How accurate are tree rings in predicting previous global temperatures?

Question

Several leading global warming studies rely on the measured growth of trees for the last 1,000 years by inspecting the rings of the tree from year to year to estimate previous temperatures.

How can we use tree rings to predict a global average temperature when trees largely don't grow in the winter?

Wouldn't this mean that we tried to predict the temperature using only the data from the seasons of the year that the Tree grew?

Should we leave 1/4 of a year out of the previous estimations for an average temperature?

What other factors influence tree growth besides just the temperature and how to we account for them?

http://www.foxnews.com/story/0,2933,163999,00.html

@Anders,

Its a common tactic to attack the source of the material and the poster. Are you going to accuse me of being in bed with Big Oil next? Its much easier than actually refuting what I've said huh? You can't beat the truth.

And by the way your link didn't work and I FIRST learned about the tree ring idea on climateaudit.org. On a posting that took me 2 hours to read. I thought it would be easier for people to read a short article than a long posting that had many off topic remarks.

THIS IPCC Report uses a tree-ring study.
http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Pub_Ch02.pdf
Check the sources list for Jones.

Also the tree ring idea is mentioned here:
http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Pub_Ch03.pdf
on page 89 look for the name gray.

This report also uses tree rings as a marker of past climate:
http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Pub_Ch06.pdf
http://news.nationalgeographic.com/news/2006/02/0209_060209_warming.html
http://www.uagrad.org/Alumnus/gw/tree.ht

Answer 1

I would guess there is a precipitation component and maybe a sunlight (cloudcover) component. One thing we have going for us is we have some very accurate recent data on climate that we can correlate with now-living trees. That's quite helpful, and scientists probably have a good idea how strong the correlations are.

The climate is extremely complex; if you want to understand it you have a lot of work ahead of you. You could start at www.realclimate.org if you are serious. As is always the case in scientific endeavors, data from a wide variety of sources must be considered.

Answer 2

Different ways of measuring temperature tell about the same story.

Here are ten different peer reviewed studies, some of which use different methods than tree rings.

http://www.globalwarmingart.com/wiki/Image:2000_Year_Temperature_Comparison_png

References are given to the original articles, some with links. All the articles should be available in a good college library. Read them for more details.

Answer 3

the distance between growth rings represent how favourable a growing season was.
so if there is a large distance between rings then it was most likely a warm wet season. if there small then it was probably dry or very cold.

the distance between dosnt predict the temperature itself

also it shows the length of the growing season not the year. so the ring actually represents when growing was slow(winter in north America and europe) so trees not growing in winter would not affect calculations.

Answer 4

I am sure you can find a better source then Fox regarding methods of scientific studies.
Now, contradictory to what you say: most major studies do Not rely on tree growth for temperature measurements. It may be a component but they don't rely on them, they have far better ways of doing it then that.

Making a false statement ( global warming studies rely on measuring tree rings to find out the past temperatures. ) and then question the accuracy of such methods is very unbecoming.

I guess this is what you have instead of evidence to support your views?

Answer 5

The on an generic basis mail is the equivalent of a celebrity tabloid newspaper. the present fashions are based off of air bubble trapped in ice cores. Do you incredibly think of documents from tree rings is extra stable than documents from the incredibly air that existed a hundred,000 years in the past?

Answer 6

To pursue this line of thinking would mean cutting down thousand-year old trees just to check and verify its accuracy against other indicators and methods for predicting previous global temperatures.

NOT a good idea.

Answer 7

They're not. The trees don't live long enough to provide a good statistical basis.

Answer 8

http://en.wikipedia.org/wiki/Global_warming

Answer 9

http://en.wikipedia.org/wiki/Global_warming