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And please stop cherry-picking data to suit your predetermined conclusions, it insults both of our intelligences.

Fair enough. But let's also be clear that this: "is widely regarded by scientists as one of the most robust reviews of any scientific question in the history of mankind" means nothing. All the matters is the data.

Anyway I've been reading through the IPCC report. It is dense, but enlightening. So a few things:

It is true that over 2,500 people helped with the report, but that doesn't mean they all agreed with the conclusion. All it means is that they wrote a paragraph in there somewhere. The number who worked on deriving conclusions from that report are much smaller.

The major points everyone seems to agree on is that the world has gotten warmer recently (ie, that the measured temperature is accurate) and that adding CO2 to the atmosphere will have a net warming effect. It is not 100% certain that human pollution is warming the earth. It could be cooling it (figure 2.20 from WG1). The major difference from the last report is that we are more certain than ever that human pollution will have a net warming effect.

It is not clear how much effect CO2 is affecting the global temperature. Is most of the recent warming because of natural variation, or is it because of anthropogenic greenhouse gasses? Page 39 of the link you provided says it is very likely that most of it is due to greenhouse gasses (but they have a qualifying footnote, what the hell is that?). What is this very likely conclusion based on? If you look at WGI 9.4[warning: big PDF], they base it mainly on computer simulations. They basically say they can think of no other way to account for the warming other than anthropogenic greenhouse gasses. How much do you trust these climate modeling computers? Apparently the writers of the IPCC summary don't trust it, since they added a footnote. One thing you will never see is a graph that confidently shows how much of the earth's warming is caused by anthropogenic gasses, and how much is from other causes, because this information is not known with any degree of accuracy.

Let's move on to the next point, global disasters. At times you hear that global warming will destroy the earth. Once again, there is no scientific consensus about that. Where I live, the temperature changes as much as 20 degrees in a single day. What difference will a single degree make?

Or let's take a look at another point, rising sea levels. According to WGI chapter 5[warning: another big PDF], we are looking at an ocean rise of 3.1 millimeters or so. Is that really so bad? Even if we ignore the fact that tides vary hundreds of times that much within a single day, and waves often vary 300 times that much in a single second, it's worth remembering that the ocean level on any given coast already varies more than that based on geological processes, like plate tectonics. We have been able to handle plate tectonics so far, we should be able to handle the little added variability that may come with global warming.

Finally, I maintain that almost no one thinks the cap and trade bill in the US congress right now is a good idea. Except New York bankers (read this article, I don't know whether it should make me laugh or cry).

And please stop cherry-picking data to suit your predetermined conclusions, it insults both of our intelligences.

Fair enough. But let's also be clear that this: "is widely regarded by scientists as one of the most robust reviews of any scientific question in the history of mankind" means nothing. All the matters is the data.

Anyway I've been reading through the IPCC report. It is dense, but enlightening. So a few things:

It is true that over 2,500 people helped with the report, but that doesn't mean they all agreed with the conclusion. All it means is that they wrote a paragraph in there somewhere. The number who worked on deriving conclusions from that report are much smaller.

The major points everyone seems to agree on is that the world has gotten warmer recently (ie, that the measured temperature is accurate) and that adding CO2 to the atmosphere will have a net warming effect. It is not 100% certain that human pollution is warming the earth. It could be cooling it (figure 2.20 from WG1). The major difference from the last report is that we are more certain than ever that human pollution will have a net warming effect.

It is not clear how much effect CO2 is affecting the global temperature. Is most of the recent warming because of natural variation, or is it because of anthropogenic greenhouse gasses? Page 39 of the link you provided says it is very likely that most of it is due to greenhouse gasses (but they have a qualifying footnote, what the hell is that?). What is this very likely conclusion based on? If you look at WGI 9.4[warning: big PDF], they base it mainly on computer simulations. They basically say they can think of no other way to account for the warming other than anthropogenic greenhouse gasses. How much do you trust these climate modeling computers? Apparently the writers of the IPCC summary don't trust it, since they added a footnote. One thing you will never see is a graph that confidently shows how much of the earth's warming is caused by anthropogenic gasses, and how much is from other causes, because this information is not known with any degree of accuracy.

Let's move on to the next point, global disasters. At times you hear that global warming will destroy the earth. Once again, there is no scientific consensus about that. Where I live, the temperature changes as much as 20 degrees in a single day. What difference will a single degree make?

Or let's take a look at another point, rising sea levels. According to WGI chapter 5[warning: another big PDF], we are looking at an ocean rise of 3.1 millimeters or so. Is that really so bad? Even if we ignore the fact that tides vary hundreds of times that much within a single day, and waves often vary 300 times that much in a single second, it's worth remembering that the ocean level on any given coast already varies more than that based on geological processes, like plate tectonics. We have been able to handle plate tectonics so far, we should be able to handle the little added variability that may come with global warming.

Finally, I maintain that almost no one thinks the cap and trade bill in the US congress right now is a good idea. Except New York bankers (read this article, I don't know whether it should make me laugh or cry).

Look, what's the scientific consensus that we have?

Isn't all this predicated on whether man-made (anthro-something) Global Warming is real or not?

Not really..
if population growth is exponential, and we live in a closed system (spaceship earth) with only energy input (sunlight), then we are *GUARANTEED* to run into some kind of resource limit at one point because our bodies need food:
Whether it's the end of cheap energy from hydrocarbons, the end of cheap energy for cheap Nitrogen fertilizer via the energy-intensive Haber-Bosch process for NH4 (I quote

"he Haber process is important because ammonia is difficult to produce on an industrial scale, and the fertilizer generated from the ammonia is responsible for sustaining one-third of the Earth's population."

, or the phosphate mines running out. Funnily enough, you never read about those things in the newspapers, instead you read about "economy" which doesn't, ultimately, exist. I say bring the discussion back to the real issues.
I don't think that anthropogenic global warming is really disputed anymore (will you please read chapter 2 of the AR4 synthesis report?). And I believe it has serious repercussions for food production (chapter 3), especially in Africa. (heat stress). Have you any idea how many Africans would emigrate if it becomes too hot for agriculture?
But really global warming is just an additional stress factor; if it didn't exist, some other stress factor would become more urgent for humanity's survival. Ultimately, an exponential process is .. well.. exponential, and people (voters) aren't schooled sufficiently to understand what that entails, otherwise we would already live in a very different society right now.

The mountains of research done on this is pretty clear about why
it's happening. But I don't expect facts to get in the way of beliefs
anytime soon. Be that as it may, why is not the important. The
important questions, and the ones the climate scientists spend a lot of
time working out, are how it's going to affect us and what we can do to
prepare for it.

There are no mountains of research that show why any climate change is
happening or even IF climate change is happening. Arctic ice cover has increased
every year since 2007, for example, while the AGW models pushed by the NSIDC and IPCC
don't allow for any such increase. Carbon dioxide is
routinely pushed by politicians as the cause of global warming and yet
it is a simple calculation to show that there is already more
than sufficient carbon dioxide in the atmosphere to absorb ALL of the
IR radiation radiating from Earth that is in the wavelength where it
can be absorbed by carbon dioxide... within the first few hundred
meters of the atmosphere. It is even easier to show
that gas-phase H2O in the atmosphere (commonly referred to as humidity)
is present in much higher concentrations in the atmosphere than CO2 and
is a far more potent 'greenhouse' gas than CO2...and yet the planet is
obviously still able to radiate sufficient heat to space in the
non-absorbable IR wavelengths to cool itself. Finally,
supposing for argument's sake that atmospheric carbon dioxide
concentration really was: 1) a problem and 2) correctable, why
would it be the 'climate scientist's' job (read IPCC and NSIDC) to tell
us how to prepare for it's impact? They seem even less qualified
for that job than they are for the investigation of global
warming.

I dislike the doom-laden 'climate change will wreck our environment' crowd for one key reason: they can't provide any evidence that I wouldn't prefer the climate after it has changed.

And neither can I, since I don't know your personal situation, or the climate forecasts for where you live. As to the idea that major global warming would be anything other than disastrous for most of humanity, the 976-page second chapter of the IPCC 4th assessment report deals with it fairly comprehensively. You might want to consider that, even if the weather becomes more to your liking in your particular location, you are tied to the global economy and will feel the impact of adaptation costs in other regions, in the form of things like higher prices for goods and higher taxes. Unless of course you're living a self-sufficient off-grid lifestyle, in which case congratulations, you're probably part of the solution!

Well then here: IPCC FAQ for your perusal. Not the whole report, mind you, seeing as I'm sure that you don't have the time or patience to sort through the information. I'm guessing that you're referring to CBS as being the "obviously politically motivated" party here? You don't actually say, so I have to assume this.

I wish I had mod points - this needs modding up!

I don't doubt the anthropogenic basis for climate change - you can take a look at the IPCC Synthesis Report for a persuasive outline of the case. However, once you get past the most basic assertions, the scientific community is doing an absolutely terrible job. Most of the time when I read a paper on climate change I can immediately spot lots of methodological and deductive errors, and, conveniently, they always come out in favour of anthropogenic climate change. Some argue that science is just another religion. This isn't true. However, the sort of 'science' most climate scientists are doing nowadays may as well be a religion, basing conclusions on manifestly insufficient data, and inferring causation based on correlation alone. Right now the climate sceptics don't need to make straw men to argue against - the scientific community is making the straw men for them.

Scientists shouldn't be arguing against sceptics - scientists should be the sceptics. Even ignoring faulty reasoning, many published scientific results are wrong (see this article). Scientists should be constantly questioning results to try to arrive at a refined, unbiased analysis of the facts - instead we have become defensive, treating every sceptical inquiry as an attack, and as a result, the research doesn't get the sort of scrutiny necessary to advance our understanding. Something needs to change.

Don't link to realclimate.org; its heavily partisan and apologetic for even bad science and outlandish claims.

Maybe, but in this case they have science on their side. See section 2.3.1 from the IPCC Working Group I report. For example, page 139:

Measurements of both the 13C/12C ratio in atmospheric CO2 and atmospheric O2 levels are valuable tools used to determine the distribution of fossil-fuel derived CO2 among the active carbon reservoirs, as discussed in Section 7.3. In Figure 2.3, recent measurements in both hemispheres are shown to emphasize the strong linkages between atmospheric CO2 increases, O2 decreases, fossil fuel consumption and the 13C/12C ratio of atmospheric CO2.

Please take a look at the IPCC Fourth Assessment Report (AR4)

On page 4 of the 'summary for policy makers', the graph shows that CO2 is the most significant human produced contributor to radiative forcing.

I am no expert but I find this report trustworthy and therefore think that CO2 is a pretty good thing to focus on. Dog ownership is another question!

Or maybe you could re-read my point that the natural carbon cycle is a closed cycle. That means any CO2 emitted by respiration and decomposition was very recently absorbed from the air as the plant grew. So it doesn't change the overall concentration of CO2 in the atmosphere. Another independent line of evidence is that the isotopes in vegetative CO2 don't match the current isotopes of CO2 in the atmosphere. The CO2 in fossil fuels, on the other hand, has been locked underground for millions of years and has the same isotope ratios as the CO2 in the atmosphere.

Make no mistake; the current skyrocketing CO2 concentration is due to human emissions.

It's a better idea to get your science from scientists rather than politicians. The CO2 emissions by living organisms are part of a closed cycle, and those isotopes don't match the composition of the atmospheric CO2 that's currently ~26% higher than it's been in the last 650,000 years. Other sources such as volcanoes emit 100x less than humans do. Also, water vapor isn't relevant because it has a short lifetime in the atmosphere and isn't well-mixed to the top of the atmosphere. I've discussed all these issues at length.

Lets assume you are correct. Who's to say a warmer earth is bad?

On the whole, a warmer earth may be better for humans than an earth colder by an equivalent amount. However, the problem is that global temperatures have been relatively stable for the last 10,000 years, and human civilization has adapted to that temperature range. Move too far out of it in either direction, too quickly, and there will be costs. People can't just easily shift their agricultural production or settlement patterns into neighboring countries.

It wasn't long ago we were told we were heading in to a new ice age.

Not really.

Climate cycles actually suggest we are (were) heading down that path. Wouldn't we WANT to warm the earth?

Over tens of thousands of years, we might head into another ice age. If you're so concerned about that, you should argue that we should save our fossil fuels for later, when we'll need them, instead of using them all up now, when we don't.

Ice age aside, wouldn't an increased crop growth durations help battle famine?

Depends on where you are. In the mid-latitudes, you tend to get small benefits for 1-2 degrees C warming. The tropics suffer. For more than 3 C of warming, everybody tends to suffer. On top of that, you have to account for the fact that precipitation patterns change, and many agricultural regions may suffer drought.

Lets study the impact

Uh, yeah, people have studied impacts.

rather than demand we do stuff that will destroy not just the developed worlds economy, but potentially starve millions when the industrial world can no longer afford to produce food and medicine on the current scale.

Nobody is interested in "destroying the economy". That's the conservative alarmist version of "the planet will burn up". Just ask economists, e.g. here.

Citation needed

Sure.

Interesting. That's not a citation, merely a pointer to an organisation whose mandate it is to report on climate change. From your link:

The preparation of the AR5 pursues the overall mandate of the Panel, the main activity of which is to prepare at regular intervals of five to seven years comprehensive assessment reports about climate change.

If this were mandate by Bush & Co., /.ers would be all over it, pointing out, and rightfully so, that an organisation whose mandate it is to report on something necessarily has a vested interest in it, because if the underlying item being reported on went away or proved fraudulent, then the organisation would also go away.

That said, the URL you point to doesn't actually have evidence itself, though another link on the same site might. As far as a citation for the above claim is concerned, this does not qualify. Please try again, though.

Citation needed

Sure.

Oops. The 35x faster link referred to CO2, not temperature. My bad.

Chapter 3 of the 4th IPCC report says temperatures in the last ~30 years have increased faster than at any point in the last ~1000 years, a rate which is steadily increasing.

This isn't nearly as impressive as the anomaly in the CO2 record compared to the last several million years of proxy data. But Meehl 2004 shows that the warming since ~1970 is primarily caused by anthropogenic emissions, and they used models that are consistent with a climate sensitivity having a maximum likelihood value of 2.9C, with a 95% confidence that it's less than 4.9C but greater than 1.7C.

Oops. The 35x faster link referred to CO2, not temperature. My bad.

Chapter 3 of the 4th IPCC report says temperatures in the last ~30 years have increased faster than at any point in the last ~1000 years, a rate which is steadily increasing.

This isn't nearly as impressive as the anomaly in the CO2 record compared to the last several million years of proxy data. But Meehl 2004 shows that the warming since ~1970 is primarily caused by anthropogenic emissions, and they used models that are consistent with a climate sensitivity having a maximum likelihood value of 2.9C, with a 95% confidence that it's less than 4.9C but greater than 1.7C.

Oops. The 35x faster link referred to CO2, not temperature. My bad.

Chapter 3 of the 4th IPCC report says temperatures in the last ~30 years have increased faster than at any point in the last ~1000 years, a rate which is steadily increasing.

This isn't nearly as impressive as the anomaly in the CO2 record compared to the last several million years of proxy data. But Meehl 2004 shows that the warming since ~1970 is primarily caused by anthropogenic emissions, and they used models that are consistent with a climate sensitivity having a maximum likelihood value of 2.9C, with a 95% confidence that it's less than 4.9C but greater than 1.7C.

However, its a question whether the climate reacts to warming by positive feedback, and if so how strongly, or by negative feedback.

There's a debate about how much positive feedback exists, but the case for negative feedback is very weak. For example, events such as Heinrich and Dansgaard-Oeschger events are the best examples of abrupt climate change in the paleoclimate record. These ancient events are worrying because they show the climate has a propensity to shift quickly from one state to another, given even small forcings. That requires positive feedback.

Also, the estimated magnitude of the Milankovitch cycles and other forcings are insufficient to account for the temperature variations observed in ice cores from Vostok and EPICA. This requires positive feedback. In fact, the estimates of positive feedback are too small to bridge the gap.

The decisive evidence for feedback would be if the climate were now genuinely warming faster than or differently from ever before.

Approximately 35x faster, which isn't surprising because of the unprecedented (in the last 2 million years) CO2 levels. Also, the warming is happening after the CO2 increase, which makes this warming qualitatively different from all previous deglaciations.

And this is where the question of the refusal of the climate science community to reveal their data becomes important.

Proxy data are available, Wahl and Ammann have made their code available, the CMIP3 database makes model output public for researchers to perform comparisons, etc. I've previously complained about the (widespread) tendency of scientists to keep their data private to wring every last discovery out of it before making it public. It's worrying, but not a problem unique to climatology. Nor ar all climatologists so hesitant to release their code and data. I publish all my code under the GPLv3, for instance.

Duh!

http://www.ipcc.ch/

Working group 3, chapter 4, page 283. Nice graph.

... But we care SO MUCH about a prediction that at our current use something which will kill off life on this planet in hundreds of thousands of years? ... before anything "bad" happens as a result of any man-made climate problems (even if they are true -- though largely unproven), they, their children, and children's great great grandchildren will be all dead and gone. ...

I got tired of repeating myself on Slashdot, so I wrote an article showing that abrupt climate change is a matter of serious concern. Climate change is already have negative effects, and they'll get worse over the next century. Hundreds of thousands of years is wishful thinking according to the best scientific evidence available today.

... "Cap and Trade" is not a constructive tax -- it is destructive. We have technologies other than coal and oil to produce energy ...

I've directly addressed cap and trade, which seems like a very constructive, capitalistic approach that will jumpstart a new industrial revolution. My hope is that the United States invests heavily in nuclear fission technology, preferably using waste reprocessing and newer designs like pebble bed reactors.

... It's just the next buzz-word in politics: "omgs, it might destroy human life on the earth in a few hundred years in a worst case scenario!!" ...

As I've stressed, the existence of abrupt climate change is a scientific topic. It's a good idea to ignore politicians and their ridiculous claims, and focus on the science.

and natural CO2 production is 20x mans ... but it damn well won't stop the "consensus" train. The only good thing about N2O is that its not something you can tax the population over, at least directly. Can't wait to see who the N2O bogeymen are going to be.

I got tired of repeating myself on Slashdot, so I wrote an article showing that abrupt climate change is a matter of serious concern. There seem to be an endless number of internet ninjas promoting claims like this, despite the fact that CO2 hasn't risen above 300ppm in the last 650,000 years. But then we come along and the concentration skyrockets to 380ppm in a matter of decades, which is 35x faster than any increase in the last 650,000 years.

As other posters have remarked, natural CO2 production and absorption aren't relevant to the current CO2 problem because they balance each other. Our emissions and volcanoes are the only sources of CO2 that aren't balanced, and humans emit 100x more CO2 than volcanoes.

What evidence?

The scientific articles referenced all over this article, which is what the whole issue is about... and with all due respect you still haven't said exactly which point I've made that you think is wrong.

Certainly no evidence of consensus.

As I said in a comment: First of all, I've repeatedly stressed that science isn't democratic, so I don't give "consensus" any weight. For example, I once said "... I don't see how the popularity of an idea has anything to do with its veracity."

And later: "Uniformity of opinion is neither expected nor desired. Consensus is irrelevant; evidence is all that matters."

So if you have some credible evidence, please let me know.

Does the phrase "cherry picking" mean anything to you?

Where- exactly- in the article did I do that?

A peripheral observation: the earth's climate is a complex adaptive system. I know of no computer model that takes this into account.

A good place to start is chapter 8 of the IPCC report. I've also previously discussed this general issue.

That's why they can't predict the past, much less the future.

Hindcast validations are one of the standard ways to validate dynamical climate models. They've been tested against instrumental records and proxy data like borehole measurements, tree rings and ice cores. The eruption of Mt. Pinatubo showed that climate models can predict climate response very accurately.

Even if they did, the best they could produce is probabilities with wide multimodal distributions. They'd be useless for decision making.

Yes, the error bars are large, but the separation between the future scenarios is larger still. The models are plenty good enough to see that we need a new industrial revolution, or risk further damaging the climate.

What evidence?

The scientific articles referenced all over this article, which is what the whole issue is about... and with all due respect you still haven't said exactly which point I've made that you think is wrong.

Certainly no evidence of consensus.

As I said in a comment: First of all, I've repeatedly stressed that science isn't democratic, so I don't give "consensus" any weight. For example, I once said "... I don't see how the popularity of an idea has anything to do with its veracity."

And later: "Uniformity of opinion is neither expected nor desired. Consensus is irrelevant; evidence is all that matters."

So if you have some credible evidence, please let me know.

Does the phrase "cherry picking" mean anything to you?

Where- exactly- in the article did I do that?

A peripheral observation: the earth's climate is a complex adaptive system. I know of no computer model that takes this into account.

A good place to start is chapter 8 of the IPCC report. I've also previously discussed this general issue.

That's why they can't predict the past, much less the future.

Hindcast validations are one of the standard ways to validate dynamical climate models. They've been tested against instrumental records and proxy data like borehole measurements, tree rings and ice cores. The eruption of Mt. Pinatubo showed that climate models can predict climate response very accurately.

Even if they did, the best they could produce is probabilities with wide multimodal distributions. They'd be useless for decision making.

Yes, the error bars are large, but the separation between the future scenarios is larger still. The models are plenty good enough to see that we need a new industrial revolution, or risk further damaging the climate.

Earth cooled a degree last year ...

As I've explained, ENSO events are irrelevant to the long term climate.

Satellite images show arctic ice cap growing the last three years ...

In the same link as above, I referenced this paper titled "Arctic sea ice decline: faster than forecast."

... lack of sunspots is pointing to a scary minimum.

Again in the same link, I explain that this means the Sun is unusually dim, which (if anything) would tend to cool the Earth slightly.

The CO2 increase contributes to less than a than 1/2 of a percent increase in green house gasses ...

As I explain in the fifth paragraph of that article, CO2 has jumped 26% above the highest value it's reached in the last 650,000 years. And this staggering increase occurred in the span of several decades due to human emissions, which is 35x faster than at any point in the last 400,000 years.

... (do not exclude the largest green house gas, water vapor)

As I've explained, water vapor reaches equilibrium in a matter of weeks, so we can't change its concentration except by changing Earth's average temperature. Water vapor is also not present in the top level of the atmosphere where the greenhouse effect is most important. CO2, on the other hand, is well-mixed even to the highest level of the atmosphere, and it stays in the atmosphere for many decades which is why it's so dangerous.

Now, you are not trying to tell me that the tuning of adjustable numerical parameters, grid size, time steps, simplifications, linearisation techniques, and choosing of unknown physical parameters in the simplified mathematical models are not of the utmost importance, are you?

No, just that these parameterizations are only performed for the mean climate, and shouldn't change over a timespan measured in decades. Over geological time shifting continents and increasing solar brightness will matter, but not from the period 1900 to 2010.

The validations I have seen for those models (single curve fitting over small period) are not convincing enough, too much local errors for such a model to be reliable imho.

I presume you're referring to the model validations via the Pinatubo eruption. There are other validations, chief among them being comparisons to proxy data which extends over hundreds of thousands of years. Initial conditions ensembles are taken to average out the weather, and models with completely different parameterizations are averaged in a bigger ensemble to produce the IPCC results (see chapter 8).

It would be nice if someone who has evidence of global warming would actually produce it instead of just saying because I am a scientist and smarter than you.

Here you are.

Clean, as in: do you know how much greenhouse gases are emitted when getting uranium/plutonium out of the ground and processed to be able to use it in a nuclear reactor?

I do. See for example the IPCC 4th assessment report, working group 3, chapter 4 "Energy Supply". In particular 4.3.2 pp. 269-270 "Nuclear Power", and also the summary graph Figure 4.19 on page 283, which compares the lifecycle CO2 emissions per unit energy of different primary sources.

In short, considering the entire energy cycle, nuclear power has comparable CO2 emissions to wind, hydro, and solar power, and actually appears rather cleaner than the latter two.

This isn't surprising at all, when you consider the extreme energy density of nuclear fission. Annual uranium mining is on the scale of merely tens of thousands of tons / year, contrasted for instance with coal which is billions of tons - a tiny fraction. The scale is ridiculously small, and correspondingly so are the environmental impacts.

This all comes with a non-obvious disclaimer, that these lifecycle CO2 emissions are only valid in the present context, that most electricity and all transportation are still fossil-fuel powered. Nuclear only emits CO2 at all because there is not enough of it yet, and so the steel mills are powered by coal, and the transport trucks by oil. When we transition to clean energy and electric vehicles or clean synfuels, NONE of the clean energy sources will have ANY lifecycle CO2 emissions at all, and the debate will be moot. (Well, there are two exceptions - inputs of concrete, whose manufacture necessarily emits CO2, in the reduction of CaCO3 -> CaO + CO2, and with hydropower (see the same IPCC chapter, 4.3.3.1, p. 273-4), which emits the GHG methane from anaerobic decomposition of plant matter that is flooded when reservoirs are filled.))

Oh one more thing - plutonium isn't extracted from the ground, it is synthetic, created by nuclear transmutation. One neutron capture U-238 + n -> U-239, followed by two spontaneous beta-decays (neutron turns to proton, emits electron and antineutrino), U-239 -> Np-239 -> Pu-239.

Therefore, the statement in AR4 that "It is more likely than not (>50%) that there has been some human contribution to the increases in hurricane intensity." is likely an exaggeration, not supported by the actual research.

Months ago, I was careful to say that hurricane intensity can't be linked to climate change, and that a quick look at the IPCC guidance note on uncertainty indicates that this statement is essentially the weakest statement they could make without being utterly silent. (See table 4.) In fact, I later corrected another poster who was under the impression that a clear correlation between hurricanes and climate change was in the data.

If the IPCC report had used any other qualifier from table 4, you might have a more convincing point. Furthermore, another paper in Science says "Results show that the increasing trend in number of category 4 and 5 hurricanes for the period 1970-2004 is directly linked to the trend in SST [sea surface temperature]." Dr. Landsea is a legitimate scientist, but he's not the only one studying hurricanes, and I fail to see how his claims automatically rule out those of other scientists-- especially when they're making such an weak claim given the observed trends.

And, yes, those "natural forcings" include variations in solar output, which can be measured by satellites at L1 so there's no need to search for weak correlations in sunspot data.

Please be specific. "Solar output" can mean many things.

I was quoting Meehl 2004 in that sentence, which itself quotes Meehl 2003 to show that variations in solar luminosity affect the climate. Of course, Meehl 2004 shows that this effect isn't responsible for the warming in the latter half od the century, which is shown to be due to anthropogenic CO2 emissions.

Previously, you cited luminosity data when I had clearly stated that the correlation was with period length, not luminosity.

That's because, as you now seem to agree, other correlations have been disproven by later research. I was just trying to steer you back towards the only correlation that's well-established in the peer-reviewed literature.

But the main problem with this sort of approach is that some kind of mechanism other than variations in luminosity would be needed to support your thesis. For example, in this post you claim "The sunspot activity tends to blow away the solar winds, allowing more radiation to get through to Earth's surface."

This is indeed a claim made in a real journal. But it's far more controversial than you're implying. The maximum impact of this mechanism has been estimated to be responsible for no more than 23% of the 11-year cyclical variation of cloud cover. Furthermore, there's no long term trend in Svensmark's data, which would be necessary to explain the long-term warming trend that's been observed. For more information, see chapter 7.10 of

Mon Dieu! Quantity != quality. You'd get a lot more respect if you'd simply link to one or two legitimate, peer-reviewed articles instead of dozens of pseudo-scientific websites. I don't have time to relieve you of your many misconceptions, but here are the most glaring errors:

On the contrary, if you had watched those YouTube videos I linked to...

We're scientists, not preteen girls looking for cat videos. Link to peer-reviewed articles or expect to be ignored.

Anthropogenic CO2 is the cause of a small, but measurable, increase in average global temperature. This temperature increase is a detectable deviation away from the statistical variations due to natural causes, and is now quite well understood."

That is the most ridiculous thing I have heard to date. It is NOT known, precisely because it has been impossible to statistically separate it from other influencing factors. (Including sunspots!) While many scientists believe that it probably has some effect, nobody has yet managed to measure it with any real statistical significance. Where did you get this idea, anyway? Do you have any sources that purport to have this measurement? The fact is that such a beast does not exist!

Geoffrey's statement is most certainly not ridiculous. I suggest looking at the IPCC 4th report. Download chapter 3, open the PDF to page 15 (which is labeled 249) and look at figure 3.6. The trend obtained from the data in figure 3.6 is 0.65 C plus or minus 0.2 C over the period from 1901 to 2005. The report notes that this rate is higher than at any other point since the 11th century. Meehl 2004 shows that this warming can't be explained by natural forcings alone, but including anthropogenic CO2 emissions matches the observations very well. And, yes, those "natural forcings" include variations in solar output, which can be measured by satellites at L1 so there's no need to search for weak correlations in sunspot data.

Furthermore, as I've repeatedly argued, Vostok shows that the current CO2 level is higher than it's been in half a million years. If you don't think that CO2 can warm the planet, I suggest you remember your sophomore-level physics classes and examine the spectrum of the sun. Then open a textbook and examine the absorption spectrum of CO2. Notice that the peak of the sun's radiation goes through? Now open your thermodynamics textbook and calculate the blackbody radiation of a planet at 286K. Notice that the CO2 absorbs more of this radiation.

That's why scientists say that CO2 is warming the planet. It's not exactly cutting-edge science.

Most of the science that is used to support the greenhouse warming model come from the IPCC Assessment reports, and much of that "science" has been shown to be flawed, not to mention that the reports themselves are heavily politicized, and their conclusions do not match the actual science that they reference.

That's exactly backwards. The IPCC reports are simply compilations of pre-existing, peer-reviewed science. I've read their reports and talked with scientists whose work is referenced in the IPCC reports. No scientist I've met (in public or private) thinks your conspiracy theory is valid. In fact, I've personally confirmed the mass loss in Greenland's glaciers with my own research. I've seen climate change happening with my own data and my own personal algorithms. Does that mean I'm part of the conspiracy too?

Below I link to a letter from Chris Landsea, who is the one who actually did the research on wh

Mon Dieu! Quantity != quality. You'd get a lot more respect if you'd simply link to one or two legitimate, peer-reviewed articles instead of dozens of pseudo-scientific websites. I don't have time to relieve you of your many misconceptions, but here are the most glaring errors:

On the contrary, if you had watched those YouTube videos I linked to...

We're scientists, not preteen girls looking for cat videos. Link to peer-reviewed articles or expect to be ignored.

Anthropogenic CO2 is the cause of a small, but measurable, increase in average global temperature. This temperature increase is a detectable deviation away from the statistical variations due to natural causes, and is now quite well understood."

That is the most ridiculous thing I have heard to date. It is NOT known, precisely because it has been impossible to statistically separate it from other influencing factors. (Including sunspots!) While many scientists believe that it probably has some effect, nobody has yet managed to measure it with any real statistical significance. Where did you get this idea, anyway? Do you have any sources that purport to have this measurement? The fact is that such a beast does not exist!

Geoffrey's statement is most certainly not ridiculous. I suggest looking at the IPCC 4th report. Download chapter 3, open the PDF to page 15 (which is labeled 249) and look at figure 3.6. The trend obtained from the data in figure 3.6 is 0.65 C plus or minus 0.2 C over the period from 1901 to 2005. The report notes that this rate is higher than at any other point since the 11th century. Meehl 2004 shows that this warming can't be explained by natural forcings alone, but including anthropogenic CO2 emissions matches the observations very well. And, yes, those "natural forcings" include variations in solar output, which can be measured by satellites at L1 so there's no need to search for weak correlations in sunspot data.

Furthermore, as I've repeatedly argued, Vostok shows that the current CO2 level is higher than it's been in half a million years. If you don't think that CO2 can warm the planet, I suggest you remember your sophomore-level physics classes and examine the spectrum of the sun. Then open a textbook and examine the absorption spectrum of CO2. Notice that the peak of the sun's radiation goes through? Now open your thermodynamics textbook and calculate the blackbody radiation of a planet at 286K. Notice that the CO2 absorbs more of this radiation.

That's why scientists say that CO2 is warming the planet. It's not exactly cutting-edge science.

Most of the science that is used to support the greenhouse warming model come from the IPCC Assessment reports, and much of that "science" has been shown to be flawed, not to mention that the reports themselves are heavily politicized, and their conclusions do not match the actual science that they reference.

That's exactly backwards. The IPCC reports are simply compilations of pre-existing, peer-reviewed science. I've read their reports and talked with scientists whose work is referenced in the IPCC reports. No scientist I've met (in public or private) thinks your conspiracy theory is valid. In fact, I've personally confirmed the mass loss in Greenland's glaciers with my own research. I've seen climate change happening with my own data and my own personal algorithms. Does that mean I'm part of the conspiracy too?

Below I link to a letter from Chris Landsea, who is the one who actually did the research on wh

As that saying goes: there is no "disagree" button, and troll, off-topic, and overrated are not substitutes.

Or maybe climate is a complex beast and if you want you can probably find a paper to support your position. Therefore to truly understand you need to know the majority of the subject and its recent findings. Please read chapter 2 pages 188-192
Here is a general paper on the subject.
Of course I don't really expect you will be swayed.

A) There isn't, that is media driven.

To be fair to the mas-media they just reprint the lobbyists press-releases because conflict makes a good story and the psuedo-skeptics keep inventing new names for their think tanks but most of them can be tracked back to the Heartland Institute. If you remeber the "tabacco scientists" from the 80's you will recognise some of the names (eg: Fred Singer). They are nothing more than proffesional lobbyists in lab coats. That is not to say there are no arguments about the finer details but the idea our emmission can warm the Earth is now over a century old and the National academies of science first warned the US government that it was happening in the 50's.

Yes peer-review is imperfect but I challenge you to find one paper in a reputable journal such as Science or Nature that disputes the much maligned "consesus". As you can see there are nearly 40,000 papers in just those two prestigious journals alone. I realise that's an unfair challenge because it's a daunting task and since the IPCC have already done it I'm pretty sure you won't find anything. I would prefer genuine skeptics (and I think you may be one), read what the editors of (say) Nature think about the problem, talk to some IPCC scientists and look at thier reports.

I also agree it's true that it's possible to be paid by a FF company and still do honest science, however I ask you to be skeptical of people such as Carter who disagree with mainstream science, can't get a paper published on the subject and are paid by think tanks because, those traits put the in the same boat as young earth creationists. I also ask genuine skeptics to do a bit of their own geeky mythbusting before posting psuedo-skeptical drivel to slashdot as anything other than an example of anti-science.

B) The "gap" in opinions exists because one side is driven by lobbyists, the other by science. I agree it's a complex subject and I admit that without some background it can appear to be a simple case of experts who can't agree on basic answers. However that's exactly what the psuedo-skeptics want you to think in order to delay any action that would upset their sponsers. They are a cynical bunch of pricks who know they have lost the science argument, they just want to drag it out as long as it's possible to be paid to do so.

Here is just one example of that kind of political dishonesty.

"We're all going to look back 50 years from now and probably laugh at BOTH sides as more or less equally flawed."

In 50yrs I will either by getting a telegram from the Queen or be dead but I think in the next decade the coal industry are in for the same treatment the tabacoo companies recieved in the 90's. What this proponent of emmission control is saying is let's slow down this uncontrolled experiment on our biosphere and carefully examine how we can replace (or clean up) coal and let's do it with a free market based approach such as cap and trade rather than just another useless tax that allows the rich to pump out as much pollution as they can pay for while the rest of us suffer.

Disclaimer: Politically I describe myself as a "fiscally conservative, science based greenie" but I have not been interested enough to vote since 1978. OTOH I have followed the scientific and political arguments over AGW for almost three decades now and became convinced we have a serious problem when the IPCC released their 1997 resports, I have never seen Gore's movie simply because I knew

I really appreciate you passing this along. I plan on reading this.

Cheers.

One note: Would the Intergovernmental Panel on Climate Change be the best place to look for evidence of if climate change exists, on the scale we're talking about, and whether CO2 affects this process and by how much? I would expect they would assume an outcome to justify their entire existence.

The best place to look would be on an academic abstracting and citation service. Going this way, however, would require a lot of time and effort. The IPCC Working Group 1, reports are the most convenient place to look. When I was reading Science, being the lazy sod that I am, I'd always look for review articles (if only to locate relevant primary articles). You can think of the IPCC Assement Reports as review papers on steriods.

As such they must ultimately cite published work from recognised peer-reviewed journals. The idea of using the Executive Summary of this technical paper is that the numbers in the brackets direct you to relevant areas of the paper, which in turn direct you to the published work. It's turtles all the way down.

If you don't want to spend that much time, but want somewhat more detail than is contained in the cited summary, you could consult the Summary for Policy Makers and/or the Technical Summary in the last AR4 WG1 Report. These will also link to the relevant parts of the report and in turn to the published work.

The name alone implies a huge conflict of interest. Yet, I don't think in this politically charged atmosphere we are going to find anything but politically patronized studies.

Well IPCC was set up around 1990 to evaluate the emerging science on the issue so the name should not surprise. It is good to be sceptical of sources, and of course once you have more than 2 people in a room you'll get politics. But Science, at least, has established a set of epistemological rules which eventually (though it may take decades) seem particularly suited to establishing "truth" in the face of such politics. Particularly in a highly contested field, as this was at one time, an eventual consensus ought to give you some faith in the results. You can expect the Working Group on Mitigation to be far more ideologically contested.

And when you think about it, if they were merely trying to justify their existence their line would be "much uncertainty still remains ... more funding is needed."

If you you of any good place to read some papers of the causal links. I'd like something to read and bookmark for future uses.

If you don't have access to an academic library, or the electronic resources thereof, that may not be easy.

I think anyone can access the ISI Search Page (An ISI listing of a journal is perhaps the best guarantee of its repute, and will steer you clear of "phish-journals") And perhaps even the abstracts (sorry it's hard for me to tell, I'm working at a uni) Accessing the actual articles though is another matter. But search away and see what you get.

I really appreciate you passing this along. I plan on reading this.

Cheers.

One note: Would the Intergovernmental Panel on Climate Change be the best place to look for evidence of if climate change exists, on the scale we're talking about, and whether CO2 affects this process and by how much? I would expect they would assume an outcome to justify their entire existence.

The best place to look would be on an academic abstracting and citation service. Going this way, however, would require a lot of time and effort. The IPCC Working Group 1, reports are the most convenient place to look. When I was reading Science, being the lazy sod that I am, I'd always look for review articles (if only to locate relevant primary articles). You can think of the IPCC Assement Reports as review papers on steriods.

As such they must ultimately cite published work from recognised peer-reviewed journals. The idea of using the Executive Summary of this technical paper is that the numbers in the brackets direct you to relevant areas of the paper, which in turn direct you to the published work. It's turtles all the way down.

If you don't want to spend that much time, but want somewhat more detail than is contained in the cited summary, you could consult the Summary for Policy Makers and/or the Technical Summary in the last AR4 WG1 Report. These will also link to the relevant parts of the report and in turn to the published work.

The name alone implies a huge conflict of interest. Yet, I don't think in this politically charged atmosphere we are going to find anything but politically patronized studies.

Well IPCC was set up around 1990 to evaluate the emerging science on the issue so the name should not surprise. It is good to be sceptical of sources, and of course once you have more than 2 people in a room you'll get politics. But Science, at least, has established a set of epistemological rules which eventually (though it may take decades) seem particularly suited to establishing "truth" in the face of such politics. Particularly in a highly contested field, as this was at one time, an eventual consensus ought to give you some faith in the results. You can expect the Working Group on Mitigation to be far more ideologically contested.

And when you think about it, if they were merely trying to justify their existence their line would be "much uncertainty still remains ... more funding is needed."

If you you of any good place to read some papers of the causal links. I'd like something to read and bookmark for future uses.

If you don't have access to an academic library, or the electronic resources thereof, that may not be easy.

I think anyone can access the ISI Search Page (An ISI listing of a journal is perhaps the best guarantee of its repute, and will steer you clear of "phish-journals") And perhaps even the abstracts (sorry it's hard for me to tell, I'm working at a uni) Accessing the actual articles though is another matter. But search away and see what you get.

I really appreciate you passing this along. I plan on reading this.

Cheers.

One note: Would the Intergovernmental Panel on Climate Change be the best place to look for evidence of if climate change exists, on the scale we're talking about, and whether CO2 affects this process and by how much? I would expect they would assume an outcome to justify their entire existence.

The best place to look would be on an academic abstracting and citation service. Going this way, however, would require a lot of time and effort. The IPCC Working Group 1, reports are the most convenient place to look. When I was reading Science, being the lazy sod that I am, I'd always look for review articles (if only to locate relevant primary articles). You can think of the IPCC Assement Reports as review papers on steriods.

As such they must ultimately cite published work from recognised peer-reviewed journals. The idea of using the Executive Summary of this technical paper is that the numbers in the brackets direct you to relevant areas of the paper, which in turn direct you to the published work. It's turtles all the way down.

If you don't want to spend that much time, but want somewhat more detail than is contained in the cited summary, you could consult the Summary for Policy Makers and/or the Technical Summary in the last AR4 WG1 Report. These will also link to the relevant parts of the report and in turn to the published work.

The name alone implies a huge conflict of interest. Yet, I don't think in this politically charged atmosphere we are going to find anything but politically patronized studies.

Well IPCC was set up around 1990 to evaluate the emerging science on the issue so the name should not surprise. It is good to be sceptical of sources, and of course once you have more than 2 people in a room you'll get politics. But Science, at least, has established a set of epistemological rules which eventually (though it may take decades) seem particularly suited to establishing "truth" in the face of such politics. Particularly in a highly contested field, as this was at one time, an eventual consensus ought to give you some faith in the results. You can expect the Working Group on Mitigation to be far more ideologically contested.

And when you think about it, if they were merely trying to justify their existence their line would be "much uncertainty still remains ... more funding is needed."

If you you of any good place to read some papers of the causal links. I'd like something to read and bookmark for future uses.

If you don't have access to an academic library, or the electronic resources thereof, that may not be easy.

I think anyone can access the ISI Search Page (An ISI listing of a journal is perhaps the best guarantee of its repute, and will steer you clear of "phish-journals") And perhaps even the abstracts (sorry it's hard for me to tell, I'm working at a uni) Accessing the actual articles though is another matter. But search away and see what you get.

I just visited that website and reviewed all PDFs in their Glossary. Not once does it explicitly define CO2 as a pollutant.

I doubt that you will find CO2 explicitly "defined" as a pollutant anywhere on their site. You are more likely to find that in a legal context where an Act needs to define what is and what is not a 'pollutant' for purposes of said Act. What you will find is the current (well slightly behind now) science surrounding the effects etc. of CO2 and other GH forcing agents on the climate system. These effects are clearly deliterious. If you want to play semantic games, you might want to argue that merely being environmentally damaging doesn't make something a pollutant, but that would run perilously close to argument by definition. I think we all understand how the terms 'pollutant' and 'emissions' are being used in this discussion.

Please point me to a portion of their site that does, because I cannot find it

I'm pointing you in the direction of the Executive Summary, because, semantics aside, that is the quickest way to get a handle on the substantive issue.

I just find this notion that CO2 is a pollutant quite absurd.

I assure you, that is a problem just a little honest self-education will fix. You could start here: Fourth Assessment Report. It is difficult to find any other area of science where so much authoritative information has been so conveniently assembled. You can read just the executive summary or conveniently delve into the specifics of any area you choose. Really, on this issue ignorance is unforgivable. As is reliance on non-credible sources of pseudo-scientific disinformation.

Because it's not so much as science as it is indoctrination by statist regimes usurping power and control.

Or you can wallow in ignorance, self-delusion based on your particular ideological predilcctions. That's a choice you alone can make. Look, I'm no enemy of freedom or proponent of over-governance, far from it, but the Science here really does speak for itself.

Climate models show a steep increase of temperature at the north pole and flat or even slight cooling at the south pole. I have never understood the reason that the poles are different in this regard. These results are no surprise to the IPCC, more sea ice at the North pole would really be surprising. The projections for the future showing high warming at the north pole and less at the south can be found at the bottom of the summary for policy makers; http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-spm.pdf The IPCC physical science report showing a high probability of short-term warming at the south pole http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter3.pdf

Climate models show a steep increase of temperature at the north pole and flat or even slight cooling at the south pole. I have never understood the reason that the poles are different in this regard. These results are no surprise to the IPCC, more sea ice at the North pole would really be surprising. The projections for the future showing high warming at the north pole and less at the south can be found at the bottom of the summary for policy makers; http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-spm.pdf The IPCC physical science report showing a high probability of short-term warming at the south pole http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter3.pdf

Yep, sample size matters. I agree we needed the sattelite that's now at the bottom of the southern ocean. However we don't need it to be sure our CO2 is a problem, we already have satellites such as MOPITT, GOME, OMI, TES to measure atmospheric gasses/areosols and their distributions, there are at least two gravity probes that yeild data on ice loss plus information that is vital for modeling ocean currents. Add to that highly sensitive altimiters for, snow depth, sea level, etc plus all the run of the mill weather satellites and we have a sizeable armarda of sattelites collecting evidence from space.

There are also litterally millions of sensors spread across the globe in various networks bobbing about in and under the sea, on land, on glaciers, in rivers, in aircraft, weather ballons, rooftops, submarines, ocean liners, etc, we started building and maintaining this massive data set in earnest about 150yrs ago when physicists argued over wether the sun was made of coal or not. Then you have paleotologists who look at dust and gas trapped in ice cores, tree rings, the tickness of sea shells, isotopes in microsopic samples, pollen distribution, the independent lines of evidence are vast and go all the way back to Fourier in the 1820's. To seriously debunk the claim that AGW is the major factor in the observed warming requires extrodinary evidence that is currently only noticable by it's absence.

What we needed the OCO satellite for was to more acurately pinpoint the major changes in emmision sites (NO2 is also a GHG as is Methane). If an international treaty is to be effective this type of data is essential and the more acurate the more certainty there is for business in a future carbon market. If the treaty includes land use issues such as tree planting, highly accurate data will be needed to audit those claims and monitor this experiment we call the industrial revolution.

Personally without such data I think the planting of trees for carbon credits is of dubious value to fixing AGW and ripe for corruption. Trees are valuable in their own right, far better if a farmer got a credit when he plows biochar into the ground. Making and burrying biochar is an efficient carbon negative process that can run on raw sewarge and other waste organic matter, not only does it's sequester the carbon for 1000yrs but will also fertilize the soil and reduce the need for oil based fertilizers. However, even on a massive scale, biochar alone is not enough to counter our current emmissions.

If you haven't read the IPCC reports the best place to start skimming is here, the reports go back nearly two decades and it's interesting to read some of the older ones and compare their warnings to recent events. These people are certainly not infallible but nothing is, they represent the world's scientific institutions and IMHO getting that many experts to agree virtually gaurentees their statements will be qualified, conservative, and backed by a mountain of evidence.

You mean this data? ... Or this one?

Interestingly, I posted another reply to your parent comment that also included those links. Except, I linked to the main page. I was referring to the figures above the one you directly linked to. Figures A2 and A show the Global Annual Mean Surface Air Temperature Change, measured using two different data sets. Uncertainty is indicated by the green bars. Notice the trend in both figures.

The graph you're talking about from 1880 onwards is from this paper, where they specifically state that the warming in the U.S. is known to be smaller than the rest of the world. The reasons for this are not (to my knowledge) completely understood. But the rest of the world have had temperature sensors too, and we've had satellites up for decades which provide the basis for the statement that global temperatures are increasing faster than temperatures in the U.S.

In my opinion, any evidence based on "global temperature" that includes data from more than just recent years should be viewed with scepticism, because our worldwide measurement and calculation techniques have changed dramatically, which likely skews the results in one direction or another.

Figure A (linked to above) is based on this article, which describes adjusting for inhomogeneities in station records and station history adjustments. Sensibly integrating differing datasets is an irritating task, and it's an ongoing process. But it doesn't seem to be a problem climate scientists are ignoring- the techniques for dealing with non-uniform noise characteristics for different data sets are well known.

Furthermore, we don't just have to rely on mechanical recording devices. Tree rings, coral growth rates, borehole measurements and ice core proxies can be used to independently verify the temperature record. They agree to within the limits of experimental uncertainty.

NASA presents data on mean global temperature extending from today back to 1880 as a single line graph with no error bars, which is ridiculous.

Yes, the particular graphs you linked to on that page aren't very detailed. Instead, I suggest the IPCC 4th report. Download chapter 3, open the PDF to page 15 (which is labeled 249) and look at figure 3.6. It includes 5-95% error bars. The trend obtained from the data in figure 3.6 is 0.65 C plus or minus 0.2 C over the period from 1901 to 2005. The report notes that this rate is higher than at any other point since the 11th century.

My point is that arriving at a "mean global temperature" is a very difficult calculation to make.

I wholeheartedly agree. I think scientists should be careful to state the estimated uncertainty in all their statements, and abrupt climate change is no exception. It's just that the error bars are now small enough to rule out the hypotheses "climate change isn't happening" and "climate change is largely natural."

Just out of curiosity, would you say that the IPCC reports are conservative in their pronouncements due to the inherent difficulty of getting that many experts to agree on the claims they publish in their reports?

Absolutely. Their error bars are quite large, indicating the uncertainty of the data. All their language is defined at the beginning of the report: words such as "likely" and "very likely" are given precise meanings based on normal distributions. They've avoided making any strong statements about climate change affecting hurricanes (for good reason, IMHO.)

Since so many people here think that they're Nobel Prize worthy, I'm sure it won't be hard for those who want to brush me off for not linking to a source to find exactly what I'm talking about.

No. I brush you off because I've got links to Nobel Prize winners and the results of studies of other world-renowned scientists available. You, on the other hand, are doing some handwaving about the little ice age, which is only tangentially related to the current issue of Global Warming. You seem to take yourself far more seriously than you even accuse the rest of Slashdot to be.

Most scientists agree that humans have contributed a small change to the climate, but all agree that the majority of the change is due to natural cycles (solar, long term atmospheric fluctuations etc). The only people claiming that humans are the sole or majority cause of climate warming/change are involved in politics, vote gathering, and selling 'technology' concepts to 'save the planet' in order to bilk the public out of money.

I am a climate scientist. I've never been in politics and I've never sold anything (professional student here). I also think you're completely wrong. My experiences at the 2008 Fall Meeting of the American Geophysical Union are that most (9/10) of the scientists I met agree with the IPCC report on abrupt climate change.

But you've made an even more fundamental mistake. Science isn't democratic-- it's about evidence. Open up the IPCC reports yourself and focus on what's really important, instead of trying to count how many people are on each side.

For example, Vostok ice core data confirms that for nearly half a million years, the climate has changed cyclically. But in all that time, the maximum CO2 concentration never went above 300 ppm. (It's hit higher levels millions of years ago, but that was a slow and gradual change. Plus the Earth was essentially a different planet back then, with a different solar luminosity and biosphere so comparisons across that much time are tricky.)

You're right to say that natural variations are evident in the data, but the most prominent cycles over geological time are governed by (among other effects) Milankovitch cycles which are caused by periodic variations in the earth's orbit.

But, CO2 concentrations are at 380 ppm today. That's a level it hasn't hit in the last half million years. If we're seeing natural variability alone, it's quite a coincidence that it occurs right when we started excavating fossil fuels to fuel a billion cars.

Plus, the Vostok data is a little difficult to analyze in this manner, but it seems like at Vostok the CO2 always increased 600 years AFTER the temperature started to increase. At least, that's the way it used to work. Right now, the CO2 concentration is at an unprecedented level but the temperature is barely above normal. Again, that suggests that we're not facing natural climate change, we're dealing with anthropogenic abrupt climate change.

"In other words, the IPCC picks and chooses the data that will push the agenda of its supporting members (Kyoto, for example) and backs up the UNFCCC."

Yes it informs the UNFCCC, how many nations in the UNFCCC? I'll leave that as an exercise but the IPCC has 300 odd memeber nations, look it up in the financial records available by searching for "budget" on their site (it's a research method called the original source). Yes, there are a handfull of nations that do not CONTRIBUTE but that has fuck all to do with kyoto. The IPCC is a "state of the science" report written by thousands of scientists using thousands of peer-reviewed papers as input, the papers must be at least a year old so that scientists have time to digest them and see any counter arguments. It's nothing less than a giant fucking textbook that is 2yrs out of date when published. The improbability of getting that many experts to agree on anything virtually dictates that the reports will be scientifically conservative.

In other words it's one of the largest, longest running, and most rigorous, peer-review excercises ever undertaken.

Now before you troll me again with politics we have to agree there is a problem, if you disagree there is a problem then I need to see some extrodinary scientific evidence that one or more of the three basic claims in "the consensus" is either false or exagerated. Since I have been following this shit for 25+yrs I think you will have a hard time but if I didn't look at contra-evidence then I wouldn't be a skeptic would I?

And please, I'm not interested in dragging around red-herrings, give me something orginal, all you have done so far is played the part of the shop keeper in monty python's dead parrot sketch.

As I said before, there is no point in discussing the politics of the issue if you refuse to accept the scientific evidence in favour of your dogmatic belief that (all?) science is agenda driven. Your insistence that it's some sort of conspiracy indicates you have not reasoned yourself into your position. Experience tells me it's unlikely I can reason you out of it since you're the only one who can question your own political dogma with any effectiveness (re: sig below).

You will never understand the problem by analysing the politics but you can often understand the politics by analysing the problem.

This nerd with a lame hat will set you straight, no politics, plain english and way more information that you want. Go to the "no holds barred #1" clip if you want to see a good rundown of where I'm coming from with the IPCC.

One more thing. Your statement that it's closed to non-kyoto nations is bullshit, there are a truckload of scientists and organisation from the US (a non-kyoto nation), including but not limited to NAS, NAAS, NASA, NOAA. Do you even know what the letters WMO stand for?

The evalutation for the models can be sarcastically summed up as "they do a pretty good job with the 20th century":

http://www.grida.no/publications/other/ipcc_tar/?src=/climate/ipcc_tar/wg1/309.htm
http://www.grida.no/publications/other/ipcc_tar/?src=/climate/ipcc_tar/wg1/336.htm

(a later edition of the report is available here:

http://www.ipcc.ch/ipccreports/ar4-wg1.htm

but only as pdf, I am talking about Chapter 8; skimming it a little bit indicates that the above statement continues to hold.)

I'm not qualified enough to pretend to have an opinion on the accuracy of the reports or the likelihood of significant anthropogenic climate change, but I get an uneasy feeling when I compare the apparent confidence of the scientists and the apparent confidence of a lot of advocates.

As a climate scientist, I've seen that shift in wording too. I think it was largely a PR move, designed to combat fundamental misconceptions that laymen have regarding "Abrupt Climate Change" (the officially accepted title).

1. Most people don't understand the difference between weather (purely local phenomena, hard to predict because it requires extremely complex vector-valued numerical models of the motion of the atmosphere) and climate (purely global phenomenon, easier to predict because it just requires summing energy input and subtracting energy output). They stuck the word "climate" in there to emphasize that today's cold temperatures in Joe Schmoe's town don't "disprove" climate change.
2. Global warming is a little simplistic. A more accurate description is that our addition of greenhouse gasses has reduced the volume of energy leaving the planet while leaving the energy input constant. As a result, the average energy in the atmosphere is increasing, which allows the system to "explore more of its phase space". More energy means more opportunities for extreme weather- even weather that involves colder temperatures! (Again, note that weather is local.)
3. The word "abrupt" was added to emphasize that what we're experiencing isn't a natural process. The ice core from Vostok shows that CO2 hasn't risen above 300 ppm in the last half million years. It's at 380 ppm now, which is almost certainly due to human activities. This rapid increase hasn't happened in the hundreds of thousands of years over which we have records. The consequences aren't likely to be pretty. Hence, "abrupt".

I'm embarrassed to admit it, but climate change has me pretty scared. I might live to see some of the effects (drought, famine, extreme weather) and I wonder if my life will be as comfortable as my parents was. I used to assume that advancing technology would make my life much better, and I'm just now coming to grips with the possibility that it won't.

But what really scares me is the ostrich-like manner with which people react to the problem. They seem to be in denial, which is understandable. Scientists aren't bringing good news, so it's natural to be resentful. But I figured that some deep survival mechanism would kick in eventually as people looked at the rigorous nature of the modeling, the diverse data sets all leading to the same conclusions, and the myriad positive feedback effects that makes climate change accelerate on its own.

Instead, people seem to react as though the existence of climate change is somehow a political question rather than a scientific question. They don't seem to be looking at that evidence. Instead, they seem to decide that their political party's position on climate change is "X", so they believe "X". (Note that I'm talking about the existence of anthropogenic abrupt climate change. I realize that our response to climate change is a legitimate political question.)

Solar forcing remains the same as in the SAR, in terms of best estimate, the uncertainty range and the confidence level. Thus, the range is 0.1 to 0.5 Wm-2 with a best estimate of 0.3 Wm-2, and with a very low Level Of Scientific Understanding .

Don't believe me? Here's their link
So don't mind me if I don't take all these "it can't be the sun" arguments very seriously.

RealClimate, and their FAQs as well, are accessible to a motivated person (it's easier if you've got some sort of grasp of science and "how she is spoke", of course.)

Many workers in the field have published books for the general reader; again, RC has some good pointers. Finally, the IPCC assessment reports are reasonably accessible (the summaries in particular.)

Now, you could say that getting into this level of research is a non-trivial thing to do, and you'd be right. There's jargon and shorthands for concepts and acronyms that mean little to the outsider. Climate is also, fundamentally, a very complicated phenomena; work in the field covers a multitude of specialist disciplines, an understanding of statistical methods, chemistry, biology, emergent phenomena, atmospheric physics, paleoclimatology (ice and sediment cores and the like), and so on and so forth. Fair enough, if you don't want to put that amount of effort in, you get to *take their word for it*.