The Biggest Control Knob: CO2 in Earth's Climate History
It's been a busy past two months of weather and climate change news, and I haven't found time to blog about the research presented at December's American Geophysical (AGU) meeting in San Francisco. That is the world's largest scientific conference on climate change, and the place to be if you want to get the pulse of the planet. The keynote speech at the AGU meeting was given by Dr. Richard Alley of Penn State University. Dr. Alley is the Evan Pugh Professor of Geosciences at the Pennsylvania State University, and one of the most respected and widely published world experts on climate change. Dr. Alley has testified before Congress on climate change issues, served as lead author of "Chapter 4: Observations: Changes in Snow, Ice and Frozen Ground" for the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), and is author of more than 170 peer-reviewed scientific articles on Earth's climate. He is also the author of a book I highly recommend--The Two Mile Time Machine, a superb account of Earth's climate history as deduced from the 2-mile long Greenland ice cores. A standing-room only audience of over 2,000 scientists packed the lecture hall Dr. Alley spoke at, and it was easy to see why--Alley is an excellent and engaging speaker. I highly recommend listening to his 45-minute talk via a very watchable recording showing his slides as he speaks in one corner of the video. If you want to understand why scientists are so certain of the link between CO2 and Earth's climate, this is a must-see lecture.
Figure 1. Dr. Richard Alley of Penn State University, delivering the keynote speech at the 2009 AGU conference on climate change.
The Biggest Control Knob: CO2 in Earth's Climate History
Earth's past climate has been shaped by a number of key "control knobs"--solar energy, greenhouse gas levels, and dust from volcanic eruptions, to name the three main ones. The main thrust of Dr. Alley's speech is that we have solid evidence now--some of it very new--that CO2 has dominated Earth's climate over the past 400 million years, making it the climate's "biggest control knob". Dr. Alley opens his talk by humorously discussing a letter from an irate Penn State alumnus. The alumnus complains that data of temperatures and CO2 levels from ice cores in Antarctica don't match:
"CO2 lags Earth's temperature...This one scientific fact which proves that CO2 is not the cause of recent warming, yet...Dr. Alley continues to mislead the scientific community and the general public about 'global warming'. His crimes against the scientific community, PSU, the citizens of this great country, and the citizens of the world are significant and must be dealt with severely to stop such shameful activities in the future".
Dr. Alley explains that the irate alumnus is talking about the Antarctic ice core record, which shows that as we emerged from each ice age, the temperature began increasing before the CO2 did, so increased CO2 was not responsible for the warmings that brought us out of these ice ages. Climate change scientists and skeptics alike agree that Earth's ice ages are caused by periodic variations in Earth's orbit called Milankovich Cycles. "There's no doubt that the ice ages are paced by the orbits", says Dr. Alley. "No way that the orbit knows to dial up CO2, and say 'change'. So it shouldn't be terribly surprising if the CO2 lags the temperature change. The temperature never goes very far without the CO2. The CO2 adds to the warming. How do we know that the CO2 adds to the warming? It's physics!"
Dr. Alley then discusses that the physics that govern how CO2 absorbs and re-emits heat energy, when plugged into state-of-the-art climate models, show that about half of the observed 5 - 6°C natural warming that occurred since the last ice age ended was due to extra CO2 added to the atmosphere. At the peak of the Ice Age, CO2 was about 190 ppm. By the end, it was about 280 ppm (Figure 1). Earth's orbital variations "forced" a warming, which caused more CO2 to escape from swamps and oceans, with a time lag of several centuries. The increased CO2 reinforced the warming, to double what it would have been otherwise--a positive feedback loop. "Higher CO2 may be forcing or feedback--a CO2 molecule is radiatively active regardless of how it got there", says Dr. Alley. "A CO2 molecule does not remember why it is there--it only remembers that it is there". In other words, the fact that higher CO2 levels did not trigger an end to the Ice Age does not mean that the CO2 had no warming effect. Half of the the observed 5 - 6°C natural warming that occurred since the last ice age ended was due to the extra CO2 added to the atmosphere. So, the irate PSU alumnus was half right. The CO2 does lag temperature. However, we can only explain approximately half of the warming since the last ice age ended if we leave out the increase in CO2 that has occurred. "If higher CO2 warms, Earth's climate history makes sense, with CO2 having caused or amplified the main changes. If CO2 doesn't warm, we have to explain why the physicists are so stupid, and we also have no way to explain how a lot of really inexplicable climate events happened over Earth's history. It's really that simple. We don't have any plausible alternative to that at this point".
Figure 2. Ice core record from Vostok, Antarctica, showing the near-simultaneous rise and fall of Antarctic temperature and CO2 levels through the last 350,00 years, spanning three ice age cycles. However, there is a lag of several centuries between the time the temperature increases and when the CO2 starts to increase. Image credit: Marian Koshland Science Museum of the National Academy of Sciences: Global Warming Facts and Our Futures, originally provided to that site by Kurt Cuffey, University of California, Berkely.
CO2 and temperatures rise and fall in synch
Dr. Alley continues with a discussion of how CO2 and temperature levels have risen and fallen in synch over most of geologic time. But for many years there was still a mystery: occasionally there were eras when temperature changes did not match CO2 changes. But new paleoclimate research, much of it just in the past two years, has shown that nearly all of these mis-matches were probably due to suspect data. For example, the mismatch in the Miocene Era has significantly improved, thanks to a new study published this year by Tripati et al. Another example occurs during the Ordovician Era 444 million years ago, as discussed in a recent post at the excellent skepticalscience.com blog.
Figure 3. Atmospheric CO2 and continental glaciation, 400 million years ago to the present. The vertical blue bars mark where ice ages have occurred. The length of the blue bars corresponds to how close to the Equator the ice sheets got (palaeolatitude, scale on the right side of the plot). The left scale shows atmospheric CO2 over the past 400 million years, as inferred from a model (green area) and from four different "proxy" fossil sources of CO2 information. This is Figure 6.1 of the Palaeoclimate chapter of the 2007 IPCC report.
Is there anything else we should be worried about?
Dr. Alley continues with a discussion of other influences that may be able to explain global warming, such as volcanos, changes in solar output, and cosmic rays. A whole bunch of the competing hypotheses don't work", says Dr. Alley. "When there's a bunch of big volcanos, they make it cool. If volcanos could get organized, they'd rule the world. There might be a tiny bit of organization due to flexing of the crust, but they're not controlling the world".
Regarding solar changes: "When the sun changes, it does seem to show up in the temperature record. As far back as we can see well, the sun is friendly, it doesn't change much. If the sun changed a lot, it would control things hugely. But it only changes really slowly--as far as we can tell. The record doesn't go back as far as we'd like, and there's work to be done here--but it just doesn't seem to be doing much".
Figure 4. Greenland ice core proxy measurements of temperature (top curve) and cosmic ray flux (bottom curve) for the past 60,000 years. The Earth's magnetic field weakened by 90% 40,000 years ago, for a period of about 1,000 years, but there was no change seen in the temperatures in Greenland.
Regarding cosmic rays: "The sun doesn't change much, but the sun modulates the cosmic rays, the cosmic rays modulate the clouds, the clouds modulate the temperature, and so the sun is amplified hugely. It's really interesting hypothesis, there's really good science to be done on this, but there's reason to think its a fine-tuning knob". He goes on to show an ice core example from a period 40,000 years ago (Figure 4) where the Earth magnetic field had near-zero strength for hundreds of years. This allowed a massive flux of cosmic rays to penetrate to the Earth's surface, creating a huge spike in ice core Beryllium-10, a radionuclide made by cosmic rays. If cosmic rays were important to climate, we would expect to see a corresponding major swing in temperature, but the ice core shows no change during the period of enhanced cosmic ray bombardment 40,000 years ago. "We had a big cosmic ray signal, and the climate ignores it", Dr. Alley comments.
How sensitive is climate to a doubling of CO2?
The IPCC report talks extensively about computer climate models' calculations of "climate sensitivity"--how much Earth's climate would warm if CO2 doubled from pre-industrial levels of 280 ppm, to 560 ppm (we're currently at 390 ppm). A mid-range number from the 2007 IPCC report often used by climatologists is that the climate sensitivity is 3°C for a doubling of CO2. Dr. Alley takes a look at what paleoclimate has to say about the climate sensitivity to CO2. "The models actually do pretty well when you compare them to the past. The best fit is 2.8°C.
Dr. Alley concludes, "Where we really stand now, is, we're not quite at the pound on the table, this story is very clearly not done. But an increasing body of science indicates that CO2 has been the most important controller of global average climate of the Earth."
I'll have a new post Sunday or Monday.
Jeff Masters
Reader Comments
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But I'm refusing a possible case of hives; benadryl doesn't really agree with me.
msnbc.com news services
updated 3 minutes ago
South Korea is investigating whether a naval ship sinking off the west coast of the peninsula was hit by a torpedo fired by the North.
The 1,500-ton vessel, which had more than 100 people on board, started sinking between 9 p.m. and 10 p.m. local time (8 a.m. to 9 a.m. ET) near the island of Baengnyeong in the Yellow Sea. There were unconfirmed reports it had already sunk.
South Korean broadcaster SBS said many sailors were feared dead. A rescue operation was under way.
This could get very nasty. Kim Jong is a nutt case! Big time!
WRC's Hurricane OCSI Gives West Florida the Highest Chance of Experiencing a Tropical Storm or Hurricane This Summer. The OCSI Also Calls for a Below Average Season with Only 8 Named Storms.
I just don't see that. It appears to be a slight above average year coming IMO. But, its too early to tell yet.
I rather wait till the CSU comes out next month before I agree with this
Thats a little Drastic but, YA! Kim Jong is gonna be trouble down the road for sure. I really don't think we should Nuke them YET!
Now that would be a welcome addition to the month of Sept if it comes to pass. Seems a lot is still dependent on the Waning El Nino and long term forecasts, this year especially, could be very dicey and unreliable. Above what is usually considered dicey in the first place that is.
607. wunderkidcayman
I don't see that kind of season either, just putting it out there as another data source. Their method is, should I say "unique".
I just realized it said West Florida. What the hell is wrong with the PanHandle or EAst Florida.....J/K you all know!
LOL!!!!!!!!!!!!!!!!!!!
Wow! The really need to go through withdraws and get off that stuff. Bro they also painted our Coastline as a target. Are they nuts. Everyone knows the Panhandle and East Florida is the target this year.
2010 Baengnyeong incident
From Wikipedia, the free encyclopedia
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Location of Baengnyeong Island
On March 26, 2010, a South Korean Navy ship carrying more than 100 personnel sank in waters off the country's west coast near Baengnyeong Island in the Yellow Sea. The island, inside South Korea's (ROK) territorial waters, is located near the Northern Limit Line, dividing South from North Korea (DPRK).[1] There were no immediate reports of casualties and there was reportedly an unspecified explosion in the rear of the ship.[2] There were speculations a torpedo attack was a possible cause of the incident.
Later, it was reported that S. Korean Navy units shot at an unidentified ship toward North Korea.[3]
[edit] References
1. ^ http://news.bbc.co.uk/2/hi/asia-pacific/8589507.stm
2. ^ http://english.yonhapnews.co.kr/national/2010/03/26/18/0301000000AEN20100326008600320F.HTML
3. ^ http://english.yonhapnews.co.kr/national/2010/03/26/0301000000AEN20100326008700315.HTML
Stub icon This Korea-related article is a stub. You can help Wikipedia by expanding it.
West hit in FL means, East & N in due time. Because of the geography of the peninsula, they should say just that the peninsula is at highest risk. These things don't loose much of it's punch on the way across the state.
Well, I agree, but I'll play devil's advocate anyway and point out that it's never impossible for anything to happen. Look at 1972, a strong El Nino year, which also peaked that December, and then 1973, which saw things reverse to a moderate-strong La Nina during the hurricane season.
1972:
1973:
I haven't done any research into why 1973 was such a bust. Maybe it was the sheer strength and rapid reversal into a strong La Nina, but in any case, you can never say never :)
Hmm, interesting. Statistical model predictions are always missing stuff though. You'd really have to incorporate a lot of variables to get a great predictor.
I mean, this really isn't all that great....it follows the long-term trend well enough (because the AMO is in it), but the short-term spikes are mostly missed.
I did find the stuff about the NAO interesting. I had never heard about a correlation between northeast winter precipitation and ridging during the following summer. On that note, this winter was normal to above normal precipitation-wise for the entire east coast, including their area of Ohio to Mass.
from BBC News
2009: One North Korean sailor killed in a naval battle
2002: Four South Korean sailors and an estimated 30 North Koreans killed in a naval battle
1999: At least 17 North Korean sailors believed killed in naval fire fight
1998: South Korea captures a North Korean mini-submarine in its waters
1996: A North Korean submarine runs aground in South Korean waters
Yeah I know, a negative AMO was present during that time, but so was a cold PDO. I'm not sure about the lagging, though you're probably right. My first guess at determining whether the oceans or atmosphere is leading is looking at the SOI, but the SOI follows the SSTs pretty closely in 1972 and 1973. The SOI went positive in May and stayed that way through the end of the year. I don't know...it's an interesting case. I'll have to delve into it sometime when I'm bored.
Yeah. Using analogs from before the satellite era and before precise El Nino/AMO/NAO measurements. And also saying the Florida west coast has a 71% climalogical chance of a storm, and the east coast of FL has a 41% chance. Another thing that stood out is their claim of 88.5% accuracy based on probabilities of landfall. I may just be dumb statistically, but that math just doesn't make sense in my mind. I think their forecast goes out there as an "outlier".
"Goddess" Glacier Melting in War-Torn Kashmir
The Kolahoi glacier, in Kashmir, is receding at a rate of nearly 10 feet (3 meters) a year.
The Kolahoi glacier in the western Himalaya is known as Gwash Brani—"goddess of light"—to the millions of people in India and Pakistan who depend on its yearly run-off for survival.
"Kolahoi is our everything," said Ashraf Mohammed Ganai, 24, a lean Kashmiri man who makes his living guiding scientific expeditions to Kolahoi. "Without her, we are lost."
Because of climate change, these glaciers, and the people who rely on them, may now need some divine intervention.
(Read National Geographic magazine's "The Big Melt.")
Surrounded by the snow-capped peaks of the world's tallest mountain range, the Kashmir region, disputed over by India and Pakistan, is home to thousands of glaciers. Until recently scientists had claimed they would be gone in just a few decades, mostly based on data from the United Nation’s (UN) 2007 Intergovernmental Panel on Climate Change report.
However, in 2009 scientists discovered major flaws with this prediction. A report published in November 2009 claimed the glaciers in the Himalayas are not receding and some have even expanded.
Despite the errors, it's clear that at least some glaciers, including Kolahoi, are still retreating. The latest data from the New Delhi-based Energy and Resources Institute (TERI) shows that in the past four decades, Kolahoi has lost between 15 to 18 percent of its total volume. The research also shows that the glacier is retreating by almost ten feet (three meters) a year.
Locals such as Ganai say they do not need scientists to tell them that the glacier is shrinking.
"My father tells me the tip of the glacier used to be there," said Ganai, pointing to a dried-up river bed visible several kilometers down the mountain. "Now the glacier ends up here."
He lives in a small village called Aru, the last town on the path to Kolahoi, and he spent his youth listening to gunfire crackle through these mountains. For nearly two decades India and Pakistan have waged a bloody dispute over who should lay claim to the Kashmir region, laying down arms in 2002. Prior to 2002, scientists were forced to gather glacial data solely by satellite imaging.
But as relative peace returns to the region, scientists have returned. Last year, TERI established the first program to measure Kashmir's glaciers, selecting Kolahoi, in the Liddar Valley (see map), as a focus area. Ganai was hired by TERI to help with the expeditions to Kolahoi, making him the first in his village to study climate change.
It's 6 a.m. on day two of an expedition led by Ganai, which includes two glaciologist, three journalists, and 24 mountain guides and pony wallahs—men who hire out their ponies to haul supplies.
"Today we are going to dig snow pits on the accumulation zone, at the top of the glacier," explained TERI glaciologist Shresth Tayal as he strapped ice clips to his boots.
As he walked, Tayal's assistant, Nathaniel Dkhar, suggested thinking of Kolahoi "as a huge bucket with a hole in the bottom."
"If you have more water going out than you have coming in, you have a negative mass balance, and the glacier is shrinking," Dkhar said. "That's exactly what's happening to Kolahoi and thousands of other glaciers across the Himalaya."
http://news.nationalgeographic.com/news/2010/03/100324-himalaya-glacier-melt-water/
I see this as an outlier forecast.
(bold mine) That is very astute.
Thanks for posting that, Dan, it kind of puts it in perspective. I will hope for the best...and expect? duct tape and plastic sheets? LOL, don't think so!
Living here, I've always said I'm taking a glass of wine outside to watch the fireworks and go "poof!"
From my understanding they use no climatology at all, but statistical from solar cycles:
"WRC uses a model called Orbital Cyclone Strike
Index (OCSI) which uses the solar cycle (an indication of the solar system's orbit) to
predict the risk for coastal residents each hurricane season. The OCSI model is based
on the premise that there are orbital influences that are reflected in the global circulation
pattern on the sun as well as the global circulation pattern of the earth. These orbital
influences are reflected in the 11.1-year sun spot cycle."
The climo I was mentioned is what WRC is comparing against. WRC has West FL as 90%, with 71% climo. And East FL was 70%, 41% climo. The climo numbers seemed way off.
section of the United States coastline has the highest risk of experiencing a tropical
storm or hurricane. The 2010 forecast is based on activity in the following years: 1880,
1891, 1903, 1915, 1925, 1935, 1946, 1956, 1966, 1978, 1988 and 1998.
Oh my....10-11 years between each analog, and the last analog is 12 years before this year. That means their analogs are solely based on the sun's solar cycles! That is something I have never seen.
The years before 1950 I can't challenge as analogs because of lack of data, but 1956? Holy cow, at the time of 1956's hurricane season, we had been in a moderate-strong La Nina for 2 and a half years! I mean, imagine how much heat had been sucked out of the global tropics by that time. That's a pretty poor ONI Analog. 1988....ishy. 1978...ok. 1966 and 1998 are two of my analogs too. Those other 4 all reversed from El Nino to La nina or neutral, which may or may not be a coincidence with the solar cycle.
Anyway, that's kind of unexpected and interesting. Solar cycles...but nothing else....definitely a different way of forecasting.
news on north korea
Don't worry xcool, I'm volunteering to take your place, I don't believe in them drafting daddy's with new babies.
Believe me, when they don't turn out right, my matzoh-balls are lead weapons of destruction.
Skorea has a highly disciplined, American-trained force of people fighting to save their country, with American weapons and aircraft. North Korea has 40 year old equipment and a infantry that is there because of fear tactics, not out of pride for country. Once the first offense (if it happens) is blunted, I would expect mass desertions/surrenders similar to the first gulf war.
JMHO -
A decent possibility of that happening, if that all goes down as you say.
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