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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 problem is that this isn't relevant to the social issue of global warming, and many "skeptics" will claim that it is relevant. Even if the change in temperature ends up being a blip on the radar in geological time, it only takes a few years of drought to decimate food stores and cause a world-wide pandemic. THIS is the issue that should be relevant to us these days, and I'm afraid that all these newly minted arm-chair scientists (more accurately described as big business apologists) are going to ensure that we delay action until it is too late.
Another thing I should say is that we have a very reliable model for showing that increased CO2 can cause warming on a small scale. "skeptics" claim that the burden of proof is on those who say it will happen on a large scale, despite evidence that it IS happening on a large scale. This has never been the way science works. The burden of proof is on "skeptics" to explain why a reproducible, verifiable model on a small scale won't work on a large scale. They have no evidence, and are quite dishonestly trying to shift the burden of proof back on the scientists, knowing full well that on a large scale it will take a much longer time to acquire the kind of evidence they are seeking.
An analogy would be if we said that since Pluto's orbit is 248 years, then we've probably only recorded it orbiting the sun a few times (arguably less than that if we only count modern record-keeping), and so therefore we haven't collected enough data to determine that orbital mechanics apply to Pluto. After all, maybe the 7th observed cycle around the sun it will veer off into space, violating all of our current models. This type of reasoning is nonsense. Science always seeks to apply the simplest, most general theory to all systems. Science only creates a new theory if it absolutely has to. The burden of proof would be on the orbital mechanics "skeptics" to show why it would behave differently on a large scale, not on those who can show without a doubt that it happens on a small scale, and have shown that all measurable results indicate it is happening on a large scale. The idea that we should start with two separate models, one for large scale and another for the small scale, is precisely the opposite of what science seeks to do, and is a severe mis-representation of science.
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.
I'm pretty sure more CO2 in the atmosphere is very beneficial to plant life and will help it flourish in forests and agriculture, not sure about in the ocean(i.e. plankton) since disolved CO2 in water leads to acidity issues. It is possible mother nature could counterbalance increasing CO2 levels by putting CO2 consuming organisms in to overdrive.
Ocean physics, chemistry and biology is so complex I seriously doubt there is any one who can claim they have a accurate holistic understanding, could model changes in it with any accuracy or make any reliable predictions about what it will do.
The one issue I have with the global warming chicken littles is that there is no inherent reason that recent CO2 levels or temperatures are some kind gold standard that must be maintained at all costs. Our planet has been all over the map on both temperatures and atmospheric chemistry, whose to say that some of those other levels weren't actually better overall.
On the other hand the rate at which are changing the atmosphere's composition thanks to industrail scales, and the rate at which we could change global temperatures and sea levels may prove to be very problematic to a lot of species including our own, especially since, as a species we are very fond of building large amounts of infrastructure on the coasts.
We could have a runaway climatic catastrophe, we could muddle along, or mother nature could eventually counterbalance our mistakes. Absolutely no one knows, anyone who claims to know with certainty is not being particularly truthful, anyone who claims to have an accurate computer model of our climate is really being untruthful.
It is safe to say burning fossil fuels at our current rate probably isn't a particularly great idea. It obviously does pose a greenhouse gas risk, no one knows how much, and equally important we are going to eventually run out of them so we really should be working hard to find alternatives. Pretty much the last thing the U.S. government should be doing is subsidizing fossil fuels with things like huge tax breaks for oil companies but good luck getting rid of those.
On the other hand taxing fossil fuels in to the ground to force the switch to alternatives isn't exactly a great idea either. It hammers your economy and it really hammers lower income people who spend a lot of their income on energy.
@de_machina
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.
Interesting - several major city ports from Roman times, referenced in the New Testament (I think Ephesus is one of them), are now miles from the Mediterranean. If sea level rises, then maybe those cities might become ports again.
It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
This is true if you are talking about Europe, but IMO the AMOC (Atlantic Meridional Overturning Current) makes all European climate analysis too chaotic to be of any real use, globally. Look up the Elder and Younger Dryas, when France was reduced to arctic tundra (twice) while the rest of the world was largely unaffected. Whoever is claiming that their warming trend was global (based on one data point) is claiming victory without even playing the game Europe's climate may be the most chaotic in the world, and its temperature changes have always been decoupled from (and occasionally opposed to) the rest of the planet. There is already too much evidence that the medieval warming period was isolated for this to be overturned so easily.
"Will future ages believe that such stupid bigotry ever existed!" -- Ivanhoe
Either it is the long-term climatic change that the IPCC and others have been warning about, or it isn't. You say "a few years of drought" - that isn't long-term climate at all, but short-term weather patterns. Anyway, the US east of the Rockies (which I'll bet is where you are) is yammering about hot temperatures and drought being signs of global warming. Meanwhile, lots of the rest of the planet is having a cool, rainy summer. Your local weather is exactly that: local, and short term.
I am definitely a skeptic. There is no question that CO2 contributes to a greenhouse effect, however, there is no evidence (and never has been) that this triggers large positive feedback cycles. It has all been based on computer models, and most of the predictions of those models have been wrong.
Enjoy life! This is not a dress rehearsal.
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.
For 2,000 years the world was cooling, probably heading to a new Glacial Period, but now the temperatures are spiking dramatically in the other direction. Read the abstract carefully and look at the diagram. It is interesting but we'll have to see if it holds up. The current interglacial is a bit odd, we should be heading well and truly into a new glacial period, the temperature has seemed unusually stable; this paper would imply that it has not been stable at all.
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