Iceland could really mess things up...

Because of Bárðarbunga.  Daily Kos's Rei tells the story:

The winter of 1783-1784. The Revolutionary War had just ended, and Benjamin Franklin was puzzling over the nation's bizarre weather. Congress had been delayed getting to Annapolis to vote for the Treaty of Paris because the Chesapeake Bay just wouldn't melt. The Mississippi River froze down to New Orleans, and ice was reported floating in the Gulf of Mexico. Reports from Europe were of a bizarrely hot summer with thick fog that was choking people to death in Scotland, massive hailstones, lightning, and crop failures. The sun was blood-red at noon. Mass starvation that would ultimately kill 1/6ths of Egypt's population took hold due to a historic drought of the Nile. As many as six million people would die from the bizarre weather.

Franklin was one of the few scientists of the era to (almost) correctly speculate as to its cause:

"The cause of this universal fog is not yet ascertained [...] or whether it was the vast quantity of smoke, long continuing, to issue during the summer from Hekla in Iceland, and that other volcano which arose out of the sea near that island, which smoke might be spread by various winds, over the northern part of the world, is yet uncertain."

He, however, had mixed up his Icelandic volcanoes, for it was not Hekla that erupted that year, causing the planet-altering weather, but Laki (Eldgjá). A rift 23 kilometers long opened up in places up to 100 meters wide with lava fountains at times reaching over a kilometers into the air - and it continued erupting for 8 months.

The total quantity of lava erupted - 14 cubic kilometers - was not that much more than Mount Pinatubo (largest eruption of the 20th century)'s 10 cubic kilometers. But the eruption kicked out a staggering 120 million tons of sulfur dioxide, compared to Pinatubo's 17 million - nearly supervolcano levels. Also unusually, Laki emitted 8 million tons of hydrogen fluoride - normally a trace volcanic gas. These gasses created the "Laki Haze" across Europe. In Iceland, the consequences were most severe - a quarter of the population starved or died of fluoride poisoning, and most of the livestock died. Denmark considered evacuating the entire island.

Is Laki threatening to go off? No. Then why do I mention him?

Because his big sister IS threatening to go off.

Bárðarbunga (BOWR-thar-Boon-kah, "Bárður's Bulge") is part of the same volcanic system, but is much larger than Laki. Barðárbunga stretches out over 200 kilometers long. It has a large eruption every 250-600 years. One of its eruptions before settlers arrived was 21-30 cubic kilometers of lava. Like her little brother Laki, she's associated with massive amounts of toxic gas release.

Update:
Rei's update.

By the way... Yellowstone is melting.

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Rep. Joe Barton thinks wind is a finite resource:

Barton has used the threat of global warming to combat something he hates even more: wind energy. In a 2009 hearing, Barton implied that wind is a "finite resource" and that harnessing it would "slow the winds down" which would "cause the temperature to go up."

Ever get the feeling the universe and Mother Nature are getting a little irritated at us?

Jupiter:

Something has smashed into Jupiter, leaving behind a black spot in the planet's atmosphere, scientists confirmed on Monday.

This is only the second time such an impact has been observed. The first was almost exactly 15 years ago, when more than 20 fragments of comet Shoemaker-Levy 9 collided with the gas giant.

"This has all the hallmarks of an impact event, very similar to Shoemaker-Levy 9," said Leigh Fletcher, an astronomer at NASA's Jet Propulsion Lab in Pasadena, California. "We're all extremely excited."

The impact was discovered by amateur astronomer Anthony Wesley in Murrumbateman, Australia at about 1330 GMT on Sunday. Wesley noticed a black spot in Jupiter's south polar region (see image) – but he very nearly stopped observing before he saw it.

Venus:

A strange spot emerged on Venus last week, and astronomers are not sure what caused it. They hope future observations will reveal whether volcanic activity, turbulence in the planet's atmosphere, or charged particles from the sun are to blame.

Amateur astronomer Frank Melillo of Holtsville, New York, first spotted the new feature, which is brighter than its surroundings at ultraviolet wavelengths, on the planet's southern hemisphere on 19 July.

Supervolcanoes:

Gary Egbert of Oregon State University in Corvallis, who is a magnetotellurics specialist but not a member of Hill's team, is cautious about the idea of a nascent supervolcano where Mount St Helens sits. "It seems likely that there's some partial melt down there," given that it is a volcanic area, he says. "But part of the conductivity is probably just water."

If the structure beneath the three volcanoes is indeed a vast bubble of partially molten rock, it would be comparable in size to the biggest magma chambers ever discovered, such as the one below Yellowstone National Park.

Every few hundred thousand years, such chambers can erupt as so-called supervolcanoes - the Yellowstone one did so about 640,000 years ago. These enormous eruptions can spew enough sunlight-blocking ash into the atmosphere to cool the climate by several degrees Celsius.

Could Mount St Helens erupt like this? "A really big, big eruption is possible if it is one of those big systems like Yellowstone," Hill says. "I don't think it will be tomorrow, but I couldn't try to predict when it would happen."

Looks like we'll have to go back to sacrificing goats and tipping them into the volcano's mouth....