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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",
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.
The article said:
What the fuck?
-Peter
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.
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.
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
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?
When I was a 4 year old kid, the snow was so deep it came up to my waist; I can remember making tunnels thru it. Now that I'm over 40, it barely comes up to my knees - there's definitely less snow these days.
try { do() || do_not(); } catch (JediException err) { yoda(err); }
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."