Monday, January 09, 2012

Global Warming - A Coolist's View

The article below was received via email from a person who wishes to remain anonymous but who has degrees in the physical sciences

The global warming concept hinges upon the idea that greenhouse gases cause an increase in mean global temperatures. The basis for this concept is that such gases are better radiators than non greenhouse gases and as a result keep the global mean temperatures higher as a result of feeding back radiation to the Earth's surface. Let us investigate this hypothesis:

First of all we need a model upon which all can agree is a good approximation to the real thing. The model I have chosen is familiar to most engaged in the debate and in my view lies closest to the hearts of the so-called global warmists. In this model we are concerned only with radiation from the sun which interacts thermally with the Earth's surface and atmosphere. We are not concerned with radiation that is reflected either specularly or diffusely back into the space from which it came. Neither are we concerned about radiation which is absorbed and re-emitted without intermediate thermal processes. Without such processes there can be no warming of the Earth's surface and atmosphere so such non thermal interactions can be neglected

Removing such non thermal processes from our model leaves us with this: the Earth's surface is treated as an approximation to a black-body, it absorbs radiation from the sun, becomes hotter and then re-emits radiation more typically at longer wavelengths. We also have an atmosphere which is composed of two types of gas: greenhouse gases and non greenhouse gases, both of which may or may not absorb and re-emit radiation or receive thermal input via convection and conduction from the Earth's surface as is their wont. It does not concern us for now as to the nature of these processes.

To further the debate we have the concept propounded by the pro-greenhouse warming lobby that because greenhouse gases are better radiating gases than non greenhouse gases they re-radiate more radiation back to the Earth's surface than do non greenhouse gases. This leads us to an obvious thought experiment:

We replace all greenhouse gases in the Earth's atmosphere with an equal volume of non greenhouse gases. There are then three logical possibilities:

1) Greenhouse gases are less good radiating gases than non greenhouse gases.

2) Greenhouse gases are equally good radiating gases as non greenhouse gases.

3) Greenhouse gases are better radiating gases than non greenhouse gases.

If (1) or (2) are true then the theory of global warming is falsified. If (3) is true then greenhouse gases produce relative global warming. I believe (3) is true.

We now consider the Earth's radiation budget.

Integrating over a sufficient time period to average out the effects of night and day and the seasons then at equilibrium the average energy received by the Earth in the form of radiant energy from the Sun must equal the average energy lost by the Earth in the form of radiation. This is the only significant form of energy capable of influencing global mean temperatures. I take a warmist's view here and do not include such effects as the solar wind, the Sun and Earth's magnetic field coupling lateral flare currents into the oceans, cosmic rays inducing cloud formation or variations in solar energy output or spectrum.

We then consider the Earth's outgoing energy budget. It has three components: that from greenhouse gases, that from non greenhouse gases and that from the black body Earth itself. We then perform the same thought experiment we performed above, and replace the greenhouse gases in the Earth's atmosphere with an equal volume of non-greenhouse gases:

As discussed above, we know that if (1) or (2) are true that the hypothesis of global warming is falsified. If (3) is true then greenhouse gases cause absolute global cooling. This is because they contribute significantly to the Earth's outgoing radiation budget. If they are removed from the Earth's atmosphere the amount of energy radiated away into the absolute zero of space goes down and in consequence the temperature of the Earth and its atmosphere will rise, I neglect here the 4 degrees Kelvin background radiation left over from the Big Bang. It is thus demonstrated that:

A) Greenhouse gases cause absolute global cooling.

B) In order to believe that greenhouse gases produce relative global warming it is first necessary to believe that greenhouse gases produce absolute global cooling.

At first sight the hypothesis of global warming through feedback radiation is self contradictory. Can we simultaneously have the situation in which greenhouse gases produce both relative warming and absolute cooling of the planet? The answer is yes! This is because the so-called feedback radiation is a negative feedback on the absolute cooling caused by greenhouse gases. This means that the presence of the feedback term in the equation of global cooling reduces the rate at which radiation is lost from the Earth by re-cycling energy back to the Earth's surface. This amounts simply to an observation that secondary radiators are not 100% efficient. What this means is perhaps better explained with reference to the analogous system of coupled primary and secondary radiators we find under the hood of a typical auto-mobile:

In the Earth model above we treat the Earth's surface as the primary radiator. We can do this because the amount of radiation fed back to the real primary radiator of the system, the Sun, is negligible. The secondary radiator of our system is the Earth's atmosphere which is closely thermally coupled to the surface of the Earth by conduction and convection as well as radiation. In our auto-mobile engine analogy the primary radiator is the engine block and head with the secondary radiator being not surprisingly, the radiator! (If you like the engine can be treated as being supplied with both gasoline and air through a pipe so it can be run in vaccuum and thus tighten up the analogy).

We now imagine that our engine and radiator are sitting in an auto-mobile on our collective drive and that the engine has been running for some time and has reached thermal equilibrium with the environment. We lift the hood and examine the engine in operation with reference to a manual: The engine generates heat energy some of which it loses directly to the environment. Most heat energy however is removed from the engine by a water based coolant which is pumped though a series of channels in the block and head then via a radiator hose to the radiator. A second feedback radiator hose returns the cooled water from the radiator to the engine and closes the system loop.

We have just concluded that the engine and cooling system is working satisfactorily when our collective neighbour, a Mr. Gore, drops by and with the skilful use of a thermometer amidst all those moving parts demonstrates that the return hose from the radiator is operating above ambient temperature and is thus maintaining the engine at a higher temperature than it otherwise would be. Mr Gore is completely correct of course; feeding warm water into the auto-mobile engine will maintain it at a higher operating temperature. Mr Gore therefore prevails upon us to disconnect the feedback hose from the radiator to the engine block in order to keep the engine cooler.

Would you take Mr. Gore's advice? Your answer to this question will not only determine your position in the global warming debate but whether or not you drive to work next week!

The lessons learned above can be reinforced by considering the black-body Earth and atmosphere in a little more detail. Consider a black-body Earth without any atmosphere whatsoever. Without an atmosphere not only will more radiation get through to the Earth's surface because there are no greenhouse gases to intercept any of this radiation and re-radiate it back out into space without it having first to interact with the Earth's surface, but there will be no conduction and convection into the non-existent atmosphere to keep the surface cool. The job of re-radiating energy into space will fall squarely on the surface of the black-body Earth itself. Increasing the radiation from a black-body can only be accomplished by increasing its radiative temperature.

If we now add an atmosphere of non-greenhouse gases to our black-body Earth we find that heat energy can leave the surface not just by radiation but by conduction and convection as well. If we also include surface water the latent heat of evaporation of water will contribute to this heat loss mechanism too. The situation is now similar to that of a domestic central heating radiator which loses heat to heat a room mainly by conduction and convection with a small component of radiative loss; the central heating radiator would be better described as a convection heater. Of course if the atmospheric gases did not radiate away any energy into space eventually the Earth's surface would rise to the temperature it had before we added any atmosphere. However all gases radiate and the non-greenhouse gases do so too. The reason for this is that all accelerating charges radiate and all molecules in the atmosphere accelerate, often negatively, as they constantly collide with each other. The faster the molecules move the more frequent are the collisions, the greater the accelerations and the greater the loss though radiation. The atmosphere can now be seen for what it is, a secondary radiator which by adding to the Earth's outgoing radiation budget keeps the Earth's surface cooler. The non-greenhouse gases component of the Earth's atmosphere are thermally radiating gases. In other words in order to radiate more they must be at a higher temperature, just like the black-body Earth itself.

Finally we add to the Earth's atmosphere the greenhouse gases. While these gases radiate thermally just like non-greenhouse gases they have a secondary mechanism too based on a form of electronic transition related to quantised states of dipole moments. Greenhouse gases as a result are not only able to radiate much more energy at lower temperature but are also able to pick up thermal energy from both the Earth's surface and non-greenhouse gases and radiate this energy into space as well. Greenhouse gases thus add very significantly to the Earth's outgoing energy budget and thus keep the Earth's surface and atmosphere very much cooler than they would be in the absence of these lower temperature radiating gases.

From consideration of the arguments given above it is very easy to see that the concept of greenhouse gases as a planet warming blanket is completely erroneous. Greenhouse gases are cooling gases, part of a secondary radiator system and in my view the principal mechanism by which the temperatures at the Earth's surface are kept cool enough for life to exist across the globe.

In the face of such obviousness the real question is why has the concept of greenhouse gas induced global warming has persisted for so long in the face of so much entrenched opposition from global warming sceptics? The answer is perhaps surprising: The global warming debate has three factions which can be loosely described as warmists, luke-warmists and sceptics. These factions however all have one thing in common: they all believe in global warming!

These three groups all believe that warming is produced by greenhouse gases to greater or lesser degrees with the warmists predicting large increases in global mean temperature with increasing man made emissions of carbon dioxide and the sceptics predicting very small increases in global mean temperatures as a result of these same emissions. The global warming debate has been monopolised by these three groups since the inception of the IPCC. It is a one sided debate in which no voices of opposition are heard.

The simple reality is that greenhouse gases cause global cooling and lots of it. It is only by stepping outside the radiative feedback paradigm foisted upon us by warmists and sceptics alike and then viewing the system as a whole using overarching energy arguments that we begin to glimpse the truth.

Safe driving!

Tornadoes declining

Graphic from NOAA

Himalayan glaciers stable

Discussing: Hewitt, K. 2011. "Glacier change, concentration, and elevation effects in the Karakoram Himalaya, upper Indus Basin". Mountain Research and Development 31: 188-200.

Hewitt (2011) writes that "in recent decades the consequences of climate change for Himalayan glaciers has become of great concern," noting that it has been "widely reported that the Indus basin is threatened with severe losses," although he says that "emerging evidence suggests that such reports are, at best, exaggerated," citing Raina (2009) and Armstrong (2010).

In a review of the pertinent scientific literature, Hewitt "seeks to explain evidence of distinctive late- and post-Little Ice Age glacier change in the Karakoram Himalaya and a recent, seemingly anomalous, expansion," with attention directed to "processes that support and concentrate glacier mass, including an all-year accumulation regime, avalanche nourishment, and effects related to elevation."

The Canadian researcher reports, first of all, that Karakoram glaciers have only declined by 5% or so since the early 20th century, "mainly between the 1920s and 1960s." Thereafter, he notes that "losses slowed in the 1970s (Mayewski and Jensche, 1979), and some glaciers underwent modest advances, as elsewhere in the region (Kotlyakov, 1997)." Retreat then prevailed from the mid-1980s through the 1990s, "but without dramatic losses." And he says that "since the late 1990s we have reports of glaciers stabilizing and, in the high Karakoram, advancing (Hewitt, 2005; Immerzeel et al., 2009)," while "total snow cover has [also] been increasing in the high Karakoram (Naz et al., 2009)."

Hewitt additionally writes that the "sheer extent and sustained high elevations" of the main Karakoram, together with the "all-year accumulation regime," both "help to buffer glaciers against 'warming'." And he says that "with high-altitude precipitation occurring as snowfall in summer and winter, they may benefit from increased moisture transport from warmer oceans." In addition, he notes that "various investigations report cooler summers recently and greater summer cloudiness and snow covers (Fowler and Archer, 2006; Naz et al., 2009; Scherler et al., 2011)," stating that these phenomena "can also reduce average ablation rates or numbers of 'ablation days'."

Considering all of these things together, and compared with "past predictions for the upper Indus," Hewitt concludes that "these observations seem good news."


The Medieval Warm Period in Southern South America

Discussing: Neukom, R. et al., 2011. "Multiproxy summer and winter surface air temperature field reconstructions for southern South America covering the past centuries". Climate Dynamics 37: 35-51.

In order to know how unusual, unprecedented or unnatural the global warming of the 20th century was, it is necessary to do what the eighteen authors of this important paper did, so as to be able, as they describe it, "to put the recent warming into a larger temporal and spatial context."

Working with 22 of the best climate proxies they could find that stretched far enough back in time, Neukom et al. (2011) reconstructed a mean austral summer (December-February) temperature history for the period AD 900-1995 for the terrestrial area of the planet located between 20øS and 55øS and between 30øW and 80øW -- a region they call Southern South America (SSA) -- noting that their results "represent the first seasonal sub-continental-scale climate field reconstructions of the Southern Hemisphere going so far back in time."

The international research team -- composed of scientists from Argentina, Chile, Germany, Switzerland, The Netherlands, the United Kingdom and the United States -- write that their summer temperature reconstruction suggests that "a warm period extended in SSA from 900 (or even earlier) to the mid-fourteenth century," which they describe as being temporally located "towards the end of the Medieval Climate Anomaly as concluded from Northern Hemisphere temperature reconstructions." And as can be seen from the figure below, the warmest decade of this Medieval Warm Period was calculated by them to be AD 1079-1088, which as best as can be determined from their graph is about 0.17øC warmer than the peak warmth of the Current Warm Period.

Figure 1. Reconstructed mean summer SSA temperatures. Adapted from Neukom et al. (2011)

The findings of Neukom et al. go a long ways towards demonstrating that: (1) the Medieval Warm Period was a global phenomenon that was comprised of even warmer intervals than the warmest portion of the Current Warm Period, and that (2) the greater warmth of the Medieval Warm Period occurred when there was far less CO2 in the air than there is nowadays, which facts clearly demonstrate that the planet's current -- but not unprecedented -- degree of warmth need not be CO2-induced.


Taking Fears Of Acid Oceans With A Grain of Salt

Matt Ridley

Coral reefs around the world are suffering badly from overfishing and various forms of pollution. Yet many experts argue that the greatest threat to them is the acidification of the oceans from the dissolving of man-made carbon dioxide emissions.

The effect of acidification, according to J.E.N. Veron, an Australian coral scientist, will be "nothing less than catastrophic.... What were once thriving coral gardens that supported the greatest biodiversity of the marine realm will become red-black bacterial slime, and they will stay that way."

This is a common view. The Natural Resources Defense Council has called ocean acidification "the scariest environmental problem you've never heard of." Sigourney Weaver, who narrated a film about the issue, said that "the scientists are freaked out." The head of the National Oceanic and Atmospheric Administration calls it global warming's "equally evil twin."

But do the scientific data support such alarm? Last month scientists at San Diego's Scripps Institution of Oceanography and other authors published a study showing how much the pH level (measuring alkalinity versus acidity) varies naturally between parts of the ocean and at different times of the day, month and year.

"On both a monthly and annual scale, even the most stable open ocean sites see pH changes many times larger than the annual rate of acidification," say the authors of the study, adding that because good instruments to measure ocean pH have only recently been deployed, "this variation has been under-appreciated." Over coral reefs, the pH decline between dusk and dawn is almost half as much as the decrease in average pH expected over the next 100 years. The noise is greater than the signal.

Another recent study, by scientists from the U.K., Hawaii and Massachusetts, concluded that "marine and freshwater assemblages have always experienced variable pH conditions," and that "in many freshwater lakes, pH changes that are orders of magnitude greater than those projected for the 22nd-century oceans can occur over periods of hours."

This adds to other hints that the ocean-acidification problem may have been exaggerated. For a start, the ocean is alkaline and in no danger of becoming acid (despite headlines like that from Reuters in 2009: "Climate Change Turning Seas Acid"). If the average pH of the ocean drops to 7.8 from 8.1 by 2100 as predicted, it will still be well above seven, the neutral point where alkalinity becomes acidity.

The central concern is that lower pH will make it harder for corals, clams and other "calcifier" creatures to make calcium carbonate skeletons and shells. Yet this concern also may be overstated. Off Papua New Guinea and the Italian island of Ischia, where natural carbon-dioxide bubbles from volcanic vents make the sea less alkaline, and off the Yucatan, where underwater springs make seawater actually acidic, studies have shown that at least some kinds of calcifiers still thrive—at least as far down as pH 7.8.

In a recent experiment in the Mediterranean, reported in Nature Climate Change, corals and mollusks were transplanted to lower pH sites, where they proved "able to calcify and grow at even faster than normal rates when exposed to the high [carbon-dioxide] levels projected for the next 300 years." In any case, freshwater mussels thrive in Scottish rivers, where the pH is as low as five.

Laboratory experiments find that more marine creatures thrive than suffer when carbon dioxide lowers the pH level to 7.8. This is because the carbon dioxide dissolves mainly as bicarbonate, which many calcifiers use as raw material for carbonate.

Human beings have indeed placed marine ecosystems under terrible pressure, but the chief culprits are overfishing and pollution. By comparison, a very slow reduction in the alkalinity of the oceans, well within the range of natural variation, is a modest threat, and it certainly does not merit apocalyptic headlines.


Antarctic Temperature Trends

Almost exactly two three years ago, a prominent paper became a media darling as it, according to the alarmist website Real Climate "appeared to reverse the `Antarctic cooling' meme that has been a staple of disinformation efforts for a while now."

The Nature paper, by Eric Steig and colleagues, made the cover on the January 22, 2009 issue.

Despite Real Climate's predictable take on the situation, many long-time students of Antarctic climate change (including usn's here at WCR) yawned. It has been known for decades that there is a net warming in Antarctic surface temperature that began during the International Geophysical Year in 1957. However, what is also well known, is that the vast majority of the observed warming in Antarctica took place from the late 1950s through the early 1970s and that since then-during a period going on 40 years now-there has been very little net temperature change over Antarctica taken as a whole.

What the Steig et al. analysis did do, was to alter the generally accepted spatial pattern of the temperature change across Antarctica. Whereas previous studies showed that the warming was largely limited to the Antarctic peninsula region of West Antarctica with vast areas of cooling occurring distributed across the other parts of the continent, the Steig et al. analysis effectively spread the warming across the entire continent, both during the complete period of record since 1957, as well as during the most recent two-to-three decades

Almost immediately, speculation popped up across the blogosphere that something was seriously amiss with Steig's methodology. Analysts zeroed in on the problems and went on to publish in the scientific literature their own version of the spatial patterns of temperature change across Antarctica using the same data as Steig et al. used (a combination of surface observations and satellite-borne measurements) but employing a new and improved technology.

Surprise, surprise. The "new" map of temperature change across Antarctica produced by O'Donnell et al. wasn't all that much different from the pre-Steig vision of the temperature changes which had taken place. Once again, the warming was primarily constrained to the Antarctica Peninsula, and cooling could be found across large regions of the rest of Antarctica

For those who still question whether or not the O'Donnell et al. methodology is superior to the Steig et al. methodology, there is an independent arbiter-the satellite-derived temperature of the lower atmosphere that has been compiled and maintained by Roy Spencer and John Christy, and which just celebrated its 33rd birthday on December 1, 2011. The Spencer and Christy temperature record employs a different sort of satellite-borne temperature instrument (a microwave sounder unit, or MSU) than the satellite data melded with the surface observations in the Steig et al. and O'Donnell et al. studies, and is as a completely independent temperature data source.

Notice that there is a lot of blue shading on this map indicating regions where the temperature trend is negative (cooling), and that the regions of warming are primarily located along the continental margins.

The Spencer and Christy trends from the lower atmosphere are a decent (although imperfect) match with the O'Donnell et al. temperature trends of the surface. The Steig et al. trend analysis as the odd-one-out.

In the two years since the big flash at Nature, further and better analysis confirms that what has been going on in Antarctica is pretty much what we knew to be happening all along-that during the last 3-to-4 decade period of rapid build-up of atmospheric carbon dioxide, the temperature has changed little at the continental scale, and instead is characterized by a complex pattern of regional warming and cooling. Such changes do not foreshadow a rapid loss of continental Antarctic ice nor an alarming Antarctic contribution to the rate of current and future sea level rise this century as a result of surface ice melt. In fact, measurements from a different satellite data set that begin in 1979 show that the extent of ice in the southern high latitudes is increasingly significantly.

SOURCE (See the original for links and graphics)


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