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Nature: Global Temperatures Are a Falling Trend
New submitter sosume writes "An article in Nature shows that temperatures in Roman times were actually higher than current temperatures. A team lead by Dr. Esper of the University of Mainz has researched tree rings and concluded that over the past 2,000 years, the forcing is up to four times as large as the 1.6W/m^2 net anthropogenic forcing since 1750 using evidence based on maximum latewood density data from northern Scandinavia, indicating that this cooling trend was stronger (0.31C per 1,000 years, ±0.03C) than previously reported, and demonstrated that this signature is missing in published tree-ring proxy records."
Yeah, you can ask anybody who studied antique history. We all know that the romans grew wine in England. How do people think they managed to do that? Of course it was warmer back then than nowadays.
And then in the 1750's we had a very cold period where we can deduce from paintings that the East Sea was often frozen shut in the winter.
Is this really news to anybody?
The "hockey stick" graphs were never proven in the first place. Taking a dimensionless tree ring history and scaling and gluing it to a thermometer record based on a brief period of co-movement, and then ignoring a subsequent period of strong deviation by handwavingly saying that "something must have caused" tree rings to stop being affected by temperature, was always terrible and rotten science.
To provide specific details, this refers to the famous "Hockey Stick" chart. The statement from the Climategate emails about "hiding the decline", as referenced here: http://climateaudit.org/2009/11/26/the-deleted-portion-of-the-briffa-reconstruction/ ... refers specifically to ignoring the subsequent period of deviation between tree ring records and thermometer records, after just in the years prior taking that relationship as extremely strong and using it to give scale and units to the tree ring records.
To illustrate the problem:
- Let's say you want to assess how much food people ate during the medieval times.
- The only long term record you have is an overview of how many apples were harvested from a sample of orchards for 1000 years.
- And your short term record going back 100 years is however much more detailed, and shows how much food people have eaten recently
- It turns out that for a period of 50 years it looks like there was a strong degree of co-movement between these measures.
- So you basically overlay these and scale the orchard record until it co-moves with the food record, letting you estimate food consumption 1000 years ago.
- Oh wait, for the subsequent period of 50 years, it turns out that measured food consumption has actually wildly diverged from orchard records and there is no relationship detectable.
- This should indicate that the previous 50 year period you have used to scale orchard records was simply a statistical fluke.
- But you ignore this and conspire with your friends to "hide" these later 50 years, pretending that the relationship between food data and orchard output is actually very strong.
In other words: estimates of temperature in medieval/Roman times based on tree ring data may well be too low.
Global Warming Alarmists will point to this and say we have reversed a cooling trend that has lasted at least 2000 years.
Global Warming Denialists will use this to show that it's been warming in the past and previous data that shows global warming is now suspect.
I think this new data shows that we don't have a clue what we are talking about when it comes to the climate. I believe the best we can do is take measurements and say what it's like RIGHT NOW. Judging the past is inaccurate. In the future, we'll look back on today and say, "those guys didn't know what they were talking about!" I agree with our future selves.
There is no "I disagree" mod for a reason. Flamebait, Troll, and Overrated are not substitutes.
It shows that humanity thrived in a world that was about as warm as now. A world which had no additional greenhouse gas forcing like the one added by the industrial age. That's the data presented. The rest is made up conjecture by you.
Ubi solitudinem faciunt, pacem appellant.
We're basically entering an ice age
please provide a source when making claims. how can you tell?
I encourage every slashdotter interested in the global warming debate to take a hard look at the Vostok Ice Core Data. This is the most solid (ahem) evidence of global temperature change over any sort of significant time scale. It's hard data, not "interpreted" or "adjusted" measurements. Longer term data is here.
Obviously, we're currenty in an Ice Age - when the Earth is in a warm period there is no year-round ice anywhere, not even the poles. The Earth gets much warmer during the warm periods, though mostly it warms at the poles and becomes a more even tropical temperature, IIRC.
It's possible that we're actually exiting the long term ice age, but that's a heck of a claim to make (since it's ~50 million years old, the odds would be very low), and would require a heck of a lot of evidence.
Socialism: a lie told by totalitarians and believed by fools.