difference will the implementation of an emissions trading scheme (ETS) have? Anne07, could you please explain this conundrum?
* atmospheric carbon dioxide levels have risen since 1880
This is debateable as it is based on ice core records that are inexact and the statistical smoothing involved in the blending of CO2 graphs derived from different sources. CO2 is not well mixed in the atmosphere: 600ppm have been recorded on some days in the recent past and there are higher individual levels recorded prior to 1880. (Continued)

* global mean temperature has risen since 1880
Again debateable. An analysis of weather records from long-sited Grade 1 weather stations in remote areas unaffected by deforestation and urbanisation show an oscillation of around plus or minus 1 degree Celsius that approximates to variations in the Pacific Decadal Oscillation and ENSO events with long-term trends showing no increase in average temperatures, ie no global warming temperature signal. A comparison with increasingly urbanised sites show an increase of up to 4 degrees Celsius. IWO the increase in global mean temperature is mostly due to urbanisation (urban heat island, as well as deforestation and resultant declines in atmospheric humidity and soil moisture) rather than increasing CO2 from whatever source.
* a significant fraction of that rise (greater than 50%) over the past 50 years, is due to human activity
Again, probably true – see last sentence above.

Anne07, as a geography honours graduate you should be well aware of what I have outlined above, especially the logarithmic decay of CO2 against atmospheric temperatures and the effects that deforestation has on soil moisture and consequently ground surface temperatures. To do otherwise is to mislead your readership, especially as you seek to position yourself as an advocate for change. If you are not aware of what is really basic physics and physical geographical knowledge then you need to inform yourself before making accusations about crimes against humanity. Basing your advocacy on scientific ignorance will always engender a strong reaction. Now, if you can honestly answer the conundrum I posed above then I will tell you why the world is getting an ETS even though it will make no difference whatsoever. A deal?

Modernidealist and Anne O’Brien

I suggest you read Raredog’s comments again. Slowly.

<< (there is a greenhouse effect)
“Yes, natural atmospheric gases, including CO2, raise the Earth’s temperature to an estimated global average during the current epoch to something like 14 degrees Celsius ...”

<< (carbon dioxide is a greenhouse gas)
“Yes, it is an important one too: from 0ppm to around 50ppm it raises atmospheric temperatures by around 20 degrees; between 50ppm and 200ppm it contributes about 4 degrees; between about 200ppm and 800ppm it contributes less than one degree ...” >>

<< (adding more carbon dioxide to the atmosphere can be expected to cause a warming)
“Again yes, but only by an extremely small amount; a doubling from the current 380ppm to 760ppm would be barely half a degree ... >>

Check his arithmetic against his assertions (they contain, umm ... errors). And do some homework on ‘climate sensitivity’

<< ... and anything from 60% to 90% of this increase is due to natural CO2 outgassing from, primarily, the oceans – that is up to 90% of the increase we humans can do nothing about, which begs the question: what difference will the implementation of an emissions trading scheme (ETS) have? Anne07, could you please explain this conundrum?” >>

The oceans warm for a reason. Adjusting to maintain equilibrium, they release CO2 - ever wonder where the extra lot came from?

What really gives the game away is the typical circular argument (as has been said before):

<< which begs the question >>

Example: An expert provides a ‘simplified’ explanation of 'whatever'.

An antagonist in rebuttal states “this begs the question" (insert your own).

The expert explains why the rebuttal is incorrect and provides a more detailed explanation of 'whatever'.

The antagonist argues the science is too complex to understand.

The scientist attempts to provide a ‘simplified’ explanation to the ‘antagonist’s rebuttal to 'whatever' ... and around and around it goes.

Cont’d

Cont’d

<< atmospheric carbon dioxide levels have risen since 1880 >>

“This is debateable as it is based on ice core records that are inexact and the statistical smoothing involved in the blending of CO2 graphs derived from different sources. CO2 is not well mixed in the atmosphere: 600ppm have been recorded on some days in the recent past and there are higher individual levels recorded prior to 1880.”

Raredog is not ignorant; he is deliberately distorting and misrepresenting what we know from carbon auditing and isotope studies.

<< global mean temperature has risen since 1880 >>

“Again debateable. An analysis of ... (whatever noise might confuse the uninformed)

No matter which data set is used, time series analysis shows an increasing rise in temperatures since the industrial revolution.

____________

Raredog

You should be well aware of what I have outlined above. To do otherwise is to mislead your readership, especially as you seek to position yourself as an advocate for ‘deny-n-delay’.

You deliberately distort and misrepresent basic physics and chemistry to justify your own ideological reasoning. Basing your advocacy on scientific ignorance will always engender a strong reaction, from those working at the coal face.

I am but a mere scientist who knows something about coupled atmosphere/ocean/land climate systems, particularly as they relate to things water. I don’t know jack-sh!t about ETS or carbon taxes – that belongs in the realm of politicians and economists. I am willing to put my toes in, if it helps.

Your last statement: “I will tell you why the world is getting an ETS even though it will make no difference whatsoever” is the only thing that remotely interests me (notwithstanding its condescending overtones). What you have preceded that with is just gas-bagging for your own ideological ends.

So, first part is how we know that CO2 has indeed risen since 1880. Second question is what caused that rise.

First, our knowledge of past CO2 levels comes from ice cores (now extending back 800,000 years) and direct measurement (since 1950s).

The two complement each other as the ice cores don't answer well the most recent events, while the direct measurement (Keeling curve) answers for recent events extremely well.

As snow is compressed to ice, it traps air bubbles. When we core ice sheets and sample those bubbles, we get a sample of the ancient air. For the modern sampling, we take a flask of air exposed to the free atmosphere.

The ice core sampling shows that there is a glacial to interglacial swing of about 80 ppm in CO2, associated with the 5 K global warming/cooling. The interglacial level is about 280 ppm while glacial is about 200. See the Vostok core papers from the mid 1980s. The time scale for this swing is a few centuries. We had been around the 280 ppm for the last several thousand years prior to industrialization.

Since direct measurement started in the 1950s, atmospheric CO2 has risen from 315 ppm to about 385 now. So 70 ppm in 50 years.This as compared to 80 in a few centuries recorded by ice cores. Both the magnitude and the rate are well above anything recorded for the previous 800,000 years.

When you sit down and try to make the total carbon level change as observed and the isotopic levels change as observed, you see the magnitude of human activity and wiggles in the CO2 curve e.g pointing to the 1973-4 oil embargo, for instance.