Nature: Global Temperatures Are a Falling Trend 786
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."
What a Surprise (Score:5, Interesting)
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?
Re:This will mean nothing... (Score:3, Interesting)
K. Caldeira and M. E. Wickett, "Anthropogenic carbon and ocean pH", Nature 425:365, 2003
K. Caldeira and M. E. Wickett, "Ocean model predictions of chemistry changes from carbon dioxide emissions to the atmosphere and ocean", J. Geophys. Res. 110:C09S04, 2005
J. C. Orr, et al., "Anthropogenic ocean acidification over the 21st century and its impact on calcifying organisms", Nature 437: 681-686, 2005
C. L. Sabine, et al., "The oceanic sink for anthropogenic CO2", Science 305:367-371, 2004
H. O. Portner, "Climate change affects marine fishes through the oxygen limitation of thermal tolerance", Science 315:95-97, 2007
H. O. Portner, "Climate change and temperature dependent biogeography: Oxygen limitation and thermal tolerance in animals", Naturwissenschaften 88:137-146, 2001
R. A. Feely, et al., "Impact of anthropogenic CO2 on the CaCO3 system in oceans", Science 305:362-366, 2004
which, in turn, has a number of devastating consequences for marine life, among other things:
Y. Shirayama and H. Thorton, "Effect of increased atmospheric CO2 on shallow water marine benthos", J. Geophys. Res. 110: C09S08, 2005
S. Widdicombe and H. R. Needham, "Impact of CO2-induced seawater acidification on the burrowing activity of Nereis virens and sediment nutrient flux", Mar. Ecol. Prog. Ser. 341: 111-122, 2007
H. L. Wood, et al., "Ocean acidification may increase calcification rates, but at a cost", Proc. Royal. Soc. B-Biol. Sci. 275: 1767-1773, 2008
M. D. Iglesias-Rodriguez, et al., "Phytoplankton calcification in a high-CO2 world", Science 320: 336-340, 2008
S. Collins and G. Bell, "Phenotypic consequences of 1000 generations of selection at elevated CO2 in green alga", Nature 431: 566-569, 2004
M. A. Gutowska, et al., "Growth and calcification in the cephalopod Sepia officinalis under elevated sewater pCO2", Mar. Ecol. Prog. Ser. 737: 303-309, 2008
S. Dupont, et al., "Near-future level of CO2-driven ocean acidification radically effects larval survival and development in the brittlestar Ophiothrix fragilis", Mar. Ecol. Prog. Ser. 373: 285-294, 2008.
A. J. Anderson, et al., "Life on the margin: Implications of ocean acidification on Mg-calcite, high latitude and cold-water marine calcifers", Mar. Ecol. Prog. Ser. 373: 265-273, 2008
W. M. Balch and V. J. Fabry, "Ocean acidification: Documenting its impact on calcifying phytoplankton at basin scales", Mar. Ecol. Prog. Ser. 373: 239-247, 2008
J. A. Berge, et al., "Effects of increased sea water concentrations of CO2 on growth of the bivalve Mytilus edulis", L. Chemosphere 62: 681-687
T. F. Cooper, et al., "Declining coral calcification in massive Porites in two nearshore regions of the northern Great Barrier Reef", Glob. Change Biol. 144: 529-538, 2008
F. Gazeua, et al., "Impact of elevated CO2 on shellfish calcification", Geophys. Res. Lett. 34: L07603, 2007
K. R. Hinga, "Effects of pH on coastal phytoplankton", Mar. Ecol. Prog. Ser. 283: 281-300, 2002
O. Hoegh-Guldberg, et al., "Coral reefs under rapid climate change and ocean acidification", Science 318: 1737-1742, 2007
P. L. Jokiel, et al., "Ocean acidification and calcifying reef organisms: A mesocosm investigation", Coral Reefs 27: 473-483, 2008
H. Kurihara, "Effects of CO2-driven acidification on the early development stages of invertebrates", Mar. Ecol. Prog. Ser. 373: 275-284, 2008
S. I. Siikavuopio, et al., "Effects of carbon dioxide exposure on feed intake and gonad growth in green sea urchin, Strongylocentrotus droebachiensis", J. Aquac. 266: 97-101, 2007
H. Kurihara, et al., "Effects of raised CO2 concentration on the egg production rate and early development of two marine copepods (Acartia steueri and Acartia erythraea)", Mar. Pollut. Bull. 49: 721-727, 2004
H. Kurihara, et al., "Effects of increased seawater pCO2 on early development of the oyster Crassostrea gigas", Aquat. Biol. 1: 91-98, 2007
H. Kurihara, et al., "Sub-leath effects of elevated concentration of CO2 on planktonic copepods and sea urchins", J. Oceanogr. 60: 743-750, 2004
Re:Headline should say... (Score:4, Interesting)
You know what? This might be hard to believe... but I don't think we're very good at predicting the weather...
All that aside... pollution is bad for many other reasons that don't involve global warming. So maybe you need to stop beating a dead horse and focus on something a little more tangible like "we're going to run out of oil rather soon" or "That shit causes cancer"
Re:Headline should say... (Score:4, Interesting)
"Most importantly, humanity survived higher temperatures in the past."
But there were much less of us and the available food to human ratio was at least POTENTIALLY better for humans during the Roman period... Not much we can do for 2 or 3 billion people of crops burn or flood.
BTW, I'm a skeptic on AGW...
Re:Headline should say... (Score:5, Interesting)
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.
Re:Headline should say... (Score:5, Interesting)
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.
Re:Headline should say... (Score:5, Interesting)
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.
Re:Headline should say... (Score:5, Interesting)
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.
Re:Manmade climate change is centuries old (Score:1, Interesting)
This is the most illogical argument I've ever heard. I'm all for data, of which you provide none. But that's a neat theory! Let's talk it out.
1-18 million Native Americans spread over all North America, from Canada to Mexico, cleared enough forest to "heat" the earth? With stone axes? Most of the farmsteads of Native American culture were along rivers, bayous, or on the plains. No tribe clear cut forests. They cleared small areas to make camps and small communities. The amount of forest, and thus CO2 debt, one would need to clear to account for the "Little Ice Age" wouldn't match up. Even if the Native American's had been wholesale burning every North American forest from sea to shining sea. Which we know they didn't do.
Feel free to insert any data or logic you have to dispute the above, I'm interested!
Simple Explanation: (Score:0, Interesting)
It's an old thing, well known to those who actually know their stuff:
We're basically entering an ice age right now. So it should be much colder than it even is now.
But with global warming, we're mitigating the trend, holding it up artificially.
The problem is, that we’re very soon not only overcoming the ice age, but shooting way above that in a nearly vertical upwards curve.
You can see that nicely in all the temperature charts.
(And 2000 years is nothing in geological terms.)
Re:Headline should say... (Score:4, Interesting)
All the article says is that forcings related to orbital mechanics may have been larger on a millenium time scale than estimated before. Even that is speculation - the core of the paper is presenting a improved method for evaluating tree ring proxies. The paper, however, does not call into doubt that the industrial age has added a significant greenhouse gas forcing, which gets bigger as we continue to add CO2 and methane.
It calls into doubt the idea that global warming itself is a catastrophe. It suggests that humanity thrived on a significantly hotter world than any living person has known.
Re:Headline should say... (Score:5, Interesting)
Re:Headline should say... (Score:5, Interesting)
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.
Re:Headline should say... (Score:4, Interesting)
The point you seem to miss, all high and mighty up there, is that claiming we can predict long term climate change based on historical weather patterns and/or small scale and short term models hurts the position of changing how we consume energy. It's just as silly as those who say "well it isn't hotter HERE, so there's no warming going on at all, liar!"
There are so very, very, very many reasons to effect energy changes that focusing entirely on something that is inherently unreliable, and being snarky about it, is worse than a waste of time. Yes, it's getting warmer. Yes, it's likely our consumption has a quantifiable but unmeasurable effect on it. It's also true that we are gonna run out of oil, it's expensive, and we need to be self-sustaining.
By the way, he knows the difference between weather and climate, as do I. Your'e the one who assumed we didn't. So, the joke becomes about using weather (a small and short term historical model, with high precision and increasingly low accuracy as we move back in time) to predict climate (a large and long term model, with less precision and low accuracy). What other large-scale predictions have we made using small-scale models?
Re:Headline should say... (Score:5, Interesting)
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.
You can't have it both ways (Score:5, Interesting)
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.
Re:Simple Explanation: (Score:5, Interesting)
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 [wikipedia.org]. 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 [wikipedia.org].
Obviously, we're currenty in an Ice Age [wikipedia.org] - 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.
Re:Simple Explanation: (Score:4, Interesting)
Here's one of my favorite sources [wikipedia.org]. Examine the graphs, and you'll find that few inter-glacial periods lasted over 20 thousand years, and we've been in ours for... 20 thousand years. Add to that the trend over the last 10 million years, and it seems that these ice ages are getting colder and colder. Straight line projection for another 10 million years puts us in snow-ball Earth territory. It's entirely possible that higher life on land was (and still may be) nearly at an end.
However, if you just want to be anal, like most Fox News fans when it comes to the topic of global warming, we can just take NASA's satellite measurements of surface temperatures since 1972. The Earth is warming. There's no way an intelligent person can look at that graph and not draw the obvious best line fit conclusion. Actually, that's not quite right, because there are plenty of intelligent people who are simply incapable of seeing what they don't want to see.
Re:You betcha! (Score:5, Interesting)
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.
Re:Scientists and "skeptics" (Score:4, Interesting)
"National Science Association"? I'm a scientist and I've never heard of them. But it is no single science association that has reviewed the evidence and concluded that concerns about CO2 are well-founded--it is pretty much every elite scientific society in the world. Here is a partial list [wikipedia.org]
In fact, there have been multiple peer-reviewed surveys using valid statistical survey methods [wikipedia.org] of opinion in the field. All have found that there is a high degree of consensus among qualified scientists.
Yes, there are people who are "skeptical" about anything that challenges their fixed beliefs, yet remarkably credulous about such things as the ability to deduce medieval global climate from third hand accounts of agricultural practices in northern Europe.
Just to pick a couple of examples, Koch Industries has spent over $30 million [polluterwatch.com] on lobbying efforts to create public doubt of the reality of global warming. Exxon has spent over $10M. It is worth noting that a million dollars can fund a pretty robust research project. Imagine all of the science that could have been done if these companies had spent the money funding real scientists. But clearly, they knew that funding genuine science would not help their case. So they spent it on public relations instead.
Yet somehow, nobody has managed to produce the unpublished work that (according to climate science "skeptic" myth) they supposedly prevented from being published. A genuine skeptic would find that odd, don't you think?
Yet nobody has managed to find any important conclusions or recommendations of the IPCC report that are not solidly based in peer-reviewed science (and by the way, it is a climate science "skeptic" myth that the IPCC is only allowed to cite peer-reviewed studies). So the "skeptics" are reduced to picking on inconsequential, and long-corrected, errors like the one on the Himalayas. But oddly, these "skeptics" be