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For you to suggest that the long term climate patterns are just as trackable as a three day forecast is just ridiculous.
I like though how you try to make it look like we can accurately track localized weather patterns but refuse to acknowledge that Climate patterns are just as trackable.
Deep in the frozen vault of the National Ice Core Laboratory in Lakewood, Colorado, pieces of ice up to nearly a half a million years old are helping researchers unravel the mysteries of climate change. The ice samples were collected in Antarctica and Greenland. They are part of one of the world’s largest collections of ice cores in a program funded by the National Science Foundation and the U.S. Geological Survey.
Antarctica and Greenland have layers of snow and ice preserved in thick glaciers over hundreds of thousands of years. Through studies of the ice cores extracted by drilling thousands of meters into these glaciers, scientists can create mathematical models of Earth’s climate history. They’ve discovered extreme climate swings in Earth’s past, some of which occurred very rapidly, in less than a decade.
Ice core samples provide information on atmospheric composition, temperature and other climate data in a very long and continuous record, making them one of the most important tools for climate researchers.
“It’s very important in climate change research to know just what time is represented by a particular thickness in an ice core,” said former ice core lab director and USGS climate scientist Todd Hinkley. “It doesn’t really do you much good to say, ‘Well, we went in pretty deep, so this must be old’. You’ve got to be precise about it, and the ice cores do allow this. This is their strength as a scientific research tool.”
Ice sheets have one particularly special property. They allow us to go back in time and to sample accumulation, air temperature and air chemistry from another time[1]. Ice core records allow us to generate continuous reconstructions of past climate, going back at least 800,000 years[2]. By looking at past concentrations of greenhouse gasses in layers in ice cores, scientists can calculate how modern amounts of carbon dioxide and methane compare to those of the past, and, essentially, compare past concentrations of greenhouse gasses to temperature.
originally posted by: D8Tee
a reply to: peter vlar
And we can model the earths climate hundreds of years back and get rid of that pesky global medieval warm period with around a dozen data proxy data points!
We don't need mountains of data! We'll just build a model that suits our purposes!
Models are great!
I wonder how all the cold spots got into that model when there's not even any proxy data for thousands of miles near to them.
Firstly, evidence suggests that the Medieval Warm Period may have been warmer than today in many parts of the globe such as in the North Atlantic. This warming thereby allowed Vikings to travel further north than had been previously possible because of reductions in sea ice and land ice in the Arctic. However, evidence also suggests that some places were very much cooler than today including the tropical pacific. All in all, when the warm places are averaged out with the cool places, it becomes clear that the overall warmth was likely similar to early to mid 20th century warming.
Since that early century warming, temperatures have risen well-beyond those achieved during the Medieval Warm Period across most of the globe. The National Academy of Sciences Report on Climate Reconstructions in 2006 found it plausible that current temperatures are hotter than during the Medieval Warm Period. Further evidence obtained since 2006 suggests that even in the Northern Hemisphere where the Medieval Warm Period was the most visible, temperatures are now beyond those experienced during Medieval times (Figure 1). This was also confirmed by a major paper from 78 scientists representing 60 scientific institutions around the world in 2013.
Secondly, the Medieval Warm Period has known causes which explain both the scale of the warmth and the pattern. It has now become clear to scientists that the Medieval Warm Period occurred during a time which had higher than average solar radiation and less volcanic activity (both resulting in warming). New evidence is also suggesting that changes in ocean circulation patterns played a very important role in bringing warmer seawater into the North Atlantic. This explains much of the extraordinary warmth in that region. These causes of warming contrast significantly with today's warming, which we know cannot be caused by the same mechanisms.
medieval warm period
That is correct, and you can see from the images I have posted, Michael Manns paper that attempts to do away with a global Medieval Warming period has not much data.
originally posted by: Kashai
a reply to: Xenogears
The more data you have the more accurate the result wherein the less data the less accurate the result.
This was also confirmed by a major paper from 78 scientists representing 60 scientific institutions around the world in 2013.
The team compared their best estimate reconstructed temperature for 1971–2000 with all other consecutive 30-year periods within each regional reconstruction.
In Asia and Australasia, reconstructed temperature was higher during 1971–2000 than any other 30-year period.
The Arctic was also warmest during the twentieth century, although warmer during 1941–1970 than 1971–2000 according to their reconstruction.
In South America, the 1971–2000 reconstructed temperature was similar to the record maximum in 1251–1280.
In North America, data were not available for the warm decades since 1980; therefore, the reconstruction underestimates the actual temperature during the 1971–2000 interval.
In Europe, slightly higher reconstructed temperatures were registered in 741–770, and the interval from 21–80 was substantially warmer than 1971–2000.
Antarctica was probably warmer than 1971–2000 for a time period as recent as 1671–1700, and the entire period from 141–1250 was warmer than 1971–2000.
Overall, the team concluded that current temperatures are probably warmer than any other 30-year period in the last 1,400 years. Europe appears to have been hotter during the 'Roman Warm Period', but the Arctic is hotter now.
"of the 52 individual records that extend to AD 500, more sites (and a higher proportion) seem warmest during the twentieth century than during any other century. The fraction of individual records that indicates the highest temperatures during 1971–2000 decreases with increasing record length, consistent with an overall cooling trend over the past two millennia
originally posted by: D8Tee
That is correct, and you can see from the images I have posted, Michael Manns paper that attempts to do away with a global Medieval Warming period has not much data.
originally posted by: Kashai
a reply to: Xenogears
The more data you have the more accurate the result wherein the less data the less accurate the result.
originally posted by: TheScale
a reply to: Kashai
one issue with ice core samples is that u can have a period of warming and a mass melting of the glaciers deleting hundreds or thousands of years of layers on those glaciers. this can be be countered slightly by comparing cores from around the world that didnt succumb to the melting but it gets real iffy if u dont have that data. so while ice cores are great they also are not perfect by any means
originally posted by: D8Tee
a reply to: peter vlar
For you to suggest that the long term climate patterns are just as trackable as a three day forecast is just ridiculous.
I like though how you try to make it look like we can accurately track localized weather patterns but refuse to acknowledge that Climate patterns are just as trackable.
Ask anyone who sails offshore if they would be wiling to accept the long range forecasts. They will tell you of course they wouldn't. Three days or five days is about all they will accept, after that, it's a craps shoot.
These are guys that would end up at the bottom of the ocean if they accepted your assertion that long term patterns are just as trackable.
It is important to remember that there is a 10 to 30 year lag between the emission of carbon and when we can see the consequences manifest. Sixty-three percent of all human-generated carbon emissions have been produced in the last 25 years.-climate change beyond tipping point
Trends
Over the last 800,000 years atmospheric CO2 levels as indicated by the ice-core data have fluctuated between 170 and 300 parts per million by volume (ppmv), corresponding with conditions of glacial and interglacial periods. The Vostok core indicates very similar trends. Prior to about 450,000 years before present time (BP) atmospheric CO2 levels were always at or below 260 ppmv and reached lowest values, approaching 170 ppmv, between 660,000 and 670,000 years ago. The highest pre-industrial value recorded in 800,000 years of ice-core record was 298.6 ppmv, in the Vostok core, around 330,000 years ago. Atmospheric CO2 levels have increased markedly in industrial times; measurements in year 2010 at Cape Grim Tasmania and the South Pole both indicated values of 386 ppmv, and are currently increasing at about 2 ppmv/year.