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Myths Concerning Global Warming
Introduction

Are the skeptics correct? Is climate change a hoax? a myth? an effort by liberals to advance a socialist agenda or even to install a one-world government? Do tens of thousands of atmospheric scientists really disagree with the "established science" of some liberal so-called experts in politically powerful positions? Here you can examine a number of fairly common myths about so-called "global warming". Climate change is by its very nature a scientific question. The climate will change or not, whether you elect Democrats or Republicans, liberals or conservatives, to office. The simple fact, however, is that if you alter the chemistry of the atmosphere, you will alter the climate. Finding out whether significant or insignificant climate change will occur is the job of science.

Myth No. 1: The Earth is getting hotter.

Myth No. 2: Carbon dioxide and other greenhouse gases must be insulators to hold in the heat. (So why don't we use them to insulate our attics, if they're so great?)

Myth No. 3: Greenhouse gases are causing the Earth as a whole to get hotter.

Myth No. 4: Some years there is no net temperature rise and even a little cooling. This proves global warming is wrong.

Myth No. 5: The Earth's climate has always changed. We have had glacial periods and warm periods. Recent changes are just a continuation of natural processes.

Myth No. 6: Hurricanes Katrina, Rita, Wilma, Ike, and other extreme weather events prove global warming is here. Counterpoint: Outbreaks of extreme cold and severe winter weather prove global warming is not occurring.

Myth No. 7: Global warming will change the meridional overturning circulation (MOC), leading to a new ice age.

Myth No. 8: Global warming will cause the West Antarctic ice sheet to melt, raising sea level catastrophically.

Myth No. 9: A single volcanic eruption, such as Mount St. Helens, releases more carbon dioxide into the atmosphere than humans ever have.

Myth No. 10: Global warming is not science, just politics.

Myth No. 11: Global warming is based on a bunch of computer programs that will produce any result you desire depending on your input. "Garbage in, garbage out."

Myth No. 12: The East Antarctic ice sheet is growing, contradicting the notion of a warming Earth.

Myth No. 13: The reports of the Intergovernmental Panel on Climate Change (IPCC) are written by liberal politicians.

Myth No. 14: Records show that the 1930s were warmer than it is now. Hence, we are actually cooler today in contradiction of global warming.

Myth No. 15: Scientists were warning of drastic climate cooling fifty years ago. It didn't occur. Now they are warning about climate warming. Obviously, they don't know what they are talking about.

Myth No. 16: Water vapor is a much stronger greenhouse gas than carbon dioxide. The effect of human-introduced carbon dioxide on the climate is negligible.

Myth No. 17: Satellite data show the Earth is actually cooling, not warming.

Myth No. 18: Global warming and cooling in the past have preceded increases and decreases, respectively, in carbon dioxide concentration. Warming causes an increase in carbon dioxide, not the other way around.

Myth No. 19: Tens of thousands of scientists believe global warming is a myth.

Myth No. 20: The scientific community has accepted global warming as an article of faith. The hacked e-mails from the Climate Research Unit at East Anglia University prove this.

Myth No. 21: Sea levels have ceased to rise and have actually dropped in the past few years.

Myth No. 22: The ocean is not warming and may in fact be cooling.

Myth No. 23: Climate scientists are in it just for the money.

Myth No. 24: It's the sun, stupid!

Myth No. 25: The claim that 97% of scientists believe in man-caused climate change is a lie.



Myth No. 1: The Earth is getting hotter.

The Earth as a whole can only warm up if one of two things, or both, occur (according to the laws of thermodynamics). (1) The Earth gets virtually all of its energy from the Sun. If the Sun increases its output, the Earth will absorb more energy and will heat up. (2) How much solar energy the Earth absorbs depends on how "dark" it is, not only in visible light, but also in the other wavelengths of light the Sun produces. If either the Sun increases its output or the Earth grows darker, or both, the Earth, as a whole, will warm up. In getting warmer, the Earth will emit greater amounts of (mostly) infrared radiation to space as it attempts to re-establish the balance between energy input and energy output (in accordance with the second law of thermodynamics) and come into "thermal equilibrium" with its environment. However, there is no evidence the Sun is gradually growing hotter, and not much evidence the Earth is getting darker. So what is the big deal about "global warming"? See Myth No. 3

Myth No. 2: Carbon dioxide and other greenhouse gases must be insulators to hold in the heat. (So why don't we use them to insulate our attics, if they're so great?)

Greenhouse gases are "optically active", meaning they affect the flow of electromagnetic radiation. In the visible, they are transparent, but they intercept and re-radiate thermal infrared light. Thermal infrared is the radiation you feel from a fire or a hot stove. The thermal radiation emitted by the Earth's surface due to it being warmed by the sun is not as evident except, for example, from hot pavement. The net flow of thermal infrared radiation is from the Earth's surface into space. However, when that radiation is intercepted by greenhouse gases, it is re-radiated in all directions, including back down toward the surface. This property, not insulation as a lot of people seem to think, makes greenhouse gases important in regulating the climate.
We should all be familiar with this phenomenon, aware of it or not. You have probably observed that nighttime temperatures decrease more quickly when the air is dry than when it is humid. That is because water vapor is a very effective greenhouse gas, more effective than carbon dioxide. Insulation has nothing to do with the effectiveness of greenhouse gases in regulating the climate.

Myth No. 3: Greenhouse gases are causing the Earth as a whole to get hotter.

(See also "Myth No. 1".) Greenhouse gases have no ability to change the Earth's average temperature directly, because they neither control the heat input from the Sun nor (at least directly) the darkness of the Earth. Greenhouse gases change the flow of radiation in the atmosphere. This is good to a great extent, as the Earth would be a frozen ball without carbon dioxide. The planet Mars, with its thin carbon dioxide atmosphere, is in such a condition. On the other hand, too much greenhouse gas can cause the surface to heat up even as the outer parts of the atmosphere cool due to the change in the radiation flow (which has been the fate of Venus due to its thick carbon dioxide atmosphere). It's not that the whole Earth heats up. Some parts (the surface and lower atmosphere) heat up at the expense of others. Unfortunately, the surface and lower atmosphere are where we live.

Myth No. 4: Some years there is no net temperature rise and even a little cooling. This proves global warming is wrong.

This argument neglects a very important component of the Earth: the ocean. The temperature of the atmosphere can change much more rapidly than that of the ocean. The ocean has much greater density, plus it is almost entirely water which has a high "specific heat". This means it can absorb a lot of heat without changing its temperature appreciably. When cold water is at the surface, as during a La Niña episode, the cold water will absorb significant heat and the atmosphere won't warm up as much as it would were warm water at the surface (as during El Niño). All this means is that heat is being stored in the ocean, ready to be released to the atmosphere in later years.
Update. Opponents of the idea of global warming have long pointed to the so-called global warming "hiatus" in climate data, implying there has been essentially no global warming between 1998 and 2013. A look at the average surface temperatures based on the data during that time period appears to bear out this contention, as there was little or no warming trend. However, there are problems with this observation. The Earth is still experiencing the warmest temperatures over the past several thousand years, according to paleotemperature data. More importantly, there is good evidence the "hiatus" is not real. For example, in a recent issue of Geophysical Research Letters, scientist Balmaseda and his group presented research indicating that much of the unseen warming may have occurred in the ocean, below 700 meters. Changes in surface winds over the past five decades appears to be responsible for this phenomenon. Also a report by Xianyao Chen and Ka-Kit Tung in Science 22 August 2014: 897-903 claims the Atlantic may be just as important as the Pacific or even more so in accounting for missing heat. The Pacific mechanism involves cold upwelling deep water in the eastern Pacific, which cools the atmosphere by absorbing heat and subsequently sinking below the surface. However this report contends, based on a large data set of ocean temperatures accumulated since 1970, that the meridional overturning circulation (MOC) is sequestering heat into the North Atlantic. Another study, in Nature Climate Change, August 17, 2014, cites evidence the warming Atlantic is enhancing the upwelling in the Pacific. Now it appears (Science, 6 June 2015, p. 1066) that some of the "hiatus" is due to biases in the data themselves, which are getting better as more and more observing sites are installed. For example, it appears the tropical Pacific has not warmed but rather cooled in areas due to the ENSO (El Niño-Southern Oscillation) phenomenon, whereas the poorly monitored Arctic has warmed substantially. The question is therefore raised, what will be the effect on global temperature when the next strong El Niño occurs?

Myth No. 5: The Earth's climate has always changed. We have had glacial periods and warm periods. Recent changes are just a continuation of natural processes.

I'm a bit reluctant to put this down as a myth, for the reason that a lot of scientists have thought about this, and a few still think it is true. However, the preponderance of scientific evidence seems to be that the changes seen recently are not due to natural causes. It is true that rapid changes in climate have occurred in the past (which is one reason many scientists worry about "unforeseen consequences" due to our changing the composition of the atmosphere). The current rapid changes, however, have no identified natural cause. The most likely cause is increased greenhouse gases. (However, other types of man-made pollution, for example tiny dark sooty particles, called "black carbon" in the scientific literature, have been coming under increasing scrutiny for their possible roles in climate change.) We know that the temperature of the Earth's surface in the past rose and fell along with greenhouse gas concentration. The cause and effect of this relationship is still unclear, but we would be foolish to dismiss it.

Myth No. 6: Hurricanes Katrina, Rita, Wilma, Ike, and other extreme weather events prove global warming is here. Counterpoint: Outbreaks of extreme cold and severe winter weather prove global warming is not occurring.

Both assertions are equally wrong. If you change the composition of the atmosphere with greenhouse gases and thus the flow of radiation in it, you will change weather patterns. There's no way around that. What was it like today where you were? Sunny? Had humans added no greenhouse gases to the atmosphere, maybe it would have still been sunny, or cloudy, or rainy, but very likely it wouldn't have been exactly like you experienced. So, without global warming would Katrina have occurred exactly as she did? Not likely. But there could have been a worse hurricane in a different place at a different time. Or, possibly, no hurricane striking the U.S. at all that year.
The atmosphere is very chaotic and small changes here and there can lead to large changes in just a few weeks' time. Some call this the "butterfly effect". You can only judge whether or not global warming is having an impact on severe weather events by analyzing these events statistically. Even then, we don't have a "control" Earth where greenhouse gases have not increased for comparison. You cannot point to any single weather event and say it is evidence of global warming. (However, some scientists have presented evidence that certain extreme events in recent years are likely to have been related to climate change.) On the other hand, you can point to today's overall weather patterns and say they are different from what they would have been without global warming. Whatever the weather is today, it would have been different with no global warming.

Myth No. 7: Global warming will change the meridional overturning circulation (MOC), leading to a new ice age.

The scenario was that fresh water from the melting of the Greenland ice sheet and increased rainfall in the high northern latitudes would spread over the North Atlantic, reducing or eliminating the sinking of relatively heavy cold and salty water that drives the MOC. The result would be catastrophe, as warm ocean currents that keep Europe from freezing would die out. The Earth would enter another ice age. (Has the makings of an exciting movie, wouldn't you think?) The truth is, this is highly unlikely.
It is actually true, however, that scientists did consider this a possibility. Further research has shown this scenario is highly unlikely. It was, at first, really just mere speculation (although speculation, hypothesizing, and theorizing is the creative spirit of science). It began as speculation, and there it has died, unless new research contradicting the current view appears. So, not so much a myth as a remote possibility. The movie, however, was a myth.
Update. Recent research has indicated that at the end of the last ice age, the rapid melting of glaciers that then covered much of North America and northwestern Europe introduced much fresh water into the North Atlantic, inhibiting the MOC, and increasing the amount of sea ice in the winter, leading to very cold winters across Europe. (This didn't much affect the summer, however, since the glacial melting was driven by natural changes in the Earth's orbit.) Very important point: No new ice age was generated.

Myth No. 8: Global warming will cause the West Antarctic ice sheet to melt, raising sea level catastrophically.

While not impossible, most scientists think this is a remote possibility. There are disturbing signs of diminishing ice sheets in both Greenland and West Antarctica, but also evidence that at least the West Antarctic ice sheet survived even warmer periods in the past. We would be smart to continue to fund research to study these ice sheets, but the danger seems to have been overplayed by some people, right Al?
Update First of all "Don't Panic!" However, the West Antarctic ice sheet may well be doomed in the long run. Recent studies published in Science and Geophysical Research Letters indicate a major glacier in West Antarctica, the Thwaites Glacier, may collapse in 200 years (some researches say perhaps sooner due to a warming ocean). If this does happen, that could mean the collapse of the entire West Antarctic ice cap, resulting in a sea level rise of over 3 meters (about 10 feet). That would be on top of any sea level rise due to other factors, such as ocean warming and melting glaciers in Greenland, the Pacific Northwest, and other areas.

Myth No. 9: A single volcanic eruption, such as Mount St. Helens, releases more carbon dioxide into the atmosphere than humans ever have.

I first heard this one in an editorial where the writer prefaced this remark with something like, "Let's bring some real science into this." I guess "real science" to this writer does not involve gathering evidence. For decades the concentration of carbon dioxide in the atmosphere has been monitored. The gradual increase due to human emission is apparent in these data. Were this claim true there would be a huge spike in concentration at the time of the Mount St. Helens eruption, and even a greater spike due to the eruption of Mount Pinatubo, which was much larger than that of St. Helens. You don't even see a blip. Why? Because, although volcanoes are the most important source of new carbon dioxide to the atmosphere over geological time, they cannot compete with human emission over the short term.

Some numbers may be in order. Although it is not straightforward to estimate the amount of carbon dioxide humans are putting into the atmosphere, due to all the different sources (fossil-fuel burning, manufacturing processes, land-use change, etc.), an annual amount of around 40.5 billion tons was estimated for 2010. According to the U. S. Geological Survey, an average of about 130 million tons of carbon dioxide is emitted yearly by volcanoes. (Of course, it varies greatly from year to year, depending on dates and sizes of eruptions.) Thus, human emission is about 200 times that of volcanic activity.

Myth No. 10: Global warming is not science, just politics.

This claim was made in an editorial enjoying nationwide exposure. And what ignorance it exposes of the writer! I was embarrassed for the person making this incredibly naive statement.

Myth No. 11: Global warming is based on a bunch of computer programs that will produce any result you desire depending on your input. "Garbage in, garbage out."

Another claim made to a nationwide audience. It is true that scientists depend on so-called global circulation models (GCMs) when studying climate change, but these models are not involved in saying whether climate change is actually occurring or not. They are tools to try to understand the causes of the change and what we might expect in the future. The ocean-atmosphere system is extremely complex and "chaotic". "Chaotic" means that if you change the initial conditions a little bit (temperature, pressure, humidity, etc.), the output will be different, often markedly different (the so-called "butterfly effect"). However, climate modelers depend on statistical analyses. After all, you are trying to predict the climate, not the weather on a particular day. You can run your models many times with different assumptions of how the composition of the atmosphere changes from human activity to get averages and deviations. Although all models are based on the physics of the atmosphere and ocean, the ocean-atmosphere system is so complex you have to make approximations. This is actually true throughout science - even in freshman physics. What the modelers are after is not certainty, which is unobtainable, but plausible causes for what is observed and possible future outcomes.
The difference between predicting the climate and predicting the weather is analogous to the difference between predicting the number of deaths per year due to motor vehicle accidents and predicting when and where accidents will occur.

Myth No. 12: The East Antarctic ice sheet is growing, contradicting the notion of a warming Earth.

Yet another claim made to a national audience by a syndicated columnist. He added that scientists won't tell you this. I nearly fell off my chair. Excuse me, but did this columnist go to Antarctica and find this out by conducting his own research? Or, just maybe, possibly, it was reported in the scientific literature? By scientists, even? There is no contradiction anyway. Most of the glaciers in the world are retreating, but a few aren't, and some are even growing. Glaciers respond not only to temperature but the amount of snowfall. Increasing temperature can lead to increasing snowfall, since warmer air can "hold" more moisture than colder air. Therefore, it is no surprise that some glaciers may receive greater snowfall and grow in spite of warmer temperatures. Anyway, climate change is not uniform. Even though the Earth's surface as a whole is warming, a few regions are, in fact, cooling. Now, you can't expect a pundit to be a glaciologist or climatologist, but you might expect him to at least realize he isn't.

Myth No. 13: The reports of the Intergovernmental Panel on Climate Change (IPCC) are written by liberal politicians.

Actually, these reports are written by atmospheric scientists. However, the final product is edited by politicians from nations involved in the reports, who often water down the wording of the scientists, as most of them are decidedly not what you would call "liberal". It is actually quite a feat to get scientists from all over the world to produce a single document; there has to be a large body of agreement for this to happen.

Myth No. 14: Records show that the 1930s were warmer than it is now. Hence, we are actually cooler today in contradiction of global warming.

That's true - if you are only talking about the United States. Records indicate that global temperatures were cooler than today, but the U.S. was unusually warm. The implication this heat was worldwide, made by some ideologues, is quite disingenuous. Some scientists have pointed out that, with today's global temperatures, a repeat of the 1930s weather pattern would be disastrous for our country.
Update: This argument should be given the last rites as the warmest 12 months ever recorded in the United States have occurred over the year of June 2011-June 2012, as widely reported in the news.

Myth No. 15: Scientists were warning of drastic climate cooling fifty years ago. It didn't occur. Now they are warning about climate warming. Obviously, they don't know what they are talking about.

The International Geophysical Year (1957-1958) produced many important discoveries. One was that the Earth has undergone a series of glacial periods, not just four as previously thought, interrupted by relatively short and warmer interglacial periods. The Earth was seen to be, on average over the past million years, much cooler than it is at present, the latest interglacial. Even more astounding, the data suggested that we were toward the end of the current interglacial, and a new glacial period was imminent.
Now "imminent" to a geologist does not mean "tomorrow". It was clear there could be hundreds or even thousands of years before the glaciers began to advance again through Canada and Scandinavia into the United States and Europe. However, the story made for sensational copy in the news media. It could be a few scientists went off half-cocked - there are apparently still a few predicting imminent (really imminent in this case) cold, like one anti-global warming guest on a conservative talk show I saw at one time, but these people are considered... well, "crackpot" is probably too strong a word... not well backed up by the evidence as far as the scientific community is concerned. (After all, scientists are human too.)

Myth No. 16: Water vapor is a much stronger greenhouse gas than carbon dioxide. The effect of human-introduced carbon dioxide on the climate is negligible.

This is actually true, so far as it goes. Were water vapor concentration to change in the same proportion as carbon dioxide concentration, we would be looking at much greater changes in the climate. However, there is a big difference between water vapor and carbon dioxide. Water vapor can condense out of the atmosphere as rain, snow, ice pellets, hail, dew, frost, etc., reducing its concentration, but carbon dioxide can't.
Studies of past climate and carbon dioxide variations (from ice cores taken from glaciers in Greenland and Antarctica) show that carbon dioxide, and the third major greenhouse gas, methane, have gone up and down naturally with temperature, in spite of any changes in water vapor concentration. There appears to be a rather complex relationship between temperature and greenhouse gas concentration, rather than simply one being the cause and the other the effect. The important result is that greenhouse gas concentrations are correlated with temperature.
This discovery leads to another obvious question. Can changing carbon dioxide and methane levels change the water vapor levels? It seems quite reasonable that this may be the case, as warmer temperatures lead to greater evaporation and warmer air can contain larger amounts of water vapor. Studies indicate that the average relative humidity of the Earth doesn't change much. That means more water vapor in the atmosphere as temperatures rise.
But then another obvious question arises. Would greater concentrations of water vapor lead to more clouds, making the Earth "brighter" and lowering its temperature? (see Myth No. 1) The answer to this question is becoming more clear from recent research, and the answer seems to be that the relative humidity of the atmosphere remains constant even with increasing temperature and evaporation. This should not result in an increase in cloud cover but rather an increase in temperature as atmospheric water vapor content increases. That means the greater the water vapor concentration, the higher the temperature. This is in agreement with studies of past climates where a strong water-vapor feedback coupled with changes in greenhouse gas concentrations is necessary to explain the data.

Myth No. 17: Satellite data show the Earth is actually cooling, not warming.

This one hasn't been mentioned much (if at all) lately, so perhaps the word has gotten out that the satellite data controversy has been settled (at least as far as scientists are concerned). The problem was that temperature changes being observed by satellite were only a fraction of a degree, such that even small errors in the data could lead to false results. Finally, professor Qiang Fu, a climate scientist at the University of Washington, led an investigation demonstrating that cooling of the stratosphere (a by-product of global warming - see Myth No. 1 - and thinning of the ozone layer) was skewing the data to make it look as if the troposphere was not warming. The satellite data now confirm ground measurements of temperature.

Myth No. 18: Global warming and cooling in the past have preceded increases and decreases, respectively, in carbon dioxide concentration. Warming causes an increase in carbon dioxide, not the other way around.

Amazingly, I heard this statement (paraphrased) from someone introduced as a climate scientist, although he did appear on a television show featuring a conservative host. The problem is, the relationship between greenhouse gases and climate is very complex, and much of the data is ambiguous, due to difficulty in getting the timing right. For example, the changes in temperature and carbon dioxide as indicated by ice cores (after correction for age differences due to the fact that diffusion effects make the air trapped in bubbles in the ice younger than the ice itself) is very close, and the jury is still out on which occurs first. The statement above is not so much a myth as it is a premature conclusion.
However. The commentator was not exactly comparing apples to apples here. He was talking about natural changes in the Earth's climate. The question of global warming concerns increases in carbon dioxide that are due to human input, not due to natural processes. The undeniable fact is temperature and carbon dioxide concentration (and methane concentration) go up and down in a very tight correlation. If the commentator was implying the carbon dioxide concentration in the atmosphere today is increasing due to a natural rise in temperature, where is all the carbon dioxide produced by humans going? To confound his argument more, not all human emissions are staying in the atmosphere, since the increase in carbon dioxide concentration is not as large as it would be if all human-emitted carbon dioxide stayed in the atmosphere. (The ocean, for example, is absorbing much of it, leading to ocean acidification.) This would mean that natural emissions of carbon dioxide to the air would be decreasing as the temperature rose, and the commentator is thus caught in a contradiction of his own making. In short, it was a very foolish argument, and he should have been embarrassed.
Update. A study published in the March 1, 2013, journal, Science, shows that the correlation between temperature and carbon dioxide concentration in the atmosphere is very tight over the past 20 000 years, at least in the Antarctic, from where the data for the study came. The uncertainty is large enough, 200 years, that there is no way to show from this study (and from another recent study, also in the Antarctic) which comes first, temperature change or carbon dioxide concentration change. As noted above, the causal relationships are likely to be very complex, since so is the ocean-atmosphere system. The jury is still out on this one.

Myth No. 19: Tens of thousands of scientists believe global warming is a myth.

You may, like I have, seen impressive lists of scientists who have signed petitions opposing the theory of climate change. There are thousands and thousands of names on the lists. However, if you look at the credentials of these people, the lists become less impressive. There are very few well-known atmospheric scientists included. Many are engineers or part-time instructors. Few have advanced scientific degrees. Very few are currently engaged in atmospheric research. I got the impression from going down one of these lists that these people were lending their names more for political than scientific reasons. Of course, I can't prove that, but it would certainly carry more weight if there were names of prominent scientists with research credentials included. There are a few, but these are people that have opposed the idea of climate change almost from the beginning of the investigation, so you think they may have an ax to grind.

This is not to say there aren't scientists who disagree over the extent and details of climate change. That would be extraordinary, given the constant and heated debates that characterize true science. However, most earth scientists, including the vast majority of climate scientists, are convinced humans are changing the climate. They are convinced by the evidence. Nature is not a democracy; signers of petitions don't get a vote. Scientists have to heed the will of Nature, not the other way around.

Myth No. 20: The scientific community has accepted global warming as an article of faith. The hacked e-mails from the Climate Research Unit at East Anglia University prove this.

There were four issues here regarding the e-mails in question.

It is fairly clear one scientist behaved badly in the e-mail "scandal". There is no evidence for any other improper behavior, however. And, to tell the truth, scientists are (shock!) human also. They can get upset, angry, defensive, annoyed, and so forth. They can sometimes use exaggeration and colorful language, especially in what they think is private correspondence. Why would we expect otherwise? Such responses rarely get past peer review as they are not appropriate in professional scientific discourse.

Myth No. 21: Sea levels have ceased to rise and have actually dropped in the past few years.

A prominent scientist has been quoted in sensationalist articles claiming there is no evidence for sea level rise. For example, he states that the satellite data show "absolutely no trend whatsoever" from 1992 to 2002, yet the posted results of the University of Colorado, which does this research, show a net rise over this time interval. I'm at a loss to explain his statement, unless he just got confused. If you look at the satellite data expressed as a graph (use link above), you see that the data are quite variable, but do indicate trends (smoothed line). The mean global sea level is computed every 10 days from the satellite data collected over that ten day period and is uncertain by about 3 to 4 millimeters (mm), accounting for much of the variation seen in the graph. From 1992 to 2005, global mean sea level increases by about 37 mm, approximately 3 mm per year, which is the figure you often hear cited. From 2005 to 2009, there is indeed no upward trend in sea level, but beginning in 2009, the sea begins to rise significantly again. These trends are supported by tidal gauge data. (However, it should be understood that where the land is subsiding, local mean sea level will rise and where the land is rising, local mean sea level may actually be falling. Tidal gauge data have to be corrected for this. Additionally, sea level at a given location responds to ocean currents and weather conditions, which is why the satellite data are so important.)

Myth No. 22: The ocean is not warming and may in fact be cooling.

The Argo project of the University of California, San Diego, has been cited to support this claim. The Argo project has around 3000 floating sensors in the world's oceans and seas collecting data, including temperature data from the upper 2000 meters (m) of the ocean. According to the Argo Web site (as of this writing), not enough data have been collected to form any conclusions about the temperature trends in the ocean, in contradiction to those who would try to misrepresent their work so far.

Measuring the overall temperature of the ocean is a daunting task, which the people propagating this myth don't seem to understand. Think about it. Has anyone actually dived with a thermometer all over the oceans of the Earth to check the ocean's temperature on a global basis? Not even Jacques Cousteau would be up to that challenge. However, there are studies that indicate the ocean has been warming over the past century. For one thing, the rise in mean sea level (see Myth No. 21) can't be explained without factoring in a thermal expansion of the ocean. (Most substances expand as their temperature rises.) Also, studies of the heat balance of the Earth (Kevin E. Trenberth and John T. Fasullo in Science 16 April 2010 328: 316-317) imply that thermal energy is being stored in the ocean.

Update. New research indicates the oceans are indeed warming, but largely beneath a depth of 700 meters. See Myth No. 4 for more details.

Myth No. 23: Climate scientists are in it just for the money.

I watched this hilarious comedy show on Fox News where the comedian was talking about climate scientists lounging around in their "lavish" laboratories, planning their next exciting vacation to exotic arctic locations where they can relax and frolic in the luxurious accommodations, replete with taxpayer funded wet bars, call girls, and star-studded shows. Well, I may exaggerate a bit, but I'm not exaggerating about the "lavish laboratories" and "arctic vacations". Those were mentioned by this, ahem, comedian. In order that there be "fair and balanced" coverage, the "comedian" had someone with an opposing view. I think his name was Harvey Milktoast, PhD (Poor hapless Doofus). (Actually, he looked like a mild-mannered version of the Muppet character, Dr. Bunsen Honeydew. Where the heck did Fox find him?)

I have worked as a scientist. Was a physics and geology professor. I have been in lots and lots of scientific laboratories. The last word that would come to my mind when I was there was "lavish". That is, unless you consider equipment mostly built by graduate students in university machine shops and covered with aluminum foil and duct tape lavish. And what about those exotic vacations? You mean like the Russian research ship that got stuck in ice and the crew had to be rescued? That kind of exotic? It's just amazing that tourists aren't signing up in greater numbers for such exotic vacations. OK, I suggest we stop being silly and look at the science.

Myth No. 24: It's the sun, stupid!

I live in Austin, Texas, and recently (June, 2015) a city council member, Don Zimmerman, lectured a climate scientist from Texas A&M on how she was such an ignoramus: Every school kid knows it is the sun that warms the earth, not carbon dioxide! Actually, he has a point, sort of. (See Myth No. 1.) Carbon dioxide indeed does not emit heat on its own. Some say it "traps" heat, but that isn't exactly a correct description. What it does is absorb photons of thermal infrared energy and re-emit them in random directions, up, down, and laterally, in a process physicists call "spontaneous emission". Hence the flow of heat in the atmosphere is altered such that it is increased in the lower atmosphere. It is the flow of heat that is important in global warming, not the total amount. (Actually, for the purists out there, "flow of heat" is an oxymoron, since heat itself is a flow of random energy.)

The question therefore is, is the sun getting hotter? Or, are we getting closer to the sun? Some have invoked the Milankovitch cycles implicated in the glacial climate cycle as being important. For example, what about the cycle where the earth gets into a more elliptical orbit and moves closer to the sun at perihelion? The problem with the Milankovitch cycles is that they are tens of thousands of years long. You can't change the climate over a few decades with cycles that lengthy. Then what about the sun itself? What about coronal mass ejections and solar flares? These phenomena are linked to the sunspot cycle. The sun has a 22-year magnetic cycle (where its magnetic poles reverse twice) that produces two 11-year sunspot cycles. The solar output only changes by 0.1% between a solar minimum (with few sunspots) to a maximum (with a maximum number of sunspots). Coronal mass ejections and solar flares are more common at solar maximum, but don't have much effect on solar energy output. There is a minor effect on climate due to the solar cycle, but it does not correlate to the average temperature of the lower atmosphere. Councilman Zimmerman is the one who needs a lecture - in basic solar physics and thermodynamics.

Myth No. 25: The claim that 97% of scientists believe in man-caused climate change is a lie.

The charge is that only about 77 climate scientists out of over a thousand scientists responded to an American Geophysical Union survey on climate change. Of these 75 responded positively to the claim of man-made global warming, thus the misleading 97% figure. All the other scientists were not included in the claim. The 97% figure is thus called a "lie".

In fact, there have been a large number of surveys conducted on this question. (See Surveys of scientists' views on climate change.) The one that is most telling to me is the one that examined close to 12 000 abstracts of peer-reviewed papers where global warming was mentioned. (Cook, John et al (May 2013). "Quantifying the consensus on anthropogenic global warming in the scientific literature". Environmental Research Letters 8 (2)). 35.5% of the papers took no position, most likely because (for those familiar with scientific literature) most of the papers were addressing a topic other than whether or not climate change is occurring or whether or not humans were involved. Of those papers that did express a position, 97% agreed with the proposition that climate change was occurring and was due to human activity. If you read the Wikipedia article link cited above, you will see this is typical of the scientific response. Cook et al conclude that the number of papers rejecting the scientific consensus is vanishingly small.