My belief in Global Warming is getting shaky

[Moontanman]

Litespeed just might have a point, it was warmer than today in recent geology and a warming did coincide with human civilization.

 

7(x) Earth's Climatic History

 

Holocene - Wikipedia, the free encyclopedia

[InfiniteNow]

But, as Freezy has repeatedly pointed out, both the cause and the rate of current warming are what generates the alarm, and which makes the mass extinctions taking place so much more troubling.

[modest]

I have provided all sorts of facts that do not constitute a 'dump'. For instance, CO2 concentrations now are at the low end of planetary history.

 

Most of our planet's history involves no complex life. [ce]CO_2[/ce] reconstructions from ice cores concerning earth's recent history (past half a million years) shows current levels to be well-above normal.

 

-source

 

In addition, the undeniably warmer Roman times saw the development and expansion of not only Rome, but the Chin dynasty in China. I have proposed that warmer temperature was more conducive to civilization then the climate we have now.

Global surface temperatures over the past 2,000 years as represented from various ice cores and reconstructions are shown in the following graph with references on the source page,

-source

 

Notice the current global surface temperature marked 2004 as opposed to "Roman times". Your claim above does not seem consistent with this data.

 

:Exclamati Can you please provide a scientific source backing up the claim that Roman times were undeniably warmer than today. Doing so is required by the site rules.

 

~modest

[litespeed]

moon - You wrote: "...Do you actually think that during roman times the world was warmer than it is now?..." I challenged you and I to google contest on subject. Here is my submition:

 

1) Roman Warm Period (Europe - Northern) -- Summary

CO2 Science

This paper includes many climate studies with links, and citations.

 

2) This is an interesting paper on historical sunspot cycles

Timo Niroma: Sunspots: The 200-year sunspot cycle is also a weather cycle

 

3) The following link is from the roman summary aboveis an include link in citation 1)

CO2 Science

 

It estimates actual temperature changes in degrees C. The warm eras are estimated to be even greater then I suspected ['a FEW degrees C].

"... 550 to 450 BC (Roman Warm Period), when summer temperatures were the warmest of the entire record, exceeding the 1961-1990 mean by more than 6°C,

 

"... AD 300 to 400 (Dark Ages Cold Period), which was "the longest period of consecutive cold summers," averaging 1.5°C less than the 1961-1990 mean..."

[Moontanman]

litespeed. check out post #1395

[litespeed]

Modest - You wrote: "Most of our planet's history involves no complex life." That is true. However, your CO2 chart is one or two orders of magnitudes short, assuming predatory lizards qualify.

 

"The [newly discovered] creature appeared long before the dinosaurs... It was a protorosaur, part of an order of diverse, predatory reptiles that lived as far back as 280 million years ago." I will need to revisit my source to to check that out for CO2 levels.

[litespeed]

M

 

I have relocated my source at Climate during the Carboniferous Period

 

It shows Jurasic period with more then 2500 ppm CO2 with average global temperature about 12 degrees warmer then today. And, according to my Roman era sources, that would be about 6 degrees C warmer then the Roman era. Further, about 200 of the last 250 million years show CO2 well in excess of what it is today.

 

I am out of here!

[REASON]

M

 

I have relocated my source at Climate during the Carboniferous Period

 

It shows Jurasic period with more then 2500 ppm CO2 with average global temperature about 12 degrees warmer then today. And, according to my Roman era sources, that would be about 6 degrees C warmer then the Roman era. Further, about 200 of the last 250 million years show CO2 well in excess of what it is today.

 

I am out of here!

 

Litespeed is referring specifically to this chart below from a website that is focused around Plant Fosils of West Virginia, and includes research into the environment and climatic conditions during the Carboniferous Period. It has been presented or referred to several times before in this thread.

 

[img=http://www.geocraft.com/WVFossils/PageMill_Images/image277.gif]http://www.geocraft.com/WVFossils/PageMill_Images/image277.gif[/img]

 

I don't think anyone is denying that the Earth has been significanly warmer and contained far greater levels of atmospheric CO2 over hundreds of millions of years ago, and that there was prolific plant and animal life that existed during those periods.

 

What modest's chart demonstrates is the natural rates of change in atmospheric CO2 that were occuring over a much more specific length of time (hundreds of thousands of years), and the apparent dramatic increase, or shift, with the corresponding temperature that has occurred over a very short period more recently. The graph above does not indicate rapid rates of change because it covers such a vast amount of time. The concerns expressed by climatologists today revolve around the seeming stark rate of change upward we are currently experiencing and what can explain its occurance.

 

It is the responsibility of scientists in the related fields to investigate these issues to try and understand their implications for our civilization. While our impact on the atmosphere may prove to be negligible to our way of life, there is also the real possiblity that it could be damaging or even catastrophic. Maybe that sounds like alarmist rhetoric to some, but how can we not consider the risks?

 

What could be the cost of our negligence vs the cost of a change in energy production capabilities that are more environmentally conscious? Which would provide a better, more sustainable long term goal for success?

 

These are the questions I think we are facing.

 

 

And by the way, I don't intend on responding to your strawman argument that I want the planet to be colder other than to say I've never made such a statement and that's not what I want. I would prefer that the climate evolve naturally with as little undue influence by humankind as possible.

[Eclipse Now]

Modest - You wrote: "Most of our planet's history involves no complex life." That is true. However, your CO2 chart is one or two orders of magnitudes short, assuming predatory lizards qualify.

 

"The [newly discovered] creature appeared long before the dinosaurs... It was a protorosaur, part of an order of diverse, predatory reptiles that lived as far back as 280 million years ago." I will need to revisit my source to to check that out for CO2 levels.

 

Irrelevant, because they did not build a civilisation dependent on the current conditions. Sure there were some advanced forms of life in 'warmer climates', even 'hot climates'. There also seem to have been some extinction events related to super-greenhouses as well. However, OUR species, which I'm quite a fan of (apart from our destructive tendencies), doesn't tend to like mass-starvation due to agricultural collapse, or bankrupted economies due to... any and every climate disaster mentioned above. (Drought, flooding, increased hurricane strength, unpredictable weather, storm damage, etc).

 

So.... YEP, the Co2's been MIGHTY high in the vastly distance prehistorical past. MUCH higher than today if we are to believe the ABC's documentary "Crude" and some of the links you've shown. However, you have not proved the relevance of these conditions back then to what we might experience now. I don't really want a Carboniferous forest right now... I want/need crops to feed the world. And that is becoming increasingly difficult to do.

[modest]

moon - You wrote: "...Do you actually think that during roman times the world was warmer than it is now?..." I challenged you and I to google contest on subject. Here is my submition:

 

1) Roman Warm Period (Europe - Northern) -- Summary

CO2 Science

This paper includes many climate studies with links, and citations.

 

2) This is an interesting paper on historical sunspot cycles

Timo Niroma: Sunspots: The 200-year sunspot cycle is also a weather cycle

 

3) The following link is from the roman summary aboveis an include link in citation 1)

CO2 Science

 

It estimates actual temperature changes in degrees C. The warm eras are estimated to be even greater then I suspected ['a FEW degrees C].

"... 550 to 450 BC (Roman Warm Period), when summer temperatures were the warmest of the entire record, exceeding the 1961-1990 mean by more than 6°C,

 

The first article you quote has:

There is, however, one data point at about

1500 years BP

(during the Roman Warm Period) that rises above this line by ~0.5°C

 

CO2 Science

while the third has:

Several periods of anomalously warm and cold summers were noted throughout the record: (1)

550 to 450 BC

(Roman Warm Period), when summer temperatures were the warmest of the entire record, exceeding the 1961-1990 mean by more than 6°C

 

CO2 Science

There appears to be a thousand year difference between the two. I don't have time to reconcile this, so perhaps you (or another member who wants to help litespeed out) can explain when exactly the Roman warm period was and which of these two articles is mistaken.

 

Your quote,

"... 550 to 450 BC (Roman Warm Period), when summer temperatures were the warmest of the entire record, exceeding the 1961-1990 mean by more than 6°C"

is on this page which gives this source:

Linderholm, H.W. and Gunnarson, B.E. 2005. Summer temperature variability in central Scandinavia during the last 3600 years. Geografiska Annaler 87A: 231-241.

The abstract of which has:

A Scots pine (Pinus sylvestris L.) tree-ring width chronology from Jämtland, in the central Scandinavian Mountains, built from living and subfossil wood, covering the period 1632 BC to AD 2002, with a minor gap during AD 887-907, is presented. This is the first multi-millennial tree-ring chronology from the central parts of Fennoscandia. Pine growth in this tree line environment is mainly limited by summer temperatures, and hence the record can be viewed as a temperature proxy. Using the regional curve standardization (RCS) technique, pine-growth variability on short and long time scales was retained and subsequently summer (June-August) temperatures were reconstructed yielding information on temperature variability during the last 3600 years.

Several periods with anomalously warm or cold summers were found:

450-550 BC (warm), AD 300-400 (cold), AD 900-1000 (the Medieval Warm Period, warm) and AD 1550-1900 (Little Ice Age, cold). The coldest period was encountered in the fourth century AD and

the warmest period 450 to 550 BC. However, the magnitude of these anomalies is uncertain since the replication of trees in the Jamtland record is low during those periods.

The twentieth century warming does not stand out as an anomalous feature in the last 3600 years.

Two multi-millennial tree-ring chronologies from Swedish and Finnish Lapland, which have previously been used as summer temperature proxies, agree well with the Jämtland record, indicating that the latter is a good proxy of local, but also regional, summer temperature variability.

 

Summer temperature variability in central scandinavia during the last 3600 years

 

I am satisfied that this establishes that peak summer temperatures in the Scandinavian Mountains was greater 2500 years ago than peak summer temps in the Scandinavian Mountains in the last century. However, the statement "However, the magnitude of these anomalies is uncertain since the replication of trees in the Jamtland record is low during those periods." leaves at least some doubt.

 

Litespeed, do you have a link to this paper? I would not feel comfortable letting co2science.org characterize a paper that I am unable to read.

 

Nevertheless, climatologists agree (as I think it's been pointed out by others recently in this thread) that temperatures have generally been declining since the Holocene optimum,

 

You should take care to differentiate between summer temperature fluctuations in one area vs. global temperature fluctuations averaged over a decade or a half century. Where you say 6° C in your quote above and your last few posts, you make no distinction. Were global average temperatures to rise 6° C the effects would be drastic (notice the graph above).

 

~modest

[litespeed]

Modest - You asked: "... do you have a link to this paper?"

Summer temperature variability in central scandinavia during the last 3600 years

 

No. In fact I have not vetted ANY of the sub listings in the original Roman Era Summary. That is because I was simply providing Moon with information that might simply support The Roman Era Warming. One discouraging thing here is I continue to encounter people who are unaware of even the simplest controversies.

 

How is it even possible that educated people who have solid positions on GW are not even AWARE that more then a few scientist have presented evidence of Roman Warming, or other warming and cooling events in the last 2000 years? How is it even possible to even progress to the relatively uncomplicated proposals made in that SUN SPOT cycles Timo Niroma: Sunspots: The 200-year sunspot cycle is also a weather cycle

 

Accordingly, I will limit my discussions here to convincing some people the issue is NOT closed, and that a complete consensus has NOT been achieved. In my next post I will attemp to provide a list of GW recanters. This will show not only a lack of universal consensus, but prominent people who have changed their minds in the other direction.

 

That post might take awhile, since 1) I want to do it right, and 2) I want to watch TV this afternoon!

[litespeed]

Mosest

 

I have apparently found either a typo or an apparent point of controversy in one of my sources. Specifically:

 

"There is, however, one data point at about 1500 years BP (during the Roman Warm Period) that rises above this line by ~0.5°C." CO2 Science

 

The era of the Roman warm period does not have consensus. Further, the Roman Era itself has no consensus. I do not believe 500 AD includes the [Western] Roman Era, let alone the era of Roman Warming.

 

But thats just me.

[modest]

The first article you quote has:

There is, however, one data point at about

1500 years BP

(during the Roman Warm Period) that rises above this line by ~0.5°C

 

CO2 Science

while the third has:

Several periods of anomalously warm and cold summers were noted throughout the record: (1)

550 to 450 BC

(Roman Warm Period), when summer temperatures were the warmest of the entire record, exceeding the 1961-1990 mean by more than 6°C

 

CO2 Science

There appears to be a thousand year difference between the two. I don't have time to reconcile this, so perhaps you (or another member who wants to help litespeed out) can explain when exactly the Roman warm period was and which of these two articles is mistaken.

 

Mosest

 

I have apparently found either a typo or an apparent point of controversy in one of my sources. Specifically:

 

"There is, however, one data point at about 1500 years BP (during the Roman Warm Period) that rises above this line by ~0.5°C." CO2 Science

 

Yes, I recall pointing it out to you a few hours ago.

 

The era of the Roman warm period does not have consensus. Further, the Roman Era itself has no consensus. I do not believe 500 AD includes the [Western] Roman Era, let alone the era of Roman Warming.

 

But thats just me.

 

So, you have no idea when the "Roman Warm Period" occurred or what global temperatures were like during this unknown era. By the veracity with which you've been waving your hands about one would assume you've studied this issue in depth.

 

I believe it's possible global temperatures were as warm as today (and perhaps warmer) at some point between 500 BC and 500 AD. It's also possible they were quite a bit colder than today. We've established neither in this thread. Bring some data to the table. Do a proper scientific investigation.

 

If you want to debate the politics of anthropogenic global warming, we have a politics forum for that. This forum is for environmental studies.

 

You might check out:

 

Progress in reconstructing climate in recent millennia - What makes science different from politics?

 

and, on the topic which Freeztar, Reason, and others have been telling you:

 

There is a bigger issue of course. For the sake of argument, let's accept that medieval times were as warm in England as they are today, and even that global temperatures were similar (that's a much bigger leap, but no mind). What would that imply for our attribution of current climate changes to human causes? ……. Nothing. Nowt. Zero. Zip.

 

Why? Well, warm periods have occured in the past, and if not the medieval period, then probably the last interglacial (120,000 years ago), certainly the Pliocene (3 million years ago), without question the (Eocene 50 million years), and in particular the Paleocene-Eocene Thermal Maximum (55 million years ago), and so on. Current theories of climate change do not rely on whether today's temperatures are 'unprecedented'. Instead they examine the physical causes of climate change and match up what we know about their physical effects and time history and see which of the multiple drivers or combination can best explain the observations. For the last few decades, that is quite clearly the rise in greenhouse gases, punctuated by the occasional volcano and mitigated slightly by the concomittant rise in particulate pollution.

 

-

Medieval warmth and English wine

 

~modest

[Eclipse Now]

Again from a study Tim Flannery quotes in "Weather Makers", apparently the MWP was a local phenomenon and other data indicates the global temperature was actually cooler. How can this be? Apparently a cooler stratosphere can cause "patchy" weather systems and local climate systems. I would not have guessed in a million years that a slightly cooler globe would have caused the so called "Medieval Warm Period" but there you have it. With our Euro-centric historical perspective, we've taken a local trend and applied it to the globe. Apparently data from South America indicates the global trend was cooler.

 

Anyway, I've got to rush... I'll try and find which study Tim Flannery was quoting and link to it later.

[Michaelangelica]

Boy on a Stick and Slither

 

"My interest in the future is because I am going to spend the rest of my life there."

- Charles F. Kettering, inventor.

[litespeed]

Modest provided:

 

[Originally Posted by litespeed - The era of the Roman warm period does not have consensus. Further, the Roman Era itself has no consensus. I do not believe 500 AD includes the [Western] Roman Era, let alone the era of Roman Warming.]

 

Then Modest wrote: "So, you have no idea when the "Roman Warm Period" occurred or what global temperatures were like during this unknown era."

 

UNKNOWN ERA? What educated person believes The Roman Empire was an 'unknown era'. Further, my citations included a broad based summary specifically directed at this "unknown era" but you, apparently, failed to notice any of them. My skepticism that 500 AD included the Roman era specifically implies I DO have ideas of both, and that 500 AD does not match them. You, however, inferred I had no idea. You really need to study Vhen Diagrams.

 

I came here today with my list of GW recanters and deniers, but I see no need to bother. Just ban me, and genuflect your Idol: large poster of " Forelorn Polar Bear on Small Ice Berg." I suggest you buy the same incence used by Roman Catholic Church.

[freeztar]

I came here today with my list of GW recanters and deniers, but I see no need to bother. Just ban me, and genuflect your Idol: large poster of " Forelorn Polar Bear on Small Ice Berg." I suggest you buy the same incence used by Roman Catholic Church.

 

 

I suggest you watch your tone and carry on within a scientific capacity.

 

Nobody here is suggesting the world is going to end and carrying flags with polar bears. Your hyperbole is unwarranted and unnecessary in a scientific discussion and analysis of facts.

 

Stick to the science please. If you'd like to rail against those that you might label "AGW fanatics", then perhaps this is the wrong forum for you.