No Link Between Current Warming, Solar Activity - New Scientist

[hatrack]

A study of Irish bogs has thrown doubt on claims that global warming is being caused by increased solar activity
CLAIMS that increased solar activity could explain the world's warming climate are challenged by a study of Irish bogs. The research, which is a fresh blow to climate sceptics, shows that while there are cyclical changes in both climate and the sun's activity, there is no obvious link between the two.

"The data shows that there is no simple one-to-one relationship, as some researchers have touted," says Chris Turney of the University of Wollongong in New South Wales, Australia, who led the work.

Other studies have claimed to find a link, but what sets this one apart is that the figures for the sun's heat output and those for climate are from the same source - trees growing in the bogs. This avoids any problems of accurately matching the dates of climate data from one source to solar activity from another, Turney says.

EDIT

Sorry, pay article - that's all I could copy.

http://www.newscientist.com/channel/opinion/mg18825194.600;jsessionid=EDJJIBJLNFAG

Hah! Take that, New Scientist!

EDIT

Dr Turney said the interest in what drives climate change has intensified in recent years with the identification of climate cycles, of which the Medieval Warm Period and Little Ice Age are the most recent examples.

A popular view pinpoints changes in the Sun's output for driving these changes, he said. Several records have been produced from North Atlantic Ocean sediment cores that show these climate cycles apparently correlate to the Sun's past activity. To get a handle on the long-term behaviour of the Sun, scientists have looked at how it controls changes in the radioactivity of the air. By measuring changes in the radioactive version of carbon preserved in tree rings, a precise year-by-year record of the Sun’s activity can be made.

He said to test this idea he and his co-researchers at Queens University Belfast in the UK looked at the 7,468 year-long Irish bog oak record. The trees have been preserved growing on the bog surfaces in the past when the surface was dry enough to colonise.

“By matching the distinctive tree ring patterns, an absolute, year-by-year record of the number of trees growing on the bogs can be made. Amazingly, this measure of tree population mirrors the climate cycles over the past 10,000 years. Basically, when the Atlantic waters get cooler, Ireland gets wetter. So when the North Atlantic sneezes, Ireland gets a cold,” Dr Turney said.

Fortunately, Dr Turney said the Irish trees have also been used to develop the global record of past changes in atmospheric radiocarbon content so the research team had no uncertainties in correlating changes in the climate cycles to changes in the Sun's output.

Here, the team found no simple relationship between the Sun's activity and climate change in the North Atlantic region.

“If it is the Sun it’s a lot more complicated than many people have claimed – and this is of enormous importance to the global warming debate.

“Many who don't believe humans are causing what is happening in today's climate blame the Sun but it’s not as simple as that,” Dr Turney said.

EDIT

Mods - pls note this is a press release.

http://media.uow.edu.au/releases/2005/0920a.html

[tompayne1]

1. I thought

It was bloody greenhouse gasses.

[Richard D]

2. Another study published today . . .

. . . says that solar activity is responsible for 10-30 percent of global warming: http://news.yahoo.com/s/space/20050930/sc_space/studysunschangestoblameforpartofglobalwarming

[mcscajun]

3. Solar Activity is way down the list from Human Activities.

But wait for someone to manage to misinterpret this as knocking the principle of global warming altogether. Or, to point to as an example about how "scientists are not in agreement on global warming."

Even money says it'll be a RWNut.