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a) Is "global warming" really happening?

Unless you are being perversely skeptical, the answer to that is "yes". We have historical temperature records going back to 1850. You can read the FAQ for such datasets and download the data for yourself if you like, or read the articles detailing data collection, analysis, and uncertainties. There is an obvious upward trend.

Going back further requires use of proxy data such as tree rings, ice cores, coral data, glaciers, etc. There have been numerous different studies by different scientists collecting, and cross referencing such data to create historical temperature reconstructions. Here is a plot showing 10 different reconstructions by various authors. There is some variability, but the recent upward trend is again clear. Again, you can get the datasets yourself, and read more reports detailing how they are analysed. At about this point skeptics point to Greenland being green, or Wine growing in Europe in 1000AD, but I've discussed those before, so I won't go into detail again.

The result is that, to claim that the earth is not presently getting warmer requires either a belief that limate scientists are almost universally incompetent, or that they are colluding en masse in a grand conspiracy to falsify data and delude the public. Either of those options would seem, to me, to be a much greater leap of faith than simply assuming that the world is, indeed, getting warmer. As I said, it requires a rather perverse skepticism more on par with 9/11 conspiracy theorists like the maker of Loose Change.

b) If "global warming" is really happening, is it due to anything mankind is doing?

An interesting question. Certainly mankind is doing something: since 1850 atmospheric carbon dioxide levels have risen from around 280ppm to 385ppm. That's a significant change - in fact given atmospheric carbon dioxide levels over the last 650,000 years (via ice core data) the current levels are 5.5 standard deviations from the mean; that's significant! Are humans responsible for this change? Certainly it correlates with the industrial revolution, but still... As it happens we can do isotope analysis of atmospheric carbon dioxide, since isotope ratios for fossil fuels are different from thoses of the rest of the carbon cycle. It turns out that indeed, the sudden increase in atmospheric carbon dioxide is from humans burning fossil fuels. Now a little basic physics and the absorption spectra of carbon dioxide is enough to tell us that we should expect greater atmospheric carbon dioxide to result in a warmer planet. It turns out that is indeed what we are seeing, and that it correlates well. There's more than just that however. Have a read through the chapter on attribution of the IPCC Third Assessment report. A wide variety of techniques are used to attempt to attribute the observed warming to various potential causes. The end result is that the IPCC found that while warming prior to 1950 could possibly be accounted for by other factors, including solar variation, warming since 1950 can only be reasonably accounted for via anthropogenic atmospheric carbon dioxide. Feel f

The Little Ice Age is not a disputed idea.

Yes, it is. According to the The Intergovernmental Panel on Climate Change, part of the United Nations Evonmental Prgramme - tasked specifically with examination of the scientific evidence - they wrote: Thus current evidence does not support globally synchronous periods of anomalous cold or warmth over this timeframe. Online version is located here: http://www.grida.no/climate/ipcc_tar/wg1/070.htm I'd say that's a dispute.

You keep saying the same line of reasoning repeatedly, you're asserting things that are clearly false (I claim the statement I quote from above is clearly false.), and you are asserting your opinions without and any supporting evidence or proof at all.

Here, with this post, you propagate more FUD - Fear, Uncertainty, and Doubt:

F = "in spite of what Al Gore might say"
U = "It is entirely possible"; "to have ended somewhere around"
D = "It is still disputed if humans actually,"

What ever happened to the value in truth? Somewhere over the last 6 years it became in vogue to NOT connect ones reasoning as close as possible to objective reality.

The debate is over. As I see it, rational discussion as to weather or not human pollution is a factor in global temperatures occurs now only with people who are significantly underinformed about the current scientific evidence in the story. Those who understand the science see the connection: humans have caused and are causing significant changes to the environment. These changes affect the temperature. You can choose not to see or believe it. I will stand up and cut through the obvious guilt-ridden FUD-driven drivelish. It will take a lot more people doing this to rid ourselves of the current tendency toward accepting blatant untruths.

The basic nature of this text interchange is one in which you are not engaging me, addressing my points, or answering the questions I raise.

I don't have time to continue this thread and will not reply further.

I welcome a closing post from you.

Climate change is not about local weather prediction.

'In common parlance the notions "weather" and "climate" are loosely defined1. The "weather", as we experience it, is the fluctuating state of the atmosphere around us, characterised by the temperature, wind, precipitation, clouds and other weather elements. This weather is the result of rapidly developing and decaying weather systems such as mid-latitude low and high pressure systems with their associated frontal zones, showers and tropical cyclones. Weather has only limited predictability. Mesoscale convective systems are predictable over a period of hours only; synoptic scale cyclones may be predictable over a period of several days to a week. Beyond a week or two individual weather systems are unpredictable. "Climate" refers to the average weather in terms of the mean and its variability over a certain time-span and a certain area. Classical climatology provides a classification and description of the various climate regimes found on Earth. Climate varies from place to place, depending on latitude, distance to the sea, vegetation, presence or absence of mountains or other geographical factors. Climate varies also in time; from season to season, year to year, decade to decade or on much longer time-scales, such as the Ice Ages. Statistically significant variations of the mean state of the climate or of its variability, typically persisting for decades or longer, are referred to as "climate change".'

http://www.grida.no/climate/ipcc_tar/wg1/index.htm

However AFAIK there is no solid proof that human activity is a major or even significant factor in the changes over the last 200 years.

I would have to disagree. Aside from the simple correlction of timing of changes, and accounting of carbon dioxide emissions, there is the analysis of carbon isotopes in atmospheric carbon dioxide. In summary, by measuring the ratios of different carbon isotopes in the atmosphere, and knowing that carbon from fossil fuels will have different isotope ratios than carbon from natural sources, it is possible to establish how much of the recent change in atmospheric carbon dioxide levels are due to human activities through burning of fossil fuels. The results are that the rise in carbon dioxide levels of the past 200 years are almost entirely anthropogenic.

This claim has been made many times, but so has the claim that human activity is only responsible for some tiny fraction of global CO2 emissions.

I have never seen any credible evidence to support the counter claim that the change in atmospheric carbon dioxide levels is not due to human activity. It is true that in terms of the total carbon dioxide produced in the carbon cycle, human produced carbon dioxide is just a fraction, but if I have a tank that is draining water at 10 liters per minute and having water added at 10 liters per minute then adding more water, even at a small fraction of that rate, will cause the otherwise stable tank to overflow. In terms of change human factors are very relevant, and quoting other figures about total carbon produced is, while accurate, disingenuous and misleading with regard to the actual issue at hand.

Our current cycle of global warming isn't natural. Note "hasn't happened before" isn't proof.

Well this isn't something that can be "proved", but in terms of history (last 800,000 years) we are in the middle of an interglacial which peaked some time ago, so we shouldn't be expecting further increases in temperature from the galcial/interglacial cycles. From a more recent historical perspective (last 200 years or so) the recent warming is quite unprecedented according to almost all historical temperature reconstructions (and there are many). In terms of our current understanding of climate and all the things that could effect it, without including atmospheric carbon dioxide changes, we cannot properly account for the present warming. That is, to the best of our current knowledge the warming is not natural. That could change, but we would have to learn some significant new informnation to change our understanding of the climate for that to occur.

Human activity is a major factor in global warming.

As noted above, recent increases in carbon dioxide levels are the only way to account for the recent warming given our curent understanding of climate. Also noted above is the fact that human activity has been a major factor in increasing levels of atmospheric carbon dioxide. If you want more details on how attribution of recent warming has been determined so far the IPCC TAR attribution chapter is a good place to start - it summarises a number of different studies using a variety of techniques to attempt to determine the most likely factors driving the current warming.

dentify the other factors influencing global warming.

That is certainly being worked on. I'll again refer to the IPCC TAR for a figure showing various radiative forcings, which is to say factors affecting global warming (both positive anmd negative effects). There are several besides atmospheric carbon dioxide. One of the most s

However AFAIK there is no solid proof that human activity is a major or even significant factor in the changes over the last 200 years.

I would have to disagree. Aside from the simple correlction of timing of changes, and accounting of carbon dioxide emissions, there is the analysis of carbon isotopes in atmospheric carbon dioxide. In summary, by measuring the ratios of different carbon isotopes in the atmosphere, and knowing that carbon from fossil fuels will have different isotope ratios than carbon from natural sources, it is possible to establish how much of the recent change in atmospheric carbon dioxide levels are due to human activities through burning of fossil fuels. The results are that the rise in carbon dioxide levels of the past 200 years are almost entirely anthropogenic.

This claim has been made many times, but so has the claim that human activity is only responsible for some tiny fraction of global CO2 emissions.

I have never seen any credible evidence to support the counter claim that the change in atmospheric carbon dioxide levels is not due to human activity. It is true that in terms of the total carbon dioxide produced in the carbon cycle, human produced carbon dioxide is just a fraction, but if I have a tank that is draining water at 10 liters per minute and having water added at 10 liters per minute then adding more water, even at a small fraction of that rate, will cause the otherwise stable tank to overflow. In terms of change human factors are very relevant, and quoting other figures about total carbon produced is, while accurate, disingenuous and misleading with regard to the actual issue at hand.

Our current cycle of global warming isn't natural. Note "hasn't happened before" isn't proof.

Well this isn't something that can be "proved", but in terms of history (last 800,000 years) we are in the middle of an interglacial which peaked some time ago, so we shouldn't be expecting further increases in temperature from the galcial/interglacial cycles. From a more recent historical perspective (last 200 years or so) the recent warming is quite unprecedented according to almost all historical temperature reconstructions (and there are many). In terms of our current understanding of climate and all the things that could effect it, without including atmospheric carbon dioxide changes, we cannot properly account for the present warming. That is, to the best of our current knowledge the warming is not natural. That could change, but we would have to learn some significant new informnation to change our understanding of the climate for that to occur.

Human activity is a major factor in global warming.

As noted above, recent increases in carbon dioxide levels are the only way to account for the recent warming given our curent understanding of climate. Also noted above is the fact that human activity has been a major factor in increasing levels of atmospheric carbon dioxide. If you want more details on how attribution of recent warming has been determined so far the IPCC TAR attribution chapter is a good place to start - it summarises a number of different studies using a variety of techniques to attempt to determine the most likely factors driving the current warming.

dentify the other factors influencing global warming.

That is certainly being worked on. I'll again refer to the IPCC TAR for a figure showing various radiative forcings, which is to say factors affecting global warming (both positive anmd negative effects). There are several besides atmospheric carbon dioxide. One of the most s

You said the SUMMARY not the chapter. The centerpiece of the SUMMARY was the thoroughly discredited "Mann Hockey Stick" a piece of shit so bad that not even Mann bothered to defend it when he testified in Congress recently.

Do the studies you like to cite which attempt to attribute observed climate data to various models (anthropogenic and otherwise) include uncertainties on their theoretical natural climate models? If so, what are they?

THe funny thing is that you actually believe that.

Sheesh, where do you get your beliefs? On the contrary, rich countries have roughly ten times higher CO2 emission per capita than developing countries. And the US is indeed among the world's worst polluters per capita.

The climate changes on Earth are entirely explicable as natural variation as the IPCC TAR made clear in 2001. The man-made hypothesis is based upon the attribution studies based on climate models.

• "The observed warming is inconsistent with model estimates of natural internal climate variability."
• "The observed warming in the latter half of the 20th century appears to be inconsistent with natural external (solar and volcanic) forcing of the climate system."
• "The observed change in patterns of atmospheric temperature in the vertical is inconsistent with natural forcing."
• "Anthropogenic factors do provide an explanation of 20th century temperature change."
• "It is unlikely that detection studies have mistaken a natural signal for an anthropogenic signal."
• "The detection methods used should not be sensitive to errors in the amplitude of the global mean forcing or response."

Yes. Now we know that the centerpiece of that summary, the "Mann Hockey Stick", turned out to be a scientific fraud.

If we knew for sure that we humans are causing changes, then we should mend our ways rapidly. But when history shows larger fluctuations than the current one, it could be easily inferred that the changes are all due to mother nature, and all our actions would be noise.

First of all, I've never advocated seizure. Merely making the market cost of production match its actual cost. This is not seizure, this is common sense. If I find a way to make product X cheaply by dumping the by-products in the municipal water supply, then it makes sense for the government to charge me for the cost of cleaning up the municipal water supply. Replace "water supply" with "air supply" and you begin to understand the ideas involved in legislating cleaner technologies.

Somehow, I suspect you'll object even to that little bit of common sense legislation. If it makes it easier for you to sympathize with, imagine that instead of dumping the by-products into the municipal water supply, it's even cheaper to dump them straight into your veins. Surely that shouldn't be legal. Where do you draw the line? Polluters need to be responsible for the cost of cleaning up their pollution. If you're going to argue that CO2 isn't pollution, fine. The same argument applies regardless of what you label it.

Personally, I have no reason to trust "experts" in the area of climate change.

First, of all I was referring to economists, not climatologists. Secondly, I'm not surprised. It seems the only expert you trust are those funded by oil companies.

I look at the greenies own data and I see a blip of an increase since 1980. Most of the 20th century was pretty flat. Wouldn't CO2 emissions have started affecting climate hundreds of years earlier if the climate was as sensative anthrogenic changes as you suggest? Or is that a discussion you are uncomfortable with?

Really? You don't notice that it started off quite negative, rose to an average of 0 between 1960 and 1990 (which is how 0 is defined on that graph) and then became quite positive? No wonder you have a hard time believing the experts, when you can't notice what's in front of your own eyes. And yes, as you yourself mentioned in the GGP post, CO2 emissions did start climbing hundreds of years earlier. However, the most drastic changes in temperature not surprisingly coincide with the most drastic increases in production of CO2.

Although the figure you cite might qualify as nothing, the upper bound, IMO, does not. Further more, if successful, we will also learn more about what we're capable of doing, and what the effect will be on the environment.

This is precisely why Kyotoists will fail in America, Australia, India, China... You have no significant justification for a brazen seizure of unprecidented wealth. So it will continue to be rejected.

Some economists (as opposed to us on the sidelines) actually speculate that measures to help the environment might actually stimulate the economy. Granted, this is speculation. It might stress the economy some. Not as much as global warming will, but some.

Personally, I have no reason to trust "experts" in the area of climate change. There are none. If you are refering to the so called "carbon market", the Europeans came up with that term. Their growth levels are so enemic they might actually consider it stimulus. Consider the source. It is a standard misguided rationing program. Such constructs have never built wealth for anyone other than a few insiders who can sell the initial issues. I'm surprised they suggest such a discredited vehicle.

The drastic climate change has only come in the last 100 or so years. The next 50 years will likely result in more drastic changes.

I look at the greenies own data and I see a blip of an increase since 1980. Most of the 20th century was pretty flat. Wouldn't CO2 emissions have started affecting climate hundreds of years earlier if the climate was as sensative anthrogenic changes as you suggest? Or is that a discussion you are uncomfortable with?

Well, as for as the nay-sayers favourite line of criticism towards anthropogenic global warming -- the sun, it breaks down like so: the sun's activity cycles are 10 to 20 years long, and the sun's gradual warming takes place over billions of years. The global mean temperatures has been showing an increase over the last century -- too long to be accounted for by the sun's activity cycle, and far, far too short to be accounted for by the increasing rate of fusion in the sun.

Riddle me this: If a decrease in the sun's output is felt more or less immediately (you can find ample mention of that), why does the converse take millions of years to be noticable? You have an energy source, and a thermal mass, so there should be a pretty good correlation between increased and reduced energy input above and below a given "norm" and the temperature of that mass (as well as the temperature delta), right?

Saying "yeah, the sun's changing, but so what, it can't have anything to do with global warming" doesn't jibe with thermodynamics, if you accept the fact that the sun's output has risen over the past century.

There is also, of course, the issue of why mars is warming on what appears to be roughly the same timeline as earth (projections based on current polar ice sublimation and when the last martian ice age was at its zenith). I'm fairly certain we can take manmade emissions out of that equation.

in any case, prevention is easy. Install CO_2 scrubbers on the goal and gas plants.

...and if we eliminate every device made by man, we eliminate about 3 percent of total (manmade and natural) CO2 emissions.

I understand the arguments on both sides. One of the more interesting things I've seen, as far as long-term trend indications go is this graph. Of particular interest to me was the cycle of CO2 concentrations shown in Graph D, which covers a timeline from 400,000 years ago to present, and shows a 80-100 thousand year cycle, of which we are currently at a peak.

That graph is one of many of differing timescales, but one of the more interesting, just because of the amount of time it encompasses, and because of the fact that it is able to demonstrate not only an existing trend, but a recurring pattern. Granted, it only shows 4 cycles, but that's more than the tail-end of a single one.

I'm not saying we shouldn't work to reduce pollution...I live in Dallas, and I get seriously tired of air-quality warnings and worrying about my youngest daughter's athsma. I don't think anyone disagrees that pollution is still a problem, but the mindset that man is the only or even the biggest cause of global warming is not based on irrefutable evidence.

If you include water vapor as a greenhouse gas, humanity contributes 0.28% of the total greenhouse gases in the atmosphere, of which 0.117% is CO2. It's not likely that such a small amount is significant.

Using the concentrations in the atmosphere as a percentage is silly: the forcing potential of each of the gasses is different.

See the IPCC report on the relative contributions of each gas. If CO2 was the only greenhouse gas present, the radiative forcing would be 25% of what it currently is. Humanity has increased the concentration of CO2 by 35%.

The forcing of each of the gasses isn't additive, so it's not entirely fair to say upping the CO2 fraction by 35% will up the atmospheric forcing by ~8%. Still, saying "it's insignificant" is very misleading - the radiative forcing of water vapor is small compared to carbon dioxide.

And incidentally, while the methane emissions from living plants will likely be significant, it would (at most) reduce anthropogenic methane emissions to about a third of the total.

...And frankly, I'm a lot more afraid of WW3 than global warming. While I'm all for alternative energy, recycling, minimizing fossil fuel consumption, and what not, all the bullshit from BOTH SIDES of the global warming argument have made me extremely cynical of wether or not it should be taken seriously.

Frankly (and I have absolutely no credentials to back up my opinion) I think the sea levels rising several meters of more in the next 20-30 years has about as much chance of occuring...

...as Bush resigning from office so he can star in the next gay cowboy movie.

The statement that CO2 correlates well with temperature is incorrect. CO2 has been steadily increasing over the last 100 years, while temperatures rose from the 1880's to about 1940, cooled until about the 1970s, and has risen again of late.

The 30 year dip is potentially contributed to by a number of factors including solar variation and less solar energy reaching the surface due to greater cloud cover (partly due to particulate pollutants but for other reasons too). Yes it represents an abberation in the correlation, but that does not prevent the existence of generally good correlation otherwise (particulrly over things like rate of increase and the fact that the current warming trend stands out as anomolous - just as the current atmospheric carbon dioxide spike.

CO2 is not a pollutant. It is, in fact, the lifeblood of the planet, required for growth of vegetation. It is the cornerstone of the food chain.

And no one said carbon dioxide was, in and of itself, bad. The fact remains that there is a natural carbon cycle that has, for the last several million years, been keeping a great deal of carbon sequestered and out of the atmosphere. The problem is not carbon dioxide in the atmosphere, the problem is dramatic abberation from the natural cycle caused by our release of the previously sequestered carbon into the atmosphere. We are providing a new forcing to the natural cycle - a new forcing to a complex system: it is reasonable to expect that this forcing, differing from the natural fluctuations, could introduce significant new changes in the behaviour of the system. While changes will have both positive and negative effects, the reality is that for humans in general rapid change is, in and of itself, a negative effect.

Water vapor is by far the primary contributor of the greenhouse effect, accounting for 96 to 99%.

I would like to know where you got that figure - I can't find any respectable sources that give a figure anywhere near that high. For example this paper on the subject gives a figure of 60% clear sky contribution for water vapour and 26% clear sky contribution for carbon dioxide. The 1990 IPCC report estimates around 60%-70% contribution from water vapour.

The fact that water vapour contributes significantly to the greenhouse effect is, at least, not in dispute. The point is not that the greenhouse effect is bad, but that humans are providing a forcing on the system that has the potential to destabilise it, or at the least create significant change: The water cycle, like the carbon cycle, is a natural process that maintins a rough equilibrium (there is, of course, some fluctation due to all manner of other causes and factors), and the introduction of massive amount of carbon dioxide to the atmosphere is not a part of that natrual system, thus we can reasonably expect significant change.

During the current interglacial period, the Earth has been about 2C cooler (The "Little Ice Age" around 1600-1700, when the Thames regularly froze over)

Again I'll have to ask you for sources on that because all the reputable sources I can find put the little ice age as at most 1.2C colder than 2004 temperatures, while most studies (which the IPCC sumarises well) put the figure at less than 1C. More importantly, while there were local fluctuations, the actual degree of fluctuation in mean global temperature was a lot less. Certainly Europe experienced some cold years - that does not mean that everywhere did.

and it has also been about 2C warmer (The medieval warm period around 1000 - 1200, when Greenland was colonized by the Vikings and exported surplus crops.)

I've seen nothing claiming the medieval warm period was as warm as that! Greenland was indeed settled by the Norse around that time - they settled in a couple of fjords that offered some

Currently funding is much easier to get if your project is geared to "proving" global warming than "disproving" it.

Uh, right. There's no one out there interested in funding research that attempts to undermine the scientific consensus on climate change.

Predictions are made and tested with models, the most authoritive report to date has been the IPCC. These predictions (along with others) have proven to be on the conservative side. However, had it not been for the predictions we would not be out there measuring the stuff.

We are seeing many changes in feedbacks that were predicted to happen not now but 50yrs from now, that is why the speed of Greenland's glaciers, and rotting permafrost is alarming.

By contrast, other studies have shown that DU ammunition has no measurable detrimental health effects, either in the short or long term. The International Atomic Energy Agency reported in 2003 that, "based on credible scientific evidence, there is no proven link between DU exposure and increases in human cancers or other significant health or environmental impacts," although "Like other heavy metals, DU is potentially poisonous. In sufficient amounts, if DU is ingested or inhaled it can be harmful because of its chemical toxicity. High concentration could cause kidney damage." [46]

Thus major health impact of depleted uranium relate to its chemical toxicity as a heavy metal rather than to its radioactivity, which is relatively low. In fact, there is some evidence to suggest that low-level radiation, such as that from uranium, is beneficial to human beings. [47] [48] [49] As with any heavy metal, the overall hazard depends on the amount of exposure.

"The question arises: why governments of various countries do not relocate populations living in areas where lifetime dose of natural radiation is higher than 350 mSv. For example, why are people not evacuated from Norway where all country average lifetime dose is 365 mSv (Henriksen 1988), or from high background regions in India with a lifetime dose of >2000 mSv (Sunta 1990) and in Iran with lifetime dose of >3000 mSv (Sohrabi 1990)? Perhaps in Iran, for example, the government considered not to follow the ICRP guidelines when it considered the fact that in a house in the city of Ramsar several generations were receiving average individual lifetime doses of natural radiation of 17,000 mSv (240 times more than the current ICRP limit for exposure of members of the public to natural sources of radiation). Yet these individuals show no increased incidence of any disease, and some of them lived to 110 years of age (Sohrabi 1990)."

There have been times in the planet's past (within the last 100,000) years where the climate was MUCH warmer with much higher concentrations of C02.

Carbon dioxide levels are at their highest from the last twenty million years. That's 20,000,000 years. You know, 200 times longer than your 100,000 number.

Here's a chart for the last 400,000 years. See the gigantic spike on the left? That's us.

The IPCC relevant quote for the 20 Myr number.

but to attribute current climate conditions over the last 20 years or even 40 with human activity

Carbon dioxide levels in the atmosphere are absolutely from human activity. That's proven - really, proven - by isotopic abundances.

Why is it politics to assume that if we can change - significantly - the atmospheric composition of the planet, we can change the climate?

Fair point about co2science.org. But to be equally fair, realscience.org's main contributors seem to be Mann et el. so I wouldn't expect objective criticisms of MBH98.

Does it matter if we read the Yadav summary at co2science or here?

I think you misread me about MBH98 being a "cornerstone". Whatever it might not be, it certainly seems to be the cornerstone of the IPCC Report. Everything stems from MBH98. Without its 20th century anomaly there's no anthropogenic CO2 correlation.

realscience's answer to myth#1 is figure 1., of which four of the curves are other mann models so they're not from "other groups" at all. And anyway, the graph really tells us nothing about whether the temperature anomalies are natural or not.

I started out believing there was a link between warming and anthro CO2. But after I started digging a little I found it wasn't as easy to establish as I thought it would be.

I have no problem with the Vostok ice core CO2 data.

We're not denying it, we're just questioning wether it's linked to CO2.

The cornerstone to the IPCC Report is the Michael Mann (et el) "hockey stick" graph of which the model used to generate it has been found to contain errors. I'm talking about errors according to climatologists, not politicians or newpaper editors.

Here's a wiki article that mentions it.

More info and details here.

Two reseachers from Canada, Stephen McIntyre and Ross McKitrick, attempted to reconstruct the so-called MBH98 graph and wrote that the method used by Mann contained "collation errors, unjustifiable truncation or extrapolation of source data, obsolete data,"

AFAIK there is no more conclusive data available than what MBH98 gives. If MBH98 is fatally flawed then the whole of the IPCC's conclusions are drawn into question.

That is presuming gloabl warming is real and that it's linked to CO2.

You may be completely right and it's great for everyone to have an opinion on global warming and carbon dioxide. But is your opinion based on what you got from the media or was it formed through scientific reasoning?

Wether for or against, could any of us make a good scientific argument to support theories?

How much do you we all know about climatology?

What models did the IPCC researchers use in temperature prediction?
How were the models verified?
What's the MBH98 hockeystick graph?
What are the criticisms of the MBH98 graph?
How is temperature measured?
What's an urban heat island?
What's a microwave sounding unit?
What's the percentage of CO2 in the atmosphere?
What's Hubert Peak Theory?


For anyone who's unsure, may I suggest less BBC and more science. Here's some links.

IPCC Report

realclimate

CO2 science

Temp for last 100 years

The Intergovernmental Panel on Climate Change (IPCC) was jointly established by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) in 1988.

http://www.grida.no/climate/ipcc_tar/wg1/index.htm

Please list all scientific facts (or accepted theories) that have been censored by the government. If you can't list a single one, then I can only assume that they are 'censoring' this scientist from making policy statements as head scientist of NASA.

1. Climate change is happening
2. Something can be done about it
3. It needs urgent action now

4. 1. Over to you.

Please list all scientific facts (or accepted theories) that have been censored by the government. If you can't list a single one, then I can only assume that they are 'censoring' this scientist from making policy statements as head scientist of NASA.

1. Climate change is happening
2. Something can be done about it
3. It needs urgent action now

4. 1. Over to you.

Nothing is non-controversial if someone wants to stir up a controversy. That last year was strong confirmation of accelerating anthropogenic global warming (the point we are supposedly debating) is not controversial among the relevant scientific communities. It wouldn't be controversial elsewhere either, if there weren't a systematic campaign of disinformation by people who have a lot of wealth sunk into fossil fuel reserves.

You have a recipe for any party to disrupt effective use of information by the government. Of course, it isn't original. It's exactly the recipe that is in use. Scientific consensus is meaningless if there is "controversy" or "politics"? Don't like where the science is leading? OK, drum up some controversy.

The IPCC Report is not really a scientific study, it's a meta study, a study of studies.

The problem with this approach is it tends towards argumentum ad populum which basically means if enough people believe in something it must be true which is not at all how science works.

Wein's displacement law gives Earth's radation peak in the infrared region at about 10 micrometers. H20 makes up 2% (50 times more than CO2) of the amosphere and has a much higher reflectivity in the 10 micromenter region.

As water vapor, H2O has a positive feedback causing further "warming" but when it forms clouds it has a negative "cooling" affect. So there's a least one model than suggests CO2 will cool the Earth. Also, more clouds means more rain which means more plants which means less CO2. So it's quite possible for the Earth to self regulate itself.

I'm not saying CO2 isn't a problem but what the IPCC has done is to take the worse possible senario out of a whole bunch of other options.

Don't forget, CO2 makes up only 0.04% of the atmosphere and over 90% of CO2 came from natural, non anthropogenic sources.

There's also some evidence that about 30% of the 8 gigatons of annual CO2 can be accounted for by forest fires

Let's not even get into volcanic activity.

Forgot to post the link where I got the 0.27% number from: Global warming--a closer look at the numbers

However, as show in this graph, http://www.grida.no/climate/vital/graphics/large/2 .jpg, the case can be made that the temperature turns up before the CO2 increase.

That's a very valid criticism of the climate models of around 1985. Slab oceans are not used in state-of-the-art climate models.

modelers set up the model so that CO2 holds more heat in the model

Well, nature set things up that way too. It's been known since the 1890s.

do they just solve for two of the three (pressure and temperature, but not volume)

um, ever hear of an equation of state?

I can go on for hours about how completely inaccurate these models are.

You are very creative indeed. Unfortunately, you show no signs of knowing what computer models are in use, why, or how they relate to the science.

we have data that all of the inner planets are now heating up.

Where? The Mars matter is addressed here.

Trillions of dollars and Millions of lives will be lost if the "we should take action just in case" crowd wins.

I don't know why you are only interested in the risks on one side.

We have no hard evidence to support anthropogenic global warming theories.

Hope this helps

Where is the evidence?

Pretty much everywhere. If you google scholar global warming anthropogenic, Like so, you'll find that the literature pretty much accepts that global warming has a significant human created component.

This report was particularly telling in it's time. You have to read the whole whack if you want to believe it, but these charts tell the story they found, by evaluating a range of models that existed in 2001.

Where is the evidence?

Pretty much everywhere. If you google scholar global warming anthropogenic, Like so, you'll find that the literature pretty much accepts that global warming has a significant human created component.

This report was particularly telling in it's time. You have to read the whole whack if you want to believe it, but these charts tell the story they found, by evaluating a range of models that existed in 2001.

Calculations here:

http://www.grida.no/climate/ipcc_tar/wg1/412.htm#t ab113

-molo

If you read the article, you would see that a source was cited for that statement:

http://www.grida.no/climate/ipcc_tar/wg1/412.htm#t ab113

-molo

For example, the Mount Pinatubo eruption

lowered the temperature by the addition of aerosols (dust and sulfuric gasses), which mostly leave the atmosphere over the next several years. CO2 does not (there is sequestering, but it's a slow process). CFCs do not (half-lives often over a hundred years). Methane does not, although it is one of the shorter lived greenhouse gasses (12 years) and some of our actions have added new permanent influxes (for example, dambuilding). Etc. Mt. Pinatubo actually helped validate models of global warming

There is nothing unique in time scale or magnitude

Yes, there distinctly is.

The little climatic optimum ... the little ice age

Was nothing compared to recent temperature change; check the graphs. Some conservative sites distort the issue by citing temperature changes *In Europe* during this period, not global temperatures. If you want to talk *regional* climate change, be my guest - compare Europe's little ice age change to the modern Arctic climate change.

lasting about 1000 years on average

Completely false (unless you're, for some reason, talking about small-fraction-of-a-degree changes, as opposed to real ice ages). Again, look at the graphs; I can't stress enough that you review the data again, because you're wrong about what it says.

The pre-holocene glacial period had prpbably some of the most rapid climate changes in history, yet they still took a 650-3000 years to accomplish what we've done in a two hundred, and what we will repeat in 50 or less.

Looking at this Vostock ice core chart you can see that we're *long* overdue for the next ice age. 5-10k years - hard to blame man for that. Is this a cycle larger than the (geologically) short cycles from the Vostoc data asserting itself? We know there are drivers for CO2 levels far greater than what Man is doing, but on very long cycles.

Changing the pH of the ocean even slightly would make a huge difference in atmospheric CO2, for example (oddly, CO2 concentration in the ocean doean't feed back into the pH significantly - in fact, this is the most complicated feedback system I've ever looked at, and no one really understands it). But what drives that?

We have data for the 100kya-100mya range that seems related to temperature, but nothing certain. Climate 100mya was clearly very different than current patterns: http://www.ngdc.noaa.gov/paleo/ctl/cliscibeyond.ht ml with temperatures hardly varying with lattitude.

You have made everyone feel dumber for a few seconds by making them read what you just wrote.

Actually Co2 concentrations in the atmosphere are almost 20% higher than they were 50 years ago. I would hardly call that 'changing very, very little'.

Sunlight does not 'come in' during an aurora. And ozone is not created in them.

Three cheers for the US school system!!! Its making me rich!

For somethign to float, it must have an equal amount or more of liquid to float on, it doesn't have to produce it. That is the ocean.

When ice is melted, it takes up SLIGHTLY more space, and when many tons of ice melt, it is quite an impact.

Thus, the global sea level would rise, AS IT HAS BEEN for quite some time on both poles.

http://www.grida.no/climate/vital/19.htm/ However, considering your input is correct, the impact from the South Pole would be much greater than North's, though each would influence global sea level.

Figure 1 and Figure 2.
These graphs indicate the average global tempature. The first graph is of the last 140 years. The second graph is the last 1000 years.

Figure 3 and Figure 4.
The first graph shows the concentration of positive radiative emissions. The second graph shows negative radiative emissions. After reading the definition of radiative forcing, I admit it is very confusing to me. From reading other sources, it seems to suggest that a positive radiative force leads to warming, while a negative radiative force leads to cooling.

Figure 5.
This graph shows the radiative forcing effect of different sources. It is from the year 2000 and is relative to the year 1750. I believe this means that starting from 1750 and going to 2000, each bar represents the total effect through the entire 250 years.

Figure 6, Figure 7, and Figure 8.
The first graph compares temperatures using both a climate model and recorded observations from natural forces: solar variation and volcanic activity. The second graph compares temperatures using a climate model and only anthropogenic forces. The third graph compares temperatures with a climate model and combined natural and anthropogenic forces.

These graphs were all taken from the 2001 IPCC report. That report can be found here. The report, along with these graphs, seems to indicate that "most of the warming observed over the last fifty years is attributed to human activities."

According to the report, volcanic eruptions only effect the climate for a few years. The report mentions that "combined change in radiative forcing of the two major natural factors (solar variation and volcanic aerosols) is estimated to be negative for the past two, and possibly four decades."

Figure 1 and Figure 2.
These graphs indicate the average global tempature. The first graph is of the last 140 years. The second graph is the last 1000 years.

Figure 3 and Figure 4.
The first graph shows the concentration of positive radiative emissions. The second graph shows negative radiative emissions. After reading the definition of radiative forcing, I admit it is very confusing to me. From reading other sources, it seems to suggest that a positive radiative force leads to warming, while a negative radiative force leads to cooling.

Figure 5.
This graph shows the radiative forcing effect of different sources. It is from the year 2000 and is relative to the year 1750. I believe this means that starting from 1750 and going to 2000, each bar represents the total effect through the entire 250 years.

Figure 6, Figure 7, and Figure 8.
The first graph compares temperatures using both a climate model and recorded observations from natural forces: solar variation and volcanic activity. The second graph compares temperatures using a climate model and only anthropogenic forces. The third graph compares temperatures with a climate model and combined natural and anthropogenic forces.

These graphs were all taken from the 2001 IPCC report. That report can be found here. The report, along with these graphs, seems to indicate that "most of the warming observed over the last fifty years is attributed to human activities."

According to the report, volcanic eruptions only effect the climate for a few years. The report mentions that "combined change in radiative forcing of the two major natural factors (solar variation and volcanic aerosols) is estimated to be negative for the past two, and possibly four decades."

Figure 1 and Figure 2.
These graphs indicate the average global tempature. The first graph is of the last 140 years. The second graph is the last 1000 years.

Figure 3 and Figure 4.
The first graph shows the concentration of positive radiative emissions. The second graph shows negative radiative emissions. After reading the definition of radiative forcing, I admit it is very confusing to me. From reading other sources, it seems to suggest that a positive radiative force leads to warming, while a negative radiative force leads to cooling.

Figure 5.
This graph shows the radiative forcing effect of different sources. It is from the year 2000 and is relative to the year 1750. I believe this means that starting from 1750 and going to 2000, each bar represents the total effect through the entire 250 years.

Figure 6, Figure 7, and Figure 8.
The first graph compares temperatures using both a climate model and recorded observations from natural forces: solar variation and volcanic activity. The second graph compares temperatures using a climate model and only anthropogenic forces. The third graph compares temperatures with a climate model and combined natural and anthropogenic forces.

These graphs were all taken from the 2001 IPCC report. That report can be found here. The report, along with these graphs, seems to indicate that "most of the warming observed over the last fifty years is attributed to human activities."

According to the report, volcanic eruptions only effect the climate for a few years. The report mentions that "combined change in radiative forcing of the two major natural factors (solar variation and volcanic aerosols) is estimated to be negative for the past two, and possibly four decades."

Figure 1 and Figure 2.
These graphs indicate the average global tempature. The first graph is of the last 140 years. The second graph is the last 1000 years.

Figure 3 and Figure 4.
The first graph shows the concentration of positive radiative emissions. The second graph shows negative radiative emissions. After reading the definition of radiative forcing, I admit it is very confusing to me. From reading other sources, it seems to suggest that a positive radiative force leads to warming, while a negative radiative force leads to cooling.

Figure 5.
This graph shows the radiative forcing effect of different sources. It is from the year 2000 and is relative to the year 1750. I believe this means that starting from 1750 and going to 2000, each bar represents the total effect through the entire 250 years.

Figure 6, Figure 7, and Figure 8.
The first graph compares temperatures using both a climate model and recorded observations from natural forces: solar variation and volcanic activity. The second graph compares temperatures using a climate model and only anthropogenic forces. The third graph compares temperatures with a climate model and combined natural and anthropogenic forces.

These graphs were all taken from the 2001 IPCC report. That report can be found here. The report, along with these graphs, seems to indicate that "most of the warming observed over the last fifty years is attributed to human activities."

According to the report, volcanic eruptions only effect the climate for a few years. The report mentions that "combined change in radiative forcing of the two major natural factors (solar variation and volcanic aerosols) is estimated to be negative for the past two, and possibly four decades."

Figure 1 and Figure 2.
These graphs indicate the average global tempature. The first graph is of the last 140 years. The second graph is the last 1000 years.

Figure 3 and Figure 4.
The first graph shows the concentration of positive radiative emissions. The second graph shows negative radiative emissions. After reading the definition of radiative forcing, I admit it is very confusing to me. From reading other sources, it seems to suggest that a positive radiative force leads to warming, while a negative radiative force leads to cooling.

Figure 5.
This graph shows the radiative forcing effect of different sources. It is from the year 2000 and is relative to the year 1750. I believe this means that starting from 1750 and going to 2000, each bar represents the total effect through the entire 250 years.

Figure 6, Figure 7, and Figure 8.
The first graph compares temperatures using both a climate model and recorded observations from natural forces: solar variation and volcanic activity. The second graph compares temperatures using a climate model and only anthropogenic forces. The third graph compares temperatures with a climate model and combined natural and anthropogenic forces.

These graphs were all taken from the 2001 IPCC report. That report can be found here. The report, along with these graphs, seems to indicate that "most of the warming observed over the last fifty years is attributed to human activities."

According to the report, volcanic eruptions only effect the climate for a few years. The report mentions that "combined change in radiative forcing of the two major natural factors (solar variation and volcanic aerosols) is estimated to be negative for the past two, and possibly four decades."

As usual, let me point out that the evidence is there exactly where you'd look for it.

I doubt you have friends "in climatology" (as opposed to a freshman met survey) who think global warming is not a real problem. Such people are very rare. Shaking youyr head at every "ice age is coming" panic isn;t the same thing as saying the evidence is not there.

In fact, it's there. Go look.

In fact, leaving aside the anthropogenic parts of the forcing and just running the models with natural forcing usually shows a slight cooling recently. You could say that the best estimate is that about 110% of the warming is anthropogenic, and negative 10% is natural.

see http://www.grida.no/climate/ipcc_tar/wg1/467.htm

The observed warming in the latter half of the 20th century appears to be inconsistent with natural external (solar and volcanic) forcing of the climate system. Although there are measurements of these forcings over the last two decades, estimates prior to that are uncertain, as the volcanic forcing is based on limited measurements, and the solar forcing is based entirely on proxy data. However, the overall trend in natural forcing over the last two, and perhaps four, decades of the 20th century is likely to have been small or negative (Chapter 6, Table 6.13) and so is unlikely to explain the increased rate of global warming since the middle of the 20th century.

The fraction of the observed warmng that is caused by humans is almost certainly well over 50 % and may well be over 100%.

This is polemical nonsense. If science says nothing colclusive about this matter it says nothing conclusive about anything.

This is the only planet in the known universe that supports advanced life, not a court of law. Even if the "beyond a reasonable doubt" criterion were not satisfied (a threshhold which was passed some time ago) the criterion is wrong; greenhouse gases are not innocent until proven guilty.

If you must use legalistic arguments, surely the presumption of innocence goes to the undisturbed atmosphere, not to the pollutant.

The best available evidence is overwhelming that most or even all of the observed warming is caused by humans, that most of past warming and cooling episodes were related to natural variation in greenhouse gases, and that the warming will continue to accelerate. The predictions based on this understanding that were made around 1990 are on track.

If you want to call this frenzied hair-pulling, teeth-gnashing, and I-just-pulled-this-out-of-my-ass guesswork I guess you can do that, but I think it's an empirically sound approach to call you uninformed on this matter, to say the least.

nope.

What makes you think that would be a good way to get grants, anyway? Seriously dishonest people can make a quick buck more easily than by getting doctorates in geophysics and geochemistry and gaming the grants process. Why would someone smart enough and dishonest enough to lie in this way even bother? I'm not saying it never happens, but you are saying it inevitably happens.

You also obvously don't understand how the grants process works, but that's a long story,

I'm not claiming the granting process doesn't distort science; that is an inevitable cost of doing things outside the private sector, and like anything public it requires eternal vigilance. Still, outright fraud of the sort you would like to believe in is rare because it just isn't worth the trouble.

To make matters worse for your point of view, you have to accuse the entire scientific community of complicity for your belief to make sense. The National Academy of Sciences, the American Association for the Advancement of Science, the American Geophysical Union and the American Meteorological Society are not unanimously corrupt on behalf of a small segment of their membership. They wouldn't put the whole scientific enterprise at risk for some superstitious hippie idea.

You need to reconsider who has the preconceived ideas here.

Please refer to the second graph here.

That's quite a spike we see in the last century. Yes, a lot of it was before the 1940's, but another big increase is in the last 20 years. Meanwhile, the last few centuries before this one show much less change.

Please don't say "1 degree is irrelevant". The difference between where we are now and an ice age is about eight degrees.

Another thought: Corporate America has a clear interest in convincing you that global warming is a non-threat. If they succeed at this, they earn more money. On the other hand, environmentalists have no such interest in convincing you of their side. They will not receive more money. In fact, in terms of money, they will probably end up worse-off, due to the economic damage their policies will create. Yet, they persist in arguing their case.

Who do you trust?