Thursday, March 15, 2007

Climate change debate continues...

More evidence has emerged of increased solar activity as contributing to the Earth's warming.

Earth, Mars, Pluto and other entities in the solar system are all warming together, leading some scientists to speculate that a change in the sun's activity is the common thread linking all these baking events, writes LiveScience.

Evidence suggests fluctuations in solar activity can affect climate on Earth, and that it has done so in the past.

Habibullo Abdussamatov, the head of space research at St. Petersburg's Pulkovo Astronomical Observatory in Russia, recently linked the attenuation of ice caps on Mars to fluctuations in the sun's output. Abdussamatov also blamed solar fluctuations for Earth’s current global warming trend. His initial comments were published online by National Geographic News.

“Man-made greenhouse warming has made a small contribution to the warming on Earth in recent years, but it cannot compete with the increase in solar irradiance. The considerable heating and cooling on the Earth and on Mars always will be practically parallel."

But Abdussamatov’s critics say the Red Planet’s recent thawing is more likely due to natural variations in the planet’s orbit and tilt. On Earth, these wobbles, known as Milankovitch cycles, are thought to contribute to the onset and disappearance ice ages.
Charles Long, a climate physicist at Pacific Northwest National Laboratories in Washington, says the solar activity theory is nonsense.

In 2005, Long’s team published a study in the journal Science showing that Earth experienced a period of “solar global dimming” from 1960 to 1990, during which time solar radiation hitting our planet’s surface decreased. Then from the mid-1990’s onward, the trend reversed and Earth experienced a “solar brightening.” These changes were not likely driven by fluctuations in the output of the Sun, Long explained, but rather increases in atmospheric clouds or aerosols that reflected solar radiation back into space.

However, Benny Peiser, a social anthropologist at Liverpool John Moores University who monitors studies and news reports of asteroids, global warming and other potentially apocalyptic topics, is reluctant to dismiss out of hand this coincidence.

“Global warming on Neptunes' moon Triton as well as Jupiter and Pluto, and now Mars has some scientists scratching their heads over what could possibly be in common with the warming of all these planets … Could there be something in common with all the planets in our solar system that might cause them all to warm at the same time? I think it is an intriguing coincidence that warming trends have been observed on a number of very diverse planetary bodies in our solar system,”

Penn state meteorologist, Michael Mann disagrees,

“Solar activity continues to be one of the last bastions of contrarians. People who don’t accept the existence of anthropogenic climate change still try to point to solar activity.”

Whatever you believe, one thing is for sure. The climate change debate is far from over. Though this has not stopped Tony Blair leaping on the bandwagon lock, stop and barrel.