In addition to the other observed factors such as a long sunspot cycle and minima and PDO flip, now we’ll add some aerosols to the mix. Volcanism has been quiet for the most part for a few years. This should have a cooling effect on the southern hemisphere.
I’ll point out that the effects on atmospheric albedo is yet unknown and depends on the strength of eruption, and quantity of ash and aerosols ejected into the stratosphere.
More than 1,500 people have fled their homes in southern Chile after the Chaiten volcano erupted, throwing a huge cloud of ash and lava into the sky.
The volcano, 800 miles south of the capital Santiago, had not erupted for more than 450 years and was considered dormant.
But it is now belching enormous clouds of thick ash that have drifted across a large area in both Chile and the Argentine province of Chubut, where an airport was forced to close.
Just six miles away, the town of Chaiten has a population of 7,000. Long used to the menacing form of the 3,000-foot mountain, it is now overshadowed by a towering column of ash.
Bob, Thanks.
If there’s a relationship, I wouldn’t expect it to be visible on less than geological time-scales. I would expect much of the effects to be cumulative (over time, adding up to greater aerosol output and activity and increased volcanic activity during big increases in CRF and shift in magnetic fields). I think the maunder minimum activity is interesting though.
Texas Aggie (5/3, 16:22:20),
“Prove your hypothesis”.
You don’t do your school any favors.
I stated an opinion (as have many other folks here).
AGW is a theory, not a hypothesis.
If I could prove AGW it would no longer be a theory now would it?
MattN (5/3, 17:06:59),
It would appear you have me confused with someone else.
Kanoichi (5/3, 17:33:47),
“*snort* You’re not actually saying that CO2 from volcanoes is different from that emitted by burning fossil fuels, are you?”
Not other than it has a different source. What made you think so?
Human CO2 emissions of >22 billion tons annually (I am not including metabolic emissions here) overwhelm total annual world’s volcanic CO2 emissions by more than 2 orders of magnitude. When all the world’s volcanoes begin to erupt 10 times the annual CO2 they currently do I still would not worry about it. When they begin to emit 100 times the annual CO2 they currently do, and look like they will continue to increase in CO2 emissions for at least the next several decades if not a century, then I would worry about them also (although they would still not be releasing as much CO2 as we currently do).
“…and what humans are responsible for is a tiny fraction of what the earth and all of nature emits.”
More or less a true statement, but of little relevance to the discussion as the amount of CO2 that nature has been emitting to the atmosphere (over the last 10k years) nature has also has the power to sequester (from the atmosphere). Nature currently only has the additional power to sequester about half of the additional CO2 we humans are currently emitting into the atmosphere on top of the job it was already doing with “it’s own” emissions.
crosspatch (5/3, 17:47:54),
“I don’t think anyone has shown that CO2 from fossil has had any measurable impact whatsoever.”
Few have predicted that it would thus far. The concern is about the future. Our emissions continue to rise.
“I would say that land use changes have had more of an impact on land temperatures than fossil fuel burning does.”
Land use changes are currently releasing almost as much carbon into the atmosphere as fossil fuel burning is, so you have some credence here. UHI effects are negligible on a global scale. Human albedo change effects are largely offset by evaporation effects so the net effect is unlikely to be very significant. What do you base this statement on?
“The key would be for someone to look at times in the past when atmospheric CO2 content was 10 times higher than today and we were in an ice age.”
Which ice ages are you referring to and why is this “the key”? Ice ages are due to the effects of many forces other than CO2.
“In fact, I would also propose that fossil fuel burning might actually be saving us from starvation. Earth’s CO2 level was reaching the point where plant life was going to have a hard time surviving.”
CO2 levels did not change significantly over the last 10k years. Why do you think they are now reaching this point?
swampie (5/3, 18:11:43),
“Ahhhh, I’ve got it. CO2 spewing out of a volcano is “natural”, so it is good AND short lived versus bad ol’ industrial CO2 which will cause loss of ice and extinction of polar bears for hundreds of years…”
No, you didn’t get it yet. See above.
BTW, I’m not personally very concerned about polar bears. And FYI extinctions are forever (not just a couple hundred years).
This is a caldera volcano residing, no doubt, astride a rifting fault. These are a different animal than the common stratovolcanos among which are Pinatubo, El Chicon, St. Helens, etc, lying above subducting plates.
The eruption is obviously plinic, therefore VEI starts at 4. In coming weeks we might find it to continue continuously, then intermittently for a few months.
Plinic eruptions require upto 20% of the mass to be H2O and CO2 gas to support the column, H2S can also be present in quantity.
Tambora, a stratovolcano last erupting at VEI 7, and another unidentified major eruption ca. 1812, raised CO2 worldwide to 450ppm.
This eruption is believed to be the second major eruption of this small caldera so no real history has been established. If it proceeds to class, a VEI of 6 could easily result. This would definitely be felt worldwide, in the SH anyway.
“1812, raised CO2 worldwide to 450ppm”
But it takes 100 years to get co2 out of the atmosphere.
Whereas St. Helens blew out obliquely and put lots of ash into the troposphere (and even some onto my car, hundreds of mile south), this one went strait up, and shot it into the stratosphere. It will probably exceed St. Helens, greatly, in terms of climate impact.
Felt, yes, but due to ash and particulates, not CO2.
More aerosols.
http://www.honoluluadvertiser.com/apps/pbcs.dll/article?AID=/20080427/NEWS01/804270379/1001/LOCALNEWSFRONT
Heres a google map of the site. The caldera is bigger than the town of Chaiten
http://maps.google.com/maps?z=5&q=SANTIAGO
Sorry wrong google reference
http://maps.google.com/maps?z=5&q=http://maps.google.com/maps?z=5&q=Chait%E9n,%20Los%20Lagos%20Chile
Push expansion to see Caldera just Northeast of the town
New Chaitén explosion a few hours ago.
aaron: If I find the citation for the 1812 eruption also showing the 1815 Tambora eruption, I will pass along.
I find all the discussions on Volcano eruptions very interesting but I’m somewhat confused on the discussion of the effect on the earth’s cooling/heading. In the discussion between Archie and Texas Aggie they are debating the difference these two have on the earth’s temperature. Living near Dallas for the last 60 years, I’ve noticed a stark change in temperature difference in Dallas County to Collin County. Driving North anytime during the year you can see a 5-7 degree variance, warmer in the city. Our population in the world has grown from a couple of billion people to over 6 billion in the last 50 years. This means the cities have grown proportionately adding much more heat to the surface of our planet. I know adding a portable heater in the corner of my room will eventually add heat to the whole room. Maybe this argument needs to shift to how much concrete we have versus rural vegetation!
Fred in Texas wrote:
I know adding a portable heater in the corner of my room will eventually add heat to the whole room.
Only if you keep your windows shut, in which case your analogy doesn’t apply. Unlike your (closed?) room or a greenhouse, the earth releases heat into space. The reason temperatures are higher in greenhouses is because the enclosure limits convection, not because of the elevated CO2 levels.