Hard to know what to trust when it comes to climate change science.

[eyeeatingfish]

Did you miss the part where I said that Western Europe was essentially deforested during that period? Oh, and although a fair portion of that wood was used for building, a LOT of it was burned as fuel by an exploding population. I'm sure that THEY know that, but the actually climate change that happened doesn't match up with their theory about AGW, so I'm sure they ignored the facts.

I am aware of this but I do not think it in anyway compares to the amounts of fuel we burn today. Plus Europe may have been deforested but the rest of the world had not. AGW is concerning a global scale not a Europe scale.


And of course that climate change would not match their theory because man had not started to burn fossil fuels to such an extreme extent.

[eyeeatingfish]

Natural occurences hapened back then but don't happen now? I am having a hard time following that logic. Oh, and I just read that Alaska is having a record snowfall.

http://www.boston.com/news/nation/ar...s_snow_record/

No one is saying that natural global warming and/or cooling has ceased to happen. The point is to study the effects of the new variable., which is man burning fossil fuels.

Everything before that is a control, it is warming and cooling before man's influence. So we look at the data from the past without human influence, and then we compare it to data from the period with human influence.
The fact that the earth warmed and cooled in the past does not negate human influence. You need to look at the rate of change and the significance of change. If our world changes at the same rates as before human influence then this would support the idea that man's burning of fossil fuels is not significantly affecting the climate. However if we start to see more extreme or more rapid changes in the climate since man's influence then well this supports the idea that man is influencing the climate.


Consider these two graphs:
The top shows a parallel between fossil fuel usage increase and global temperatures, a pattern something that would support two theories, natural coincidence and fossil fuel usage being a cause.
The bottom shows solar activity compared to global temperatures, they do not parallel suggesting that solar activity does not explain the temperature increases. This is not conclusive but it certainly supports the theory.
http://tqe.quaker.org/2007/TQE158-EN-GlobalWarming.html



We are putting more carbon dioxide into the air when we burn more fuels and with lest forrest and greenery there is fewer plants to absorb the carbon dioxide. It doesn't just disappear.

[jdm61]

The VAST majority of the CO2 that has ever existed on Earth was absorbed by the ocean and "stored" in rocks. I may have the exact numbers wrong, but IIRC, the early part of the planet's history, maybe as much as 1 billion years, there was no life at all, so no plants to absorb the CO2. There was also no "free" oxygen, as most of what was in the air was water vapor. The atmosphere was about 60% hydrogen, 20% water vapor locked oxygen and 10% CO2 with most of the rest being nasty volcanic gases like sulphur dioxide. The absorption of the CO2 into the seas in the formcarbonate sediment happened before the carbon cycle as we know it today got started in Earth's "second atmosphere" I seem to also recall reading that the levels of O2 and CO2 were considerably higher during the Mezozoiac era than today, but that kind of makes sense since much more of the earths land mass was "green" as best as we can tell because things were much warmer..

No one is saying that natural global warming and/or cooling has ceased to happen. The point is to study the effects of the new variable., which is man burning fossil fuels.

Everything before that is a control, it is warming and cooling before man's influence. So we look at the data from the past without human influence, and then we compare it to data from the period with human influence.
The fact that the earth warmed and cooled in the past does not negate human influence. You need to look at the rate of change and the significance of change. If our world changes at the same rates as before human influence then this would support the idea that man's burning of fossil fuels is not significantly affecting the climate. However if we start to see more extreme or more rapid changes in the climate since man's influence then well this supports the idea that man is influencing the climate.


Consider these two graphs:
The top shows a parallel between fossil fuel usage increase and global temperatures, a pattern something that would support two theories, natural coincidence and fossil fuel usage being a cause.
The bottom shows solar activity compared to global temperatures, they do not parallel suggesting that solar activity does not explain the temperature increases. This is not conclusive but it certainly supports the theory.
http://tqe.quaker.org/2007/TQE158-EN-GlobalWarming.html



We are putting more carbon dioxide into the air when we burn more fuels and with lest forrest and greenery there is fewer plants to absorb the carbon dioxide. It doesn't just disappear.

[jdm61]

True, But Europe is where the Little Ice Age happened. it was, as I recall, a regional phenomenon limited to the North Atlantic region and those areas indirectly impacted by the current and weather patterns of the North Atlantic. As for the global nature of AGW, that is one of the unanswered questions, isn't it? The trend does not seem to be universal. Here is another little fun factoid. Here in the US, not only have we reduced harmful emissions in recent years, but the United States may have more forest today than at any time since the early to mid 1800'sANd in areas of the Great Plains, one could possibly argue that there may be an equal or even greater amount of plant biomass on farmland than there was when it was natural tall grasses. Anecdotal evidence from unlikely areas like indoor marijuana growing tells us that if you increase the amount of CO2, the plants will, in fact, absorb it and grow faster.

I am aware of this but I do not think it in anyway compares to the amounts of fuel we burn today. Plus Europe may have been deforested but the rest of the world had not. AGW is concerning a global scale not a Europe scale.


And of course that climate change would not match their theory because man had not started to burn fossil fuels to such an extreme extent.

[russianpolander]

I believe it is all bunk and just another way for some to profit off of their thoughts. To think that humans can affect the climate in a negative way enough to alter the planet and possibly end it all is perhaps the most egotistical line of thinking ever devised.

[A.W.U.K.]

The funny part about the medieval warm period is that you might be tempted to argue that the massive deforestation, population explosion and agricultural revolution in Western Europe from the 11th through early 14th Century may have had some significant impact on the regional climate.........but for that whole little ice age thing that hit just as late medieval society was at its zenith, after which famine and the Black Death reduced the population of the entire area by at least 30 percent. We were still dealing with the effects of that cooling trend as late as the mid 19th Century in North America.

Except that the Little Ice Age began around 1550, give or take a decade or two, at least 200 years after the beginning of the late medieval population decline.
One shouldn't exaggerate the degree of deforestation though. In Western Europe at least, Woodland was just another form of valuable farmland, usually coppiced in rotation or managed in other ways, it was not often converted to ploughland.

[jdm61]

Ummmm, in the 7th Century, Northern Europe was pretty much a green carpet. Muhc of the reputation of the Western Europeans as a "dirty" people who did not bath comes from this time. Wood had become a more expensive commodity and could not be burn in massive amounts for heating water by many folks. As for the Little Ice Age, the strange weather associated with it began as early as 1250 when the Atlantic. By 1300, people could not could on the summer growing season being regularly warm and within a few years, you had cold rains. We find evidence of plants being killed by glaciation in that time period. The associated famines, particularly the "Great Famines" of 1315-1317 are theorized to be one of the things that made the Black Death so nasty in parts of central Europe.. Many people were already vulnerable before it hit. The typical numbers given for fatalities are anywhere from 30 to 50%, but in some parts of why is today Germany, entire areas were essentially depopulated.

Except that the Little Ice Age began around 1550, give or take a decade or two, at least 200 years after the beginning of the late medieval population decline.
One shouldn't exaggerate the degree of deforestation though. In Western Europe at least, Woodland was just another form of valuable farmland, usually coppiced in rotation or managed in other ways, it was not often converted to ploughland.

[A.W.U.K.]

First of all I have to admit my historical knowledge has an English bias and I know litle about Eastern Europe.
As far as I know, the "Green Carpet" view of Dark Age Europe has been strongly challenged by recent research. In England for instance, woodland was carefully measured and recorded in 1086 in Domesday book - before the rapid population growth of the 12th and 13th centuries, suggesting it was already a limited and valuable resource. The study of charters and archaeological work tend to support the same conclusion.
Good quality building timber was certainly eye-wateringly expensive in medieval England and the collecting of firewood was closely regulated.

Looking at the graphs, there seems to be a "shoulder" between the end of the medieval warm period and the beginning of the Little Ice Age. A period of some 200 years in which temperatures were fairly stable at a mid-point.

It is certainly true that there was a series of bad harvests, aparently caused by bad summers, in the early years of the 14th century. The populations seems to have levelled off or fallen slightly at that time.

Regarding the very high levels of CO2 in the atmosphere in the distant past, The greenhouse effect of carbon dioxide works in a logarithmic way, so at high levels each additional ppm has slightly less effect than the one before, until the incremental effect is negligible.

[jdm61]

Yes, But England was a fairly advanced part of the world BEFORE the fall of the Empire more comparable to Southern Gaul or the coast of the Iberian Peninsula than the hinterlands beyond the Rhine/Danube frontier. Roman agriculture had come there in the First Century. The Britons were one of those "tribes" that was considered to be among the most Romanized of the Provincials. But, as Southern Britain is pretty tiny, anything that happened there would not have much impact. I am primarily talking about the massive stretches of territory north of the Alps. Hell, parts of Central/Eastern Europe were not even populated much at all for a while until the Germanic kings started calling for settlers. If you want a time line for that, remember that a fair number of those settlers included French Calvinists and both sub groups of Jews. As for the Medieval Agricultural Revolution and it's 3 field system of crop rotation and advanced equipment, it was already in full swing in 1050. The favorable warm weather that permitted the move into the colder lands of Northern Europe had actually been around since the mid 700's, but there was a little delay in fully exploiting the northern lands because folks were busy trying to get their act together and fighting off the invasions of the Muslims, Magyars and Vikings during that period. Another thing to consider is that the start of the Little Ice Age is a bit of a moving target. The 1550 date is arguably the SECOND cold period. which was followed by at least two more, including the one on the Atlantic seaboard of North America that some historians say was partly responsible for the increase in western migration in the US in the 1800's. The Atlantic was already icing up more by 1250 and the 1550 date is more of the "glacial maximum" which was the worst of the cold snap that ran from 1500-1700. That is one of the other things that you don't hear much about. The climate change in Greenland was such that the Vikings were forced to abandon it long before the 1500 date. We talk about how the glaciers are receding at such a rapid rate, but I never here much talk about how big they were in the days when the coast of Greenland was farmed. Having flown over Greenland a few times, I can tell you that it is anything but green today. LOL People continue to say that the land temperatures are higher today than in the height of the MWP, but you also see data that says that the sea temperatures of the middle Atlantic are no warmer than in say 1100. They were apparently almost 2 degrees F cooler in 1600 and also possibly in the time of the late Roman Empire.

First of all I have to admit my historical knowledge has an English bias and I know litle about Eastern Europe.
As far as I know, the "Green Carpet" view of Dark Age Europe has been strongly challenged by recent research. In England for instance, woodland was carefully measured and recorded in 1086 in Domesday book - before the rapid population growth of the 12th and 13th centuries, suggesting it was already a limited and valuable resource. The study of charters and archaeological work tend to support the same conclusion.
Good quality building timber was certainly eye-wateringly expensive in medieval England and the collecting of firewood was closely regulated.

Looking at the graphs, there seems to be a "shoulder" between the end of the medieval warm period and the beginning of the Little Ice Age. A period of some 200 years in which temperatures were fairly stable at a mid-point.

It is certainly true that there was a series of bad harvests, aparently caused by bad summers, in the early years of the 14th century. The populations seems to have levelled off or fallen slightly at that time.

Regarding the very high levels of CO2 in the atmosphere in the distant past, The greenhouse effect of carbon dioxide works in a logarithmic way, so at high levels each additional ppm has slightly less effect than the one before, until the incremental effect is negligible.

[Triton]

They are not looking for a man made cause of the medieval warming period.

Yes, I recognize that global warmistas only want to focus on a very narrow bit of history and ignore the rest because it doesn't fit in well with their theory, the question I'm asking is why?

, and there is not much reason to either.

So other periods where temperatures spiked are of no possible interest?

Anything before that time is limited to some natural occurrence.

I see, so that was "some natural occurrence" but now it MUST be evil humanity at work?

Perhaps but on some level we are all hypocrites.

That's hardly an excuse and certainly a reason to trust them less wouldn't you say?

[jdm61]

The question that is left out of most discussions about global warming, man-made or otherwise, is what its impact would actually be. I can tell you that there are some Russians that think is would be a grand thing!!! The former USSR contains 1/6 of the world's landmass and a fair bit of that land is pretty useless because it is either under permafrost or damn near impossible to get to for much of the year. I suspect that there might be some Canadians and Danes (who still own Greenland, IIRC) who secretly feel the same way. LOL The Chinese might get some benefit too as much of the inland portion of that country is not under cultivation for various and sundry reasons. Perhaps the biggest problem that we humans have today is that because we have advanced so much technologically, we arguably no longer have the freedom or at least the desire to pick up and move somewhere else when conditions change.

[eyeeatingfish]

Yes, I recognize that global warmistas only want to focus on a very narrow bit of history and ignore the rest because it doesn't fit in well with their theory, the question I'm asking is why?

Wouldn't it be silly to look for a human cause when humans weren't doing anything that could have caused it? It would be like asking if ciggarettes caused cancer during a period when they had not been invented yet.

So other periods where temperatures spiked are of no possible interest?

They are controls, something with which to compare current data to and see how the climate acted prior to fossil fuels.

I see, so that was "some natural occurrence" but now it MUST be evil humanity at work?

See why even discuss it when you are not taking it seriously? Injecting claims of moral superiorty and absolute statements I never made.

That's hardly an excuse and certainly a reason to trust them less wouldn't you say?

Maybe not a very good excuse but not necessarily a reason to trust less unless you are going to say since we are all humans none of us are trustworthy.

[timcsaw]

Wouldn't it be silly to look for a human cause when humans weren't doing anything that could have caused it?.

Don't you see the faulty logic in this statement?

You want to use a very narrow slice of time to determine if mankind causes the earth's temperature to rise... Well I demand that we use an even NARROWER slice of time (excluding all other times), so I choose the very, VERY specific time frame of a day ago (Sunday) and the huge snowfall that closed 180 miles of Interstate 40 in northern Arizona which PROVES that the earth is cooling. (<-- see how obvious and obtuse it is to selectively use a specific, narrow time frame (which supports only MY position) that excludes the WIDEST range of time and data available for us to use?)

If all of mankind ceased to exist in the next 20 minutes, the earth would STILL warm up to the point that "global-warmists" are screaming about! By THEIR "logic", the sea will STILL rise and displace huge numbers of "creatures" that live on islands/beach fronts/ocean coasts etc. The glaciers will STILL melt, the polar bears will STILL starve, the polar ice packs will STILL recede etc., etc., etc. and... Al Gore will STILL use more energy than any 10 humans that used to exist.

ON EDIT: News flash folks... No matter WHAT we do, or do NOT do, the average temperature of the earth is GOING to rise by more than a few degrees. That temperature rise IS going to cause a massive release of CO2 (CO2 lags temperature) which is THEN going to increase the "greenhouse effect" which will then, probably cause an additional increase in the earth's temperature.

You heard it here first.

[Triton]

Wouldn't it be silly to look for a human cause when humans weren't doing anything that could have caused it?

Why are we limiting ourselves to human causes when it's obvious that there have been other warming periods that were not caused by humans?

Maybe not a very good excuse but not necessarily a reason to trust less unless you are going to say since we are all humans none of us are trustworthy.

You often trust hypocrites with making decisions regarding your freedom?

[eyeeatingfish]

Don't you see the faulty logic in this statement?

You want to use a very narrow slice of time to determine if mankind causes the earth's temperature to rise...

Indeed the fossil fuel era is a narrow slice of history but that is all we have to work with. Just because we are talking about a short period of time does not mean it is not worth of study or not possible to study.

There is no faulty logic here.

[eyeeatingfish]

Why are we limiting ourselves to human causes when it's obvious that there have been other warming periods that were not caused by humans?

Of course there are other causes and they can and are studied, that has nothing to do with whether or not we study man made causes.

You often trust hypocrites with making decisions regarding your freedom?

Well I could refrain from voting for anyone ever again but it wouldn't make a difference.

[Codger_64]

Of course there are other causes and they can and are studied, that has nothing to do with whether or not we study man made causes.

No, if one honestly is concerned about mankind's influence on the climate, one must study the entire baseline which includes periods of climate change when man could not have influenced climate change. Such as solar activity, earth axis tilt changes, the natural effects of oceans and tides, volcanic activity and hundreds of other factors.

You do remember the "holes in the ozone layer" scam, right? It seems that after billions of dollars spent by consumers, industries and governments to meet thousands of new regulations intended to fix a man-created "problem", there really wasn't a problem afterall. It was all based upon knee-jerk reaction to naturally occuring phenomena.

http://www.discerningtoday.org/ozone_depl_twilight_.htm

[eyeeatingfish]

No, if one honestly is concerned about mankind's influence on the climate, one must study the entire baseline which includes periods of climate change when man could not have influenced climate change. Such as solar activity, earth axis tilt changes, the natural effects of oceans and tides, volcanic activity and hundreds of other factors.

I agree and have acknowledged this multiple times. I have mentioned that the period before fossil fuel burning is essentially a control when looking to see if man's action is influencing the climate. You compare the data from before fossil fuels to the data from after fossil fuels started being used.
Sceintists do already study all of the things you mentioned, and it would be impossible to even come up with a supported theory of man made global warming if you didn't have any data on the climate from prior to fossil fuels being used.

[Codger_64]

And when those true baselines are used, we see very little influence of mankind's activities on the climate. If we fudge and try to use short timelines, we can claim polar bears drowning (and put them on the Endangered Species lists), glaciers melting, extreme weather events. This is the gross dishonesty that people are speaking of, the "outcome based science" that really isn't science at all but political and economic agenda. "Crying wolf" tends to jaundice the public towards all gloom-and-doom scientific predictions. Most especially when they prove false time and again. Most especially when they are used as a basis to attempt societal engineering on falsified data (or incomplete data in some cases).

Study member John Wahr reports that worldwide about 30% less ice is melting than previously thought and that sea levels, while rising, are doing so at the glacial pace, no pun intended, of only one six-hundredth of an inch per year.

http://news.investors.com/article/60...alayan-ice.htm

At this rate of ocean rise, people will have to move a few feet uphill gradually over the next 1,200 years. Surely they can accomplish that without commiting to some overnight mass evacuation?

[eyeeatingfish]

And when those true baselines are used, we see very little influence of mankind's activities on the climate.

I am not sure I would agree with that statement. Not so much with the fact that the earth climate will change naturally and has been both warmer and colder but because of the rates of change among other things.
I do realize that it is not always that simple because now we have accurate current data while the data we compare it to is from thousands of years ago and has to be extrapolated making it not necessarily as precise, but I do not believe that makes climate study unreliable.