[Argus]

Volcanic eruptions cause global cooling. When Krakatoa blew, the result was “The Year Without a Summer”.

[RightWhale]

The effects should be restricted to the southern hemisphere.

[txhurl]

Mexicans burning their CROPS cause cooling. Ask any central Texan, in 1997 the mexican fires took the sun away for the whole summer in Texas.

[21twelve]

Yep. I have even heard the global warming types say things like “and if it weren't for Pinatubo, Mt. St. Helens, etc. - it would be EVEN WARMER!” (Almost like they are disappointed or something that the volcanoes DID blow).

[Virginia Ridgerunner]

I think that was Tambora in 1815.

Krakatoa was in 1883.

[The_Reader_David]

The ‘Year with out a summer’ was caused by Tambura in 1816. Krakatoa didn’t quite have so pronounced an effect because we’d pulled out of the Little Ice Age by then.

[Calvin Locke]

Chaiten is ~43ºS latitude, Tambora "was" at ~8ºS, Krakatoa ~17ºS, fwiw.

A better effects comparison would be Mount St. Helens @ ~46ºN

[ohioman]

The Year Without a Summer was from the effects of Tambora in 1815. At a VEI 7, Tambora was the largest eruption in recorded history. Here, the caldera collapsed as over 3,000 feet of mountain top was obliterated in the explosion. At a little less than a mile deep, it's still the deepest volcanic crater in the world.

Also, those folks who say that large volcanic eruptions only effect the hemisphere they erupt in are wrong. Katmai (Novarupta eruption in Alaska early 20th Century) was very far North and it cooled the Planet, but not to as great a degree as more equatorial Pinatubo. Scientists have also found traces of large Volcanic Eruptions in Chile in Ice Cores from Greenland, such as Hyaputina which erupted in 1600.

I doubt the Chilean officials quoted in this article are geologists or vulcanologists - especially from the following quote:
“Experts believe Chile's Chaiten volcano could continue belching out vast clouds of ash for months”

If this thing kept spewing 20 mile high columns of ash for months that would very rare and catastrophic. Of course, the truth is that no one knows. I hope a U.S. team of Geologists gets there soon so that they can get a good gas measurement of this thing. If the SO2 level is high, look out!

[American Quilter]

Volcanic eruptions cause global cooling. When Krakatoa blew, the result was “The Year Without a Summer”.

Our planet is regulating its temperature and climate. No human intervention needed (or possible).