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The Big Picture (2010 version)

Posted on 24 September 2010 by dana1981

Note: this is the initial version of our Big Picture article published in 2010. As part of our Rebuttal Update Project, the article has been updated and republished with more current data in February 2023. You can access the current version here.

Oftentimes we get bogged down discussing one of the many pieces of evidence behind man-made global warming, and in the process we can't see the forest for the trees. It's important to every so often take a step back and see how all of those trees comprise the forest as a whole. Skeptical Science provides an invaluable resource for examining each individual piece of climate evidence, so let's make use of these individual pieces to see how they form the big picture.

The Earth is Warming

We know the planet is warming from surface temperature stations and satellites measuring the temperature of the Earth's surface and lower atmosphere. We also have various tools which have measured the warming of the Earth's oceans. Satellites have measured an energy imbalance at the top of the Earth's atmosphere. Glaciers, sea ice, and ice sheets are all receding. Sea levels are rising. Spring is arriving sooner each year.  There's simply no doubt - the planet is warming (Figure 1).

warming world

Figure 1: Indicators of a warming world

Global Warming Continues

And yes, the warming is continuing. The 2000s were hotter than the 1990s, which were hotter than the 1980s, which were hotter than the 1970s. 2010 tied for the hottest year on record.  The 12-month running average global temperature broke the record three times in 2010, according to NASA Goddard Institute for Space Studies (GISS) data.  Sea levels are still rising, ice is still receding, spring is still coming earlier, there's still a planetary energy imbalance, etc. etc.

Contrary to what some would like us to believe, the planet has not magically stopped warming.  Those who argue otherwise are confusing short-term noise with long-term global warming (Figure 2).

escalator

Figure 2: The data (green) are the average of the NASA GISS, NOAA NCDC, and HadCRUT4 monthly global surface temperature anomaly datasets from January 1970 through November 2012, with linear trends for the short time periods Jan 1970 to Oct 1977, Apr 1977 to Dec 1986, Sep 1987 to Nov 1996, Jun 1997 to Dec 2002, and Nov 2002 to Nov 2012 (blue), and also showing the far more reliable linear trend for the full time period (red).

Foster and Rahmstorf (2011) showed that when we filter out the short-term effects of the sun, volcanoes, and El Niño cycles, the underlying man-made global warming trend becomes even more clear (Figure 3).

before/after filtering

Figure 3: Temperature data (with a 12-month running average) before and after the short-term factor removal

For as much as atmospheric temperatures are rising, the amount of energy being absorbed by the planet is even more striking when one looks into the deep oceans  and the change in the global heat content (Figure 4).

global heat content

Figure 4: Total global heat content. Data from Nuccitelli et al. (2012)

Over 90% of global warming goes into heating the oceans.  When taking the heating of the entire climate system into account, the planet has warmed at a rate equivalent to 4 Hiroshima atomic bomb detonations per second over the past 15 years.

Humans are Increasing Atmospheric Greenhouse Gases

The amount of greenhouse gases in the atmosphere - particularly carbon dioxide (CO2) - has been rising steadily over the past 150 years.  There are a number of lines of evidence which clearly demonstrate that this increase is due to human activities, primarily burning fossil fuels.

The most direct of evidence involves simple accounting. Humans are currently emitting approximately 30 billion tons of CO2 per year, and the amount in the atmosphere is increasing by about 15 billion tons per year.  Our emissions have to go somewhere - half goes into the atmosphere, while the other half is absorbed by the oceans (which is causing another major problem - ocean acidification). 

We also know the atmospheric increase is from burning fossil fuels because of the isotopic signature of the carbon in the atmosphere.  Carbon comes in three different isotopes, and plants have a preference for the lighter isotopes.  So if the fraction of lighter carbon isotopes in the atmosphere is increasing, we know the increase is due to burning plants and fossil fuels, and that is what scientists observe. 

The fact that humans are responsible for the increase in atmospheric CO2 is settled science.  The evidence is clear-cut.

Human Greenhouse Gases are Causing Global Warming

There is overwhelming evidence that humans are the dominant cause of the recent global warming, mainly due to our greenhouse gas emissions. Based on fundamental physics and math, we can quantify the amount of warming human activity is causing, and verify that we're responsible for essentially all of the global warming over the past 3 decades.  The aforementioned Foster and Rahmstorf (2011) found a 0.16°C per decade warming trend since 1979 after filtering out the short-term noise. 

In fact we expect human greenhouse gas emissions to cause more warming than we've thus far seen, due to the thermal inertia of the oceans (the time it takes to heat them).  Human aerosol emissions are also offsetting a significant amount of the warming by causing global dimming.  Huber and Knutti (2011) found that human greenhouse gas emissions have caused 66% more global warming  than has been observed since the 1950s, because the cooling effect of human aerosol emissions have offset about 44% of that warming.  They found that overall, human effects are responsible for approximately 100% of the observed global warming over the past 60 years (Figure 5).

knutti breakdown

Figure 5: Contributions of individual forcing agents to the total change in the decadal average temperature for three time periods. Error bars denote the 5–95% uncertainty range. The grey shading shows the estimated 5–95% range for internal variability based on the CMIP3 climate models. Observations are shown as dashed lines.

There are also numerous 'fingerprints' which we would expect to see from an increased greenhouse effect (i.e. more warming at night, at higher latitudes, upper atmosphere cooling) that we have indeed observed (Figure 6).

prints

Figure 6: Observed 'fingperprints' of man-made global warming

Climate models have projected the ensuing global warming to a high level of accuracy, verifying that we have a good understanding of the fundamental physics behind climate change.

Sometimes people ask "what would it take to falsify the man-made global warming theory?". Well, basically it would require that our fundamental understanding of physics be wrong, because that's what the theory is based on.  This fundamental physics has been scrutinized through scientific experiments for decades to centuries.

The Warming will Continue

We also know that if we continue to emit large amounts of greenhouse gases, the planet will continue to warm. We know that the climate sensitivity to a doubling of atmospheric CO2 from the pre-industrial level of 280 parts per million by volume (ppmv) to 560 ppmv (we're currently at 390 ppmv) will cause 2–4.5°C of warming. And we're headed for 560 ppmv in the mid-to-late 21st century if we continue business-as-usual emissions.

The precise sensitivity of the climate to increasing CO2 is still fairly uncertain: 2–4.5°C is a fairly wide range of likely values.  However, even if we're lucky and the climate sensitivity is just 2°C for doubled atmospheric CO2, if we continue on our current emissions path, we will commit ourselves to that amount of warming (2°C above pre-industrial levels) within the next 75 years.

The Net Result will be Bad

There will be some positive results of this continued warming. For example, an open Northwest Passage, enhanced growth for some plants and improved agriculture at high latitudes (though this will require use of more fertilizers), etc. However, the negatives will almost certainly outweigh the positives, by a long shot. We're talking decreased biodiversity, water shortages, increasing heat waves (both in frequency and intensity), decreased crop yields due to these impacts, damage to infrastructure, displacement of millions of people, etc.

Arguments to the contrary are superficial

One thing I've found in reading skeptic criticisms of climate science is that they're consistently superficial. For example, the criticisms of James Hansen's 1988 global warming projections never go beyond "he was wrong," when in reality it's important to evaluate what caused the discrepancy between his projections and actual climate changes, and what we can learn from this. And those who argue that "it's the Sun" fail to comprehend that we understand the major mechanisms by which the Sun influences the global climate, and that they cannot explain the current global warming trend. And those who argue "it's just a natural cycle" can never seem to identify exactly which natural cycle can explain the current warming, nor can they explain how our understanding of the fundamental climate physics is wrong.

There are legitimate unresolved questions

Much ado is made out of the expression "the science is settled."  The science is settled in terms of knowing that the planet is warming rapidly, and that humans are the dominant cause.

There are certainly unresolved issues.  As noted above, there's a big difference between a 2°C and a 4.5°C warming for a doubling of atmospheric CO2, and it's an important question to resolve, because we need to know how fast the planet will warm in order to know how fast we need to reduce our greenhouse gas emissions. There are significant uncertainties in some feedbacks which play into this question. For example, will clouds act as a net positive feedback (by trapping more heat, causing more warming) or negative feedback (by reflecting more sunlight, causing a cooling effect) as the planet continues to warm?  And exactly how much global warming is being offset by human aerosol emissions?

These are the sorts of questions we should be debating, and the issues that many climate scientists are investigating. Unfortunately there is a very vocal contingent of people determined to continue arguing the resolved questions for which the science has already been settled. And when climate scientists are forced to respond to the constant propagation of misinformation on these settled issues, it just detracts from our investigation of the legitimate, unresolved, important questions.

Smart Risk Management Means Taking Action

People are usually very conservative when it comes to risk management.  Some of us buy fire insurance for our homes when the risk of a house fire is less than 1%, for example.  When it comes to important objects like cars and homes, we would rather be safe than sorry.

But there is arguably no more important object than the global climate.  We rely on the climate for our basic requirements, like having enough accessible food and water.  Prudent risk management in this case is clear.  The scientific evidence discussed above shows indisputably that there is a risk that we are headed towards very harmful climate change.  There are uncertainties as to how harmful the consequences will be, but uncertainty is not a valid reason for inaction.  There's very high uncertainty whether I'll ever be in a car accident, but it would be foolish of me not to prepare for that possibility by purchasing auto insurance.  Moreover, uncertainty cuts both ways, and it's just as likely that the consequences will be worse than we expect as it is that the consequences won't be very bad.

We Can Solve the Problem

The good news is that we have the tools we need to mitigate the risk posed by climate change.  A number of plans have been put forth to achieve the necessary greenhouse gas emissions cuts (i.e. here and here and here).  We already have all the technology we need.

Opponents often argue that mitigating global warming will hurt the economy, but the opposite is true.  Those who argue that reducing emissions will be too expensive ignore the costs of climate change - economic studies have consistently shown that mitigation is several times less costly than trying to adapt to climate change (Figure 7). 

Figure 7:  Approximate costs of climate action (green) and inaction (red) in 2100 and 2200. Sources: German Institute for Economic Research and Watkiss et al. 2005

This is why there is a consensus among economists with expertise in climate that we should put a price on carbon emissions (Figure 8).

should US reduce emissions

 

Figure 8: New York University survey results of economists with climate expertise when asked under what circumstances the USA should reduce its emissions

The Big Picture

The big picture is that we know the planet is warming, humans are causing it, there is a substantial risk to continuing on our current path, but we don't know exactly how large the risk is. However, uncertainty regarding the magnitude of the risk is not an excuse to ignore it. We also know that if we continue on a business-as-usual path, the risk of catastrophic consequences is very high.  In fact, the larger the uncertainty, the greater the potential for the exceptionally high risk scenario to become reality. We need to continue to decrease the uncertainty, but it's also critical to acknowledge what we know and what questions have been resolved, and that taking no action is not an option.  Th good news is that we know how to solve the problem, and that doing so will minimize the impact not only on the climate, but also on the economy.

The bottom line is that from every perspective - scientific, risk management, economic, etc. - there is no reason not to immeditately take serious action to mitigate climate change, and failing to do so would be exceptionally foolish.

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Comments 51 to 100 out of 221:

  1. 30C colder? Are you nuts? No frickin way. Wherever you got that from is crazy.
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  2. cruzn246 #46, the 'big drops' in Beck's chart are actually returns to more accurate results. The anomalous peaks exist only because he used fragmentary records rather than a consistent series. This wasn't a matter of taking regular readings at fixed sites. Callendar gathered any and all old historical measurements he could find and Beck re-used those same records. The difference is that when Callendar found anomalously high readings in individual years / particular areas he discarded them as corrupted data while Beck decided these were indicative of a global trend which somehow magically didn't appear in the other readings. Seriously, your continued insistence on treating Beck as anything but a bad joke is a classic example of why there is so much disdain for 'skeptics'... there is NOTHING skeptical about it. Ice core records, sediment proxies, modern CO2 monitoring stations all over the world, satellite readings, and basic logic ALL say that Beck's analysis is complete nonsense. Yet still you prefer the insane ramblings (and CO2 fluctuating +/- 100 ppm over the course of a mere decade IS insane) of a high school teacher to absolute and irrefutable scientific findings by hundreds of specialists in a half dozen different fields over the course of decades. As to how warm it would be without CO2. CO2 accounts for about 26% of the 33 C greenhouse warming. That yields about 8.6 C. However, if it were 8.6 C cooler there would also be less water vapor in the air... which would make it cooler still... which would mean more ice cover and thus a higher albedo... which would make it even colder. In short, we can't determine the precise value. However, it is safe to say that most of the planet would be a frozen ball of ice. Maybe a narrow 'temperate' zone around the equator.
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  3. I have replied to cruzn246 over on the more appropriate thread for further discussion: CO2 measurements are suspect.
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    Moderator Response: Good point.

    For continued wrangling over C02 measurement accuracy, go here: CO2 measurements are suspect

    To further discuss sensitivity: A detailed look at climate sensitivity

    If you're not familiar with the comments policy here and would like to know why comments swerving deeply into specialist topics will likely vanish after more appropriate threads are pointed out, see Comments Policy
  4. #46: "how do you all explain the big drops in the CO2 chart from Beck?" Easy. From a presentation (not published?) by Massen and Beck 2006: The historic measurements have horrible standard deviations. See Fig 10: 398+/-62 ppm, Fig 11: 327+/-23ppm, Fig 12: 339+/-33.
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  5. cruzn246 #50: "So why the heck can you never go anywhere in the temperature history and find one stinking time that temperature peaked after CO2 peaked?" More denialist fiction. There ARE cases where temperature peaked after CO2 did. For instance... now, various flood basalt incidents, the snowball Earth scenario ~650 million years ago, et cetera.
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  6. Re: cruzn246 (46), doug_bostrom (47) OK, I'll take my turn at the plow, Doug.
    "Can someone tell me how warm it would be if no CO2 was in the atmosphere?"
    To even ask this questions is telling as to your state of awareness of the science. But let's pretend you have honestly asked that question. Here's a quick, quasi-sciency answer:
    If an ideal thermally conductive blackbody was the same distance from the Sun as the Earth, it would have an expected blackbody temperature of 5.3 °C. However, since the Earth reflects about 30%[4] (or 28%[5]) of the incoming sunlight, the planet's actual blackbody temperature is about -18 or -19 °C [6][7], about 33°C below the actual surface temperature of about 14 °C or 15 °C.[8] The mechanism that produces this difference between the actual temperature and the blackbody temperature is due to the atmosphere and is known as the greenhouse effect.
    So, essentially a global average temp of -2 degrees F, or about -18 degrees C. Thus, no liquid water anywhere and no life. All very well understood for over a hundred years. Water vapor acts to enhance the warming of greenhouse gases, which can then elevate CO2 levels even more, which can then enhance temps even more. This usually dampens itself out over time; temps & CO2 levels eventually reach an equilibrium. These all are quantifiable due to the physics of radiative gases (no computer or fancy GCM's required). It does get a little complicated sometimes, depending upon the rates at which CO2 changes. But, hey, no one said it would be easy to learn. BTW, CO2 is the most important of the greenhouse gases, even including water vapor. You really ought to watch this for a clear explanation. The Yooper
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  7. @cruzn246: "The whole thing about CO2 just leaves me baffled." Clearly, but just because you're ignorant of the science doesn't mean you should assume it's wrong. "Of course it is explained that CO2 lags for whatever reason when a warmup occurs." CO2 Lags Temperature "Face it people, the big greenhouse gas here is water vapor." We are not adding new water vapor to the atmosphere, but we are adding CO2 that has been sequestered for millions of years. The current warming is due to rising CO2, which is likely to increase the amount of WV in the atmosphere, thus increasing the warming. "but till we really see some temperatures out of the norm, which we are not close to seeing" We are breaking an increasing amount of temperature records, we are at the end of the warmest decade in recorded history, and the increase matches what the climate models predict. What more proof do you want? People's clothes catching on fire when they go out for a stroll? Don't be ridiculous, please. "We are still in what has been a relatively warm period called the Holocene, and the simple fact is that we will probably see higher temps then this before this whole climate system flips." Actually, we're past the climate optimum for this interglacial period, so temperatures should be (slowly) going down instead of rising. "And CO2 has little or nothing to do with it. it is a minor player in the whole climate system. Greenouse gases allow us to trap heat, but they are not the big players in climate change. [...] The whole system is so complex we barley know how it works but the balance of solar factors, albedo, and ocean temperatures and currents are all bigger players." Science disagrees with you. "Anyone who knows anything about our glacial climatology should know that we are bound to stay warm until we see a radical change in ocean currents." Why do you believe you know more than the experts in the field? Please educate yourself.
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  8. @cruzn246: "30C colder? Are you nuts? No frickin way. Wherever you got that from is crazy." Such brilliant rhetoric has convinced me. *rolleyes* I'm sorry, cruzn246, I though you were a serious commenter, but now I see you're just a common troll. Mods, can we remove cruzn246's post and this reply? They add nothing to the discussion.
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  9. As to how warm it would be without CO2. CO2 accounts for about 26% of the 33 C greenhouse warming. That yields about 8.6 26% today? How about when CO2 was at 180 or so 10,000 years ago.
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    Moderator Response: See Does high levels of CO2 in the past contradict the warming effect of CO2?. Discuss the topic on that thread.
  10. We are breaking an increasing amount of temperature records, we are at the end of the warmest decade in recorded history, and the increase matches what the climate models predict. What more proof do you want? People's clothes catching on fire when they go out for a stroll? Don't be ridiculous, please. Recorded history. Big deal. We know it was warmer than this during the Holocene many times. So we are at the warmest in the last 200 years. That isn't a big enough sample to say warmest ever. Cripes, pull some reality glasses on. These temps are well within norms. So the models got it right. Whooppeee!
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    Moderator Response: See the argument It's Not Bad.
  11. @cruzn246: "26% today? How about when CO2 was at 180 or so 10,000 years ago." Temperatures were about 8 degrees colder at that time. So, 46% less CO2 (roughly half) means 8 degrees colder. That's more than the 3C climate sensitivity currenly estimated, actually, and evidence of positive/negative feedback when CO2 levels change.
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  12. @cruzn246: "We know it was warmer than this during the Holocene many times." Actually, it wasn't (as far as global averages are concerned). Also, you should put cited text you reply to in quotes, it makes it easier to understand the points you are trying to make.
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  13. CBDunkerson at 19:09 PM, the CO2 levels recorded at the surface stations used in this study Mechanisms for synoptic variations of atmospheric CO2 in North America, South America and Europe clearly indicate the huge seasonal variation in CO2 levels which coincides with increased uptake by plants during the growing season. The annual cycle shows variations of generally 20-40ppm but can be in excess of 50ppm depending on location. Interestingly even when the stations are located in heavily industrialised regions the same seasonal variation still occurs but with some of the highest annual variations of all the locations sampled, the station at Heidelberg Germany, described as having a fairly strong industrial influence to the east being the prime example with annual variation in excess of 50ppm.
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    Moderator Response: Wrong thread for continuing this conversation. See the Moderator's Comment on Tom Dayton's comment.
  14. cruzn246 at 02:26 AM, this review of the most recently published study Fresh water may have cooled North Atlantic putting that "the decrease recorded in the Earth's temperature between the 1940s and 1970s was caused by a sudden cooling of the oceans in the northern hemisphere" may be of interest to you.
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  15. Archiesteel "Actually, we're past the climate optimum for this interglacial period, so temperatures should be (slowly) going down instead of rising." So some think. That is for folks who really don't know what the real tripping point is. Fact is, it is probability ocean currents/sea levels, and when that happens a slow fall is not what you will see. It'll be a very sharp drop. There is some chance we may not warm up fast enough to bring the sea levels up to catch the right Milankovitch cycles, but that is still something we are waiting to see. The ocean current drive may be so strong that it will even overcome what is thought to be the "wrong" time in the Milankovitch cycle. It also may be that we could miss the glacial period if we hold seal levels down for a few more thousand years. Of course that's gonna be hard to do. when you are in the warm cycle, as we are, oceans just seem to keep rising till.......the trip happens.
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  16. "Tripping point?" "till.......the trip happens?" Are you sure you've got your terminology straight, Cruzn246?
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  17. Re: cruzn246 For someone who wants to be a Climatologist, you know very little about the field. or about science or the scientific method. You are telling people here on this thread, with lifetimes of experience and working knowledge in the field, the the science they know (which is itself based on the accumulated lifetimes of study and research of hundreds of thousands of scientists) is wrong. Do you not see a problem with that? I would suggest, at the very least, going here and follow the links and try to gain a base understanding of what's actually going on in the field. If you want to learn, first admit you don't know everything. That's a prerequisite. The Yooper
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  18. For my part I'm not a researcher studying matters of climate, but I follow the topic fairly closely and that's why I can't help but notice cruzn246's disagreement with vast swathes of established research findings, a sweeping dismissal that is boldly conspicuous. Take a moment to summarize what cruzn246 disagrees with and then ask, "what's the probability 'cruzn246' knows better?" My guess is that he/she will disagree with anything smacking of an attribution of significant climate change to anthropogenic influences. The big picture, again.
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  19. It's interesting, or perhaps amusing, that this thread wants to take a step back because "often we can't see the forest for the trees". Nothing wrong with that in itself, however given that one theme that consistently plays here is that sceptics don't have just one argument to rebutt AGW but numerous ones, or numerous trees. The response then almost inevitably is that whilst there may be some correlation from the evidence presented, the individual trees, unless there is 100% correlation, then the argument presented fails. What is apparent from that general treatment of the various arguments presented is a lack of understanding that perhaps the climate, the forest, does not respond to just one dominant driver or tree, in the case of the AGW argument, CO2, but instead responds to numerous drivers that vary in timing and magnitude as to what force, positive or negative, they contribute to the overall nett result. The tree and forest analogy is very appropriate I feel given the weight given to tree rings as a means of establishing proxy temperatures. Just as many sceptic arguments do not show 100% correlation, nor do all the trees in the forests used to collect tree ring data show 100% correlation, In fact the majority of the trees don't, and it comes down to selecting just a few that show high correlation in order to compile the data sets required.
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  20. May you live in interesting times. Or "It's better to be a dog in a peaceful time than be a man in a chaotic period" (寧為太平犬,不做亂世人; pinyin: níng wéi tàipíng quǎn, bù zuò luànshì rén
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  21. God, hit me for typos (probability) and hit me for not using the terminology you all use (trip rather than tip). I meant to complete the sentence differently when I used probability, and didn't go back to fix it. I think of the big change in climate like a trip wire. I disagree with the whole premise because I have never been shown that CO2 is responsible for most of our current warmup. It's that simple. You can throw some sort of "science" at me, but when it flies in the face of the past, not just the recent past, I just don't buy it.
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  22. I do think that when, and if, the climate goes back into glaciation it will be very sudden in the N hemisphere, as far as temperature change is concerned. I think the N hemisphere drives global change. I also think the shutdown of the Gulf stream is the trigger. Will worldwide tamps show the same quick drop. heck no. It'll take time to cool of all that water in the S Hemisphere. But that doesn't mean N Hemisphere tempos will drop slow. They will almost be in a free-fall. I would bet changes on the order of 2C in a century over the N hemisphere would happen easily. I also think that could go on for 500 years or so.
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  23. cruzn246 #71: "I disagree with the whole premise because I have never been shown that CO2 is responsible for most of our current warmup. It's that simple. You can throw some sort of "science" at me, but when it flies in the face of the past, not just the recent past, I just don't buy it." And when you are presented with evidence that it DOESN'T 'fly in the face of the past', as for instance my comments in post #55, you simply ignore it. Which is how you maintain your beliefs in the face of overwhelming proof to the contrary. Deny the evidence to the contrary and you are free to continue believing what you want to believe... truth be damned.
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  24. Re: cruzn246 (72, et-way-too-many-al) Nothing you've said at any point shows you have an understanding of science. At all. Or that you're anything less superficial than what you seem to be. You ignore every scientific rebuttal of your, um, "opinions" (since they're obviously not based on science) and continue blithely on your rambling way. Give us something solid to go on that shows we should ever take you seriously again. Or that you're here to learn something and not just here to waste everyone's time. Because as of now, we've no other conclusions to draw. The Yooper
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  25. #72: "They will almost be in a free-fall. I would bet changes on the order of 2C in a century over the N hemisphere would happen easily." -2C in a century is free-fall and the current global +0.13C per decade (that's 1.3C per century) -- and more for the NH isn't a warmup you can believe in?
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  26. "There ARE cases where temperature peaked after CO2 did. For instance... now, various flood basalt incidents, the snowball Earth scenario ~650 million years ago, et cetera." These temps are not in any kind of peak now. They are just warm for the last 500 years. If they keep rising nonstop the next couple hundred years maybe. The flood basalt incidents were in a completely different type of earth climate. Snowball earth, another different climate. Things were so different 500,000,000 years ago, including continental placement, that comparing to those times is like comparing to another world. Our whole atmosphere was different. Let's try to keep this in the interglacial periods please.
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  27. "-2C in a century is free-fall and the current global +0.13C per decade (that's 1.3C per century) -- and more for the NH isn't a warmup you can believe in? " That's 1.3 per Century if it lasts a century. Don't confuse rate with actual amount. It's gone up about 1C in the last 100 years. That kind of change has happened before. Of course I believe it's warming. I am alive. I was also alive in the 70s. Thank God it's mot like that anymore, although I think our break from that kind of weather is about to end.
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  28. "There ARE cases where temperature peaked after CO2 did. For instance... now, various flood basalt incidents, the snowball Earth scenario ~650 million years ago, et cetera." There was also a huge spike in water vapor being outgassed in those eras. That is why they called those hot periods back then warm and humid. It's not like CO2 was the only thing going way up.
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  29. We just had a record summer for highest average low temperatures in my area. Guess why. Yep, we had the highest average dewpoints for the summer also. You know, that greenhouse gas no one mentions.
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  30. cruzn246, so your statement that CO2 rises never proceed temperature rises was... false, but we should ignore that and concentrate ONLY on a relatively recent period of glacial cycles during which there have been no sudden profound increases in CO2... except for the current human driven one. Which we should also ignore. Yes, once we blinder ourselves to all evidence to the contrary your position only looks slightly ridiculous. Unfortunately you then go and ruin it with; "There was also a huge spike in water vapor being outgassed in those eras. That is why they called those hot periods back then warm and humid. It's not like CO2 was the only thing going way up." I'd explain why this is nonsense, but it obviously wouldn't make any difference. Enjoy your fantasy world where long term increased atmospheric water vapor is both the cause AND effect of temperature increases.
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  31. "I'd explain why this is nonsense, but it obviously wouldn't make any difference. Enjoy your fantasy world where long term increased atmospheric water vapor is both the cause AND effect of temperature increases." Well debunkerson, tell me what the total world concentration of water vapor is today. Oh, you don't know? No, nobody can answer that question, but you all think we know exactly how this whole atmosphere works. How the heck can we know when we can't put a reliable figure on such a crucial component? You can't.
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    Moderator Response: Further discussion of water vapor needs to be on the thread Water vapor is the most powerful greenhouse gas.
  32. @cruzn246: "Well cripes man, it's amazing you have any doubters here with the way some of you treat someone who says no." You don't just come here to say no, you come here repeat debunk denier arguments and refuse to respond to actual counter-arguments with scientific evidence. What's more, you use a very aggressive tone and denigrate the fine scientists who have produced a mountain of research supporting AGW. You are not interested in learning the truth, but only want to be comforted in your non-scientific opinion. "We just had a record summer for highest average low temperatures in my area." What's a "high average low temperature"? I guess you're trying to say you've had "record low temperatures" in your area, is that it? Well, the fact it was cold in your area doesn't mean anything, especially when you agree that we are warming. "You know, that greenhouse gas no one mentions" If you're talking about Water Vapor, it is mentioned all the time. In fact, it was mentioned quite a few times in this thread alone, proving your wrong. You seem to have a problem formulating a logically sound argument. Perhaps you should learn a bit more about the science before trying to argue with people who understanding better than you do?
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  33. @cruzn246: "Well debunkerson, tell me what the total world concentration of water vapor is today. Oh, you don't know? No, nobody can answer that question" Actually, water vapor represents about 0.4% of the atmosphere. Again, don't gauge what science knows based on your own ignorance.
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    Moderator Response: Further discussion of water vapor needs to be on the thread Water vapor is the most powerful greenhouse gas.
  34. Re: cruzn246 (84) Magic 8-ball says 12,900 cubic kilometers in the air; or a bit more than the volume of Lake Superior (12,000 cubic kilometers). For extra credit, the 4% increase in atmospheric water vapor since 1970 due to the higher temperatures is about equal to the volume of Lake Erie. In case you had an enquiring mind. The (Il mio nome è Nessuno) Yooper
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    Moderator Response: Further discussion of water vapor needs to be on the thread Water vapor is the most powerful greenhouse gas.
  35. #77:"Of course I believe it's warming. ... I think our break from that kind of weather is about to end." So you do believe in warming, but you also believe its all natural? Happened before, will happen again, nbd. At the risk of repeating an oft-seen graphic: Let's see if we can spot the difference between today and previous episodes. Hint: CO2 is the middle graph, note vertical scale on the right. Left-most point on that graph (the most recent) just peaks over 280ppm, which looks like the prior warm episodes. Answer: Now we're at 390ppm, which would put the green line off the top of the chart. That didn't happen before on this time scale (you asked for glacial/interglacials only). Still believe its all happened before? And exactly when is this ice age of yours going to happen?
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  36. "Answer: Now we're at 390ppm, which would put the green line off the top of the chart. That didn't happen before on this time scale (you asked for glacial/interglacials only). Still believe its all happened before? And exactly when is this ice age of yours going to happen?" Great, we are at the highest CO2 rates in the last 450.000 years. Not even close to the highest temperatures. So what am I supposed to think? I know one thing about the end of the last interglacial. Sea levels were a heck of a lot higher than they are now. There was also a lot less ice. That is why we are still in a warm period and not cooling off yet.
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  37. @cruzn246: temperatures are at the high end of the last 450,000 years, as well, though it will take a couple of decades until we get the full effect of anthropogenic CO2. So, the reality is that temperatures are at the highest and ice cover is at the lowest since the last glacial period, even though the climate optimum was a couple of thousand years ago. In other words, you have *no* idea what you're talking about. I suggest you refrain from making any more fallacious comment and thus avoid embarrassing yourself any further.
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  38. "Actually, water vapor represents about 0.4% of the atmosphere." Actually this is wrong. It ranges from 1 to 4% with the average being between 2 and 3%, but no one is really sure what that average is on any given day. According to NASA, they say the increase in water vapor is probably playing a bigger part in warming now than CO2, but they will not put numbers on either as far as the amount each is contributing. Water Vapor Confirmed as Major Player in Climate Change http://www.nasa.gov/topics/earth/features/vapor_warming.html Here is a quote from their article. "The difference in an atmosphere with a strong water vapor feedback and one with a weak feedback is enormous," Dessler said. They are just starting to get a handle on water vapor feedback. My prediction is that in ten years they will see it as an even more important player in warming. I think all you need is a simple climate shift that has nothing to do with CO2 to put more water vapor in the air. You melt more ice, that means more water, that means less reflection , albedo, and you have a warmer more humid earth without adding any CO2. Does CO2 add to this? Sure, but I really think it's piece is grossly overestimated.
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  39. I'm responding to your erroneous Water Vapour claims on the correct thread.
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  40. "@cruzn246: temperatures are at the high end of the last 450,000 years, as well, though it will take a couple of decades until we get the full effect of anthropogenic CO2. So, the reality is that temperatures are at the highest and ice cover is at the lowest since the last glacial period, even though the climate optimum was a couple of thousand years ago. In other words, you have *no* idea what you're talking about. I suggest you refrain from making any more fallacious comment and thus avoid embarrassing yourself any further." They are at the high end? They are near a middle value for the period of the Holocene. They have been nearly 2C warmer than this in the Holocene. Temperatures during the Holocene have been above this level numerous times and dropped back again. The temperature has been bouncing around in a roughly 4C range for the last 10,000 years. The previous 4 interglacial periods all ended with temps at least 2C warmer than we are now. Ice volumes are not as low as they were prior to the last glaciation. Funny how it takes so long to get feedback from CO2. with water vapor the feedback is nearly immediate. Sure you can say high end but they are not at their warmest by any means.
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  41. @cruzn246: I don't know why I'm wasting my time debating with a fanatic, but here goes: "They are at the high end? They are near a middle value for the period of the Holocene. They have been nearly 2C warmer than this in the Holocene." Actually, no, they haven't. Temperature now are way above the holocene mean, and higher than any average temperatures since the last glaciation. "Funny how it takes so long to get feedback from CO2. with water vapor the feedback is nearly immediate." Please learn what "feedback" means.
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  42. #86: "we are at the highest CO2 rates in the last 50.000 years. Not even close to the highest temperatures. So what am I supposed to think?" Think: Temperatures will go higher. See, not that hard. "Sea levels were a heck of a lot higher than they are now. There was also a lot less ice. " References for that? "That is why we are still in a warm period and not cooling off yet." ??? We are still(?) in a warm period because sea levels were higher at the end of the last interglacial? Does that make any sense to anyone?
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  43. @muoncounter: "Does that make any sense to anyone?" No, it doesn't, and it seems the further we go the more shrill cruzn246 is becoming. I think he's starting to realize he's really in over his head with his limited scientific knowledge. He's beginning to break down, making less and less sense as counter-arguments pile up against his house of cards. The next logical step for would likely be to start making strawman aguments and ad hominem attacks.
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  44. "Actually, no, they haven't. Temperature now are way above the holocene mean, and higher than any average temperatures since the last glaciation." I'm almost from Missouri. show where you get this from.
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  45. "That is why we are still in a warm period and not cooling off yet." ??? We are still(?) in a warm period because sea levels were higher at the end of the last interglacial? Does that make any sense to anyone? If you understood the connection to sea levels and ice ages you would get it.
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  46. Re: cruzn246 (95)
    "If you understood the connection to sea levels and ice ages you would get it."
    Insofar as you have presented no evidence to support your opinion, and stand in direct juxtaposition to more than a century of scientific research, it can be safely concluded that it is YOU who do not get it. Capiche? The Yooper
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  47. Re: cruzn246 (95) "If you understood the connection to sea levels and ice ages you would get it." "Insofar as you have presented no evidence to support your opinion, and stand in direct juxtaposition to more than a century of scientific research, it can be safely concluded that it is YOU who do not get it." Oh cripes. It is a well known fact that sea levels were much higher at the end of the last interglacial and temperatures were higher also. The sea level connection to ice ages is simply this. If you bring sea levels up to the level that they reached at the end of the last interglacial you could effectively shut down the Gulf Stream. That would be what you all call a tipping point. This is how high the water was in FL at the end of the last interglacial. the blue area is what was not under water.
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  48. Re: cruzn246 (94)
    "I'm almost from Missouri. show where you get this from."
    Ok, where shall we start? How about a quick synopsis of GHG, CO2 and AGW:
    1. Increasing the level of a greenhouse gas in a planet’s atmosphere, all else being equal, will raise that planet’s surface temperature. 2. CO2 is a greenhouse gas. 3. CO2 is rising. 4. Therefore (given 1-3 above) the Earth should be warming. 5. From multiple converging lines of evidence, we know the Earth is warming. 6. The warming is moving in close correlation with the carbon dioxide. 7. The new CO2 (as shown by its isotopic signature) is mainly from burning fossil fuels. 8. Therefore the global warming currently occurring is anthropogenic (caused by mankind).
    How about a complete guide to modern day climate change? Or an illustrated guide to the latest climate science? How about every scientific body in the world endorsing the science of global warming/climate disruption (use the term of your choice), as summarized by the National Academy of Science in May of this year:
    "A strong, credible body of scientific evidence shows that climate change is occurring, is caused largely by human activities, and poses significant risks for a broad range of human and natural systems…. Some scientific conclusions or theories have been so thoroughly examined and tested, and supported by so many independent observations and results, that their likelihood of subsequently being found to be wrong is vanishingly small. Such conclusions and theories are then regarded as settled facts. This is the case for the conclusions that the Earth system is warming and that much of this warming is very likely due to human activities."
    Have you seen enough? Re: cruzn246 (97) And by presenting no mechanism to support your opinion, you amply demonstrate that you simply have no idea about what you are talking about. You are merely "hypothesizing" (the supposition that this is similar to pulling small primates out of dark places is completely unrelated). The Yooper
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  49. #95: "If you understood the connection to sea levels and ice ages" Again, what is the significance of this remark? Ice ages cause sea level to drop. But this is not about ice ages; its about causes of climate change. In today's world. BTW, your map in #97 appears to be one of the 125ka highstand. It's lovely, but no geologist on earth would put the land area in blue. Please cite your source. And check Quaternary sea-level history of the United States; it'll help you get the chronology correct.
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  50. How about a quick synopsis of GHG, CO2 and AGW: 1. Increasing the level of a greenhouse gas in a planet’s atmosphere, all else being equal, will raise that planet’s surface temperature. Yep. 2. CO2 is a greenhouse gas. Yep 3. CO2 is rising. Yep 4. Therefore (given 1-3 above) the Earth should be warming. How much is a guess at best. 5. From multiple converging lines of evidence, we know the Earth is warming. No doubt 6. The warming is moving in close correlation with the carbon dioxide. Correlation does not mean causation. Science 101. 7. The new CO2 (as shown by its isotopic signature) is mainly from burning fossil fuels. Check 8. Therefore the global warming currently occurring is anthropogenic (caused by mankind). How much is still a guess. There is no good reason we should not be warming now. We are still interglacial and still recovering from a relative low point, the "Little Ice age", in an interglacial cycle. These are the warmest temperatures lately, but not the warmest of the Holocene. We got warmer than this during the last interglacial also. muoncounter I checked the Quaternary map. It is better than the one I had. It still works for a reshaped FL that could screw up the Gulf Stream and trigger rapid cooling. If not the gulf stream than I suspect some other ocean current gets rearranged. I think that this is the trigger for ice ages. There is no way the Milankovich cycles could have that sudden an impact as what we get when we go icy.
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    Moderator Response: See the post (and comment further there, not here) We’re coming out of the Little Ice Age.

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