No rise in CO2 in air for past 150 years

The airborne fraction of carbon dioxide (CO2) has not increased either during the past 150 years or during the most recent five decades, research says.

That the fraction is increasing has been one of the key assumptions in atmospheric models that show increased man-made carbon emissions causing drastic changes in the earth's climate.

Most of the CO2 emitted by human activity is absorbed by the oceans and our ecosystems. In fact, only about 45 per cent of emitted CO2 stays in the air, says the new study.

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Laser resurfacing fixes wrinkles, study finds

Laser treatment can remove wrinkles better than some newer procedures, dermatologists reported on Monday.

Carbon dioxide laser resurfacing was very effective and while there were some side-effects, such as lightening or darkening of the skin, they almost always cleared up, Dr. Daniel Ward and Dr. Shan Baker of the University of Michigan reported.

"Use of the laser allows precise treatment, giving the surgeon more control over the resurfacing procedure than is possible with other techniques such as chemical peels and dermabrasion," they wrote in the journal Archives of Facial Plastic Surgery.

Carbon dioxide lasers vaporize water molecules inside and outside of cells, damaging the surrounding tissue. Skin cells respond by producing collagen, which in turn fills in wrinkles.

Dermatologists had been looking for alternatives, because the process can either bleach the color out of the skin or cause uneven darkened patches. It can also cause outbreaks of herpes simplex virus, which causes cold sores and skin blistering.

Ward and Baker studied 42 women and five men with an average age of 52 who had laser resurfacing of the entire face between 1996 and 2004.

Most had complications but 45 percent had none. Most of the complications were acne or milia -- the appearance of small, white bumps, most of which disappeared when treated.

Only one had a herpes outbreak and one developed sagging eyelids, they reported.

"The efficacy of treating facial rhytids (wrinkles) with the carbon dioxide laser is well established, and the short- and long-term utility of the carbon dioxide laser in treating solar facial aging has previously been documented," they wrote.

"In terms of results, carbon dioxide laser resurfacing remains the gold standard," dermatologist Dr. Paul Carnoil, of Summit, New Jersey, wrote in a commentary.

He said other types of lasers did not reduce wrinkles as well as carbon dioxide lasers.