Science a GoGo's Home Page Forums General Discussion Climate Change Forum Finnish Tree Ring Study

Some new proxy data has recently emerged from studies of tree rings in Northern Scandinavia. In part because of the cold temperatures there, wood residues from the last 7,000 years have been well preserved at the bottom of muddy lakes. From that, Finnish researchers have been able to reconstuct a temperature record covering that period.

From what I've read about the period the vegetation was what has been called mosaic, patchy. Clumps of trees provided micro-climates where warm-loving species could survive on the south side or underneath. Fire and the extinction of the megafauna destroyed this mosaic vegetation so now we have huge expanses of mono-culture. I've even read that the vast treeless praires of North America didn't exist humans arrived and performed the above. Maybe I'll look for a link.

scpg02 - I too am wondering if temperature proxies have it right. Let's not even talk about CO2 proxies!

I've been looking for any studies that have validated the proxy dataset to global temperatures calculated from modern climate stations. It seems it would be a valid excercise, and relatively straightforward. It would also give everybody some level of comfort about just how steady (or variable) our past temperature has been. Unfortunately, I have not found any such study.

I wonder why.........

That said I would also mention that many of the IPCC calculations are made using computer models that still need work. Of course there is another problem that has arisen in the past two months, the temperature stations. AGW supporters have pointed to the results of the temperature stations to confirm the calculations made by their computer models. Now we have learned that these stations have many problems that have resulted in warm biases.

Some people might say that I am jumping to conclusions when I say that the surface temperature record is invalid but they do not know what I know. To date, much of the discussion on the temperature stations has focused on blacktop, air conditioners, roofs, burn barrels and etc. Anthony Watts and his volunteers at Surfacestations.org noticed that humans are moving closer to the temperature stations and that the temperature stations are moving closer to humans. Anthony is also conducting experiments on weather or not the paint is causing a warm bias. But what has not been discussed much is the problem of the wind and how there needs to be a good distance from buildings and trees to ensure proper mixing. Otherwise the thermometer just sits there and cooks. This brings about another problem that KBSF volunteers have learned; the biological problem. It seems that wasps like to build their nests in these instruments. Also, after the instruments are installed, trees and bushes often grow around the stations causing problems with the wind.

Not only has KBSF pretty much surveyed every active station in New England, we have also spoken to some of the guys that work for NWS who actually install and calibrate the temperature stations. These guys have a lot to offer. They all say they do the best they can with what they have. They are limited by government budgets. They have to compromise with the owners of the properties where the stations are located so stations are often moved closer to structures for “convenience.” They talk about the constant changing of equipment and locations. When a property is sold and the new owner does not want to take part in the program, they have to find a new location in the neighborhood or close the historical station. They confirm that the problem is widespread. I understand that NWS personnel should maintain the instruments once or twice a year and that there is a record of each visit to the site. I am sure that these guys and their records will eventually be given more consideration by the scientists who publish surface temperature records. But what is most painfully obvious is that these stations are there to record the weather and not make the kind of scientific observations that are expected when studying climate. No one cares if the temperature that day will be 73 F or 74.5 F, but it makes a difference when the amount of global warming over 100 years is less than that amount.

The Tree Ring data could be thrown off by any number of things, It's a record of growth. Sunlight and certain variations in pollutant levels affect growth in trees. But there's definitely a rhythm there, temperature related or not.

Scpg02 wrote:

"As further support I quote your next link:

"It must have been covered with vegetation even during the coldest part of the most recent ice age (some 24,000 years ago) because it supported large populations of woolly mammoth, horses, bison and other mammals during a time of extensive Northern Hemisphere glaciation ... This vegetation was unlike that found in modern Arctic tundra".

As for the comment, "the nature of this vegetation has not been determined". My understanding is that it has been but for some reason the authors are not aware of the research.

The conclusion is that warmth-adapted vegetation could survive in much cooler regions at that time than it does today.

The ice core evidence stands.