Questions about Global Warming

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I'm a non-scientist trying to understand a bit about climate science and the state of it. It's mysterious to me why so many people (some on both sides of most debates I see!) seem to treat this as though it were a religious issue and not a scientific one.

1. My understanding is that the strongest support for human beings causing observed global warming is that computer models that have been made don't agree with observations for recent years unless human induced factors like CO2 and sulphate aerosols are included. Is this correct? Is there other strong evidence? (Surely, such a rapid change, by geological standards, coinciding with humans producing massive amounts of greenhouse gases, is very suggestive, but circumstantial.)

2. Are the models that are compelling for #1 old enough and established enough that they have been tested and confirmed with future data, and made interesting and accurate predictions, rather than just being correct by being fit to the data itself? Was the error margin of any such study small enough that current observations give a very high degree of confidence in them?

3. Do current models make future predictions in a way that makes them falsifiable? E.g. what's the margin of error on the expected global temperature in 20 years? Is there a strong consensus? What of data would be needed for scientists to throw away a notion that the earth is definitely warming in a predictable way?

4. Is there effort being spent on attempting to create a consistent model of the world's climate that does not include human induced greenhouse gases? (E.g. supposing a change in the sun's output or volcanic activity, or some other factors, have a larger than expected effect.) If this has been tried, does it turn out to be impossible to retrofit something to real observed climate data? If it does manage to fit, is it somehow less parsimonious? Were such models ever created in the past and allowed to "compete" with models that use anthropogenic greenhouse gases, using future unknown data rather than just being fit to something already known?

5. How does one address claims that the climate is inherently chaotic, and can be expected to change in something like a fractal pattern, with unpredictable shifts at all scales. How can we rule out a hypothesis of a large scale shift taking place right now simply due to chaos and sensitivity to initial conditions, and not to anything understandable?
 

Answers and Replies

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Hi William, Sorry it took a while. That’s unusual for the resident globa warming sceptic but anyway,

I'm a non-scientist
but what is a scientist then? I say the same, but I wonder how I would do in a general quiz about everything pertaining Earth's geology, geography, geophysics, oceanography, paleo-specialisms etc, What would be the criteria? Being able to make logical deductions and recognise and avoid fallacies? You'd be surprised how many "scientists" would not pass that filter. Perhaps it’s also an idea to tick off the fallacies in all the arguments for and against global warming.

It's mysterious to me why so many people (some on both sides of most debates I see!) seem to treat this as though it were a religious issue and not a scientific one.
This little essay may help.

..strongest support for human beings causing observed global warming is that computer models that have been made don't agree with observations for recent years unless human induced factors like CO2 and sulphate aerosols are included. Is this correct? (Surely, such a rapid change, by geological standards, coinciding with humans producing massive amounts of greenhouse gases, is very suggestive, but circumstantial.)
Roughly, that’s what they say. However, it is also (erroneously) believed that northern hemisphere temperatures fluctuated “ten-degrees-within-a-decade” during the last glacial without the help of mankind. Perhaps the models have not captured all the elements yet that mold our climate.

Is there other strong evidence?
What is evidence. The overall temperatures have been risen for about two centuries but have also dropped in the late 18ths, in the 1960ies, there has been a rather strong warming in the 1990ies but temps have stabilized as of 1998, what would you make of that?

2. Are the models that are compelling for #1 old enough and established enough that they have been tested and confirmed with future data, and made interesting and accurate predictions, rather than just being correct by being fit to the data itself? Was the error margin of any such study small enough that current observations give a very high degree of confidence in them?
Don’t know. http://www.physicstoday.org/vol-60/iss-1/72_1.html [Broken] from the other camp has some ideas. I guess that my model predict that in a few decades from now, it will be prohibited by law to use climate models for predictions, other than verifying an hypothesis, their original function.

Climate projections made with sophisticated computer codes have informed the world's policymakers about the potential dangers of anthropogenic interference with Earth's climate system.
Just as curiosity, any idea what the etymological meaning of the word “sophisticated” is, and why that would even be more appropriate?

3. Do current models make future predictions in a way that makes them falsifiable? E.g. what's the margin of error on the expected global temperature in 20 years? Is there a strong consensus?
here is the [URL [Broken] ]longest running prediction.[/url]. I added land and sea data. Scenario C was with direct cutting CO2 action in 1988. The actual scenario with CO2 emissions is close to B, perhaps a tad higher

What of data would be needed for scientists to throw away a notion that the earth is definitely warming in a predictable way?
Some climatologists expect a new solar minimum around 2030 like the Maunder minimum of ~1730. By then things should be straightened out.

4. Is there effort being spent on attempting to create a consistent model of the world's climate that does not include human induced greenhouse gases? (E.g. supposing a change in the sun's output or volcanic activity, or some other factors, have a larger than expected effect.)
I believe that’s standard benchmarking. I believe that has been done. I have no details however.

5. How does one address claims that the climate is inherently chaotic, and can be expected to change in something like a fractal pattern, with unpredictable shifts at all scales. How can we rule out a hypothesis of a large scale shift taking place right now simply due to chaos and sensitivity to initial conditions, and not to anything understandable?
No doubt about the chaos but it would be nice to understand the interactions a bit more which would be a formidable job to accomplish.
 
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Anthropogenic global warming supposedly began with the industrial revolution. We see this attribution made in various places. The mean global temperature seems to have increased from 1900 to around 1945: http://www.aip.org/history/climate/20ctrend.htm#temp2002.

Yet the carbon emissions over that period (1900 to 1945) were very small relative to today, roughly peaking at 1/8th of today, and almost entirely from burning coal: http://en.wikipedia.org/wiki/Image:Global_Carbon_Emission_by_Type.png

If anthropogenic global warming started at the industrial revolution, that implies the natural carbon cycle can be imbalanced by a fraction of today's emissions. Since even today's emissions only account for about 3% of natural emissions (natural plant decay, etc), that means the 0.4% peak anthropogenic carbon emissions in 1945 were sufficient to cause the significant global warming shown in the above graph from 1900 to 1945. The amount under the curve would be much less than this.

This seems like a very small amount. IOW to accept that the more recent global warming is of anthropogenic origin requires we likewise accept the 1900-1945 global warming was anthropogenic. Yet the carbon emissions in that period were very small relative to today.

That in turn implies reducing anthropogenic emissions by 7/8ths is insufficient, and would simply slow (not stop) global warming. It also implies the earth's natural carbon source/sink cycle has almost zero tolerance for imbalance -- whether the imbalance is of human or natural causes. It further implies than any natural phenomena such as increased volcanic activity, change in vegetation, etc. which imbalanced the natural source or sink only 0.4% would cause a runaway warming or cooling.

I'm struggling to understand this. Any advice or comments?
 
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Perhaps you're proving to yourself that's all a hoax.
 
baywax
Gold Member
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Perhaps you're proving to yourself that's all a hoax.
I just came across this article that states:

Earth is heating up lately, but so are Mars, Pluto and other worlds in our solar system, leading some scientists to speculate that a change in the sun's activity is the common thread linking all these baking events.
http://www.foxnews.com/story/0,2933,258342,00.html

I know its FOXNews but their just drawing on the research of

Habibullo Abdussamatov, the head of space research at St. Petersburg's Pulkovo Astronomical Observatory in Russia.

Its an interesting take on the warming of more than just our planet in the solar system. It also mentions how Mar's polar caps advance and recede with fluctuations in the temperature of the sun.
 
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BillJx
I know its FOXNews but their just drawing on the research of

Habibullo Abdussamatov, the head of space research at St. Petersburg's Pulkovo Astronomical Observatory in Russia.

QUOTE]
I'm also a non-scientist. And there's nothing wrong with trying to understand fast-changing fields in science, as long as we don't imagine that our own conclusions have any bearing on anything. Science is advanced through peer-reviewed research done by working, accredited scientists.

The solar variation theory isn't new. Most climatologists say the sun's effect is relatively minor.

http://www.msnbc.msn.com/id/17582152/
 
Solar Variation & Global Warming

Hi BillJx,

There is most definitely correlation between 20th century solar changes and 20th century warming. The correlation is however not simply, more sunspots higher temperatures. The correlation is also not due to a significant increase in the solar output, but rather due to the sun's affect on planetary cloud cover. Those climatologists who say there is no correlation, refer to number sunspot numbers or changes in solar output. It is only in the last 5 years that a mechanism has been developed to explain how solar changes could cause a change in planetary temperature.

Scientists specialize and in many cases do not explore competing hypothesis. There is often a delay from when a new hypothesis is developed, to when it is accepted.

Attached is a paper that discusses the solar parameter that correlates with the 20th century observed planetary temperature changes. (i.e. Global warming.) From that paper:

"It has been noted that in the last century the correlation between sunspot number and geomagnetic activity has been steadily decreasing from - 0.76 in the period 1868-1890 to 0.35 in the period 1960-1982, ... According to Echer et al (2004), the probable cause seems to be related to the double peak structure of geomagnetic activity. The second peak, related to high speed solar wind from coronal holes (my comment: For example coronal hole 254 that produced the Dec 16, 2006 peak in solar wind, during a sun spot minimum, see attached link to Solar Observation Data), seems to have increased relative to the first one, related to sunspots (CMEs) but, as already mentioned, this type of solar activity is not accounted for by sunspot number. In figure 6 long term varations in global temperature are compared to the long-term variations in geomagnetic activity as expressed by the ak-index (Nevanlinna and Kataga 2003). The correlation between the two quantities is 0.85 with p< 0.01."

The thread Earth and Reflectivity provides a discussion of the hypothesized mechanism and links to papers that provide data and analysis to support the assertion that a signficant portion of 20th century global warming is due to changes in planetary cloud cover. (i.e. Solar variations affects the amount of planetary cloud cover, particularly over the oceans).

As to evidence from the past, there is proxy data that indicates that there was been abrupt drops in temperature that coincide with solar changes. It is interesting to note that the sun is at its highest activity in 8000 years.

2005 paper by Georgieva, Bianchi, & Kirov “Once again about global warming and solar activity”

http://sait.oat.ts.astro.it/MSAIt760.....76..969G.pdf [Broken]

Attached is a link that to a NASA report that suggests that current solar activity that is the highest in 8000 years might be slowing down.

http://science.nasa.gov/headlines/y2006/10may_longrange.htm [Broken]

Attached is a link to the a daily solar observatory.

http://www.dxlc.com/solar/ [Broken]
 
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BillJx
Hi BillJx,

It is only in the last 5 years that a mechanism has been developed to explain how solar changes could cause a change in planetary temperature.

Scientists specialize and in many cases do not explore competing hypothesis. There is often a delay from when a new hypothesis is developed, to when it is accepted.
You can't be serious! We're talking about an extremely fast-moving field of study. Do you really think that 5 years is a short time? And that the climatologists are just too narrow minded to see the truth as clearly as you can?
 
Sun is now Spotless!!!

Hi BillJx,

Did you check out the link in my comment to the Solar Observatory? Did you notice that the sun is currently spotless? Did you know that solar scientists do not understand why the solar cycle occassionally stops for 100 years. Did you know that there are 32 different solar models all of which give in correct answers?

For some odd reason other stars that appear to be the same as the sun, also stop their equivalent to the solar cycle. Based on the Wilson observatory 50 year H-K study, where the objective was to study a group of sun like stars to try to better understand the sun. But before discussing the sun here is Bond's data about what has happened in the past.

The following is a link to Bond’s paper “Persistent Solar influence on the North Atlantic Climate during the Holocene”

http://www.essc.psu.edu/essc_web/seminars/spring2006/Mar1/Bond et al 2001.pdf


Excerpt from the above linked paper:

“A solar influence on climate of the magnitude and consistency implied by our evidence could not have been confined to the North Atlantic. Indeed, pervious studies have tied increases in the C14 in tree rings, and hence reduced solar irradiance, to Holocene glacial advances in Scandinavia, expansions of the Holocene Polar Atmosphere circulation in Greenland; and abrupt cooling in the Netherlands about 2700 years ago…Well dated, high resolution measurements of O18 in stalagmite from Oman document five periods of reduced rainfall centered at times of strong solar minima at 6300, 7400, 8300, 9000, and 9500 years ago.”
 
Last Interglacial ended Abruptly!!!

Hi BillJx,

Did you know that the last interglacial ended abruptly?

http://www.esd.ornl.gov/projects/qen/transit.html [Broken]

According to the marine records, the Eemian interglacial ended with a rapid cooling event about 110,000 years ago (e.g., Imbrie et al., 1984; Martinson et al., 1987), which also shows up in ice cores and pollen records from across Eurasia. From a relatively high resolution core in the North Atlantic. Adkins et al. (1997) suggested that the final cooling event took less than 400 years, and it might have been much more rapid.

Following the end of the Eemian, a large number of other sudden changes and short-term warm and cold alternations have been recognized; apparently many or all of these occurred on a global or at least a regional scale (Fig.3; Ice core record). The most extreme of these fluctuations are the warm interstadials and the cold Heinrich events. These are most prominent in the ice-core record of Greenland, deep-sea cores from the North Atlantic, and in the pollen records of Europe and North America, suggesting that they were most intense in the North Atlantic region (e.g., Bond et al., 1992; 1993).
 
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Abrupt Cooling Vs Gradual Warming?

Interesting and controversially it appears there have been periods in the past history of the earth, when the planet was warm when CO2 levels where low and cold when CO2 levels were high.

If the fact that the sun is now spotless, indicates that a period of strange very, very, low solar activity is now starting, then based on what has happened before, the 20th century warming will be followed by an abrupt cooling event.

See the attached link to show what happened 8200 years ago.
http://www.geo.arizona.edu/palynology/geos462/8200yrevent.html

Comment:
The papers I quoted in the thread "Earth's reflectivity" assert that solar activity forced the planet's temperature 7.5 W/m2 (1994 to 2001, or three times the estimated CO2 forcing of 2.5 W/m2). If the solar cycle stops, that forcing will of course also abruptly stop.

In the Earth Reflectivity thread I referenced papers that provide data and analysis to support the hypothesis that past major climate changes (abrupt coolings warmings, glacial/interglacial cycle, and so forth) are caused by changes in the geomagnetic field, or the solar wind, or Galactic Cosmic Rays (GCR) all of which modulation the level of cloud cover, have a reduced estimate for the magnitude of warming or cooling due to change in CO2.
 

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