Glad you enjoyed the posts. To address the points you made in your post…

Regarding the sunspot cycle, it's actually been a while since the last maximum, and we have in fact just started a new cycle (January this year). Furthermore, since around 1950 there has been no systematic trend in galactic cosmic ray or solar activity that can explain global warming, and obviously it is difficult to suggest a causation when there isn't even a correlation (to be clear, that is not to say that there is no impact from variations, just that it cannot explain the magnitude of recent changes):

http://www.agu.org/pubs/crossref/2005/2005GL023621.shtml

Regarding CO2 lag, as previously noted, the glacial-interglacial relationship between temperature and CO2 is not disputed (broadly speaking, an 800 year temperature increase, followed by CO2 release which amplifies warming thereafter). The issue is, it simply isn't relevant to the current increase in CO2, the cause is known, and it has led the temperature increase in the latest warming, it did not lag temperature as was the case with the glacial-interglacial cycles over geologic time.

As for the hockey stick graph; the claims that it would yield a hockey stick shape irrespective of the data are quite simply false. The claims originally made by McIntyre and McKitrick were rejected by Nature, and an article that can be found in the realclimate archives (dated 4 December 2004 – and titled 'False claims by…") clearly demonstrates that such a claim is false.

Furthermore, as previously noted, the 'hockey stick' graph has been independently replicated, so even if it was wildly wrong (and it isn't), separate reconstructions exist with the same hockey stick shape (an incomplete list…. Jones et al., 1998; Crowley and Lowery, 2000; Gerber et al., 2002; Bauer et al., 2003; Briffa et al., 2001; Esper et al., 2002). Clearly repeatable, and verifiable.

Regarding the CO2 figures, your numbers are a bit out. Annual anthropogenic CO2 emissions are now estimated to be over 9 billion tons (and increasing), not 600 million, with total emissions since the industrial revolution increasing the amount of carbon in the atmosphere by about 35%. When talking about greenhouse gases in relation to the entire atmospheric mass, it is important to remember that all greenhouse gases make up a very small fraction of the atmosphere, and yet in the absence of anthropogenic forcing produce the sizable natural greenhouse effect.

As covered in previous posts, without anthropogenic influence, the present balance of natural CO2 sources and natural CO2 sinks is approximately zero, so the many billions of tons of CO2 emitted naturally are also absorbed into ocean and biomass sinks, the anthropogenic emissions are overhead (a little under half of human emissions are absorbed), and entirely responsible for the atmospheric increase of CO2 we are presently seeing.

I hope that helps.

Wow, so you're deciding that I'm not allowed to refer to the prime consensus document representing the peer reviewed research of thousands of working climate scientists when discussing the state of the climate. That's a little like saying I can't reference the peer reviewed literature on evolution when discussing common descent.

Although it is clear to me that absolutely no amount of evidence will change your predetermined view (it really is incredible that you think the carbon isotope ratios don't demonstrate that humans are the source of CO2 increases – it couldn't be anymore clear; it isn't a trivial statement saying 'fossil fuel driven carbon emissions are being added to the atmosphere', it's a statement about how much of the additional CO2 in the atmosphere comes from human activities, and, again, it's ALL of it), I think I will just add a few brief comments about other claims you've made, and leave it at that, because anything further is clearly pointless.

1) IPCC FAR is a 2007 document, and my earlier references are not invalidated by their date.

2) The original 'hockey stick' graph is now an entire hockey team of multiple, independent replications that are consistent with the original graph. The McIntyre and McKitrick criticism of the original hockey stick graph was shown to be invalid by Wahl and Ammann, as noted in IPCC FAR.

3) 'Little Ice Age' and 'Medieval Warm Period'… see Chapter 6 of IPCC FAR (the IPCC's criticism is over how useful they are).

> Now you've yet to show me that CO2 isn't being emitted more than it's being asorbed

I assume you are referring to natural emissions here, and I will stand by my earlier references, the evidence is not invalidated because you don't like the source (a source which seems to include all of the thousands of working climate scientists that agree that humans are driving climate change).

You use the worse card in the deck to illustrate your point on CO2 sinks, the IPCC report! It is that card in this house of cards which is bringing the whole house down!

Did you know that it was the IPCC that insisted that ice core data proves global warming was man caused? And that the science on ice core data shows that the the ice isn't a closed system and that the CO2 in the samples represented higher concentrations of greenhouse gasses than the IPCC published? This is simple science, but the IPCC published what it needed and ignored the truth.

It's simple science the IPCC chose to ignore, like the infamous hocky stick graph that was considered the smoking gun for man caused global warming, which has been exercised from the 2007 report. When it banished the Medeivil Warm Period and the Little Ice Age (both matters of historical record), people knew something was up, but the IPCC published it anyways. The IPCC report summary is even drawn up before the actual science is done for Pete's sake!!

You can't hold up the source of the science we are questioning and say that it proves itself!! That's faith, not science – ask any good Christian about faith and holy books!!

I'm a global warming heritic and have been likened to a holocaust denier! That sounds like issues of faith to me, not science.

Now back to the science. As I've said previously, there should be lots of CO2 with the carbon isotope for fossil fuels in the air. It's NOT getting absorbed because even natural CO2 isn't getting absorbed.

Let's go back to farting in an auditorium. If for 50 years people sat in that auditorium and farted every day, you would measure the impact of these foul gasses. The percent of CO2 with the the same carbon isotope as farts would be higher due to the accumulation over the years.

Now vent the auditorium on a periodic basis in a manner to emulate CO2 sinks. Would you still be able to find evidence of the farts in the air in the auditorium?

Yes, but not as much. Vent less, more fart gas presence detected. Vent more, less fart gas.

What about natural CO2? It would be the same as fart CO2, more or less depending on the venting.

Now you've yet to show me that CO2 isn't being emitted more than it's being asorbed, I've certainly posted links to the science I'm speaking of, and the references are more recent than the ones you posted (2007 vs 2004).

I missed a response in my last post, regarding your statement about ocean/atmospheric CO2 flux…

> So with the largest natural sink for CO2 currently emitting, how can natural CO2 emissions possibly equalize to 0?

Once again, you are quite wrong in this statement. The ocean (and land) remains a net sink for atmospheric CO2, though ocean uptake appears to be reduce slightly, specifically:

Atmospheric increase: 3.2PgC/yr
Emissions: 6.3PgC/yr
Ocean/atmosphere -1.7PgC/yr
Land/atmosphere -1.4PgC/yr

These figures are from the IPCC TAR, which can be found at:

http://www.grida.no/climate/ipcc_tar/wg1/097.htm#fig31

(Table 3.1 at the bottom of the page)

The IPCC FAR doesn't provide such an explicit breakdown (at least not that I could find anyway), but does note that

"The natural sinks of carbon produce a small net uptake of CO2 of approximately 3.3 GtC yr–1 over the last 15 years, partially offsetting the human-caused emissions. Were it not for the natural sinks taking up nearly half the human-produced CO2 over the past 15 years, atmospheric concentrations would have grown even more dramatically."

This can be found on page 511 of the report.

> So what you are saying is that natural CO2 sinks selectively reject CO2 gas…

Given that I said this

"The human emissions are pure overhead, and are mostly (though not entirely) unabsorbed by natural sinks."

you know full well that, that is not what I said (note the bit in brackets), and it is extremely disingenuous of you to suggest that I said otherwise. There is a limit to what the natural sinks can absorb over a given period of time (along with the risk that they then become sources as they reach capacity), and human emissions go beyond that limit, hence why atmospheric CO2 is increasing.

You really seem to be struggling with the concept that the excess CO2 in the atmosphere can be attributed to humans, it is absolutely NOT coming from natural sources – quoting the ice core lag is completely pointless when the carbon isotopes from recent increases aren't consistent with natural emission, and when the CO2 increase over the last couple of hundred years clearly LEADS temperature increases.

If you want to claim that the increase in CO2 over the last 200 or so years is not entirely due to human activities, then you need to come up with a credible explanation of a natural mechanism that emits CO2 with a signature entirely consistent with fossil fuel burning.

> PS- these comments aren't moderated, feel free to post any link you want!

If you post a comment with multiple links in it, it gets moderated.

BTW to answer that one question I posed earlier:

> Why is it so important that man be responsible for this warming trend?

I'm giving you a link to read:

http://www.larouchepub.com/eiw/public/2007/2007_10-19/2007-11/pdf/38_711_science.pdf

So what you are saying is that natural CO2 sinks selectively reject CO2 gas that is the result of burning fossil fuels (you'll say 'No, no.. that's not what I meant!!", but it was what you said!)? And that something about history changed in the past few hundred years that makes the physics of climate change different now than it was then (there again, it is what you said)?

BTW- it is impossible for the natural sinks of CO2 to be absorbing as much as they are releasing. The single biggest sink on the planet is the oceans, and as temperatures rise they emit more and more CO2, and as temperatures fall they absorb CO2. There is a delay from the time a warming period starts before we start seeing the rise in CO2, which is happening now. So with the largest natural sink for CO2 currently emitting, how can natural CO2 emissions possibly equalize to 0? They aren't in the real world, but this CAN happen in computer models. That's a house of cards and the foundation cards simply don't support the rest of the house…

And I would say that I've hit nail on the head of the right questions to ask! Any money spent on 'man made' global warming is money wasted, except for those getting the funding. Hey somebody's got to pay for college, even for the kids of scientists and politicians!

PS- these comments aren't moderated, feel free to post any link you want!

> Well Said JamesB

The Earth Science budget is being increased by only $32 million this year. For perspective, ISS is costing an extra $476 million, and Space and Flight Support is coming in at an additional $218 million.

http://www.nasa.gov/pdf/168652main_NASA_FY08_Budget_Request.pdf

Well Said JamesB

You seem to have misunderstood the point I was making about the difference between geologic time and historical time. Geologic time covers pre-history, and this is where the ice core record comes in, which does show CO2 lagging temperature – the ice core record is part of mainstream climate science (who do you think goes to the trouble of getting the ice cores and doing the research???):

http://icebubbles.ucsd.edu/Publications/CaillonTermIII.pdf

When I refer to the FACT that CO2 leads temperature in historic time, I am referring to the recent (last couple of hundred, as opposed to 10s of thousands of years) increase (that's a standard distinction if you read through the peer reviewed literature).

> We SHOULD see a higher count of the CO2 isotope…
> Do we have more CO2 in the air than could be
> expected… NO, because…

Again, wrong. The careful measurements of the ratios of carbon isotopes are what allow determination of where the excess CO2 is coming from… the change in the ratios tells us that ALL of the additional CO2 in the atmosphere is from fossil fuel burning, not just some of it. Furthermore, whilst the total CO2 emitted by humans is just a fraction of a percent of that emitted naturally, it is irrelevant, because nature's CO2 sources are offset by nature's CO2 sinks, which currently results in a near zero net impact. The human emissions are pure overhead, and are mostly (though not entirely) unabsorbed by natural sinks.

> But we don't see the troposphere abnormally warming, now do we?

If I post another link this will get stuck in moderation, but go to the NASA GISS publications web site and search for "Amplification of Surface Temperature Trends and Variability in the Tropical Atmosphere" by Santer at al, 2005.

> Why is it so important that man be responsible for this warming trend?

You're asking the wrong question; the important issue is that people realise that humans ARE responsible for the recent rapid increase in global mean temperature, and that we take steps to reduce our dependence on fossil fuels to avoid making the problem even worse that it is already likely to become.

http://www.universetoday.com/2008/05/01/ocean-currents-may-cool-the-climate-for-a-decade/

wow, a 1° C rise in temperature every 50 years. Can't everyone just lay off and let science run its course without all the fear mongering?! I think we have a little bit of time to coolly sit back and think this one through. I keep on reading news arcticles about studies that were done and the data shows massive global warming, then a few weeks later the study is shown to be flawed by the way they calibrated the data, etc etc

Jeez, it's just science dude, take it easy. No one will be pissing on camp fires in the name of Earth any time soon. :/

Show me the studies that back you up on this 'acknowledged by mainstream climate science' claim.

The ice core record IS historical data! Please refrain from clouding the issue by trying to change the impact of the data when it doesn't support your argument!

The actual atmosphere of any particular time period is captured as a part of the ice core record and we know by where it's located in the core samples what actually made up the atmosphere at that time.

There is NO guess work involved – this is simply fact, down and dirty. Take a time 10,000 years ago, we know exactly what the mean temperature was AND how much CO2 was in the air and so on, back hundreds of thousands of years.

It's not supposition and it's not some esoteric timescale, the record is what it is. And it says that CO2 follows temperature on a ~800 year lag.

It's simple physics that a warming period 1000 years ago would result in higher CO2 now. Most science is intuitive, those who say it isn't are simply trying to get funding or hiding their ignorance, or both…

We SHOULD see a higher count of the CO2 isotope connected to the burning of fossil fuels, because we ARE burning fossil fuels and have been for a while. There's never been a question about that, the majority of the 20th century was an industrial age.

Do we have more CO2 in the air than could be expected at this point in history? That's the question.

The answer is NO, because even though man is a contributer to the overall CO2 content of the air, our relative contribution is roughly the same as farting in an auditorium.

Sure it's funny to make bodily noises, but the overall balance of gasses in the air of the auditorium remain virtually unchanged. Sure it may smell a little funny in the seats next to yours for a few minutes, but has that methane and CO2 substantially changed the air's ability in that room to produce ANY meaningful change in its environment?

No.

Now let's entertain for a moment the erroneous idea that the CO2 content is disproportionally large. What effect would that have?

If greenhouse warming were occurring, the first place we would see it is in the troposphere where the sun's radiation is actually being trapped by the greenhouse effect. It would heat up much faster than the ground would that is far below it.

But we don't see the troposphere abnormally warming, now do we?

And that's 2 smoking guns shooting down global warming as being caused by human activity:

1. Increases in temperature historically precede increases in CO2 by ~800 years, which was tested by actually examining samples of historic atmospheres in the ice core records. When the temperature rises, then CO2 rises, not the other way around despite what the Oscar and Nobel committees might have ordained! We should be seeing rises in CO2 because of the Medieval warming period 1000 years ago.

2. If greenhouse gasses were causing this warming the troposphere would warm first, which isn't happening. This is verified by both satellites and weather balloon data independently.

I could go on with several other holes in this theory, but you should ask yourself this one question:

Why is it so important that man be responsible for this warming trend?

Maybe you should ask this question too:

Who benefits the most from global warming being a man made disaster?

A couple of problems with what you say. First, the 800 year lag issue…. the records you refer to are on glacial-interglacial timescales, not historic timescales; it is acknowledged by mainstream climate science that on these very long timescales the temperature increase leads the CO2 increase by about 800 years (600-1000 years), but as the total warming takes about 5,000 years, this only shows that CO2 didn't cause the first 800 years of warming, it says nothing about the remaining 4,200 years.

On historic timescales, rather than glacial-interglacial, CO2 has definitely led, not lagged temperature. Incidentally, the temperature increase continued only until about the 1300s during the medieval warm period, so it isn't even a good analogy, because strictly speaking, the CO2 increase 'lagged' a 400-500 year fall in temperature since the medieval warm period (not exactly consistent with the ice core record you compare it to).

The second, and more important point, because it deals directly with CO2 source attribution… those carbon isotopes. If you read the article, then you should understand that CO2 released by burning fossil fuels has a different carbon isotope, and it is this fact that allows attribution of the increasing amount of CO2 in the atmosphere, and guess what, it's from humans burning fossil fuels, not from natural sources.

Interesting weblink. They do however fail to explain that one would expect a massive change in CO2 at about this time in history.

The ice core record of temperature vs. CO2 shows that CO2 follows temperature with about an 800 year lag (which is the opposite of what Al Gore said in his movie with that big 650,000 year graph, the statements he made have since been shown to be entirely wrong). Several studies of the ice core record have verified this.

Now there was a Medieval warm period what, 1000 year ago? So we SHOULD have started seeing a rise in CO2 in the atmosphere beginning somewhere in the last 200 years.

Guess what, we did.

Now how long did the Medieval warm period last? Hundreds of years. It's reasonable to expect to see the rise in CO2 continue past our lifetimes.

> No facts linking human activity to increased Co2 definitively.

Already been done:

http://www.realclimate.org/index.php?p=87

> Can someone tell me what the optimum level of
> CO2 in the atmosphere is, precisely? It's been
> far higher in pre-history, even 7000 ppm, and life
> thrived.

Life may well have thrived at 7000 ppm CO2 in the past, but it wasn't human life. Humans have spent most of their existence dealing with a climate based on CO2 levels of less than 300ppm (compared to the current ~380ppm); dramatically changing this in a short period of time is a bad idea.

Article says: All about impacts of warming, all datasets from 1970 onward. Assertion to be swallowed: impacts too severe to be anything other than AGW.

No facts linking human activity to increased Co2 definitively. This is reactionary, not scholarly work, aside from what may have been a look at datasets, I find the filtering of the 600,000 Lunar Prospector datasets on neutron detection, and how the noise of temperature and other factors were smoothed to get the snow out of the detections, far more interesting that anything by the Non-Skeptic Hansen, and anyone who isn't approaching all questions of science with skepticism isn't engaged in science.

I neither deny nor affirm AGW, I merely examine the data and not the policy implications.

Can someone tell me what the optimum level of CO2 in the atmosphere is, precisely? It's been far higher in pre-history, even 7000 ppm, and life thrived.

Also, C as a Greenhouse Gas has its effect in a logarithmic burden, needing 400 ppm to decrease infered albedo 0.01 degree K, while the base 400 ppm is needed to reach its full efficiency as a greenhouse agent, after which far more is needed to double that effect.

From the rest of the comments here, I can see a refreshing number of people who are drilling down past the headline to the source and the motivation.

Deforestation is a very real problem, but in the U.S. there are more trees now than in 1900.

A lot of questions are legitimately being raised about this issue, and it bewilders me how so many scientists dehumanize anyone who uses Anything that would question their methods and evidence.

What is driving this alarmism? I know many climate scientists who agree in warming, even AGW, but wouldn't dare try to advise a policy decision with chaotic unknowns, economically – things like starvation, not corporate profits.

The evidence is mounting of there being too many questions unanswered in this debate. The more we explore in every other area of science, the more questions are need answering… Why is Anthropomorphic Global Warming any different?

Cap and Trade? Reduction in consumption of oil is inevitable, as we've been reducing our Carbon to Hydrogen ratio for 170 years.

The present warming began prior to the Industrial age… CO2 increases FOLLOW global warming in Vice President Gore's 100000 year example – in all later examination of that same sampling, with better instrumentation.

Solar variability is .04 from minima to maxima, but solar modulation of GCRs is ~40 to 50 percent. Strong evidence is undeniably in place.

Science is a method of arriving at truth with scepticism, not consensus.