28 Apr 2008, 7:51pm
Pre-Holocene Climates
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An Urgent Signal for the Coming Ice Age

Harris, Peter John Faraday. 2008. An Urgent Signal for the Coming Ice Age

Full text [here]

Selected excerpts:

When paleoclimatologists met in 1972 to discuss how and when the present warm climate would end , termination of this warm climate we call the Holocene seemed imminent and it was expected that rapid cooling would lead to the coming ice age. These ideas were based on the 1M year analogue for climate transitions first proposed by Milankovitch over 60 years ago, which has been demonstrated to show the correlation of glacial and interglacial climate with solar insolation as it is modulated by our changing distance from the sun. These data sets may be used to serve as a signal for the coming ice age. Orbital geometry was approaching similar conditions to those of the previous transitions to ice.

But soon it was observed that global temperature was increasing and at about this time Global Climate Modeling (GCM) received more attention and the Milankovitch analogue was forgotten. There has been no further discussion about the coming ice age. …

Then using a modeled Holocene they projected climate using a range of CO2 forcing, and they reported that there was no transition to ice for at least 30KY into the future.
The algorithm for this process is not disclosed but the authors rightly list the limitations of the model in which CO2 is considered as an external forcing ie the carbon cycle is not simulated by the model. Clouds and the hydrological cycle are simplified and so is the heat transport to middle and deep ocean. In addition, regional changes such as the North Atlantic and over Europe are not simulated “and might depart from the global trend.”

It is unfortunate that these limitations appear to have been ignored and the AGW [anthropogenic global warming] hypothesis was born and has occupied science and the media ever since. The Milankovich analogue has been forgotten.
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11 Apr 2008, 11:39pm
Holocene Climates
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Reconstructing Climatic and Environmental Changes of the Past 1000 Years: A Reappraisal

Soon, Willie, Sallie Baliunas, Craig Idso, Sherwood Idso, and David R. Legates. 2003. Reconstructing Climatic and Environmental Changes of the Past 1000 Years: A Reappraisal. Energy & Environment, Vol. 14, Nos. 2 & 3, 2003.

Full text [here] (927 KB)

Selected excerpts:


The 1000-year climatic and environmental history of the Earth contained in various proxy records is examined. As indicators, the proxies duly represent or record aspects of local climate. Questions on the relevance and validity of the locality paradigm for climatological research become sharper as studies of climatic changes on timescales of 50–100 years or longer are pursued. This is because thermal and dynamical constraints imposed by local geography become increasingly important as the air-sea-land interaction and coupling timescales increase. Because the nature of the various proxy climate indicators are so different, the results cannot be combined into a simple hemispheric or global quantitative composite. However, considered as an ensemble of individual observations, an assemblage of the local representations of climate establishes the reality of both the Little Ice Age and the Medieval Warm Period as climatic anomalies with world-wide imprints, extending earlier results by Bryson et al. (1963), Lamb (1965), and numerous other research efforts. Furthermore, these individual proxies are used to determine whether the 20th century is the warmest century of the 2nd Millennium at a variety of globally dispersed locations. Many records reveal that the 20th century is likely not the warmest nor a uniquely extreme climatic period of the last millennium, although it is clear that human activity has significantly impacted some local environments.


Are the Little Ice Age and Medieval Warm Period widespread climatic anomalies? Nearly four decades ago, H. H. Lamb (1965, pp. 14–15) wrote,

“[M]ultifarious evidence of a meteorological nature from historical records, as well as archaeological, botanical and glaciological evidence in various parts of the world from the Arctic to New Zealand… has been found to suggest a warmer epoch lasting several centuries between about A.D. 900 or 1000 and about 1200 or 1300… Both the “Little Optimum” in the early Middle Ages and the cold epochs [i.e., “Little Ice Age”], now known to have reached its culminating stages between 1550 and 1700, can today be substantiated by enough data to repay meteorological investigation… It is high time therefore to marshal the climatic evidence and attempt a quantitative evidence.” …

Thirty-three years later, however, Jones et al. (1998) tentatively concluded that,

“[w]hile the ‘Little Ice Age’ cooling (with the seventeenth century being more severe over Eurasia and the nineteenth century more severe over North America) is clearly evident … we can only concur… that there is little evidence for the ‘Medieval Warm Period’… although the fact that we have only four series before 1400 and the timescale limitations described earlier [i.e., not resolving timescales of multidecades to century with tree ring proxies used in their study] caution against dismissing the feature.” …

These results are but a few of the many that have become available since Lamb’s pioneering analysis. Given advancements in retrieval of information from climate proxies, as well as their extensive surface coverage, we review the accumulated evidence on climatic anomalies over the last 1000 years. ..
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5 Apr 2008, 10:07am
Holocene Climates
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Solar Cycle 24: Implications for the United States

Archibald, David. 2008. Solar Cycle 24: Implications for the United States. International Conference on Climate Change March, 2008.

Full text [here]

Selected excerpts:

Do we live in a special time in which the laws of physics and nature are suspended? No, we do not. Can we expect relationships between the Sun’s activity and climate, that we can see in data going back several hundred years, to continue for at least another 20 years? With absolute certainty.

In this presentation, I will demonstrate that the Sun drives climate, and use that demonstrated relationship to predict the Earth’s climate to 2030. It is a prediction that differs from most in the public domain. It is a prediction of imminent cooling.

To put the solar – climate relationship in context, we will begin by looking at the recent temperature record, and then go further back in time. Then we will examine the role of the Sun in changing climate, and following that the contribution of anthropogenic warming from carbon dioxide.

I will show that increased atmospheric carbon dioxide is not even a little bit bad. It is wholly beneficial. The more carbon dioxide we can put into the atmosphere, the better the planet will be – for humans, and all other living things. …

To reconstruct climate prior to thermometer records, isotope ratios and tree ring widths are used. This graph shows the Medieval Warm Period and Little Ice Age. The peak of the Medieval Warm Period was 2° warmer than today and the Little Ice Age 2° colder at its worst. The total range is 4° centigrade. The warming over the 20th century was 0.6 degrees by comparison. This recent warming has melted ice on some high passes in the Swiss Alps, uncovering artifacts from the Medieval Warm Period and the prior Roman Warm Period. …

It was warmer again not long after the last ice age ended. Sea level was 2 metres than it is today. Since the Holocene Optimum about eight thousand years ago, we been in long term temperature decline at about 0.25 degrees per thousand years.

When I asked at the beginning of this presentation if we lived in a special time, well that is true in relation to the last three million years. The special time we live in is called an interglacial. Normally, and that is 90% of the time, the spot I am standing on is covered by several thousand feet of ice. Relative to the last four interglacials, we may be somewhere near the end of the current interglacial. The end of the Holocene will be a brutal time for humanity. …

The Holocene, the period we are in now, is tracking along with three of the four previous interglacials. Of those three, if the Holocene ends up being like the Eemian, then we may have up to 3,000 years of Little Ice Age-like conditions before we plunge into the next glacial period. If not, then the plunge could start any time now. …
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