Vulkaner - jordens ventiler - och klimatregulatorer

Large-scale volcanic activity may last only a few days, but the massive outpouring of gases and ash can influence climate patterns for years. Sulfuric gases convert to sulfate aerosols, sub-micron droplets containing about 75 percent sulfuric acid. Following eruptions, these aerosol particles can linger as long as three to four years in the stratosphere.

Major eruptions alter the Earth's radiative balance because volcanic aerosol clouds absorb terrestrial radiation, and scatter a significant amount of the incoming solar radiation, an effect known as "radiative forcing" that can last from two to three years following a volcanic eruption.

"Volcanic eruptions cause short-term climate changes and contribute to natural climate variability," says Georgiy Stenchikov, a research professor with the Department of Environmental Sciences at Rutgers University. "Exploring effects of volcanic eruption allows us to better understand important physical mechanisms in the climate system that are initiated by volcanic forcing."

Seasons of the Global Warming Sun

During today's Summer Solstice, the Sun will attain its highest point north of the celestial equator. In the Northern Hemisphere, Sol will work its light and warmth wonders on its orbiting child longer than on any other day of the year, while those living south of the equator experience a conversely cooling phenomenon. What better day to be reminded of the definitive source of all climate flux on the planet?

Indeed, scientists have observed the direct connection between solar activity and Earth's climate for centuries. In the 19th, Edward W Maunder discovered a 70 year period centuries prior in which sunspot activity all but ceased to be. That period (The Maunder Minimum) coincided with the globe's coldest of the last millennium (The Little Ice Age). Then, as sunspot activity increased again around 1750, so did average global temperatures.

Coincidence, you say? How's this -- less than 100 orbits of the Sun later, solar activity once again dropped off (The Dalton Minimum) and global temperatures again responded sympathetically. And, as before, the return of sunspot activity translated to an increase in degrees Celsius.

Since 1950, we've been in a period termed the "Modern Maximum," for sunspot levels have remained relatively elevated. Remarkably, during this current heightened solar activity era, the planet seems to once again be growing warmer.

And just which human activities might be causing this totally unexplainable shift -- alarmists want to know?

Well, hundreds of modern historical studies have successfully correlated solar variations with terrestrial climate observations. These "proxies" run the gamut from glacial core samples and tree-ring chronologies to sea sediment samples and other repositories of plant and animal materials. Contemporary dating techniques then provide remarkable association between the climactic climate stories they tell and documented solar observations of the time.

I wrote about a wonderful example of this technique in March, when a group of NASA scientists employed historical Egyptian records of the annual water level of the Nile River as a climate proxy. These intrepid explorers discovered that during times of high solar flare activity (observed on Earth as auroras and well documented) river conditions were drier while fewer outbursts from Sol left them wetter.

So then -- the common sense, if not the science, would seem to be settled, wouldn't it?

After all, faced with a demonstrable pattern of a brighter Sun (which increased sunspots signify) forcing higher global temperatures while a dimmer Sun produces a cooler climate, anyone boasting triple-digit IQ should be led to one inexorable conclusion.

Needless to say, that conclusion won't contain the words carbon, footprint, greenhouse, SUV, Kyoto, reforestation, emissions, gases, climate models, acidification, anthropogenic, targets, timetables, sinks, caps, offsets or, especially, United Nations.

Meanwhile, enjoy both the Modern Maximum and the summer season while they last. As history has taught us repeatedly - as surely as winter follows autumn -- things will be cooling down again soon enough.

http://www.americanthinker.com/blog/...l_warming.html