The cornerstone argument of climate change deniers is that our current warming is just a natural cycle, and this claim is usually accompanied by the statement, “the planet has warmed naturally before.” This line of reasoning is, however, seriously flawed both logically and factually. Therefore, I want to examine both the logic and the evidence to explain why this argument is faulty and why we are actually quite certain that we are the primary cause of our planet’s current warming.
The fact that natural climate change occurred in the past does not mean that the current warming is natural
I cannot overstate the importance of this point. Many people say, “but the planet has warmed naturally before” as if that automatically means that our current warming is natural, but nothing could be further from the truth. In technical terms, this argument commits a logical fallacy known as non sequitur (this is the fallacy that occurs whenever the conclusion of a deductive argument does not follow necessarily from the premises). The fact that natural warming has occurred before only tells us that it is possible for natural warming to occur. It does not indicate that the current warming is natural, especially given the evidence that it is anthropogenic (man-made).
To put this another way, when you claim that virtually all of the world’s climatologists are wrong and the earth is actually warming naturally, you have just placed the burden of proof on you to provide evidence for that claim. In other words, simply citing previous warming events does not prove that the current warming is natural. You have to actually provide evidence for a natural cause of the current warming, but (as I’ll explain shortly) no such mechanism exists.
Natural causes of climate change
Now, let’s actually take a look at the natural causes of climate change to see if any of them can account for our current warming trend (spoiler alert, they can’t).
Sun
The sun is an obvious suspect for the cause of climate change. The sun is clearly an important player in our planet’s climate, and it has been responsible for some warming episodes in the past. So if, for some reason, it was burning hotter now than in the past, that would certainly cause our climate to warm. There is, however, one big problem: it’s not substantially hotter now than it was in the recent past. Multiple studies have looked at whether or not the output from the sun has increased and whether or not the sun is responsible for our current warming, and the answer is a resounding “no” (Meehl, et al. 2004; Wild et al. 2007; Lockwood and Frohlich 2007, 2008; Lean and Rind 2008; Imbers et al. 2014). It likely caused some warming in the first half the 20th century, but since then, the output from the sun does not match the rise in temperatures (in fact it has decreased slightly; Lockwood and Frohlich 2007, 2008). Indeed, Foster and Rahmstorf (2011) found that after correcting for solar output, volcanoes, and El Niños, the warming trend was even more clear, which is the exact opposite of what we would expect if the sun was driving climate change (i.e., if the sun was the cause, then removing the effect of the sun should have produced a flat line, not a strong increase).
Finally, the most compelling evidence against the sun hypothesis and for anthropogenic warming is (in my opinion) the satellite data. Since the 70s, we have been using satellites to measure the energy leaving the earth (specifically, the wavelengths of energy that are trapped by CO2). Thus, if global warming is actually caused by greenhouse gasses trapping additional heat, we should see a fairly constant amount of energy entering the earth, but less energy leaving it. In contrast, if the sun is driving climate change, we should see that both the energy entering and leaving the earth have increased. Do you want to guess which prediction came true? That’s right, there has been very little change in the energy from the sun, but there has been a significant decrease in the amount of energy leaving the earth (Harries et al. 2001; Griggs and Harries. 2007). That is about as close to “proof” as you can get in science, and if you are going to continue to insist that climate change is natural, then I have one simple question for you: where is the energy going? We know that the earth is trapping more heat now than it did in the past. So if it isn’t greenhouse gasses that are trapping the heat, then what is it?
Milankovitch cycles
Other important drivers of the earth’s climate are long-term cycles called Milankovitch cycles, which involve shifts in the earth’s orbit, tilt, and axis (or eccentricity, precession, and obliquity, if you prefer). In fact, these appear to be one of the biggest initial causes of prominent natural climate changes (like the ice ages). So it is understandable that people would suspect that they are driving the current climate change, but there are several reasons why we know that isn’t the case.
First, Milankovitch cycles are very slow, long-term cycles. Depending which of the three cycles we are talking about, they take tens of thousands of years or even 100 thousand years to complete. So changes from them occur very slowly. In contrast, our current change is very rapid (happening over a few decades as opposed to a few millennia). So the rate of our current change is a clear indication that it is not being caused by Milankovitch cycles.
Second, you need to understand how Milankovitch cycles affect the temperature. The eccentricity cycle could, in concept, directly cause global warming by changing the earth’s position relative to the sun; however, that would cause the climate to warm or cool by affecting how much energy from the sun hits the earth. In other words, we are back to the argument that climate change is caused by increased energy from the sun, which we know isn’t happening (see the section above).
The other cycles (precession and obliquity), affect the part of the earth that is warmed and the season during which the warming takes place, rather than affecting the total amount of energy entering the earth. Thus, they initially just cause regional warming. However, that regional warming leads to global warming by altering the oceans’ currents and warming the oceans, which results in the oceans releasing stored CO2 (Martin et al. 2005; Toggweiler et al. 2006; Schmittner and Galbraith 2008; Skinner et al. 2010). That CO2 is actually the major driver of past climate changes (Shakun et al. 2012). In other words, when we study past climate changes, what we find is that CO2 levels are a critically important factor, and, as I’ll explain later, we know that the current increase in CO2 is from us. Thus, when you understand the natural cycles, they actually support anthropogenic global warming rather than refuting it.
Volcanoes
At this point, people generally resort to claiming that volcanoes are actually the thing that is emitting the greenhouse gasses. That argument sounds appealing, but in reality, volcanoes usually emit less than 1% of the CO2 that we emit each year (Gerlach 2011). Also, several studies have directly examined volcanic emissions to see if they can explain our current warming, and they can’t (Meehl, et al. 2004; Imbers et al. 2014).
Carbon dioxide (CO2)
A final major driver of climate change is, in fact, CO2. Let’s get a couple of things straight right at the start. First, we know that CO2 traps heat and we know that increasing the amount of CO2 in an environment will result in the temperature increasing (you can find a nice list of papers on the heat trapping abilities of CO2 here). Additionally, everyone (even climate “skeptics”) agree that CO2 plays a vital role in maintaining the earth’s temperature. From those facts, it is intuitively obvious that increasing the CO2 in the atmosphere will result in the temperature increasing. Further, CO2 appears to be responsible for a very large portion of the warming during past climate changes (Lorius et al. 1990; Shakun et al. 2012). Note: For past climate changes, the CO2 does lag behind the temperature initially, but as I explained above, the initial warming triggers an increase in CO2, and the CO2 drives the majority of the climate change.
Image from the Scripps Institution of Oceanography
At this point, you may be thinking, “fine, it’s CO2, but the CO2 isn’t from us, nature produces way more than we do.” It is true that nature emits more CO2 than us, but prior to the industrial revolution, nature was in balance, with the same amount of CO2 being removed as was emitted. Thus, there was no net gain. We altered that equation by emitting additional CO2. Further, the increase that we have caused is no little thing. The concentration has increased by over 40% since the start of the industrial revolution, and the current concentration of CO2 in the atmosphere is higher than it has been at any point in the past 800,000 years. So, yes, we only emit a small fraction of the total CO2 each year, but we are emitting more CO2 than nature can remove, and a little bit each year adds up to a lot over several decades.
These data come from Wei et al. 2009, but the legend of this figure was modified for readability by skepticalscience.com (the data themselves were in no way manipulated as you can see in Figure 4 of Wei et al. 2009)
Additionally, we know that the current massive increase in CO2 is from us because of the C13 levels. Carbon has two stable isotopes (C12 and C13), but C13 is heavier than C12. Thus, when plants take carbon from the air and use it to make carbohydrates, they take a disproportionate amount of C12. As a result, the C13/C12 ratios in plants, animals (which get carbon from eating plants), and fossil fuels (which are formed form plants and animals) have more C12 than the C13/C12 ratios in that atmosphere. Therefore, if burning fossil fuels is responsible for the current increase in CO2, we should see that ratio of C13/C12 in the atmosphere shift to be closer to that of fossil fuels (i.e., contain more C12), and, guess what, that is exactly what we see (Bohm et al. 2002; Ghosh and Brand 2003;Wei et al. 2009). This is unequivocal evidence that we are the cause of the current increase in CO2.
Finally, we can construct all of this information into a deductive logical argument (as illustrated on the left). If CO2 traps heat, and we have increased the CO2 in the atmosphere, then more heat will be trapped. To illustrate how truly inescapable that conclusion is, here is an analogous argument:
1). Insulation traps heat
2). You doubled the insulation of your house
3). Therefore, your house will trap more heat
You cannot accept one of those arguments and reject the other (doing so is logically inconsistent).
Note: Yes, I know that the situation is much more complex than simply CO2 trapping heat, and there are various feedback mechanisms at play, but that does not negate the core argument.
This figure from Hansen et al. 2005 shows the effect of both the natural and anthropogenic drivers of climate change. Notice how only anthropogenic sources show a large warming trend. Also, see figure 2 of Meehl et al. 2004.
Putting the pieces together
So far, I have been talking about all of the drivers of climate change independently, which is clearly an oversimplification, because, in all likelihood, several mechanisms are all acting together. Therefore, the best way to test whether or not the current warming is natural is actually to construct statistical models that include both natural and man-made factors. We can then use those models to see which factors are causing climate change. We have constructed multiple of these models, and they consistently show that natural factors alone cannot explain the current warming (Stott et al. 2001; Meehl et al. 2004; Allen et al. 2006; Lean and Rind 2008; Imbers et al. 2014). In other words, including human greenhouse gas emissions in the models is the only way to get the models to match the observed warming. This is extremely clear evidence that the current warming is not entirely natural. To be clear, natural factors do play a role and are contributing, but human factors are extremely important, and the models show that they account for the majority of the warming.
Correlation vs. causation
It is usually about now that opponents of climate change start to argue that scientists are actually committing a correlation fallacy, and simply showing a correlation between temperature and the CO2 that we produce does not mean that the CO2 is causing the temperature increase. There are, however, several problems with that argument.
First, correlation can indicate causation under certain circumstances. Namely, situations where you have controlled all confounding factors. In other words, if you can show that Y is the only thing that is changing significantly with X, then you can reach a causal conclusion (even placebo controlled drug trials are really just showing correlations between taking the drug and recovery, but because they used the control, they can use that correlation to reach a causal conclusion). In the case of climate change, of course, we have examined the confounding factors. As I explained in the previous section, we have constructed statistical models with the various drivers of climate change, and anthropogenic greenhouse gasses are necessary to account for the current warming. In other words, we have controlled for the other causes of climate change, therefore we can reach a causal conclusion.
Smoking and lung/bronchial cancer rates (data via the CDC).
Second, and perhaps more importantly, there is nothing wrong with using correlation to show a particular instance of causation if a causal relationship between X and Y has already been established. Let me give an example. The figure to the right shows the smoking rates and lung/bronchial cancer rates in the US. There is an obvious negative correlation between the two (P < 0.0001), and I don’t think that anyone is going to disagree with the notion that the decrease in smoking is largely responsible for the decrease in lung cancers. Indeed, there is nothing wrong with reaching that conclusion, and it does not commit a correlation fallacy. This is the case because a causal relationship between smoking and cancer has already been established. In other words, we know that smoking causes cancer because of other studies. Therefore, when you see that the two are correlated over time, there is nothing wrong with inferring that smoking is driving the cancer rates. Even so, we know from laboratory tests and past climate data that CO2 traps heat and increasing it results in more heat being trapped. In other words, a causal relationship between CO2 and temperature has already been established. Therefore, there is nothing fallacious about looking at a correlation between CO2 and temperature over time and concluding that the CO2 is causing the temperature change.
Ad hoc fallacies and the burden of proof
At this point, I often find that people are prone to proposing that some unknown mechanism exists that scientists haven’t found yet. This is, however, a logical fallacy known as ad hoc. You can’t just make up an unknown mechanism whenever it suits you. If that was valid, then you could always reject any scientific result that you wanted, because it is always possible to propose some unknown mechanism. Similarly, you can’t use the fact that scientists have been wrong before as evidence, nor can you argue that, “there are still things that we don’t understand about the climate, so I don’t have to accept anthropogenic climate change” (that’s an argument from ignorance fallacy). Yes, there are things that we don’t understand, but we understand enough to be very confident that we are causing climate change, and, once again, you can’t just assume that all of our current research is wrong.
The key problem here is the burden of proof. By claiming that there is some other natural mechanism out there, you have just placed the burden of proof squarely on your shoulders. In other words, you must provide actual evidence of such a mechanism. If you cannot do that, then your argument is logically invalid and must be rejected.
Summary/Conclusion
Let’s review, shall we?
- We know that it’s not the sun
- We know that it’s not Milankovitch cycles
- We know that it’s not volcanoes
- We know that even when combined, natural causes cannot explain the current warming
- We know that CO2 traps heat
- We know that increasing CO2 causes more heat to be trapped
- We know that CO2 was largely responsible for past climate changes
- We know that we have greatly increased the CO2 in the atmosphere
- We know that the earth is trapping more heat now than it used to
- We know that including anthropogenic greenhouse gasses in the models is the only way to explain the current warming trend
When you look at that list of things that we have tested, the conclusion that we are causing the planet to warm is utterly inescapable. For some baffling reason, people often act as if scientists have never bothered to look for natural causes of climate change, but the exact opposite is true. We have carefully studied past climate changes and looked at the natural causes of climate changes, but none of them can explain the current warming. The only way to account for our current warming is to include our greenhouse gasses in the models. This is extremely clear evidence that we are causing the climate to warm, and if you want to continue to insist that the current warming is natural, then you must provide actual evidence for the existence of a mechanism that scientists have missed, and you must provide evidence that it is a better explanation for the current warming than CO2. Additionally, you are still going to have to refute the deductive argument that I presented earlier (i.e., show that a premise is false or that I committed a logical fallacy), because finding a previously unknown mechanism of climate change would not discredit the importance of CO2 or the fact we have greatly increased it. Finally, you also need to explain why the earth is trapping more heat than it used to. If you can do all of that, then we’ll talk, but if you can’t, then you must accept the conclusion that we are causing the planet to warm.
Related posts
- Basics of Global Climate Change: A Logical Proof That it is Our Fault
- Do we need more studies on vaccines, GMOs, climate change, etc.?
- “Follow the money”: the finances of global warming, vaccines, and GMOs
- Global warming hasn’t paused
- Yes, there is a strong consensus on climate change
Literature cited
- Allen et al. 2006. Quantifying anthropogenic influence on recent near-surface temperature change. Surveys in Geophysics 27:491–544.
- Bohm et al. 2002. Evidence for preindustrial variations in the marine surface water carbonate system from coralline sponges. Geochemistry, Geophysics, Geosystems 3:1–13.
- Foster and Rahmstorf. 2011. Global temperature evolution 1979–2010. Environmental Research Letters 7:011002.
- Gerlach 2011. Volcanic versus anthropogenic carbon dioxide. EOS 92:201–202.
- Ghosh and Brand. 2003. Stable isotope ratio mass spectrometry in global climate change research. International Journal of Mass Spectrometry 228:1–33.
- Griggs and Harries. 2007. Comparison of spectrally resolved outgoing longwave radiation over the tropical Pacific between 1970 and 2003 Using IRIS, IMG, and AIRS. Journal of Climate 20:3982-4001.
- Hansen et al. 2005. Earth’s energy imbalance: confirmation and implications. 308:1431–1435.
- Harries et al. 2001. Increases in greenhouse forcing inferred from the outgoing longwave radiation spectra of the Earth in 1970 and 1997. Nature 410:355–357.
- Imbers et al. 2014. Sensitivity of climate change detection and attribution to the characterization of internal climate variability. Journal of Climate 27:3477–3491.
- Lean and Rind. 2008. How natural and anthropogenic influences alter global and regional surface temperatures: 1889 to 2006. Geophysical Research Letters 35:L18701.
- Lockwood and Frohlich. 2007. Recently oppositely directed trends in solar climate forcings and the global mean surface air temperature. Proceedings of the National Academy of Sciences 463:2447–2460.
- Lockwood and Frohlich. 2008. Recently oppositely directed trends in solar climate forcings and the global mean surface air temperature. II. Different reconstructions of the total solar irradiance variation and dependence on response time scale. Proceedings of the National Academy of Sciences 464:1367–1385.
- Lorius et al. 1990. The ice-core record: climate sensitivity and future greenhouse warming. Nature 139–145.
- Martin et al. 2005. Role of deep sea temperature in the carbon cycle during the last glacial. Paleoceanography 20:PA2015.
- Meehl, et al. 2004. Combinations of natural and anthropogenic forcings in the twentieth-century climate. Journal of Climate 17:3721–3727.
- Schmittner and Galbraith 2008. Glacial greenhouse-gas fluctuations controlled by ocean circulation changes. Nature 456:373–376.
- Shakun et al. 2012. Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation. Nature 484:49–54.
- Skinner et al. 2010. Ventilation of the deep Southern Ocean and deglacial CO2 rise. Science 328:1147-1151.
- Stott et al. 2001. Attribution of twentieth century temperature change to natural and anthropogenic causes. Climate Dynamics17:1–21.
- Toggweiler et al. 2006. Mid-latitude westerlies, atmospheric CO2, and climate change during the ice ages. Paleoceanography 21:PA2005.
- Wei et al. 2009. Evidence for ocean acidification in the Great Barrier Reef of Australia. Geochimica et Cosmochimica Acta 73:2332–2346.
- Wild et al. 2007. Impact of global dimming and brightening on global warming. Geophysical Research Letters
The Logic of Science 
Your argument that Man is the cause of increased CO2 in the atmosphere leading to warming does not stand up in light of the information contained in the following article:
FOSSIL FOREST CAUSED CLIMATE CHANGE
According to article in Science Daily 19 November 2015 and Geology, 2015; 43 (12): 1043 DOI: 10.1130/G37000.1, Chris Berry of the School of Earth and Ocean Science at Cardiff University and John Marshall of National Oceanography Centre, University of Southampton have identified a number of “fossil forests” in Svalbard, a Norwegian archipelago in the Arctic Ocean. The scientists claim the trees originally grew near the equator but the land has ‘drifted’ to its current position in the high Arctic. The fossils are mainly huge Lycopod trees, which are dated at 380 million years old, and regarded as big movers in the climate issue. (Lycopods exist today but only as tiny tassle ferns). The evolution of such large Lycopods is believed to have caused a very large change in the climate. Chris Berry explained: “During the Devonian Period, it is widely believed that there was a huge drop in the level of carbon dioxide in the atmosphere, from 15 times the present amount to something approaching current levels. The evolution of tree-sized vegetation is the most likely cause of this dramatic drop in carbon dioxide because the plants were absorbing carbon dioxide through photosynthesis to build their tissues, and also through the process of forming soils”.
Link: ScienceDaily
ED. COM. Did you catch that CO2 figure? – 15 TIMES the PRESENT LEVEL of carbon dioxide in the atmosphere? Where do they think it came from before this fossil forest supposedly used it up? If you believe in evolution, IT DIDN’T COME FROM PEOPLE burning coal or driving trucks.
Let’s look at what we know about carbon dioxide. Carbon dioxide (CO2) is a naturally occurring gas produced by a number of geological and biological processes, most of which are out of our control. (Try turning off a volcano.) There is good evidence from the study of sediments and ice cores that levels of CO2 have varied a lot in the past, but none of these changes had anything to do with man-made industry. Very large changes in carbon dioxide levels have undoubtedly influenced the earth’s temperature, but these involved catastrophic events that were also beyond our control. The 40days of rain at Noah’s Flood would certainly have dissolved much atmospheric CO2 and dumped it in the sea. Such removal of CO2 from the atmosphere would certainly have contributed to climate change in post Flood times, so God’s warning to Noah that winter and summer would become normal (Genesis 8:22) is only to be expected. But it should also remind us about who is ultimately in control of the earth’s climate – the Creator and Judge of the earth, the Lord Jesus Christ and not man. (Ref. climate, weather, atmosphere)
http://www.creation.net
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This makes no sense. There never was a Noachian flood. In addition, i personally, as a lark calculated the amount of heat that would be released by conversion of potential energy to kinetic energy for40 days of rain to cover the mountains. Th atmosphere would have a temp of 840 deg F and the ark would have burst into flames
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Let’s see your calculations which will be examined and the basis for such data
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But the Arc was magic remember!
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Your argument doesn’t make any sense and completely ignores several key points of my post. I’m going to ignore the flood nonsense because you would need to provide extremely solid scientific evidence for it before you could use it in an argument, and the idea of a worldwide flood is thoroughly refuted by fossils, geology, ice cores, varves, corals, etc. So that is a rabbit hole that I have no interest in going down at the moment. Let’s focus instead on your argument about CO2 having been higher in the past (since it’s the one that is actually relevant to this post).
Yes, CO2 has naturally been higher in the past (and to be clear, by past, we are talking about millions of years ago), but that does not in any way shape or form indicate or even suggest that the current CO2 is natural. You are committing the same non-sequtur fallacy that I addressed in the first section of this post (after the intro).
Second, how do you explain the C13/C12 ratios? They clearly show that the CO2 is from us. Finally, just look around you at all of the things emitting greenhouse gasses. It doesn’t take a genius to figure out that emitting CO2 at that rate year after year is going to result in an increase in CO2.
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‘You have to actually provide evidence for a natural cause of the current warming…’
No, that is incorrect. While your argument re: non sequitur is valid to my mind, the position you take here is a bald attempt to re-write the null hypothesis. You may refute it with evidence, but you may not re-write it to suit your purposes. Those vaunted climatologists who claim unnatural warming are required to show evidence which refutes the null hypothesis, which of course holds that the warming is indeed natural in cause. Absent such evidence, the null hypothesis remains. What you suggest is as unscientific as the fallacy you noted on which we agree. The issues are entirely separate, logically and scientifically speaking.
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You’re misunderstanding the way that the null hypothesis works.
You said, “Those vaunted climatologists who claim unnatural warming are required to show evidence which refutes the null hypothesis, which of course holds that the warming is indeed natural in cause.”
I have no problems with that statement (except perhaps the use of “vaunted”), but this entire post was on that evidence. In other words, we have ample evidence that climate change is not natural and is in fact being caused by our CO2. Thus, the null hypothesis has been rejected.
Now, if someone wants to try to claim that all of that evidence is wrong, they have placed the burden of proof on themselves, and they are responsible for providing some very strong evidence for that claim. Also, they are now accepting the null, rather than failing to reject (which, as I think you know, is not allowed). To put this another way, if you want to actually claim that climate change is natural, then you must make that your alternative hypothesis and you make anthropogenic warming your null hypothesis. However, doing so, once again, means that you are responsible for providing evidence to support your claim. In other words, in some situations (such as this one) you can structure the experiment two different ways: you can either make anthopogenic warming the hypothesis that you are testing (your alternative) or you can make natural warming the hypothesis that you are testing (in which case anthropogenic becomes the null).
To put this one final way, if the idea that warming is natural is your null hypothesis, then you can never actually state that it is true. All you could do is state that it hasn’t been ruled out (which, just to be clear, it has). If you actually want to claim that it is true, then you must provide evidence for that claim.
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Fact 2 about CO2 is not quite right. It is in the part that isn’t quite right where the disagreement lies.
Nothing about CO2 is intuitively obvious. CO2 and water vapor even to the most skilled analyst on the subject is confusing.
CO2 is at best a buffer to minimize the chance that we dive back into an ice age. It is not much of an accelerator into runaway greenhouse.
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Just because it’s confusing to you does not mean that it is confusing to everyone. That is an argument from ignorance logical fallacy. Read the link below the article about there being consensus among climate scientists. None of them are confused and that’s what really counts.
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Actually, we have a very good understanding of the relationship between CO2 and water vapor.
First, we know from laboratory experiments that if you increase the CO2 in an environment that environment will trap more heat as a direct result of the CO2 (remember, you can control things like water vapor in a lab). So my second premise stands.
Second, the water vapor in the atmosphere has increased, but here is the really important catch: water vapor only increases as a result of the temperature increasing. The only way to increase the water vapor in the atmosphere is to increase the evaporation, and that increases as a result of temperature. In other words, you need to increase the temperature before you can increase the water vapor. Thus, water vapor is a feedback mechanism wherein CO2 causes warming, which leads to more water vapor, which leads to more warming. Scientists are well aware of this relationship and include it in their projects of future climate change.
The key point is that water vapor doesn’t just increase on its own. Rather, it increases in response to warming.
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“The key point is that water vapor doesn’t just increase on its own. Rather, it increases in response to warming.”
From the point of view of the seas, in the statement above, you confuse heat with temperature. The rate of evaporation from the seas is mainly dependent on heat input, not temperature. And while I don’t argue that the amount of WV that the atmosphere can hold is certainly limited by the atmospheric temperature, this is simply an upper bound…and there is nothing to suggest that WV content in the atmosphere must necessarily follow the upper bound.
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Your dancing around the problem with your argument rather than actually dealing with it. Whether you can refer to it as temperature or heat input, the point stands that water vapor increases in response to other factors. It doesn’t just magically go up on its own.
Further, basic physics suggest that WV will be pretty close to the upper bound. There is a very direct relationship between temperature and the state of water. As the temperature (or heat input if you prefer) increases, the amount of water that transitions into vapor increases. You aren’t going to have a really warm body of water that isn’t getting converted into WV (unless something really screwy is happening with the atmospheric pressure or something like that).
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Quite simply, heat which results in a phase change does not result in a temperature change. Changes in evaporation rates can occur while T remains constant. Latent heat is at least three orders of magnitude more significant than sensible heat.
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That is quite irrelevant to the topic at hand, because it does not change the fact that to increase the amount of liquid water that is converted into water vapor, you have to increase the heat (temperature) of the system. That is the fundamental point that you are ignoring. Water vapor doesn’t just magically increase on it’s own. It increases in response to something else like temperature or pressure. This is why a cup of water doesn’t suddenly start boiling uncontrollably in your hand, and it’s why a cup of water sitting in a cool apartment will not evaporate as fast as a cup that is sitting outside in the summer sun.
To put this another way, you seem to think that latent heat and sensible heat are two different forms of energy, which is completely incorrect. They are just measures of energy exchanges. Latent heat is not, for example, a special type of heat that causes water to become vapor. Rather, “latent heat” is just the term that we use to describe the exchange of energy that took place.
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Let me try this one other way because I feel like we are going in circles here. Are you honestly arguing that the amount of water vapor present in a system is not largely controlled by temperature?
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Mic drop…
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God knows the best. Amen
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I’ve never understood why Christians seem to think that’s a good argument. If that worked, then you could use it to absolve you of responsibility for anything.
“Oh look, that child is about to get hit by a bus. Oh well, God knows best.”
“Thousands of people were left without homes or food after the storm, but God knows best so there is no need for me to do anything about it.”
“A maniac is about to commit a massive genocide, but God knows best so there is no point in try to stop him.”
“Science tells us that smoking causes cancer, but God knows best, so I’m just going to smoke away and trust him to take care of me.”
Do you see the problem?
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Oops, I raped your child! God knows best. Amen.
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Interesting the comment that the sun was responsible for temperature rise in the early half of the century, “It likely caused some warming in the first half the 20th century,” Henry’s law comes into effect then, a warm ocean holds less CO2, hence CO2 concentrations rising are a direct result of a warming event. not the other way round.
Henry’s Law
The solubility of a gas in a liquid depends on temperature, the partial pressure of the gas over the liquid, the nature of the solvent and the nature of the gas. The most common solvent is water. Carbonated beverages are an example of Henry’s law in everyday life. The dissolved carbon dioxide stays in solution in a closed pop bottle or can where the partial pressure of carbon dioxide was set at a high value during bottling. When the can or bottle is opened the partial pressure of CO2 is much lower and the dissolved carbon dioxide will gradually escape from the pop. When the new low partial pressure equilibrium is established the soda will be “flat” . This loss of dissolved carbon dioxide will happen faster for warm soda than for cold.
Gas solubility is always limited by the equilibrium between the gas and a saturated solution of the gas. The dissolved gas will always follow Henry’s law.
credit http://www.800mainstreet.com/9/0009-006-henry.html
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CO2 levels in sea water
How much CO2 gas can sea water hold? http://www.coexploration.org/bbsr/classroombats/html/co2_in_the_sea.html
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Formation of Calcium Carbonate
http://www.innovateus.net/content/how-calcium-carbonate-formed
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There are several important points here. First, I certainly don’t deny Henry’s law (in fact, I even stated in the post that one of the key factors driving past climate change was oceans warming and releasing CO2).
Second, the majority of the studies have found that the warming effect of the sun was only very slight, so although it probably caused a slight increase in CO2, it could not have caused the doubling that we have observed. Indeed, the increase in CO2 during the first half of the last century was very slight. It didn’t start going up really rapidly until the last half, which matches our emission patterns rather closely.
Third, and most importantly, you are ignoring the C13/C12 ratios. If the CO2 was coming from the ocean, the ratio in the atmosphere would not be changing. However, the fact that it is changing in the direction and by the amount expected if the CO2 was from us is extremely clear evidence that we are the source of the current increase in CO2. If you are going to argue that the CO2 increase is not from us, then you need to explain why those ratios are shifting.
Finally, when you consider the amount of CO2 that we are emitting, it is inevitable that it will build up in the atmosphere. We currently release over 9,000,000,000 metric tons of carbon each year. For those of you in America, that is around 19,800,000,000,000 pounds. Is it really surprising that doing that year after year is going to result in a change in our atmosphere? (note for clarity, that rate has been going up over time, so I don’t mean to suggest that we have been emitting that amount for the past century, but the point stands that we have been dumping tremendous amounts of CO2 into our atmosphere for many decades, and our current rate of emissions is clearly unsustainable).
https://www3.epa.gov/climatechange/ghgemissions/global.html
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CO2 is a bit of a boogie man, has little effect on temperature rise, atmospheric moisture is far more greenhouse effect producing. I agree our use of fossil fuels is insane, though won’t stop till they are depleted, check this out for an emission free answer to every thing
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Carbfix
https://www.or.is/english/carbfix-project
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You’re shifting the goal posts (i.e., first you argue that the CO2 isn’t form us, then when I show that it is, you shift arguments and claim that the CO2 isn’t that important). I provided multiple scientific papers that demonstrate the importance of CO2 for trapping heat and controlling the climate. Where is your evidence that it’s not that important?
Regarding water vapor, I am just going to copy and paste my response to Manuel from above.
The water vapor in the atmosphere has increased, but here is the really important catch: water vapor only increases as a result of the temperature increasing. The only way to increase the water vapor in the atmosphere is to increase the evaporation, and that increases as a result of temperature. In other words, you need to increase the temperature before you can increase the water vapor. Thus, water vapor is a feedback mechanism wherein CO2 causes warming, which leads to more water vapor, which leads to more warming. Scientists are well aware of this relationship and include it in their projects of future climate change.
The key point is that water vapor doesn’t just increase on its own. Rather, it increases in response to warming.
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The relationship between T and WV which you claim is neither linear nor as simplistic as you claim, provided we are discussing the atmosphere and not some ‘all other things being equal’ simplification. There is no physical reason why the hydrological cycle must run at a constant rate at any value of T. Heat inputs have multiple paths toward entropy.
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So tell me then, what is causing the water vapor to change if it’s not CO2? By making this argument, you have placed the burden of proof on yourself to provide an answer to that question.
Further, you are still ignoring the fact that CO2 is known to have a large impact on the climate. that argument still stands and you have done nothing to address it.
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Please logically explain these images
http://www.justfactsdaily.com/has-global-warming-turned-the-north-pole-into-a-lake/
There are plenty of scientist who have differing opinions to yours
https://en.wikipedia.org/wiki/List_of_scientists_opposing_the_mainstream_scientific_assessment_of_global_warming
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Now you have added an appeal to authority fallacy to the mix. No matter what crackpot position you believe, you can always find a few scientists who agree with you. That doesn’t make you right. Further, if we are going to play the appeal to authority game, I have way more scientists on my side than you have on yours. So why on earth should I listen to a tiny minority of scientists?
This is going nowhere so let me simplify. In the post, I presented a deductive logical proof showing that we are causing climate change. According to the rules of logic if you cannot either show that I have committed a logical fallacy or that one of my premises is false, then you must accept the conclusion. So can you do either of those things? Similarly, I presented you with copious evidence that we are causing climate change, and you have not addressed any of it.
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Wow, you really take this seriously bud, good luck with the fine work. Try to review as much information from both sides as possible though, easy to get skewed especially when governments start pushing causes.
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Please explain these images
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What’s your point? I can only assume that you are making the exceedingly faulty argument that “it actually got colder at this one spot and this one point of time, therefore global warming is false). If that is the case, then first, you are shifting the goal posts again. Second, no one ever said that every part of the earth will be warmer all the time (i.e., this is a strawman fallacy). You can’t just cherry pick an example an ignore the overarching picture which clearly shows that the average temperature of the planet is increasing (i.e. this is a Texas sharpshooter fallacy).
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Paul,
If there hadn’t been leads/polnya at the N Pole in the early pictures the subs couldn’t have surfaced. Every time I see someone try the argument that the Arctic Ocean isn’t in terminal decline, I see someone effectively saying they know nothing about Arctic sea ice.
Arctic sea ice is in terminal decline, if you think otherwise you are simply not cognizant with the data.
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Nah just that there is an element of alarmisim in your camp that “Quite simply” shouldn’t be there for rational scientific debate
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Fallacy Man,
I got here via AGW Observer. Shame to see the low quality of many of the comments here. Anyway. Good post, to which I would add the following paper regards solar influence.
I was an AGW sceptic until 2007, I had suspected that the sun was accounting for more of the observed warming than was commonly thought. Then I read a paper by Wild et al, “Impact of global dimming and brightening on global warming”, in particular the following paragraph (14):
“Despite the fact that surface
insolation at the turn of the millennium is rather lower than
in the 1960s, land surface temperatures have increased by
0.8C over this period (Figure 1). This suggests that the net
effect of surface solar forcing over the past decades cannot
be the principal driver behind the overall temperature
increase, since over the past 40 years, cooling from solar
dimming still outweighs warming from solar brightening.
Rather, the overall temperature increase since the 1960s can
be attributed to greenhouse forcing as also evident in the
BSRN data outlined above. Thus, speculations that solar
brightening rather than the greenhouse effect could have
been the main cause of the overall global warming over the
past decades appear unfounded.”
After a rapid re-assessment I changed my mind on AGW. Note that this solar brightening not only applies to TSI, but also to proposals such as Svensmark’s cosmic ray effect on the Earth’s albedo.
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Thanks for the suggestion, I’ve added the paper to the post.
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