"...should this evidence not also be discussed?"
Surely a quote worthy of Ahmadinejad himself.
Those local and minor fluctuations are indeed weighed and discussed ad nauseum by the people doing the real climate work, like NAS. It's a topic not meaningfully illuminated by burnt-out sci-fi authors and the like who'll snap up any factoid that supports a predetermined position.
It's reminiscent the Iranian president's Holocaust denial, or the work of the Tobacco Research Institute. Nobody believes their carp, not for a minute, but if their "debate" can forestall action against their clients, they've succeeded. The goal is no longer to win, but rather to not lose - simply to continue the play as long as possible.

When I see evidence that you are making a bona fide attempt to engage climate scientists re these objections, I'll take you seriously on this stuff.

A guy with your background could advance the debate. Why, instead, do you bring up piecemeal objections with us small fry? Doesn't make sense.

And so, I've wrestled with it, trying to figure it out.

My guess is that you sense the possibility of a serious rupture in our culture's view of the past and present. Instead of celebrating them, we may soon bewail the fossil fuel age and its captains. Even the myth of progress may be scrapped. It's a personal fight.

In a system as large and complex and chaotic as the earth, you are always going to be able to find contradictory evidence for anything that you are trying to prove. Rotating ~24 h/d and orbiting around the sun ~365d/y is just about the only thing that every single molecule on the planet does uniformly and in unison.

(Some wise guy will probably point out that even this isn't strictly speaking true, as there are always molecules that are leaving the earth's atmosphere and escaping into space.)

Absolutely, facts should be discussed. And an awareness that whatever framework we construct may be wrong is a necessary part - after all, I did mention peer review among those collecting and analyzing data compared to the decisive life long experience of a TV weatherman.

The debate currently is pretty much centered on only a couple areas of the globe - temperature/precipitation fluctuations in Europe and North America are pretty well established within certain tolerances, for various time frames. Ice cores add another element (pretty useless in the Amazon basin, though) as do seabed cores (pretty worthless in the Gobi, though).

I do realize that have a factually based debate seems to have become impossible, but in part, that is because for the last 30 or so years, we have been clearly following the wrong path - increased CO2 emissions are extremely unlikely to bring about a colder period - there is no support for this in any data over geological time scales.

But we are not interested very much in geologic time scales - even the few centuries between a 'mini' ice age and today seems extremely long term.

This is part of the real problem, especially in the U.S. - people see weather, and then extrapolate the weather to a cause - drought=global warming, mild hurricane season<>global warming. This is pretty stupid, to be honest.

But speaking broadly, those working with data studying climate are getting increasingly concerned at what they are witnessing, in part because even their frightening extrapolations do not match real time satellite data - Greenland's revving glaciers come to mind, along with ever exapanding amounts of ice free Arctic seawater - these are planetary scale feedback loops in action, ones predicted for decades in the future, if they were to occur at all.

Like with peak oil, for climate change, the future is now. And if there is one thing that seems clear about the U.S. - paying their bills is something no one wants to actually comtemplate. Better to whip out the credit card, and maybe take a drive to mall to calm one's nerves, or just watch some more TV.

The science of climate change remains open and is still fairly new, and facts are welcome. Some guy ranting that because he has presented weather information on TV over his life time he knows what he is talking about is about par for the course in a nation where the majority of citizens apparently dismiss the 'theory' of evolution.

Heading Out,

All right, I'll bite. It's fine that the Patagonian icefields are fluctuating and have fluctuated in the past. It's not fine that on average glaciers and ice sheets are losing mass. More than that, they are losing mass more rapidly than any of the proxies have shown in the past. So it's fine for you to trump up your Medieval Warm Period, but its wavelength is something like 500 years. We're changing the climate much more quickly than that right now. How quickly? Well if you don't believe the abundant proxies out there, or the photos of glaciers taken in the past compared to the present, look on this: This guy is about 5k years old. He was buring in an advancing ice sheet. Ötzi is not the only old thing to be found out of glaciers though. Lonnie Thompson has been going around pulling a whole bunch of things out of melting glaciers that are around the same age, with some outliers. We didn't use to pull all this old stuff out of the glaciers, it's likely that they have melted more in this century then at any time since these items were covered up, 5-6k years ago.


I suppose next you'll say that well if the climate were warm then, we'll be fine with it warm now. The only problem: billions of very poor people live near the coasts that didn't live there then. If sea level rises appreciably, and those people start migrating, the costs of dealing with that could make your $100 barrel/oil look like a walk in the park. It's possible we're already paying for it with more damaging chaotic weather, e.g. hurricanes, but it's hard to tell because the hurricane records don't go back so far and the data isn't as good.


Apologies to the other posters who rightly pointed out that this is not a climate change forum, but once in a while I'll respond to climate trolls who whip out their one glacier as proof that the climate isn't changing.

--
Gentlemen! You can't fight in here, this is the war room!

Margaret Mitchell, via Rhett Butler: There is just as much money to be made in the wreck of a civilization as in the building of one.

"Industrial civilization has centuries more of turning."

But the issue is finding the energy to turn things. Currently 86% of our energy is derived from fossil fuels. Wake me up when that figure drops below 50% while maintaining our current lifestyle.

True, but some Niall Ferguson types would argue that Western Civilization requires a dominant empire to keep the rest of the honkies in line and thus masters of a prosperous global economy. So if there had not been an America around in the 1940s to grab the torch from Britain, not only would Britain have lost its empire, but the Nazis would have begun a new Dark Age. There clearly is not another white empire warming up on the bench to take over from a broken America, so "society" would fail.

My objection to that argument is what constitutes "civilization" or even a "good life". Would a Nazi victory over Britain have actually been comparable to the fall of the Western Roman Empire in 476? The Nazis were barbaric in their behavior, but not in their administrative talents. Liberty would have regressed, but not technology. The sad story of civilization is that it is mostly composed of successful tyranny. Civilization carries out mass murder all the time - where would the West be without the crimes against Africans and Native Americans, and an endless list of little-known colonial massacres around the world? But skin color acted as a barrier to assure European/American/Israelis that within their own walls security prevailed. Is Hitler thus that different for having mainly murdered white Europeans while the German sub-set lived in some comfort?

It is telling that these "torch of civilization" arguments are sometimes heard from neocons whose own plans for saving us from Islamic or Chinese "barbarism" involve a thousand-year militarized tyranny. Their real message is: most Americans will live in comfort while a few million dissidents are sacrificed and a few billion of the mud races are triaged.

My argument is that, say, a Chinese-dominated world will be about as repressive, but the suffering might be distributed a little more evenly, so I'd call it more genuinely civilized.

As they said in "V for Vendetta",
England prevails.

Look around. How much of the alternative energy we are building, or actually how much of anything in our civilization is "decentralized"? Giant wind turbines are manufactured in big factories in Germany and Denmark, billions of solar cells are made in similar factories in Germany, Japan or China. Large utilities are installing the same wind turbines in plants taking up tens and hundreds of square kilometers... nothing small and down to the average person that I see.

I would challenge you that whether an industry is beneficial to the society or not does not depend on the size of the technology it uses. What is deterministic here is whether you can have the industry under public control or not.

You mentioned nuclear - this is one of the most heavily regulated industries worldwide. It takes forever to get a plant going, it is extremely risky, expensive and time-consuming to meet all safety and licensing requirements etc. Yet still utilities want to build it - because it is a technology that works and eventually they will make money of it delivering electricity, not because of subsidies or mandates.

Comparing it to wind is a funny thing - the reason companies want wind is because of subsidies and government imposed mandates. Initially it was the idea that these will be temporary incentatives to get the technology going but it seem we are going to be left with these temporary subsidies forever. More than that - wind is escaping public control, exploiting its carefully built image of a "green technology". Actually how green is it is questionable - after you count all the FFs that were neccessary to build, transport and maintain them, and add the additional fuel burnt in conventional plants serving as backup to wind farms, the savings are not that much.

I want to repeat again that I am not a priori against wind as it is a low polluting energy source. There are places it can do relatively well and up to a certain point it can be integrated easily in the grid. What I am against is favoring it and putting unreasonable hopes and huge amounts of public money to get such a small return - for example in Germany they are spending more than $3bln. a year on various wind subsidies to get just 7% of their electricity. Meanwhile none of their coal plants has been retired, because they are needed as a backup. Neither good for the environment or for us IMO.

Try this experiment:

Put a single drop of India ink from a bottle into a glass of water. Stir. Rather murky, eh? The ink molecules represent a minuscule percentage of the total, but they are the only ones which are absorbing the visible light. CO2 has the same effect in the atmosphere with infrared radiation emitted from the earth's surface.

It is my understanding that the proportion of CO2 in the atmosphere from fossil fuels can to be determined to a fairly accurate degree because of the differences in CO2 isotopes.

But, as Asebius has pointed out, we on this list are overwhelmingly not climate experts, nor do we have in the TOD editorial staff any climate experts (that I know of).

I, too, deeply resent HO's continual insinuating his 'evidence' cloaked by bald-faced 'innocence' as 'just facts, letting people make up their own minds.'
Definitely BS. TOD would definitely be better without it.

NEVER will AGW be proven by scientific method.

Ergo, NOTHING should be done about possible Global Warming, and we should keep driving Hummer and burning coal as the climate "naturally" changes dramatically around us, MANY billions die from famine, rising sea levels, cultural and social collapse and other effects of climate change.

Unlike other areas of scientific endeavor, the consequences of indecision on the issue of Global Warming are beyond devastating !!

BTW, the IPCC report did NOT say "humans cause GW", they said (from memory) there is a greater than 90% probability that humans are the dominant cause of GW.

i.e. No further scientific inquiry is required before policy makers take URGENT action !

Yes, scientific inquiry can continue (perhaps we will find that a natural warming trend is being accelerated by humans by a factor of x2.5) BUT ACTION SHOULD NOT BE DELAYED !

Best Hopes for Questioning NOT slowing action,

Alan

I guess you don't really understand the scientific method then, since by definition nothing is ever proved by the scientific method. Thankfully science cares not one iota what you are or are not willing to accept, even if you use CAPS to insist on it.

And by the way, methane is a greater GHG than CO2, 60 times more powerful to be exact, but CO2 is 200 times more abundant than methane in the Earth's atmosphere, so overall has a larger impact:

http://en.wikipedia.org/wiki/Image:Radiative-forcings.svg

While water is a GHG, its concentration is dependent solely on temperature. It's called a feedback gas; the higher the temperature, the more water evaporates, exerting its own effect on temperatures.

Water vapour: feedback or forcing?
— gavin @ 7:51 pm
Whenever three or more contrarians are gathered together, one will inevitably claim that water vapour is being unjustly neglected by 'IPCC' scientists. "Why isn't water vapour acknowledged as a greenhouse gas?", "Why does anyone even care about the other greenhouse gases since water vapour is 98% of the effect?", "Why isn't water vapour included in climate models?", "Why isn't included on the forcings bar charts?" etc. Any mainstream scientist present will trot out the standard response that water vapour is indeed an important greenhouse gas, it is included in all climate models, but it is a feedback and not a forcing. From personal experience, I am aware that these distinctions are not clear to many, and so here is a more in-depth response (see also this other attempt).

http://www.realclimate.org/index.php/archives/2005/04/water-vapour-feedb...