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20th Century Warmest In 1200 Years
gcranston writes "Research from the University of East Anglia in Norwich, U.K. shows that the 20th century was the warmest for the northern hemisphere since approximately 800AD. Historical climate data were calculated from weather 'proxies' such as tree rings, ice cores, and seashells from Europe, Asia, and North America, and attempted to address the shortcomings of earlier studies. The findings support the argument for global warming as a result of human interference rather than natural climate change."
It's "Global Climate Change",
The findings of this study are hopelessly flawed in that they conflict with the principle that only the scientific positions of the campaign contributors to the ruling party in the United States are in any way valid. Please take your actual science with its actual testing and actual methods of deduction elsewhere, as we've got Italian sports cars, mansions, and private jets to buy.
This sig, aah-ah, is comin' like a ghost-sig...
There has been a 19.4% increase in the mean annual concentration of CO2 in the atmosphere from 1959 to 2004.
During the 1959-2002 period, the total CO2 emissions equaled ~220 gigatons; ~14% of the atmospheric CO2 in 1959.
In 2002, Humanity pumped 7 gigatons (6975 megatons) of CO2 into the atmosphere. That is almost 4 times the emissions from 50 years ago (1952: 1795 megatons), and is more than was released from 1751-1886 (136 years: 6732 megatons).
There is a close correlation between Antarctic temperature and atmospheric concentrations of CO2. The extension of the Vostok [antarctic ice core] CO2 record shows the present-day levels of CO2 are unprecedented during the past 420 thousand years.
Cites:
Atmospheric carbon dioxide record from Mauna Loa [ornl.gov]
Global CO2 Emissions [ornl.gov]
Historical carbon dioxide record from the Vostok ice core [ornl.gov]
Earth's atmosphere [wikipedia.org]
Let's take a pool on exactly how many posts this story will receive from partisans claiming that because the earth has been this warm in the past (the 800s) through natural causes, the earth either is not unusually warm now, or if it is warm now it must be because of natural causes--
not realizing that (1) the thing that makes manmade global climate change distinguishable from natural global climate fluctuations is not how warm the earth has become, but how quickly and consistently the earth has warmed since the industrial revolution;
and (2) the problem with manmade global climate change is not how warm the earth is now, but how warm it will become if this consistent, quick rise continues...
What's your guess? 10? 40? 100?
Help me out here. If it was warmer in 800 AD, what 'human interferance' caused the global warming in the 9th century?
Vikings in SUVs, duh.
Quidquid latine dictum sit, altum sonatur.
And, in a few years, when melting arctic and Greenland ice has disrupted the Atlantic Conveyor, northern europe, including Great Britain and Scandanavia, will be much, much colder.
The article doesn't say what happened in the 8th century, just that tree rings don't reliably go back any farther. They must be using only specific species of trees, though, because there there are several species of living trees that are much, much older. Do their rings not reflect temperature, too?
The article contains almost no technical data, but it does say there have been been conflicting results:
"In 2003, a team led by researchers from the Harvard-Smithsonian Center for Astrophysics announced that it believed the 20th century wasn't the warmest, nor the one with the most extreme weather of the past 1,000 years.
"But this research has been criticized for its selection of the indicators used to estimate historic temperatures, among other problems."
The article doesn't say what indicators the Harvard-Smithsonian group used, just that they think their indicators are better.
No, it's not. Modeling climate change is far more complicated and difficult than a simpleminded approach like that. For one, it's difficult to predict the effects of aerosol and cloud formation, both of which reflect/scatter light and reduce the total incident solar energy. It's also necessary to model the CO2 harvesting charactersitics of oceans, and glacial movement as well.
I'm not saying global warming *doesn't* exist, or that it's anthropogenic, but real climatologists will tell you that saying CO2 + IR absorption = warming doesn't cut it.
The warming of the globe as a whole will cause some locations to actually cool down, as air and water currents re-route.
This does not change the fact that the globe as a whole is warming.
(And frankly it is irrelevent whether humans are to blame or not. It is warming, which is going to cause climate change. Are we ready for it? If not, we may want to try to stop it (or at least slow it down).
I doubt we are.)
'Sensible' is a curse word.
I'd be willing to guess (although I won't be around long enough to find out) that we're just in some sort of cycle ... it's warm now ... but in a few hundred thousand years or so we'll be back to another ice age again!
Good guess. We're in the middle of an ice age right now (ice ages last a long time). We're in a brief worm period between long cold periods. The Vostock ice core data shows a cycle that's about 100 k years long. Based on the limited data we have (only 4 cycles), we should have begun a rapid return to normal conditions for this ice age about 10 k years ago. It's not clear why we haven't.
The thing is, no one really understands what drives that 100 k year cycle - does CO2 gradually accumulate until some threshhold is reached, which kicks of some powerful feedback mechanism? Is it all about Solar activity levels? Why didn't it start getting cold again 10 k years ago?
We understand the feedback mechanism involved in the longer (100 M year or longer) cycle between ice ages and a tropical Earth. The weathering of rock removes CO2 from the air, and the more of the land are that is covered by glaciers, the less this happens. That cycle is huge and powerful, but slow: it's pretty unlikely we happen to be alive at the end of the current ice age.
Socialism: a lie told by totalitarians and believed by fools.
Earth is way overdue for a magnetic field reversal. They have an average interval of 1/4 million years and it has been 3/4 million already since the last one. Some say it is beginning with the loss of a magnetic pole in certain places in the southern hemisphere. It could be the cause of the ozone layer loss because as the field weakens it radius at the poles grows. When the field is strong the field meets at the poles in a tight radius.
Here are some cool sims from Los Alamos National Laboratory.
As we lose protection more radiation gets through and mother earth gets a temperature. I'm not saying that 100 years of intense burning hasn't contributed but this seems to be an ignored fact that may be contributing in a large manner.
I first heard of this from watching a NOVA program. Here is the NOVA site on earths magnetic fields with some animations.
Ok, now where did I put the SPF 10,000?
Gizmos Gagets For Ninjas
Not that I disagree with the overall belief that it is humans causing the warming trend, but your arguments are not valid. Pick any part of a cycle and you can say the same thing as above. Replace "warm" with "cold". If you believe the models we are on the way upward too, so it's not even a distinct point like a peak high or low. If the cycle is 1000 years of normal temps, 10 years of high temps, and 1000 years of normal temps, then I can see your argument (a 1/100 chance of being in the warm spot when we happen to figure out the cycle). But not something that could cycle over hundreds to thousands of years that we don't have sufficient data to get full cycles for. (Or even not a cycle, just a natural trend with or without us.)
The second argument (b) says nothing about the validity of a cycle argument. Newton's models of motion accurately portray what happens if I drop a hammar. That doesn't make them "right" and rule out other explanations such as relativity. (Fine, pick on the analogy, but the point is that 1 model working in some cases does not invalidate other possible models.)
I do think that we play a part in global climate change. But that's just a belief on enough circumstantial evidence. The data is not conclusive and no model (natural or human-caused) explains some of the major observations.
You need to be modded "-1 Has Stick In Ass."
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That's an important point. Calling the phenomenon Global Warming is perhaps misleading. Some places will get warmer, others colder. Some will be wetter, some dryer. Dumping more energy into a chaotic system like the climate means more extreme climates, not necessarily warmer ones.
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If the data they considered stops 1200 years ago then it can be correct that this was the warmest century in those 1200 years *and* it was colder before that. Similarly, if this was the hottest January on record that doesn't mean the hottest January ever.
Not necessarily:
Assume we are looking at n time intervals numbered 1, 2, ..., n. If the maximum observed temperature was in interval n, we can assert that this interval was the warmest of the last n intervals.
Now consider interval 0. If this interval is warmer than n, the strongest assertion we can make is that the recent interval is the warmest of the last n. If the recent interval is warmer than 0, we could make a stronger assertion. However, the validity of 'warmest of the last n remains.
In effect, you are assuming that the researchers made the strongest possible assertion. Another alternative is that they were only able to measure a certain number of intervals.
Global warming is a direct effect of the shrinking numbers of Pirates since the 1800's.
Most linux users don't know this, but the man pages were named after Chuck Norris. Chuck Norris fsck'ing hates noobs!
So here we are again, another long rant from two sides of an argument where those arguing are not in possesion of most of the facts.
It always amazes me that these two sides will get into bitter feuds over this subject and no one seems to want to put it in any context. For me what it comes down to is this: we can spend a lot of money, time, and research trying to find out if we are a contributing factor to global warming, only to discover it may be too late, or we can spend even more money, time, and research trying to change the way we interact with the atmosphere. And in the end if those who claim that global warming is impacted by humans are right and we listened to them then we are on our way to fixing it and have a cleaner environment for the future. If they are wrong and we listened to them we still have a cleaner environment and we might just find that all those chemicals we were pumping into the atmosphere had other effects which would then be limited. If, on the other hand we don't listen to them and they are right then we have to learn to live in a new world climate and deal with the vast ammounts of crap we have been pumping into the atmosphere for centuries.
What it comes down to, for me, is this: do we want to risk the global climate on this? Is it worth the piece of mind to know that what happens is out of our control instead of our fault?
They're saying that it was every bit as warm in 800 A.D. then? That kinda discounts their theory that modern man is causing global warming then doesn't it?
From TFA Reliable records from trees and other sources go back only about 1,200 years. So no, they're NOT saying that it was as warm in 800 AD. They are saying that this is the warmest year since 800 AD and that they don't have have any reliable records before that! This is a big difference.
I know that this is Slashdot but you really should try reading the article before making inflamatory statements like "Another crackpot theory bites the dust."
They're saying that it was every bit as warm in 800 A.D. then? That kinda discounts their theory that modern man is causing global warming then doesn't it?.
No they didn't and no it doesn't.
1) Nothing was said about the temperature in 800 AD.
2) Nothing was said about the rate of change in temperature in 800 AD.
We didn't have the modern industrial society that is thought to be the primary cause of global warming today. They're just using the tree ring study by Esper, Cook, and Schweingruber as the end point for as far back as we can go. Check out this graph and its explanation on the Wikipedia for more data points.
Basically, the Medieval Warm Period was still an average of 0.4 C cooler than modern times. It took about 800 years for temperatures to drop 0.4 C to the minimum before the Industrial Revolution and only 200 years since then to rise 0.8 C, an 8X difference in rate of change. Global climate does change on its own naturally, but the change since the dawn of the Industrial Age is still the fastest we've ever seen, and we have solid science that shows how it happens in the form of the greenhouse effect. What more will it take for you people to quit filtering the world for the few tenuous scraps of information that back up your preconceived notions?
If it's for-profit but free, you're not the customer -- you're the product (e.g., the Slashdot Beta's "audience").
I don't think Australia signed either. They must hate the Earth, too. Things haven't been right down there since they dropped ".oz"
You're right about Kyoto, though. The biggest problem with it is the nations that didn't jump on: China and India. Save the "developing nation" crap. Yes, they're dirt poor. They're also huge polluters because they can't afford proper scrubbing on their stacks. There's also a zillion of them, and CO2 isn't the only way to measure pollution. Think particulate matter. I hear lots of environmentalists saying that 300,000,000 Americans make more pollution than 3,000,000,000 Chinese and Indians. Then how come the skies of our cities aren't choked dark orange in midday like in China? (Yes, I've been there, I know.)
Oh, and for the record: Germany is the only European country actually reducing pollution to meet its Kyoto obligations. CO2 output is up 7% in France, 11% in Italy, and 29% in Spain (numbers from 2003 - the most recent available). They're supposed to reduce their emissions 8% by 2012. Looks like arrogant Europe is going the wrong way and should get its own house in order before jumping ugly with the U.S.
Good thing I've got Excellent karma. I'm going to need it after this one.
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