Recording climate change in stalactites

[Paracelsus]

Via 'Science' magazine online: http://www.sciencemag.org/cgi/content/full/317/5837/448

Speleotherms = stalactites and stalagmites

Speleothems form in limestone caverns over millennia as water seeps through soil and, upon infiltrating a cave, deposits minerals on the ceiling or floor. Since the late 1980s, researchers have dated speleothems using thermal ionization mass spectrometry, which measures the ratio of uranium-234 to thorium-230 and can pinpoint age as far back as 600,000 years, deep into the Pleistocene epoch. Scientists may soon be able to reach even deeper into antiquity thanks to a method for measuring uranium's decay into lead. This dating technique, which several teams are now refining, could extend speleothem climate records by several million years--far beyond ice core climate reconstructions, says Giovanni Zanchetta, a paleoclimatologist at the University of Pisa, Italy. Meanwhile, measuring the ratio of oxygen-18 to oxygen-16 in calcite tells the climate story, as temperature and rainfall control the ratio.

Researchers are using stalactites to determine the relationship between shifts in precipitation in the Northern and the Southern hemisphere; to examine monsoon variations in the Middle East 10,000 years ago; and to determine whether flooding of the Dardanelles strait by the Atlantic was sudden or gradual.

Hopefully, they will be able to extend the speleotherm climate records to the Thermal Maximum (45 My) and beyond. The biggest puzzle in paleoclimatology is the speed at which climate shifts took place. This will be a critical piece of knowledge, considering what we are dealing with right now in terms of global warming.

[snowbird]

Global warming??


Dear Editor, July 30/07


Recent research by Henrik Svensmark and his group at the Danish National
Space Center points to the real cause of the recent warming trend. In a
series of experiments on the formation of clouds, these scientists have
shown that fluctuations in the Sun's output cause the observed changes in the
Earth's temperature.

In the past, scientists believed the fluctuations in the Sun's output were
too small to cause the observed amount of temperature change, hence the need
to look for other causes like carbon dioxide. However, these new
experiments show that fluctuations in the Sun's output are in fact large
enough, so there is no longer a need to resort to carbon dioxide as the
cause of the recent warming trend.

The discovery of the real cause of the recent increase in the Earth's
temperature is indeed a convenient truth. It means humans are not to blame
for the increase. It also means there is absolutely nothing we can, much
less do, to correct the situation.

Thomas Laprade
480 Rupert St.
Thunder Bay, Ont.
Ph. 807 3457258
Canada


Your readers might be interested in these websites.

Please paste these links in your browser.

http://www.canadafreepress.com/2007/global-warming020507.htm

http://www.foxnews.com/story/0,2933,288195,00.html


http://www.abc.net.au/westqld/stories/s1971899.htm?backyard

http://epw.senate.gov/public/index.cfm?FuseAction=Minority.Blogs&ContentRecord_id=927b9303-802a-23ad-494b-dccb00b51a12&Region_id=&Issue_id=&IsTextOnly=True


http://www.worldclimatereport.com/

http://www.nytimes.com/2007/07/06/opinion/06fri1.html?hp

http://www.breitbart.com/article.php?id=070705191403.gahmdtoi&show_article=1

http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/20070705/greenland_dna_070705/20070705?hub=SciTech

http://www.aip.org/history/climate/solar.htm

http://www.foxnews.com/story/0,2933,289149,00.html

[Paracelsus]

Snowbird, scientists have examined the evidence for solar output playing a role in global warming--and have concluded that changes in solar output are NOT responsible for the observed increases in global temperatures over that past half-century. Please see the following reports:

http://news.bbc.co.uk/2/hi/uk_news/6290228.stm

A new scientific study concludes that changes in the Sun's output cannot be causing modern-day climate change.

It shows that for the last 20 years, the Sun's output has declined, yet temperatures on Earth have risen.

http://www.sciam.com/article.cfm?articleid=C053EDAB-E7F2-99DF-356454A74454CBEB&chanId=sa028

There is now much better understanding of the relative roles of these forcing terms. For a start there are now decades-long, high-quality satellite solar measurements: These establish that there have been no significant changes in solar irradiance since 1979. In the longer term, reconstructions suggest a solar forcing since preindustrial times less than 10 percent that of the total human-induced forcing (Figure 2). In addition, the pattern of observed temperature changes-warming throughout the troposphere (the lowest 10 kilometers or so of the atmosphere), but cooling above that in the stratosphere-is inconsistent with solar-dominated forcing, but consistent with greenhouse gas (and other human-induced) forcing.

http://www.ucar.edu/news/releases/2006/brightness.shtml

Changes in the Sun's brightness over the past millennium have had only a small effect on Earth's climate, according to a review of existing results and new calculations performed by researchers in the United States, Switzerland, and Germany.

The review, led by Peter Foukal (Heliophysics, Inc.), appears in the September 14 issue of Nature. Among the coauthors is Tom Wigley of the National Center for Atmospheric Research. NCAR’s primary sponsor is the National Science Foundation....The new study looked at observations of solar brightness since 1978 and at indirect measures before then, in order to assess how sunspots and faculae affect the Sun’s brightness. Data collected from radiometers on U.S. and European spacecraft show that the Sun is about 0.07 percent brighter in years of peak sunspot activity, such as around 2000, than when spots are rare (as they are now, at the low end of the 11-year solar cycle). Variations of this magnitude are too small to have contributed appreciably to the accelerated global warming observed since the mid-1970s, according to the study, and there is no sign of a net increase in brightness over the period.

[mattweather]

Global warming isn't real. I am sure.

[Ronald Brak]

Global warming isn't real. I am sure.

Check out what the CSIRO says:

http://www.dar.csiro.au/information/observedchange.html

[mattweather]

Check out what the CSIRO says:

http://www.dar.csiro.au/information/observedchange.html

LOL the dates back to 1870? That isn't a proof of global warming, yeah well i couldn't find a site of the temperatures back in thousands to millions years ago. Back then was alot hotter than today and the future, if we say it might be like that hot; this means we might go back where it was. Necessarily the room temperature today become the outside temperature in the future.

[Ronald Brak]

LOL the dates back to 1870? That isn't a proof of global warming, yeah well i couldn't find a site of the temperatures back in thousands to millions years ago. Back then was alot hotter than today and the future, if we say it might be like that hot; this means we might go back where it was. Necessarily the room temperature today become the outside temperature in the future.

So you are saying that increased temperatures around the globe does not mean there has been global warming? So just what would indicate global warming then? Because I can't really think of a better indicator that something has gotten warmer than increased temperature. Can you?

[mattweather]

The indicator involved in natural cycle of climate and weather over the world. We have caused something but not majority. Majority is the cycle performs in the evolution processes of life on earth. You see this good example of different role of photosynthesis, therefore we have it same thing but we have different roles. This is from the natural cycle of life on earth.

Lets think about opposite things, for example; hot or cold, positive or negative etc. Well climate have performed on this basis and the global resources aswell. Many things over the world is still evolving, we can't stop it. This is happening to our climate system, many times it have been for million of years.

Using the less emissions light bulb does not tend to stop global warming, scientifically it helps your power bills. How would we know that humans caused global warming? I say this is a silly question; typically from politicians idiots.

Sincerely Mathew

[Ronald Brak]

The indicator involved in natural cycle of climate and weather over the world. We have caused something but not majority. Majority is the cycle performs in the evolution processes of life on earth. You see this good example of different role of photosynthesis, therefore we have it same thing but we have different roles. This is from the natural cycle of life on earth.

Lets think about opposite things, for example; hot or cold, positive or negative etc. Well climate have performed on this basis and the global resources aswell. Many things over the world is still evolving, we can't stop it. This is happening to our climate system, many times it have been for million of years.

Using the less emissions light bulb does not tend to stop global warming, scientifically it helps your power bills. How would we know that humans caused global warming? I say this is a silly question; typically from politicians idiots.

Sincerely Mathew

So I'm guessing you are saying that global warming has occurred but that human activity isn't responsible? If that's right, then I would ask:

1. Do you believe that CO2 is a greenhouse gas?

2. Do you believe that human activity has increased the concentration of CO2 by over a third since the start of the industrial revolution?

[Kwalish Kid]

I am truly amazed at the speed with which anti-global warming spam appears. It's like the industries that have a lot to lose from climate change-based regulation have been hiring PR firms...

Perhaps even the same PR firms that the tobacco companies used to try to fight the science on cigarettes...

Perhaps these PR firms even hire the same scientists to make their pro-PR-client claims...