Warming and cooling is a natural cycle.

[Old Rocks]

Past Climates on Earth
"Hark! The faint bells of the sunken city
Peal once more their wonted evening chime!
From the deep abysses floats a ditty
Wild and wondrous, of the olden time".
- Wilhelm Mueller, "The Sunken City", translation from the German

We wish to learn:

• What do we mean by "paleoclimate"?
• What evidence exists for ancient climate change?
• What causes the climate to change?

Format for Printing
Paleoclimates Causes of change Summary

Figure 1. Vegetation during glaciation in North America in the last Ice Age. The geologic record indicates several ice surges, interspersed with periods of warming, called "interglacials." (Source: Oak Ridge National Laboratory)


One of the most pressing concerns for humans on Earth today is climate change, and what will happen in the future. Given that the climate is definitely warming, it is logical to ask two questions: First, have such changes happened before in the history of the Earth? And second, what is causing this change? In the next two lectures we will examine past climates (paleoclimates) and the forces that caused them to change. This information will set the stage for asking if the same forces that caused past changes are causing climate warming today, and for making predictions about what will happen in the future (upcoming lecture on climate models).

From abundant geological evidence, we know that only three hundred and fifty years ago the world was in the depths of a prolonged cold spell called the "Little Ice Age," which lingered for nearly 500 years. Twenty thousand years ago, in the middle of the last glacial period, large continental scale ice sheets covered much of North America, Northern Europe, and Northern Asia. Fifty million years ago, global temperatures were so high that there were no large ice sheets at all.

The speed at which climate can change has also recently become clear: Transitions between fundamentally different climates can occur within only decades. In order to understand these variations, we need to reconstruct them over a wide range of temporal and geographical scales. The importance of this task is underlined by the growing awareness of how profoundly human activity is affecting climate. As with so many other complex systems, the key to predicting the future lies in understanding the past

We need to ask several questions: What happened? Why did it happen? Has it happened before? Will is happen again? How do we know about it in the first place? Clickthe image to the right to explore the hypothesized changes in ice cover and vegetation.

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Paleoclimatology
Related readings:
Cultural Responses to Climate Change During the Late Holocene
University of Michigan students can access this Science On-Line article through this link.
Paleoclimatology is the study of past climates. It is a fascinating, multidisciplinary field, combining history, anthropology, archaeology, chemistry, physics, geology, atmospheric, and ocean sciences. Clues about past climate conditions are obtained from proxy indicators (a proxy is a "substitute"), which are indirect forms of evidence that can be used to infer climate. These include:

• Isotopic Geochemical Studies: The study of rock isotopic ratios, ice core bubbles, deep sea sediments, etc.
  
  
• Dendochronology: the study of tree rings
  
  
• Pollen Distribution: the study of plant types and prevalence from pollen found in sediments, ice, rocks, caves, etc.
  
  
• Lake Varves: (like dendochronology, but with lake sediments - a varve is an annual layer of mud in the sediment)
  
  
• Coral Bed Rings
  
  
• Fossils: Studies of geological settings, etc.
  
  
• Historical documents, paintings, evidence of civilizations, etc.

Paleoclimates

And many more methods are also being used and developed.

 

[Muhammed]

our climate is not controlled or effected by the things that man does. It is controlled mostly by the sun. It has been that way ever since the fireball cooled, coalesced and became the earth.

AGW is a lie perpetuated by the Democrat Party in this country and socialists all over the world. The purpose of which is to bleed money and power from the world's top countries, especially the USA.

NOAA Website on Climate: Earth’s Hottest Period Occurred Before Man Existed

And? And the coldest period also before man existed. Now there were reasons for both. And were you to read what the scientists have to say instead of a bunch of knuckleheads as ignorant as you are, you might learn something.

I've read what your doomsday cult "scientists" had to say and found that their reasoning was flawed.

The damning climategate e-mails were leaked by Wikileaks. They prove that it wasn't merely junk science, it was fraud.

 

[Crick]

The "climategate" emails stolen from the UEA's CRU were not "leaked by Wikileaks. They were stolen by an insider and sent to several well known deniers.

From Climatic Research Unit email controversy - Wikipedia, the free encyclopedia

The Climatic Research Unit email controversy (also known as "Climategate")[2][3] began in November 2009 with the hacking of a server at the Climatic Research Unit (CRU) at the University of East Anglia (UEA) by an external attacker,[4][5] copying thousands of emails and computer files to various internet locations several weeks before the Copenhagen Summit on climate change.

The story was first broken by climate change critics[6] with columnist James Delingpole popularising the term "Climategate" to describe the controversy.[7] Several people considered climate change sceptics argued that the emails showed global warming was a scientific conspiracy, that scientists manipulated climate data and attempted to suppress critics.[8][9] The CRU rejected this, saying the emails had been taken out of context and merely reflected an honest exchange of ideas.[10][11]

The mainstream media picked up the story as negotiations over climate change mitigation began in Copenhagen on 7 December.[12]Because of the timing, scientists, policy makers and public relations experts said that the release of emails was a smear campaignintended to undermine the climate conference.[13] In response to the controversy, the American Association for the Advancement of Science (AAAS), the American Meteorological Society (AMS) and the Union of Concerned Scientists (UCS) released statements supporting the scientific consensus that the Earth's mean surface temperature had been rising for decades, with the AAAS concluding "based on multiple lines of scientific evidence that global climate change caused by human activities is now underway...it is a growing threat to society."[14]

Eight committees investigated the allegations and published reports, finding no evidence of fraud or scientific misconduct.[15]However, the reports called on the scientists to avoid any such allegations in the future by taking steps to regain public confidence in their work, for example by opening up access to their supporting data, processing methods and software, and by promptly honouringfreedom of information requests.[16] The scientific consensus that global warming is occurring as a result of human activity remained unchanged throughout the investigations.[17]
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The word "wikileaks" does not appear anywhere in this quite extensive article. Now I have no trouble believing that Assange might have gotten his hands on a copy and put them on his site, but he had nothing to do with the theft (one hopes) and if he published them on his site, it was a pathetic attempt to join the bandwagon.

 

[Crick]

PS, your ability to make valid judgments regarding the reasoning of scientists, from what we have seen of you here, is vanishingly close to nil.

 

[Weatherman2020]

Leftists are so narcistic they think they control the weather too.

And yet deniers say the temperature data is flawed because of the "Urban Heat Island" effect caused by .... wait for it .... PEOPLE

Takes a real parrot to link urban effects on temperature to say that equates to climate change of the world.
Congratulations, here is your cracker.

 

[Crick]

The original claim, from Anthony Watts et al, has been that temperature data has been biased upwards by UHI effects and that bias is responsible for some significant portion of the observed warming. The claim fails for a number of reasons, such as the match between warming trends in urban, rural and marine areas and, to be honest. UHI has disappeared along with cosmic ray clouds, TSI and volcanoes. Deniers remaining arguments are all paranoia-based: temperature data is being manipulated by a global conspiracy among climate scientists in order to produce the appearance of warming that isn't really present. The fringe around here have lately been claiming that CO2 is not a greenhouse gas or that the greenhouse effect is not real.

 

[edthecynic]

Leftists are so narcistic they think they control the weather too.

And yet deniers say the temperature data is flawed because of the "Urban Heat Island" effect caused by .... wait for it .... PEOPLE

Takes a real parrot to link urban effects on temperature to say that equates to climate change of the world.
Congratulations, here is your cracker.

Just as a group of people locally can affect the climate locally, a larger global group of people can affect climate globally.
There are a lot of urban centers around the globe.
The point is the effects of people are CUMULATIVE, not individual, and therefore not narcissistic.

 

[Weatherman2020]

Leftists are so narcistic they think they control the weather too.

And yet deniers say the temperature data is flawed because of the "Urban Heat Island" effect caused by .... wait for it .... PEOPLE

Takes a real parrot to link urban effects on temperature to say that equates to climate change of the world.
Congratulations, here is your cracker.

Just as a group of people locally can affect the climate locally, a larger global group of people can affect climate globally.
There are a lot of urban centers around the globe.
The point is the effects of people are CUMULATIVE, not individual, and therefore not narcissistic.

Like I said, takes a real narcistic person to think he can control the weather.

 

[Billy_Bob]

Last time for you.. Wouldn't be putting this up again for just any ole denier.. Take notes. I'm not going down this rathole again...


https://html1-f.scribdassets.com/55430jptfk27j6ng/images/11-dea67dc7e8.jpg

A new stomatal proxy-based record of CO2 concentrations ([CO2]), based onBetula nana(dwarf birch)leaves from the Hässeldala Port sedimentary sequence in south-eastern Sweden, is presented. The recordis of high chronological resolution and spans most of Greenland Interstadial 1 (GI-1a to 1c, Allerød pollenzone), Greenland Stadial 1 (GS-1, Younger Dryas pollen zone) and the very beginning of the Holocene(Preboreal pollen zone). The record clearly demonstrates that i) [CO2] were significantly higher thanusually reported for the Last Termination and ii) the overall pattern of CO
2 evolution through the studiedtime period is fairly dynamic, with significant abrupt fluctuations in [CO2] when the climate moved frominterstadial to stadial state and vice versa

A new loss-on-ignition chemical record (used here as a proxyfor temperature) lends independent support to the Hässeldala Port [CO2] record. The large-amplitude fluctuations around the climate change transitions may indicate unstable climates and that “tipping-point” situations were involved in Last Termination climate evolution. The scenario presented here is in contrast to [CO2]records reconstructed from air bubbles trapped in ice, which indicate lower concen-trations and a gradual, linear increase of [CO2] through time. The prevalent explanation for the mainclimate forcer during the Last Termination being ocean circulation patterns needs to re-examined, and a larger role for atmospheric [CO2] considered

And there's plenty more of this...


Fig. 14) Kouwenberg (2004) Figure 5.4: Reconstruction of paleo-atmospheric CO2 levels when stomatal frequency of fossil needles is converted to CO2 mixing ratios using the relation between CO2 and TSDL as quantified in the training set. Black line represents a 3 point running average based on 3–5 needles per depth. Grey area indicates the RMSE in the calibration. White diamonds are data measured in the Taylor Dome ice core (Indermühle et al., 1999); white squares CO2 measurements from the Law Dome ice-core (Etheridge et al., 1996). Inset: Training set of TSDL response of Tsuga heterophylla needles from the Pacific Northwest region to CO2 changes over the past century

NOTE -- in both of those (as in all of the HI RES studies of CO2 -- the ice core data is nothing more than a general mean value -- showing little or any response to changes under a 1000 years in duration..

Excellent!

Both graphs show that a 50 year rise, similar to the one we have just experienced, is not only possible but it has happened previously, several times.

It's a shame that old fraud and crick cant read graphs or data, they might learn something about the AGW meme that shatters it..

 

[Crick]

So you are suggesting that the rise in atmospheric CO2 is not from anthropogenic sources? And you are suggesting this because CO2 has been produced by naturogenic sources in the past?

Besides the complete logical failure there (this man has blonde hair, therefore all men have blonde hair) there is the unaddressed point that isotopic analysis shows that virtually every molecule of CO2 added after the beginning of the Industrial Revolution comes from the combustion of fossil fuel. How, exactly, is that addressed by your Swedish birch leaves.

 

[westwall]

So you are suggesting that the rise in atmospheric CO2 is not from anthropogenic sources? And you are suggesting this because CO2 has been produced by naturogenic sources in the past?

Besides the complete logical failure there (this man has blonde hair, therefore all men have blonde hair) there is the unaddressed point that isotopic analysis shows that virtually every molecule of CO2 added after the beginning of the Industrial Revolution comes from the combustion of fossil fuel. How, exactly, is that addressed by your Swedish birch leaves.

There is more evidence to support the theory that the current rise in CO2 is attributable to the MWP than to mans sources. Mankind is such a vanishingly small amount of the global CO2 budget that the claim it is all from mankind is simply ludicrous.

 

[Crick]

So you are suggesting that the rise in atmospheric CO2 is not from anthropogenic sources? And you are suggesting this because CO2 has been produced by naturogenic sources in the past?

Besides the complete logical failure there (this man has blonde hair, therefore all men have blonde hair) there is the unaddressed point that isotopic analysis shows that virtually every molecule of CO2 added after the beginning of the Industrial Revolution comes from the combustion of fossil fuel. How, exactly, is that addressed by your Swedish birch leaves.

There is more evidence to support the theory that the current rise in CO2 is attributable to the MWP than to mans sources. Mankind is such a vanishingly small amount of the global CO2 budget that the claim it is all from mankind is simply ludicrous.

Yeah, isn't it something that hundreds and hundreds of PhDs can't do basic arithmetic? Who woulda thought it.

I didn't see an answer as to how your Swedish birch leaves addressed the isotopic analysis results. Do you have one? And do you have something more than the logically fallacious "it happened this way in the past so this must be how it happened now"? Would you care to withdraw that before you get laughed out of fashion?

So, that "more evidence" that says the CO2 is from... the MWP? And came out of solution did it? Odd, then, that every bit of the increase bears the isotopic signature of fossil sources. Odd that the amount added to the atmosphere so closely matches the amount calculated via simple bookkeeping to have been produced by fossil fuel combustion. Odd that the rate at which it is increasing in the atmosphere is so astronomically high while the MWP was a such a mild and gradual event.

So, where is this "more evidence"?

 

[Old Rocks]

So you are suggesting that the rise in atmospheric CO2 is not from anthropogenic sources? And you are suggesting this because CO2 has been produced by naturogenic sources in the past?

Besides the complete logical failure there (this man has blonde hair, therefore all men have blonde hair) there is the unaddressed point that isotopic analysis shows that virtually every molecule of CO2 added after the beginning of the Industrial Revolution comes from the combustion of fossil fuel. How, exactly, is that addressed by your Swedish birch leaves.

There is more evidence to support the theory that the current rise in CO2 is attributable to the MWP than to mans sources. Mankind is such a vanishingly small amount of the global CO2 budget that the claim it is all from mankind is simply ludicrous.

And this fellow claims to be a Phd Geologist. LOL

The Gigaton Question: How Much Geologic Carbon Storage Potential Does the United States Have? | Science Features

On May 9, 2013, the level of carbon dioxide in the atmosphere officially passed the 400 parts per million mark, an atmospheric concentration of carbon dioxide not seen in more than 800,000 years, according to the National Oceanic and Atmospheric Administration. In 2011 alone, the United States emitted 5.5 metric gigatons of CO2 from energy production, and the world released a total of 31.6 metric gigatons, according to the U.S. Energy Information Administration.

In any realistic discussion of ways of solving the looming problems of climate change due to the increasing levels of CO2 in the atmosphere, carbon sequestration must play a role. Carbon sequestration is a method of securing carbon dioxide (CO2) to prevent its release to the atmosphere and contribution to global warming as a greenhouse gas. Geologic carbon sequestration is the deliberate storage of CO2 in porous and permeable rocks and involves injecting high pressure CO2 into a subsurface rock unit and displacing the fluid that initially occupied the pore space. The USGS has been working for the past several years to help inform that discussion with the best available science on carbon storage potential in the United States.

On Tuesday, June 25, 2013, USGS added a significant piece to the puzzle with the release of the first-ever comprehensive assessment of geologic carbon storage potential for the entire United States, with a mean estimate of 3,000 metric gigatons of potential storage. Along with the regional assessments of biologic carbon sequestration that are ongoing, this national geologic carbon sequestration assessment gives land and resource managers a powerful new tool to help determine the appropriate actions to take on mitigating climate change.

 

[Nova78]

Anyone notice that it is winter and that there is almost no snow in the NE? How about the fact that the NE is experiencing one of it's warmest winters ever?

Anyone notice it is 20 below zero in Wyoming ?

 

[Crick]

That's cold weather. An Arctic air mass?

 

[Old Rocks]

-20 in Wyoming? So? Seneca, Oregon has seen -54.

Seneca Oregons Icebox

 

[Crick]

Still waiting for Westwall to show us "more evidence" that the CO2 added to our atmosphere since the Industrial Revolution is actually the result of MWP warming. Westwall? Is there a problem with that?

 

[jc456]

our climate is not controlled or effected by the things that man does. It is controlled mostly by the sun. It has been that way ever since the fireball cooled, coalesced and became the earth.

AGW is a lie perpetuated by the Democrat Party in this country and socialists all over the world. The purpose of which is to bleed money and power from the world's top countries, especially the USA.

NOAA Website on Climate: Earth’s Hottest Period Occurred Before Man Existed

And? And the coldest period also before man existed. Now there were reasons for both. And were you to read what the scientists have to say instead of a bunch of knuckleheads as ignorant as you are, you might learn something.

ditto for you. You could be educated as well, yet you choose to use correlation of existence as an argument that has no value to the AGW theory.

 

[TNHarley]

Yes, it is stupid to think the Earth ever stops evolving.

 

[Crick]

Mankind is such a vanishingly small amount of the global CO2 budget that the claim it is all from mankind is simply ludicrous.

I guarantee you that humans have put enough CO2 into the atmosphere to be responsible for the 120 ppm increase since the beginning of the Industrial Revolution. 120 of the current 400 ppm test out as having come from the combustion of fossil fuel. Was anyone burning large amounts of fossil fuels (oil and coal) before the Industrial Revolution? So... where's the "ludicrous"?