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Comments 127301 to 127350:

127301. Ned at 23:20 PM on 7 October 2009
        Are humans too insignificant to affect global climate?
        RSVP writes: "Do plants generally grow faster in warmer or cooler climates?" That depends on water and nutrient levels. I used to work here, and at temperatures of 50C, there was nary a plant to be seen. In contrast, despite ten months per year of winter, there's trees growing all over here. "How do CO2 levels affect plant growth?" That also depends on water and nutrient availability, and on which photosynthetic pathway the plant uses.
127302. David Horton at 19:06 PM on 7 October 2009
        Are humans too insignificant to affect global climate?
        Good denialist questions. You know, and I know, and everyone else on this site knows they have been asked (by people like you) and answered many thousands of times. Why persist with them? You are not fooling anyone except your denialist mates. You are filling up, yet again, another thread with rubbish I suppose - is that your only aim? Sense of achievement? Have you, at last, no sense of shame?
127303. RSVP at 18:58 PM on 7 October 2009
        Are humans too insignificant to affect global climate?
        Two questions: 1) Do plants generally grow faster in warmer or cooler climates? 2) How do CO2 levels affect plant growth?
127304. RSVP at 18:52 PM on 7 October 2009
        How we know global warming is still happening
        I was being facetious, however now that you made these remarks, there seem to be two issues here. The idea of science as simply a method for providing useful conceptual models, and science, this thing that has promoted global destruction. Most of what we call science has brought on the global warming via modern medicine (ie resulting in population explosion), and the industrial revolution (resulting in population explosion). There is a word that is very rarely used these days. The word is called RESPONSIBILITY. Science can take us anywhere, good or bad. As you imply, it is indifferent, but scientists are people, and people should not be indifferent. So next time you are doing science, try to THINK about what you are really doing.
127305. hank at 15:40 PM on 7 October 2009
        How we know global warming is happening, Part 2
        Mizimi -- the known number of volcanos isn't changing, there's no unusual warming at the bottom of the ocean in volcanic areas, the earthquake maps show no change, so likely none. Same for volcanos above the ocean, these happen but not in an increasing number so they're part of the background noise, not part of the increase.
127306. David Horton at 14:38 PM on 7 October 2009
        Are humans too insignificant to affect global climate?
        The question RSVP is how anyone could possibly think that 7 billion human beings, each with an ecological footprint of varying sizes up to very large indeed, could NOT now be affecting the Earth's climate. The CO2 effect is the most obvious, significant and general one, which is why John concentrates on it here, but the effects of forest clearing, overfishing, development, pollution, species extinction, are also important to the climate in various ways and are directly down to humans. Why any of this should be a question, other than to those who think a god gave humans permission to strip the world of all its resources just before it came to an end, completely escapes me.
127307. Philippe Chantreau at 14:13 PM on 7 October 2009
        How we know global warming is still happening
        We're talking about promoting evolution among not only animals, but also the current Human population here. All through a weird, uncontrolled experiment. Can't see how that would be a good idea, but it's just me. Science does not promote ideas like marketing people promote products. It attempts to understand the world. Nobody is in charge. Not Darwin, not Einstein, not Bohr, not Schroedinger. There is nobody "in charge", only people trying to understand. Looking at it any other way indicates, IMO, a profound misunderstanding of science.
127308. neilperth at 14:02 PM on 7 October 2009
        Sea level rise is exaggerated
        In an interview with Dr. Nils-Axel Mörner (head of the Paleogeophysics and Geodynamics department at Stockholm University in Sweden, past president (1999-2003) of the INQUA Commission on Sea Level Changes and Coastal Evolution, and leader of the Maldives Sea Level Project – he has been studying the sea level and its effects on coastal areas for some 35 years) by EIR (Argentine Foundation for a Scientific Ecology) [http://www.mitosyfraudes.org/Calen7/MornerEng.html] he talked about the IPCC misrepresentation of sea level data: “Then, in 2003, the same data set, which in their [IPCC's] publications,... was a straight line—suddenly it changed, and showed a very strong line of uplift, 2.3 mm per year, the same as from the tide gauge... It was the original one which they had suddenly twisted up, because they entered a “correction factor,” ... I accused them of this at the Academy of Sciences in Moscow —I said you have introduced factors from outside; it's not a measurement. It looks like it is measured from the satellite, but you don't say what really happened. And they answered, that we had to do it, because otherwise we would not have gotten any trend! That is terrible! As a matter of fact, it is a falsification of the data set. ... So all this talk that sea level is rising, this stems from the computer modeling, not from observations. The observations don't find it! I have been the expert reviewer for the IPCC, both in 2000 and last year. The first time I read it, I was exceptionally surprised.
127309. RSVP at 05:44 AM on 7 October 2009
        Are humans too insignificant to affect global climate?
        I think there needs to be as much rigor in language as in math. The article poses the question as to whether humans can affect the GLOBAL CLIMATE. It then focuses on CO2 levels and annual fossil fuel consumption. Since CO2 increases = CLIMATE CHANGE (in everybody's mind), it proves that humans can indeed affect the Earth's climate, which doesnt even really exist since "climate", meteorolgically speaking, has to do with weather patterns associated with geographic regions. A more loose meaning could mean atmospheric molecular composition, but the term environment is probably more suitable. And what is really being sold here again is the concept that CO2 is causing the Earths TEMPERATURE to go up. Why not us that word?
        Response: I was waiting for someone to bring that up - it's a valid comment. My next post is on the question of whether increasing atmospheric CO2 changes global temperatures.
127310. cbrock at 05:42 AM on 7 October 2009
        Are humans too insignificant to affect global climate?
        Nice little post, John. It is instructive to integrate your Figure 2 to get the cumulative CO2 emissions into the atmosphere. The correspondence with the secular trend in CO2 concentrations in the atmosphere is very impressive indeed. pdt--the result of increasing CO2 concentrations is an increase in ocean acidity. There are many links to this topic. One place to look is http://www.pmel.noaa.gov/co2/OA/ . Or just start with Wikipedia.
127311. ProfMandia at 04:48 AM on 7 October 2009
        How we know global warming is happening, Part 2
        Thank you for this great post. I will be updating my site with much of this information. :)
127312. pdt at 04:48 AM on 7 October 2009
        Are humans too insignificant to affect global climate?
        Where does the other half go? How much in the oceans? Is that measurable? If so that part should count as climate too, at least for lifeforms that live in the ocean.
127313. RSVP at 00:13 AM on 7 October 2009
        How we know global warming is still happening
        It is curious that "science" promotes the idea of evolution, and yet scientist are wishing to stop it. A changing environment leads to natural selection which implies no control. Is Darwin in charge or not?
127314. John Cross at 23:01 PM on 6 October 2009
        Are humans too insignificant to affect global climate?
        Good post John. Another piece of evidence as to how we are changing the atmosphere is the reduction of O2 as the CO2 increases (burning uses up O2). While the change as a percentage of all the O2 in the atmosphere is extremely small, we have been able to observe the decrease for the last 20 years or so. A good article on it here. As an interesting note, in the article Keeling estimates the increase in sea level from the H2O produced by burning hydrocarbons. As you would expect the number is very small. Best, John
127315. WeatherRusty at 22:41 PM on 6 October 2009
        How we know global warming is still happening
        It is not a given that there are more clouds in a generally warmer environment. Cloud formation depends very much on relative humidity and also the availability of lift within the atmosphere, warm moist air must rise and cool to near it's dew point. A product of all climate simulations is a near constant relative humidity as the climate warms. Look at the tropics and near tropics today. Most cloud formation is convective in nature and where this is the result of daytime heating the clouds dissipate at night. The tropics receive the vast majority of solar radiation but cloudiness does not prevent that region from being the warmest on Earth. If the climate zones and jet streams are shifted poleward in a warming world why would the dynamics be any different in their displaced positions?
127316. Philippe Chantreau at 20:03 PM on 6 October 2009
        How we know global warming is still happening
        And whence do you infer that this is not well known of climate science, inappropriately modeled and inconsistent with observations? The water vapor/clouds feedback is a matter of much debate and, in any case, still a feedback from warming triggered by increased GH effect. Furthermore, increased cloudiness at higher temperature would seem to require a lowered relative humidity and I'm not sure whether we're seeing that. Models appear to argue against it. One fellow skeptic recently trumpeted the Trenberth and Fasullo paper suggesting that cloud feedback might actually be much lower than previously modeled, leading to a lot of extra warming from increased solar irradiance reaching the surface. For all the hooplah demonstrated by that fellow skeptic, it's worth pointing that the HADCRU model is in fact fairly close to Trenberth'runs, and HADCRU long term prognostic is not that different from GISS. It is also worth reminding that the decreased cloudiness of Trenberth' model runs was still a feedback of increased GH warming. Much a do about nothing.
127317. RSVP at 19:05 PM on 6 October 2009
        How we know global warming is still happening
        What follows is an excerpt from an article found here http://physicsworld.com/cws/article/print/17402 "The spectroscopic data that are required to model long-wave atmospheric absorptions are generally well characterized. When these data are put into atmospheric models, water turns out to be responsible for about 60% of the greenhouse effect, while the much-reviled carbon-dioxide molecule accounts for just 26%. Ozone accounts for 8%, and methane and nitrous oxide - the atmospheric concentrations of which have been increased by human activity - contribute a further 8% to the greenhouse effect. " The article goes on to say that the warmer the Earth gets, the more water vapor and therefore the more clouds that shield incoming Sun. Probably that is why we are still here to talk about this.
127318. David Horton at 17:02 PM on 6 October 2009
        Are humans too insignificant to affect global climate?
        Do we (you) know John if the difference between what we are producing and what is being dealt with is increasing? You would expect it to be with deforestation and drought on the one hand, and the changing capacity of the warming and acidifying oceans to keep absorbing CO2 on the other.
        Response: Good question. Figure 7.4 in the IPCC AR4 shows a graph of the fraction of fossil fuel emissions remaining in the atmosphere (‘airborne fraction’) since 1958 (the thick black line is the 5 year mean):
        
        
        
        Bit early to tell whether there is a long term trend there.
127319. snowman1955 at 08:40 AM on 6 October 2009
        The link between hurricanes and global warming
        Some Science! Global warming theory actually predicts strongest warming in the Arctic and secondary the Antarctic, with little change in middle to lower latitudes for several years, or decades. The idea that mid latitude storm intensities, tropical system enhancement, and severe weather events would be minimal due to less baroclinic stress (a decrease in solenoids) or less atmospheric density differences over a horizontal distance, ...if CO2 were actually causing major changes in the atmosphere. If such changes are taking place, must be from other forcing factors (maybe solar intensity fluctuations, and related magnetic flux changes). The weather should, at least if we assume CO2 warming is dominating, becomes more benign, with some trend toward increased moisture in the normally dry Arctic. Mid latitudes will be largely unaffected, and the tropic certainly not affected. The numerical models all, I repeat ALL, have parameterized processes that are very subjective,not directly included in the quasigeostrophic computations, and contribute strongly to errors in the computational output of said models. Algebraic coefficents, or fudge factors, then become necessary, largely ruining the value of the forecasts.
127320. Tom Dayton at 00:34 AM on 6 October 2009
        How we know global warming is still happening
        RSVP, in addition to the known multiple forcings in addition to CO2, the positive feedbacks are strong contributors. The temperature rise is a consequence of all of that, not just CO2.
127321. Philippe Chantreau at 16:07 PM on 5 October 2009
        How we know global warming is still happening
        RSVP, the Earth is not a closed system, no matter how you cut and slice it. Any way to look at it as a closed system is wrong. Your own water jug analogy describes an open system. "I believe something else is going on." What is? What quantitative analysis are you basing this on? In which science papers has this analysis been published? The warming effect of CO2 alone is fairly well known, based on radiative physics. There is more debate on the feedbacks, which condition the total sensitivity. Which part of that exactly does not add up for you and, again, what quantitative analysis is there to support your doubts? Considering the vocation of this site, I'd like to see science publications as support.
127322. shawnhet at 06:11 AM on 5 October 2009
        How we know global warming is happening, Part 2
        Riccardo, my point was that some of numbers quoted above refer to the Earth as a whole(Hansen & Trenberth) while Schuckmann is talking about the oceans only. That was not particularily clear above. Cheers, :)
127323. RSVP at 05:55 AM on 5 October 2009
        How we know global warming is still happening
        So, correct me if I am wrong in understanding your reply, you are saying basically that processes are non linear and to a point self limiting, and (perhaps implied) generally driven by the Earths distance from the sun, its rotation, etc. And that our burning of fossil fuels are taking the mean temperature upward. I dont see this as unreasonable, and my opinion isnt going to keep the Earth any cooler.... ...however. I am not so convinced that its just the CO2 that is the culprit. I came to this website in the first place because of an independent discussion about what a relatively mass concentration CO2 has in the atmosphere and how could it possibly be taking the Earths temperature up. I believe something else is going on besides the incremental heat trapping effect of CO2, and that if nations only attack this issue, it may be just a big waste of effort and time.
        Response: CO2 isn't the only thing going on - there are a number of forcings that affect climate but CO2 is the dominant forcing:
        
        
127324. Tom Dayton at 04:55 AM on 5 October 2009
        How we know global warming is still happening
        RSVP, you are correct that if the Earth's input and output were in equilibrium before and after the temporary reduction in input, then afterward the system would indeed remain at a lower temperature. But the Earth's (the whole thing including the atmosphere, seen from outer space) input and output were not in equilibrium before, say, Mt. Pinatubo's eruption. The input was outpacing the output. (The water level in the jug was increasing.) This is where the jug analogy breaks down, because the Earth's rate of output to space increases with the temperature of the Earth. You'll have to pretend that the jug's hole lets more water out the more water is in the jug. The Earth's temperature was on its way up toward a new equilibrium output to suit its new, higher, equilibrium temperature. Then the eruption reduced the input a little bit, for a little while. That was enough to slow down the system's progress toward its still-not-reached equilibrium output rate and temperature. After the aerosols cleared, the system continued to heat up (and to increase its output rate) still in pursuit of that before-eruption equilibrium temperature and output rate. Actually, the system's goal equilibrium temperature and output rate post-eruption are lower than they were pre-eruption, because the amount of heat in the system is lower (slightly); but those new, lower goals still have not been met, so the system continues to heat on its way toward that new goal. Meanwhile, of course, the output rate is being reduced by a factor independent from all the above: The greenhouse gasses continue to increase. (Moss is growing to block the hole in the jug.) That moves the equilibrium goal even higher, continuously. The system never reaches its equilibrium goal.
127325. RSVP at 03:48 AM on 5 October 2009
        How we know global warming is still happening
        In the analogy of the water jug, the level of the water is the Earths temperature. Water dripping in is incoming radiation. Water flowing out is outgoing radiation. If outflow is reduced the level will rise. I dont think this is different from the idea that CO2 is causing less heat to escape the Earth. Now assuming a perfectly balanced flow situation for the jug where the level never changed at 3 gallons, this would be analogous to a level of CO2 in the atmosphere wherever nature had it say 500 years ago or so. But now someone comes along and removes one gallon, which would be like volcanic ash blocking the sun in a big way for 3 years. The two gallons left would be like the temperature of the Earth dropping to say ice age conditions. As I describe, there is no reason for the water level to come back to 3 gallons. It will remain at two gallons forever unless the flow rates are altered. Similarly, after ten years, all the volcanic smoke clears, and the atmosphere is pristine again. The sun shines as before, and the processes preceding the eruption take over. The temperature should stay where it is. So far, no one has provided an answer that explains why global temperatures go back to "normal" in terms of the CO2 mechanisms described to explain recent global warming. An explanation of this type would require excess CO2 following the eruption, and CO2 subsequently reducing over time to reach stasis. However, the data supposedly shows the opposite. That CO2 rises when the Earth warms.
127326. Tom Dayton at 01:46 AM on 5 October 2009
        How we know global warming is still happening
        WeatherRusty, the duplication of your entries is due to your browser (or the server?) retaining the code for posting your comment, even after the page has reloaded to show your comment. When you reload that page by clicking your browser's reload button, that same code for posting gets sent again. It's happened to me multiple times (sorry, everybody). You might get an alert box after you click the reload button, warning that the browser will "repost" or somesuch phrasing. If you see that, click the Cancel button in that alert box. To avoid all the above, I suggest that after you post, you go to any other page, which will force the posting code to be flushed.
127327. WeatherRusty at 01:22 AM on 5 October 2009
        How we know global warming is still happening
        I have no idea why my posts are in duplicate, I hit submit only once. RSVP, "1 degree divided by 300 K = .003333" 288 K is the average surface temperature of Earth and nearly all of that is due to radiation received from the Sun including 33 K amplification due to the greenhouse effect. "0.3% is in the noise, and is due to many factors." The "noise" is not random...it is forced and the job of science is to quantify the forcing. The ~1 K increase is part of a long term trend forced by 1.6W/meter^2 increase in radiative forcing, much of which is being absorbed by the oceans.
127328. Tom Dayton at 00:48 AM on 5 October 2009
        How we know global warming is still happening
        RSVP, your water jug analogy is incorrect. The aerosols increasing and decreasing due to a volcano are instead the equivalent of a valve decreasing and increasing the flow of water into the jug. CO2 increasing is like moss growing in the hole at the bottom of the jug, reducing the flow of water out of the jug.
127329. neilperth at 00:08 AM on 5 October 2009
        There is no consensus
        Chris, ...RE your post 157 above, ( the Oerlemans paper ), the abstract you posted did not tell me much. So I did some research on the data and as far as I can see, glaciers have been generally melting and receding since about 1850, which is well before massive amounts of man-made CO2 were pumped into the air. Also, the IPCC models only require CO2 input after say 1970. According to the IPCC graphs, before 1970, natural variations can explain most of the temperature increase. Now since 1970, I agree, that glaciers have been generally receding, although in several areas they have actually been advancing. But the important points to note are that : 1) Glaciers started to recede well before 1970 and so the receding of glaciers after 1970 was to be expected simply based on historical ( natural )trends. 2)There has been little or no incresae in the rate of glacial recession since 1970. Thus there is little evidence here for me to conclude that recent man-made CO2 emissions are responsible for glacial retreat. If we look at one hypothetical glacier, is it not true that if precipitation of snow at the higher, source of the glacier decreases then there will be less weight forcing the glacier down the valley. Thus the rate of advance of the glacier can be affected by other factors besides warming.
127330. RSVP at 19:37 PM on 4 October 2009
        How we know global warming is still happening
        WeatherRusty said What you view as fanaticism derives from a strong confidence in well established physical principles as they are applied to the issue of climate change. ------------------------------- What I view as fanaticism is OVER confidence in theories that are based on well established principles. 1 degree divided by 300 K = .003333 0.3% is in the noise, and is due to many factors.
127331. RSVP at 19:19 PM on 4 October 2009
        How we know global warming is still happening
        Philippe Chantreau at 17:40 PM on 4 October, 2009 RSVP, "a closed system called Earth." Do you really mean that? --------------------------------- The expression is appropriate given that we are considering the Earth as a whole and a discussion that presupposes no changes in solar activity (which of course is not true).
127332. RSVP at 18:33 PM on 4 October 2009
        How we know global warming is still happening
        Tom Dayton answers my earlier question, "what brought the temperature back up to "normal" after the Krakatoa eruption." The answer unfortunately is not consistent with the radiation budget of greenhouse models that imply that without a net surplus of radiative energy (as in the case of extra CO2 in the atmosphere) average temperatures should remain at steady state. The model is oversimplied of course, which is the whole point of the question. An analogy may help visualize things. Assume you have a 5 gallon jug vessel containing 3 gallons of water. Water is dripping into the jug from a faucet at the same rate being lost through a hole at the bottom of the vessel, (assume no evaporation). Under these conditions, the level remains at 3 gallons forever, until one day, 1 gallon is removed. All things being equal in terms of flow rates, the level then stays at 2 gallons. There is no reason for the level to return to 3 gallons. At least I have not given one. Likewise, the greenhouse global warming theory assume equilibrium that is disrupted by CO2 levels rising. Without this happening, the Earths average temperatures would remain exactly where they are forever. And applying this same simple incomplete model to the situation after the Earths temperature drops from a volcanic explosion, it should remain low forever as well. You did not explain where the extra energy comes from to get the temperature back to "normal", nor did you explain why it should stop rising when it gets to "normal".
127333. Philippe Chantreau at 17:40 PM on 4 October 2009
        How we know global warming is still happening
        RSVP, "a closed system called Earth." Do you really mean that?
127334. Riccardo at 10:23 AM on 4 October 2009
        How we know global warming is happening, Part 2
        shawnhet why do you average the heat absorbed by the ocean over the whole earth?
127335. shawnhet at 08:16 AM on 4 October 2009
        How we know global warming is happening, Part 2
        Thanks for that Chris, I concur that the warming for that period seems to be more like 0.6Wm-2 rather than the 0.82 number mentioned above by John Cook. I just wanted to make sure I was reading it right. Cheers, :)
127336. Mizimi at 08:10 AM on 4 October 2009
        How we know global warming is happening, Part 2
        BTW..how much of the increase in ocean heat content is due to vulcanism?
127337. WeatherRusty at 03:25 AM on 4 October 2009
        How we know global warming is still happening
        RSVP said: "Socrates said, I know I know nothing. (You can even argue about what he really said). My understanding of this statement is that you cant really know anything for sure. I find the spirit of this discussion poisoned by fanaticism, as opposed to skepticism." Science is a logical methodology employed to aid in our understanding of the world. It works rather well, we have learned a great deal of how the world works even if that knowledge is incomplete. We understand quite well the physics as to how material objects are warmed and cool. The Earth is just a body floating in space and warms and cools based on the same physics as any other body. Scientists have much of this figured out. It is not like we know very little, to the contrary what we know is demonstrably the essence of what is responsible for the warming and cooling of Earth. What we don't know very well are some of the details, but the big picture is rather clear. The Earth is warming as a matter of empirical observation and the basic physics as to why that is occurring are well established. This gives us a logic basis for an expectation for a continuation of that warming and an estimation of what that warming will be, allowing for the uncertainty inherent to the less well understood details. What you view as fanaticism derives from a strong confidence in well established physical principles as they are applied to the issue of climate change.
127338. WeatherRusty at 01:54 AM on 4 October 2009
        How we know global warming is still happening
        RSVP said: "Socrates said, I know I know nothing. (You can even argue about what he really said). My understanding of this statement is that you cant really know anything for sure. I find the spirit of this discussion poisoned by fanaticism, as opposed to skepticism." Science is a logical methodology employed to aid in our understanding of the world. It works rather well, we have learned a great deal of how the world works even if that knowledge is incomplete. We understand quite well the physics as to how material objects are warmed and cool. The Earth is just a body floating in space and warms and cools based on the same physics as any other body. Scientists have much of this figured out. It is not like we know very little, to the contrary what we know is demonstrably the essence of what is responsible for the warming and cooling of Earth. What we don't know very well are some of the details, but the big picture is rather clear. The Earth is warming as a matter of empirical observation and the basic physics as to why that is occurring are well established. This gives us a logic basis for an expectation for a continuation of that warming and an estimation of what that warming will be, allowing for the uncertainty inherent to the less well understood details. What you view as fanaticism derives from a strong confidence in well established physical principles as they are applied to the issue of climate change.
127339. Mizimi at 01:25 AM on 4 October 2009
        How we know global warming is happening, Part 2
        We should also bear in mind that each component of the system responds to change differently, according to its' physical characteristics. The oceans represent an enormous buffer as they absorb and emit heat more slowly than the land or atmosphere. It seems to me that we should not expect an immediate correlation between atmospheric cooling and ocean cooling. There will be a time delay. Presently SST data suggests a diminution or even cessation in the warming trend dating from around 2003 which should eventually be reflected in the data for ocean temps. I'm not aware of any direct comparison available for both sets of data...Chris..any suggestions?
127340. Tom Dayton at 00:08 AM on 4 October 2009
        How we know global warming is still happening
        RSVP asked what brought the temperature back up to "normal" after the Krakatoa eruption. Answer: The falling out of the atmosphere, of the solar-radiation-reflecting aerosols that the volcano had thrown into the atmosphere. Technically, it's not simply a matter of gravity causing the aerosols to fall out; that is one contributor, but other processes also contribute to the rapid removal of those aerosols. See the page It's volcanoes (or lack thereof) here on the Skeptical Science site for more info. That page contains references to peer-reviewed scientific publications from which you can get all the details you care to see. Or you can go to the US Geological Survey's site, because studying volcanoes is one of their primary jobs. They even have a page titled Volcanoes and Global Cooling. Even more detail is at the USGS page Volcanic Sulfer Aerosols Affect Climate and the Earth's Ozone Layer.
127341. RSVP at 21:24 PM on 3 October 2009
        How we know global warming is still happening
        Steve L wrote... "Wind doesn't concentrate heat at ground level thousands of km from global point point sources. Further, it takes more heat to melt ice than to raise air temperature, so for this and other reasons I dispute your assertion that the Arctic and alpine glaciers are the easiest places to detect global warming." It's not about what you can measure, although I can possibly understand the temptation. I was referring to a physics concept not a meteorological concept. The physics concept being that you cant destroy energy and then applying this to a closed system called Earth. The first place you might notice the effects would be in a snow line etc. The method I am using to deduce this possibility is called thinking. Independent thinking as opposed to Googling.
127342. RSVP at 17:27 PM on 3 October 2009
        How we know global warming is still happening
        Socrates said, I know I know nothing. (You can even argue about what he really said). My understanding of this statement is that you cant really know anything for sure. I find the spirit of this discussion poisoned by fanaticism, as opposed to skepticism. It is one thing to assert that CO2 has the effect of trapping solar energy, and quite another to conclude that it is the main cause of global warming. Why even bother to continue investigating this subject? Its a done deal. It should be a crime to burn fossil fuels. I suppose that is coming. If not, for sure the price of oil will be going up, and the question of who is thriving on it will be a little more clear. To answer WeatherRusty The major ice ages precede recorded history, but there have been periods of strong cooling in recent times. http://www.drgeorgepc.com/Volcano1883Krakatoa.html Here is an abstact from this article. ---------------------------------------- Upper Atmosphere Effects Ash from the eruptions was propelled to a height of 50 miles (80 kilometers) in the upper atmosphere blocking the sun and plunging the surrounding region into darkness for two and a half days. Climatic Changes It has been estimated that at least 21 cubic Km (appr. 11 cubic mile) was ejected from the eruption of Krakatoa and that at least 1 cubic mile of the finer material was blown to a height of about 17 miles (27 Km). The volcanic dust blown into the upper atmosphere was carried several times around the earth by air currents. This volcanic dust veil not only created the spectacular atmospheric effects described previously but acted also as a solar radiation filter, reducing the amount of sunlight reaching the surface of the earth. In the year following the eruption, global temperatures were lowered by as much as 1.2 degree Centigrade on the average. Weather patterns continued to be chaotic for years and there were major climatological changes which affected the entire globe. Temperatures did not return to normal until five years later, in 1888. ------------------------------------- Whether this was an ice age or not, my question remains. After this cooling, what brought the temperature back to "normal"? This is not directed to anyone in particular, especially readers who only believe a thing is true if it can be answered by a Google search. Preferably a person who can think independently. What brought the temperature back to "normal"?
127343. WeatherRusty at 11:52 AM on 3 October 2009
        How we know global warming is still happening
        A real glass greenhouse interior is warmed more by the suppression of convection between the interior and exterior by the glass barrier than by absorption of IR by the glass. The tropopause between the troposphere and stratosphere is a barrier to convection also due to a temperature inversion. Nearly all energy leaving the troposphere and most leaving the glass of a greenhouse is in the form of radiation. This is why the forcing for a doubling of CO2 (3.7W/m^2) is measured from the tropopause I believe. When have volcanic eruptions sent the Earth into Ice Ages?
127344. WeatherRusty at 10:00 AM on 3 October 2009
        How we know global warming is still happening
        A real glass greenhouse interior is warmed more by the suppression of convection between the interior and exterior by the glass barrier than by absorption of IR by the glass. The tropopause between the troposphere and stratosphere is a barrier to convection also due to a temperature inversion. Nearly all energy leaving the troposphere and most leaving the glass of a greenhouse is in the form of radiation. This is why the forcing for a doubling of CO2 (3.7W/m^2) is measured from the tropopause I believe. When have volcanic eruptions sent the Earth into Ice Ages?
127345. Steve L at 06:56 AM on 3 October 2009
        How we know global warming is still happening
        Well, I guess what's appropriate depends to some degree on what the topic of the post is and whether or not anybody is relying on a particular bit of misinformation (eg from a misnomer) to support an argument. You're not going to get rid of the name -- too much history, etc, and I don't think anybody here gets confused by it (who is thriving upon it?). But, whatever, it was just a PS. Your response regarding your nonsense is also worthy only of a PS. Wind doesn't concentrate heat at ground level thousands of km from global point point sources. Further, it takes more heat to melt ice than to raise air temperature, so for this and other reasons I dispute your assertion that the Arctic and alpine glaciers are the easiest places to detect global warming. Finally, on to your question. Don't worry, this time I didn't get loost. Response 1: That's your question? Then what about all that other stuff about "inhospitable to life". I was going to refer you to PETM. Response 2: What don't you like about any of the internet resources already available that explain the end of ice ages? Check out "ice ages" or "Milankovitch" on Wikipedia. Response 3: Google didn't find much with "delicate sunlight balance theory".
127346. Tom Dayton at 06:33 AM on 3 October 2009
        How we know global warming is still happening
        RSVP asked "What caused ice ages to end?" Orbital mechanics (a.k.a. Milankovitch cycles) followed by feedbacks such as greenhouse gases and ice and snow. At the top left of this page, click the link "Climate's Changed Before." Also see the section titled Milankovitch cycles (finally) explained on this page of cce's "The Global Warming Debate" site.
127347. chris at 06:27 AM on 3 October 2009
        How we know global warming is happening, Part 2
        Shawnhet, I think your analysis applies to an imaginary circumstance where only the oceans absorb heat under the influence of positive radiative imbalance. But additional heat is absorbed by the land, atmosphere, and in melting ice. According to Hansen et al (2005), this amounts to around 0.05 W.m-2 globally averaged. So the globally-averaged heat uptake is of the order of 0.6 W.m-2 during 2003-2008 (according to the analysis of Schuckmann, 2009). If we’re comparing this value with the value estimated by Hansen et al (2005) for example (0.85 W.m-2 in 2003), we should probably consider the fact that the sun was radiating energy at around 1 W.m-2 more (top of solar cycle) than in 2008/9 (smack bottom of solar cycle). If we consider the effect on absorbed solar radiation at the surface, this amounts to a (temporary!) reduction near 0.175 W.m-2 (1 x 0.25 spherical geometry x 0.7 albedo) now, compared to 2003. So we should probably be comparing 0.6 W.m-2 to something quite a bit less than 0.85 W.m-2 (something around 0.75 W.m-2 perhaps). So the heat uptake data determined by Schuckmann 2009 is of a similar order to that determined by Hansen et al 5 years ago. It is somewhat lower than the value determined by Trenberth (2009); however there must be significant uncertainty in these values. The main point is that current data is increasingly at odds with the notion (see blogosphere ad nauseum!) that the oceans are cooling. They’re not. The evidence supports the rather straightforward expectation that a positive radiative imbalance results in absorption of heat and global warming.
127348. RSVP at 06:11 AM on 3 October 2009
        How we know global warming is still happening
        To Steve L. For one thing, I dont think it is so inappropriate to point out that the term GREENHOUSE is misnomer. The point here, is that the term was chosen based on a hypothesis, not a theory. If the hypothosis turns out to be in error, keeping the name around only creates more confusion, which apparently is what many people appear to be thiving on. As far my nonsense. I was saying that energy pollution from an automobile for instance is cummulative in a global sense, and if not lost into outer space spreads out wherever the wind takes it. The edges of glaciers and ice caps are the easiest places to observe the effects of global warming. And for the third time my question. The question is simple. What caused ice ages to end? If the Earth maintains a delicate equilibrium as per the CO2 greenhouse model, why in the absense of fossil fuel burning did the temperature of the Earth rise? And why did it stop rising? or did it stop? I hope I did not loose you this time.
127349. Steve L at 05:18 AM on 3 October 2009
        How we know global warming is still happening
        Just visiting briefly today -- rsvp, I don't really understand what you're asking. I half gave up on trying to understand you when you replied to my question in 14 with a bunch of nonsense about people carrying the energy all around the world such that the Arctic is the first place we should notice warming. But with the all caps and exclamation marks, it seems very important for you to get an answer to your question. Try laying out your reasoning and asking the question again. PS. I agree with Tom that you should do more reading. Right now you're diluting potentially interesting questions (we'll see) with junk about greenhouses being inadequate analogies for the enhanced greenhouse effect (which is old, well-known, and irrelevant).
127350. RSVP at 04:45 AM on 3 October 2009
        How we know global warming is still happening
        ANYONE can say, "hold your question until youve read all that material" to ANY QUESTION. That is a copout! ANSWER THE QUESTION! By the way, in a GREENHOUSE, light is REFLECTED BACK into the chamber. CO2 ABSORBS IR! It CONVECTS energy into the surrounding mass of air around it. Thus the observation that it would saturate. And if it happens to re-radiate, the radiation is isotropic unlike the surface of glass in greenhouse which points the light downward. Now please use the delicate balance theory to explain how the Earth comes out of an Ice Age, without skirting the question::::

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