Greenhouse Effect – the hidden players

 kw: analytical projects, greenhouse effect, global warming, absorption spectra, saturation

Reading a book about agriculture led me to thinking about the "hidden" greenhouse gases. I am sure almost everyone has read or heard that methane is 80 times as potent as carbon dioxide as a greenhouse gas. I recently learned that nitrous oxide (laughing gas, also a dental anesthetic) is between 250 and 300 times as potent as carbon dioxide. Both of these gases are produced by agricultural activity, so they have increased in the past 200 years as agriculture has been increasingly mechanized, and as chemical fertilizers have been used in ever-increasing amounts. (I generated this image using Leonardo AI; it is free of copyright restrictions)

I researched in several sources to find answers to these questions:

• What were the concentrations of nitrous oxide and methane prior to the Industrial Revolution?
• What are their concentrations now?
• How to they affect global warming?
• Are there other greenhouse gases we should be concerned about?

To simplify the text, I will dispense with formatting the numbers in chemical formulas as subscripts. Thus, CO2 = Carbon Dioxide, CH4 = Methane, and N2O = Nitrous Oxide (Nitrogen has several oxides; only this one is important here).

Here is the connection with agriculture: The middle-American farm belt was created by plowing the prairie and planting grain crops. Today, by far the most important crops are corn and soybeans. The thick, rich prairie soils contained a 10,000-year store of CO2, deposited by the roots of grasses and held there as they decomposed. Plowing the prairie released the CO2 at a pretty steady rate over the past century. It is still going on. Plowing also releases stored CH4.

When I lived in South Dakota in the 1970's and early 1980's, most of the agriculture in the state was cattle ranching, with some grain crops being grown in the eastern third. Since that time seed companies have developed strains of corn and soybeans that can better resist drought, begin growing at lower temperature and ripen faster. South Dakota cattle ranches are being plowed and sown with grains at a steady rate.

Secondly, overuse of nitrogen fertilizer causes much of the "extra" to be converted to N2O. Large amounts also go downstream and contribute to the Dead Zone offshore of the Mississippi Delta.

Thirdly, cattle produce a lot of methane, and the reduction in cattle numbers in the Dakotas is more than offset by continued increases elsewhere; also, plowing the prairie releases CH4, and all this is added to the amount released by fossil fuel production. I have yet to see a credible analysis of all the sources of CH4.

Yet all we ever hear about is the rise in concentration of CO2 alone. This is indeed significant, from about 280 ppm in the 1700's to about 440 ppm today. This "baseline increase" is (440-280)/280 = 0.57, a 57% increase in the past century or so. 

What of CH4 and N2O? Let us first convert them to equivalent CO2. I'll leave out a lot of words and summarize the figures:

1. CH4 as a GHG is 80x as effective as CO2. Current CH4 concentration is 1.9 ppm; times 80 that is equivalent to 152 ppm CO2. In the 1700's, CH4 was 0.72 ppm, or CO2 equivalent (CO2eq)  of 57.6 ppm.
2. N2O as a GHG is ~280x as effective as CO2. Current N2O concentration is 0.34 ppm; times 280 that is equivalent to 95.2 ppm CO2. In the 1700's, N2O was 0.27 ppm, or CO2eq of 75.6 ppm.

Added together, these two gases presently have CO2eq of 247. The preindustrial level was 133. Let's add these to CO2 to see the real picture of the greenhouse effect at these two times:

• Preindustrial: 280+133 = 413 ppm CO2eq
• Today: 440+247 = 687 ppm CO2eq
• (687-413)/413 = 0.66, a 66% increase in CO2eq

The actual increase in CO2eq is greater than the effect of CO2 alone. Suppose we could reduce CH4 and N2O to preindustrial levels. This would subtract 114 ppm CO2eq, for 573. Then (573-413)/413 = 0.39, or 39% increase in CO2eq, compared to preindustrial. To put this in context according to the mental model held by "climate crisis" folks, for CO2 only, a 39% increase over 280 ppm would be 389 ppm. That is about where we stood in 2011; it winds back the clock sixteen years!

Let us focus a moment on N2O. By itself, increase in the concentration of this gas is responsible for about 20 ppm CO2eq, the last nine years of increase. This is nearly all due to overfertilization. Guess which industry complex is bigger and has a stronger lobby in DC than oil and gas? Agriculture plus agrichemicals (particularly fertilizer). I have read in more than one place that without artificial nitrogen-based fertilizer, the world's farmland could support no more than four billion people. It is very complex to analyze just how much fertilizer could be reduced to still support the current world population, but reduce nitrate runoff and outgassing of N2O into the atmosphere. For the moment, I just have to leave these thoughts unfinished. If we could come up with a plan, powerful interests would oppose it.

At this point in my analysis I wondered what other greenhouse gases exist, and how they might modify the picture. As it happens, nothing much. Here is a table I worked from for the figures above, which adds six greenhouse gases that, together, are sometimes written about in very scary terms, but have no practical effect at present:

First, ground level Ozone (O3) has a modest Global Warming Potential (GWP: 1.5 x CO2), and exists in the 1-10 parts per billion range, so it is not effectively a greenhouse gas. Then, the industrial chemicals Sulfur Hexafluoride (SF6) and Nitrogen Trifluoride (NF3) have very high GWP, but exist at levels of a few parts per trillion. To totally eliminate them would reduce CO2eq by much less than one percent (see the black text at the bottom of the table)

Various fluorinated refrigerants, those highlighted in brown, have very high GWP, but also exist at levels of a few parts per trillion, so together, they also amount to less than one percent (the brown text). Thus, they present no useful "targets" for ameliorating the greenhouse effect.

My aim here has been to back off a few steps to see a bigger picture. As it happens, this points a finger where none has been pointed before, at farmers. A significant proportion of the increase in CO2eq results from farm practices. In particular, far too many farmers use more fertilizer than their crops really need. There is too much of, "a little more might help." No, it doesn't, it harms. It even harms the farmer, who spends more than needed on fertilizer that isn't helping.

I have a philosophical point to end with. I think that the greenhouse effect will prove to be more beneficial than otherwise. The "father of greenhouse warming", Svante Arrhenius, thought so. Another degree or two of warming is likely to make more of Canada and Siberia amenable to crop production, and let's not forget South Africa and Argentina. On another note, I saw an article recently with a headline, "550,000 will die of extreme heat." The subhead said, "The greatest cause of early death." The article never mentioned that 4.6 million will die from cold. Nine times as many! The subhead is, quite simply, a lie, and the article is utterly one-sided deception. I suspect many of those 4.6 million would love for their home country to be a little warmer.

Will Greenland get greener?

kw: book reviews, nonfiction, exploration, geography, science, greenland, global warming, climate change

The main title of The Ice at the End of the World: An Epic Journey into Greenland's Buried Past and our Perilous Future, by Jon Gertner, embodies a double entendre. Even today, to be in the middle of the Greenland ice sheet puts you at a "pole of inaccessibility", really at the end of the Earth; and what happens to that ice could indeed portend the end of the world (though not the Earth).

World versus Earth: The Earth is the physical planet, "third rock from the Sun", from its core to the edge of the atmosphere a few thousand miles above the surface, including the biosphere, of course. The world is the collection of human civilizations and systems that form the environment for human life and living. The Earth is incredibly robust. The biosphere is very robust. The world is fragile. Even the much-vaunted "western world" that provides comfort, sustenance, and amazing conveniences to about one-third of the total human population, is remarkably fragile.

About a tenth of the world population, nearly 700 million, lives at or below an elevation of 10m above sea level. For every meter of sea level rise, about a tenth of these (more at first, fewer later) will have to move uphill. But the three laws of real estate value, "location, location, location", meaning "higher ground for better view (except for that seaside vacation home!), close to conveniences (stores, etc.), and close to work" will drive costs up, and up and up.

The Ice at the End starts with the history of the exploration of Greenland. While it is called the largest island, I think of it as the smallest continent. It is nearly 1/3 the size of Australia, and is about 3 times the size of the New Guinea island. Being mostly covered with an ice cap about two miles thick makes its exploration extremely arduous at best, any time prior to the use of aircraft and tracked heavy vehicles; now it is merely "very arduous". One of my favorite turn-of-the century scientists, Alfred Wegener, died there at age 50, in 1930.

Once the early explorers, combining European and Inuit materials and methods, showed it is possible to cross the ice sheet, scientists made up a growing proportion of "visitors", a proportion that exploded once the American military began pouring money into Arctic exploration right after World War II. Now the ice volume can be measured daily by satellite, on-ice expeditions can continue to determine snowfall accumulation and compaction rates, and ice cores have been drilled to bedrock in a few locations. Now the true significance of Greenland and its ice are becoming clear.

To cut to the chase: Even if we ignore Antarctica, progressive melting of Greenland's ice alone can cause catastrophic damage to the infrastructure of every nation that has a coastline (nearly all of them). I gathered a number of calculated amounts for the amount of water in that ice. If it were all put into the ocean at once, without heating up beyond melting temperature, the seas would rise by 27 feet, or 8.2 meters. Then, as it warmed to the 40°F (4°C) average temperature of the ocean, sea level would rise about another couple of inches (5-6 cm).

Compare that to current rates. Since the 1960's, sea level has risen between 3 and 3.3 mm/yr. About a third of that is from Greenland, about half from ocean thermal expansion, and the rest from Antarctica, mainly the Thwaites glacier and a few lesser ones. See this montage:

The four images of Greenland plus Iceland were made in December of 1984, 1994, 2004, and 2014, from left to right. It may be hard to see the decrease in ice cover from decade to decade. The total difference in ice volume over these thirty years is 0.75%. Here is a closeup of the northeast quadrant, where the difference is more evident:

On first sight, one may say, "It's just a difference in snow cover," but with a careful look, one may see that the ice front has also receded, and we need to note that the entire ice sheet has gotten thinner by more than a half percent (30 ft or 9.5 m) in that time. Over that same interval the sea has risen nearly 100mm, or 4". And a third of that was Greenland's ice melting, over and above the snow that fell.

Though I am a political/social conservative, I have long known of the greenhouse effect, and what it can do to this planet. Will rising temperatures and rising seas drive human life off the Earth? That isn't likely. However, those phenomena will drive humans inland everywhere, and will likely eliminate a few oceanic nations such as the Maldives, Palau and Tuvalu. Of continental nations, Bangladesh would be one of the hardest hit: a quarter of its land area is below an elevation of 8m.

I have always been in favor of research into renewable energy, primarily solar. At present levels of efficiency, it would take less than 200,000 square miles (500,000 sq km) of solar panels to meet all energy needs for the world. That's about the area of Spain, but it would be spread everywhere, mainly within 40° of the equator. This needs to be coupled with better batteries to take care of cloudy days. At present prices, the investment would be huge, something like 200 times the world yearly GDP. However, research also results in lower prices, which can only help.

Someone who denies the importance of climate change would call this book a polemic. I do not. It is even-handed and factual, without the shrillness that pervades so much public discourse on the subject. I learned some great history and gained a better perspective on the importance of Greenland in the total ice/water/ocean budget of the planet. I recommend the book, no matter what your political stance.

Climate Change or Climate Forcing...redux

kw: musings, greenhouse effect, greenhouse warming, global warming, climate change, climatology, analysis

When I wrote a book review on the subject of climate change a few days ago, I had something in mind, but the review went in a different direction. The title actually didn't fit any more. Here are charts I made to illustrate my thinking on the terminology about "carbon pollution" and all the hype surrounding it, on both sides. Firstly, an nGram of the usage of three popular terms since 1970:

Although warming caused by the greenhouse effect, in particular that caused by carbon dioxide, was quantified by Svante Arrhenius in 1896, only after about 1970 was it brought to public attention. The great promotion of this issue really took off after 1985. This nGram shows that, in print at least, "Greenhouse Effect" was soon superseded by "Climate Change" and "Global Warning". But let's focus on a different term and its scientific synonym:

You can see from the upper chart that the term "Climate Forcing" has been scarcely a blip on the radar. But on the scale of the lower chart we see that about the time "Greenhouse Effect" peaked, "Climate Forcing" began to surge (relatively speaking), and shortly after that, "Anthropogenic Climate Change", a more scientific synonym, came along, but it is quite a mouthful.

It is a pity that Google stopped scanning books in 2008. I'd like to see how these words have fared in these past ten years. Nonetheless, I did a Google search for all these terms and a few others I've thought of in the past day or two (put in quotes to force literal searching), setting the search time to the past year, here is how they score:

• 7 - Anthropogenic Climate (allows "change" or other following words): 488,000
• 8 - Anthropogenic Climate Change: 478,000
• 6 - Carbon Pollution: 523,000
• 1 - Climate Change: 147,000,000
• 9 - Climate Forcing: 366,000
• 4 - Climate Science: 2,310,000
• 5 - Climate Warming: 975,000
• 2 - Global Warming: 56,600,000
• 3 - Greenhouse Effect: 4,360,000
• 10 - Greenhouse Warming: 295,000

The number preceding each term is its rank in this alphabetized list.

Why do people use the words they use? Impact. "Climate Change" and "Global Warming" get the public's attention. But the actual debate is not really about whether climate is changing or the globe (i.e. its atmosphere) is warming. It is about the extent that human civilization contributes to the change or the warming. However, "Anthropo..whatever" is too much of a mouthful, and "Climate Forcing" doesn't have quite the ring of the more popular terms.

But: Climate Forcing is really the best term about which to have a policy debate. The atmospheric climate will change gradually over time, whether the human race is highly civilized or goes extinct. Prior to 1975, the big worry about "Climate Change" was about "Global Cooling". A cooling trend highlighted by the first 15-18 years of weather satellite measurements triggered fears of a new ice age. And we find that the recent Solar Maximum had lower sunspot activity than most prior cycles. Based on historical records, this could indicate a cooling trend because lower solar activity heats the Earth's atmosphere less than average. Sunspot numbers are an indicator (not a cause) of the number of flares and other phenomena that send extra energy our way.

So, how big a factor is Climate Forcing? Let's call the Climate Forcing Factor the CFF. The way the media report things, one group called "climate deniers" would say the CFF is close to zero. In the same media, a group called "established science" claims the CFF is "most" or "nearly all" of the difference, in the range 50%-90%. Putting aside my conviction that the media are rather incredibly biased, we can instead identify the poles of the debate as "Large CFF" and "Small CFF" factions. Who is right? Do we have a way to know?

We don't, actually! But we can dig out an indication or two.

This article in ScienceDirect states that variations in sunspot activity account for about 40% of long term temperature rise in Norway over the past century, with a probable range of 25-56%. For a different portion of the North Atlantic, the range is 63-72%. This ought to please the Large CFF folks.

Remember the ozone hole? Starting about 30 years ago colleagues of mine at DuPont determined the great amount of damage being caused to the ozone layer some 15 miles (~25 km) overhead, and this triggered research efforts at DuPont and other chemical companies to find new refrigerants for air conditioners and new propellants for aerosol cans. The ozone "hole" was a dramatic thinning of this layer mainly over Antarctica, but spreading halfway to the equator, and there was a similar, but smaller thinning over the Arctic. But we need to be clear: the "ozone layer" isn't pure ozone; it is where ozone is concentrated to a level of about one part in 100,000 (0.001%); it is still mostly nitrogen. Ozone at sea level is around 1/30th of this, about 1/3,000,000th. Chlorine from refrigerants and propellants in use before 1980 had reduced the level of ozone over the poles by about 2/3, and elsewhere by about 20%. "Ozone hole" is the dramatic term that refers to the reduction of ozone from 1/100,000 to 1/300,000 over Antarctica during the southern summer.

Ozone is funny stuff. It is created from oxygen by ultraviolet light (UV), and then it absorbs UV, which heats it up. So the more ozone, the more the atmosphere is heated from the top. Specifically, at subtropical latitudes, surface temperature averages about 300K (27°C or 81°F), while 15 km (9½ mi) above, air temperature has fallen to about 200K (-73°C or -100°F). Ozone and other stratospheric gases absorb UV and some IR to raise the temperature back to 300K by about 50 km (30 mi) altitude. This warm gas in the mid- to upper stratosphere emits thermal radiation (longwave infrared) both upwards and downwards, which heats the air below a little. The gradual increase in stratospheric ozone levels over the past 30 years have contributed a little heating, but I have not found a rigorous analysis of the matter. "About a degree" is a general statement I have read. This is a factor that tends to please the Small CFF folks.

These things indicate that the CFF is unlikely to be greater than 50%, and is probably closer to 25% or less. I would not say, "close to zero", so I am not in the extreme Small CFF crowd, but neither do I favor Large CFF. As I have stated elsewhere, I learned that if we were to raise carbon dioxide levels to, say, ten times their present level, the amount of greenhouse heating would not exceed 4°C or about 7°F. That is quite significant. Is it enough to end civilization? I don't think so, but it will definitely change it. We are unlikely to find out, though. If we were to burn all the fossil fuels that we currently know about, it would no more than double the amount of carbon dioxide that we have already emitted. That's another way of saying that we have already burned about half the global reserve of fossil fuels. In rough terms, it means we have so far doubled atmospheric carbon dioxide, from around 200 ppm to around 400 ppm. Once we run out of natural gas, oil and coal—should we continue freely burning them—the level could become around 600 ppm. I don't think we have enough fossil fuel available to push that to 1,000 ppm, where some people begin to feel the effects.

For all that, we must continue to find other sources of energy, on all fronts. No source of energy is perfect. Wind farms (currently 4% of global electricity generation) disturb wind patterns, heat the air that passes through the fan blades, and kill migrating birds; solar panels turn about 15-20% of sunlight into solar energy and the rest is turned into heat, and much of this would be in desert areas where the sand usually reflects 75% of the light right back out into space; geothermal energy is "clean" from a heat perspective, because the heat will emerge from the earth anyway, but using geothermal energy causes pollution of surface water and ground water, a whole lot of pollution; and so forth. The more we learn about all these things, the better we can select energy generation methods that cause the least harm. That, and that alone, will reduce the CFF. It will probably never be zero, until human population is zero.

Postscript: Do you know what the global average temperature is? I am a geophysicist. Including the whole planet, the average temperature is about 4,000K (over 7,000°F). We need a different term for "global average atmospheric temperature", and we need to always specify at what elevation; is it surface, or at the average elevation of continental plains (about half or 2/3 a kilometer), or some other "standard" height?

Climate change or climate forcing?

kw: book reviews, nonfiction, astronomy, astrobiology, exoplanets, climatology, climate change, global warming

Do we need to save the planet? It doesn't need it. Do we need to save the biosphere? We don't yet have the power to end it. Do we need to save civilization? Probably. This last is the question taken up by Adam Frank in Light of the Stars: Alien Worlds and the Fate of the Earth. He takes a new approach, you could say a Galactic approach, even a Universal approach, to setting parameters around the future of human civilization.

Dr. Frank uses a quieter tone than the noisy polemicists in the toils of public debate. He is nonetheless speaking as a prophet, warning us all of the consequences of the greatest of human endeavors, "the project of civilization." I found it notable that he never mentions the IPCC Reports. This is not to say that he doesn't give them any credence, but he is preaching to the unconverted: I learned long ago, in Christian evangelism, it does no good to quote Bible verses to someone who doesn't believe the Bible. Similarly, the content and methods behind the IPCC's work are challenged at every point by "climate deniers", so it is no use appealing to those reports.

In this book the author begins with Carl Sagan's metaphor of Western civilization as a teenager, grown up in body but not in judgement. Here in the US at least, we give 15- or 16-year-olds licenses, and the keys, to drive automobiles, knowing full well that their minds won't mature, and they will have very poor impulse control, for at least ten more years. So, at the very least, we in the First World are like a teenager with the keys to the energy sources of Planet Earth, and we have shown an utterly insatiable appetite for more and more energy use. This chart is instructive:

This shows energy use per person (credit: Our Finite World). The technology to mine and use coal jump-started the nascent Industrial Revolution in about 1850. Petroleum and Natural Gas triggered a further jump beginning right after World War I, which was stalled by the Depression, and then re-invigorated by World War II. The "flat spot" from about 1970-2000 is the effect of the Arab Oil Embargo. I suspect the development of Fracking to rejuvenate oil production in non-Arab nations is responsible for the jump after 2000.

So now we use four times as much energy per person as someone in 1820. That is a global average. Per-person use in the First World is in the 250-300 GJ/yr range, or 3-4 times the global average. So that is our "car". It has a lot of horsepower.

The question Sagan asked, based on figures from the 1960's, is, "Can the Earth provide the needs of human civilization, forever?" To abolish poverty worldwide, we'd need to roughly triple global resource use, particularly energy use. But we are seeing "cracks in the wall" already. Someone once said, to raise the entire population to the American level would require four more Earths.

What is Adam Frank's line of analysis? He continues with the Drake Equation, formulated in 1961,
that uses several factors to estimate the number of alien civilizations we might find using efforts such as SETI, the Search for Extra-Terrestrial Intelligence, which uses radio frequency reception, in hopes of overhearing the alien version of "I Love Lucy". He dissects this for us and then presents the uses of a method developed by Svante Arrhenius, 122 years ago, to determine how much the earth will warm based on how much extra carbon dioxide gets into the atmosphere. "Climate science" is not new stuff, folks!

The Arrhenius method doesn't just work on Earth. It was used to understand what happened to Venus, to raise its temperature to 600°F, and why Mars is a bit warmer than it would be without any atmosphere, though daytime highs in its "Tropics" range around -10°F. Mars and Venus both have an atmosphere containing 95% carbon dioxide. Venus has a very, very heavy atmosphere while the air on Mars is very thin, about 1% of Earth-normal. But our air contains, at present, 400 ppm CO₂, or 0.04%. Martian air with enough nitrogen added to have the density of Earthly air would still have 0.95% CO₂, nearly 24 times as much! So the temperature range on, for example, airless Phobos, compared to that on Mars, validates the Arrhenius analysis for a CO₂-induced greenhouse effect (yes, Phobos is colder).

After presenting the history of exoplanet discoveries—a few thousand are now known—the author turns the Drake Equation on its head, to determine the "Pessimism Line". That is his term for how pessimistic you need to be to say we are surely alone in the Universe: Knowing that the stars in all the galaxies range in age up to 10+ billion years, and that there are about 100 billion stars in each of 100 billion galaxies (or perhaps even more) in the visible Universe, how pessimistic do you have to be to strongly aver that our Human civilization is the first and (so far) only civilization to have arisen in the Universe?

In 1961 the only factor of 7 in the Drake Equation that was known was the rate of star formation in the Milky Way Galaxy, about one per year. All the other terms were speculative, and all possible values of, for example, the chance that a planet will be at a "just right" distance from its star (in the habitable zone), were strongly supported by various people. You could find someone who'd argue that the probability was close to zero; someone else who'd argue that any star that had planets probably had at least one in the habitable zone. Now, with a few thousand known exoplanets, we know that nearly every star has multiple planets, and about 40% of those have at least one planet in the habitable zone. So the unknown terms are:

• Can life form easily, or not?
• Once formed, can life develop "intelligent" species easily, or is it very hard?
• Is the likelihood that an intelligent species will form a global civilization large, or small? and 
• Once formed, how long will such a civilization continue?

By turning all this around backwards, the combination of these "biological" and "sociological" terms needed to make it very unlikely that more than one civilization has ever been formed, was found to be 10^-22. That is one in ten billion trillion. This is a quantitative estimate of how hostile the Universe must be to civilization, for us to be alone in all space and time (to date). Effectively, this analysis presents you with a pile of sand, a trillion tons of it, containing ten billion trillion grains, and asks, "Knowing that at least one sand grain represents a civilization in the Universe, how likely is it that no other grain of sand represents a planet with a civilization? Not one single one?"

For most of us, the thought that civilization arose only once in ten billion trillion attempts is rather ludicrous. Even Peter Ward with his Rare Earth analysis, is probably not that pessimistic!

Dr. Frank then goes further, asking, "What does it take for a civilization to be sustainable, very long-term?" Numerous isolated and semi-isolated civilizations on Earth have risen and fallen. It seems even Earth, so hospitable to life of many kinds, can he hostile to civilizations…or, at least, unforgiving of egregious errors. Further, civilizations that fell, did so quickly. The environmental disasters, caused by the Easter Islanders and the Mayans all doing what people do to have a thriving society, reduced populations to about one tenth of what had once been in just one or two generations. Even today, there are fewer Mayans than there were in 1200 AD. These are two examples of civilizations that fell not because of conquest by someone else, but at their own hand. Two cases of a teenager driving right off a cliff.

The book closes with an appeal to wake up and grow up. It would be well to heed it. To my understanding, no civilization yet produced on Earth has figured out the trick to sustaining itself without perpetual growth. In the US, a growing GDP is required for a "robust" economy. The US government recently announced a 4.1% annual growth rate (that really means 0.335% growth for that particular month). It is good in a way. But if it keeps up, we can project it into the future: In just 17 years, GDP would double, and it would keep doubling again every 17 years. By 2100 AD the US GDB would be 27 times what it is today. What chance is there of that happening? Hmmm??

Suppose we finally get the analysis right, and find out that, for human civilization on Earth to be sustainable for 100, or 1,000, or 10,000 years, we would have to reduce our population to at most two billion, and the general lifestyle and level of energy expenditure (both personal and corporate) would need to match that of Peru (about ¼ of what us Americans are used to)? Then what? I'll tell you what: whatever the actual level of lifestyle really is, in time the biosphere will enforce it.

We are not divorced from Earth. We cannot act as though we were not part of nature. Nature can get along without us. We cannot get along without nature. Civilization is an experiment. It may be one that eventually fails. The Pessimism Line only tells us how unlikely it is that we are on the only planet to develop civilizations. It doesn't tell us how long they last. That part of the Drake Equation is still entirely unknown.

I would put it this way: If there is any chance for a global civilization to develop and thrive, and properly care for all its members, without constant growth in both population and standard of living, we need to figure that out right away. Or we, too, will crash, just a bigger version of the Mayans or Easter Island.

Global warming might save us

kw: observations, global warming, sunspots, ice ages

This graph, from Wikimedia Commons, is one of the most striking compilations of long-term observations to be had. The blue line charts more than 260 years of sunspot observations gathered since daily observation of the sun began in 1749. The red symbols add less regular observations that stretch back to the time of Galileo.
The most prominent feature is the regular 11-year solar cycle, followed by the significant variations in the height of the solar maximum with each cycle. The Maunder Minimum, a 40-year period in which three solar cycles passed with nearly no sunspots, coincides with the first, and coldest, phase of the Little Ice Age from 1650-1880.

There is not exact correspondence between sunspot activity and climatic heating or cooling. Solar Cycle 4, the beginning of the Dalton Minimum, lags just a little the significant cooling episode that caused the Continental Army under George Washington such suffering during the Revolutionary War. Many of our weather proverbs relate to late LIA conditions in New England. In particular, the old saw about the groundhog's shadow on Feb 2, which originated in Massachusetts in the mid-1800's, is quite a bit out of date. Clear conditions in midwinter no longer foretell a coming cold spell nearly so accurately. We are now in the midst of, or perhaps near the end of, the Modern Maximum which began with Cycle 18 about the time I was born.

The next image, also from Wikimedia Commons, shows recent cycles in more detail, plus predictions for cycle 24, which began in 2010 rather than 2007 as predicted, and 25, which is sheer speculation at this point.
The prediction for Cycle 24 is lower now. Cycle 23 peaked at around 135, while the prediction in the image below, from nwra.com, shows a prediction of about 90. That matches the range of sunspots during the early 1900's, and it was based upon those that predictions of a cooling episode were made in the 1960s, before the MMax became clear. It is not stated where the very low prediction for Cycle 25 arises, but if 24 is 90 or lower, and 25 is similar, we'll have significant cooling by the year 2030.

One feature of this chart deserves discussion. The curves go below zero! This is because sunspot number was correlated with f0F2 several decades ago, and now "official" sunspot number is taken indirectly. The f0F2 parameter refers to the critical frequency of reflection for the F2 layer in the ionosphere, measured by HF radar. Ham operators occasionally hear loud clicks in various HF bands (3-30 MHz) around sunrise, midday and sunset, caused by the radar measurements, which take only a few seconds. Since the correlation is not perfect, some measurements of critical frequency "figure out" to a sunspot number below zero. I have not located actual sunspot counts for recent years with which to compare this graph.

A lot is riding on the actual magnitude of Cycle 24. It could fool us; there is a lot we still don't know about solar dynamics. We have hardly a clue as to the cause of the Maunder Minimum. What we do know is that, although sunspots are cooler than the rest of the solar disk, the rest of the disk runs a little hotter on average, so that a strong cycle like Cycle 19 might have 1-2% greater sunlight hitting Earth than occurs during a solar minimum such as 2008 or 1995. Averaged out over twenty years or so, the reduced sunlight from a couple of weak cycles can make for stronger ENSO episodes (El Niño-Southern Oscillation) and deeper winters. A single year does not show such trends clearly, but decadal averages can. We'll have to wait and see.

In the meantime, let us consider the Medieval Climate Optimum, the period of 500-600 years before the LIA, during which global temperature was probably at least 2-3°C warmer than the decade of 2001-2010. Crops flourished and it was a time of prosperity. Global warming could drive us not just to that point, but beyond it. However, if we have a couple of weak solar cycles, the warming will likely be largely offset. Whether this is seen as coincidence or divine providence, it appears at first blush that we're going to have a postponement of the full effect of global warming, giving us time to increase the efficiency with which we use energy, perhaps even moving our transportation habits back to cars with Model A performance (they'd go 50-60 mph or 80-100 kph, but with 20HP, took a while to get there). That's what it will take to approach 100 mpg/160 kpg.

The other side of the coin is that, without global warming, we could have another series of winters such as those of the 1780's. Imagine postponing your Easter Egg hunt until the snow melts, or wearing your flannel underwear from September to April or May (add six months to these if you're in South America or Australasia). I like cold weather, but it has its limits. I have lived in South Dakota, and having SD conditions in PA would take some getting used to, such as putting our water main deeper underground where it couldn't freeze. A little global warming might just be our best friend!

To decarbonate everything

kw: book reviews, nonfiction, global warming, carbon footprints, surveys

To answer the title question, eating a banana is a very carbon-friendly way to snack. The book is How Bad are Bananas? The Carbon Footprint of Everything by Mike Berners-Lee. Make that almost everything. If you want to compare the carbon footprint of washing plastic or ceramic dishes versus using disposable paper plates, you won't find it here, but you will find nearly any other carbon-using or -saving option that there is.

I suppose there is a way to finesse the wash-versus-discard question, because there is a section on paper bags, with a carbon footprint of 12-80g CO₂e (meaning "carbon dioxide equivalent") each, depending on size and decoration and transport. There he states, "The paper industry is highly energy intensive." He goes on to discuss the energetics of paper manufacture on a per-kilo or per-pound basis, whether it is virgin or recycled, and also the carbon release by landfilling used paper rather than recycling it. You can then calculate how many kilos of paper plates you might use, that are equivalent to a dishwasher load, and compare the result with 770-990g per load, a bit more than doing them carefully by hand.

Just now much CO₂e does a banana represent? About 80g each, or 480g/kg. That includes shipping them half across the world. Compare apples at 550g/kg and oranges at 500 g/kg. Of course, if you grow any of these yourself, and don't need to water your trees, the net CO₂e is zero. They absorb carbon dioxide as they grow and release it upon use (via your sewage and trash). All the CO₂e of plant foods is in watering, fertilizer, transport and marketing.

At the other end of the scale, are you considering having a new house built? For a 2-3 bedroom bungalow, the CO₂e is 50 Tons! For a house like mine (4Br, 2Ba, full Bsmt), double that or more. The book is arranged by intensity, starting at 1-10g CO₂e, up to millions and even billions, for whole national economies and finally, for the World, meaning all of human civilization. One item never mentioned: human activities amount to about 2% of the trillions of Tons of CO₂e represented by the geologic and hydrologic cycles. However, this seemingly small amount is enough to unbalance the system a little, which is why there is global warming.

A word on CO₂e itself. Carbon dioxide is one of four prominent greenhouse gases. The most important is water vapor. Without the greenhouse energy trapping provided by water, Earth's average temperature would be sixty degrees F cooler than it is. Think Alaskan weather in Bermuda, and sea ice everywhere north of Los Angeles and Miami (and Morocco and Hyderabad; and similarly in the southern hemisphere). The other two are nitrous oxide, which is around 300 times as potent at CO₂, and methane, at about 25 times the potency. These two break down in the atmosphere over a few years' time, however, so the calculation of CO₂e depends on the time frame. They have a large effect on 10-20 year time spans, and comparatively little over fifty years. There is a small, and fortunately shrinking, level of refrigerant gases. Though more refrigeration and air conditioning are being produced each year, the chemical companies are producing better refrigerants with a smaller carbon footprint per pound or per kilo.

Throughout the book the author compares various actions with a "10-Ton lifestyle". Considering that the average Western family's present footprint is in the 15-20 Ton range, that represents quite a bit of frugality going forward. For example, over the past few years we have replaced all the windows in our 60-year-old house with tighter, more energy-efficient ones, and going back ten years or more we have replaced nearly all light bulbs with CFL's. I'd opt for LED's, but at current prices of around $30 each, they are less worth it than when CFL's were $15 some twelve years ago. My price point for LED's is $12. I can get equivalent CFL's for $6. I take my burnouts to a mercury recycler. I have spent close to $20,000, hoping for a long-term payback, but a lower-energy lifestyle in the meantime. But I am nowhere near a 10-Ton level.

Not surprisingly, transport is one of the heavy hitters. Unless a human walks or cycles everywhere, moving that heavy body (50kg and up) takes lots of energy, and most of that is liquid fuel, gasoline or diesel. Traveling about 800 miles in a small, efficient automobile produces 330 kg CO₂e. For my car, it is more like 500, which is why we rent a modern economy car for road trips. That figure of 500 is the same as a one-person plane ride of the same distance. If my wife and I both go, my car is twice as efficient as the airplane, per person, and even more so in the rental car. A recent drive from the Philadelphia area to near Kansas City, Missouri in a car with 36 highway mpg was a revelation. Fill-ups were needed rarely, and the tank only held 11 gallons. My 12-year-old Camry gets 26 mpg on the road, so its 18-gallon tank will actually go a little farther, but needs 50% more gas to fill. One of the best decisions of my life was getting a house that is only three miles from my workplace. My commute puts less than 1,500 miles on my car each year.

The book was a great deal of fun to read. I like facts, and this is a veritable encyclopedia of CO₂e information, with suggestions of reducing your own carbon impact in practical ways, ways that address the big factors while not sweating the small stuff. Mike Berners-Lee is a special advisor to Crichton Carbon Centre and founding director of Small World Consulting.

Gardening the atmosphere

kw: book reviews, nonfiction, global warming, geoengineering

A new book about global warming, pro or con, seems to come out every week. I've come to avoid them. One can only endure so many polemics. How to Cool the Planet: Geoengineering and the Audacious Quest to Fix Earth's Climate by Jeff Goodell is a middle-ground book. He takes human-caused global warming as a premise, and asks, "What can we do about it?"

It turns out there are just three approaches that could make a substantial difference:

1. Reduce carbon dioxide emissions
2. Shield the earth with a reflecting layer (AKA geoengineering)
   
3. Extract carbon dioxide from the atmosphere and store it somewhere (sometimes AKA geoengineering)
   

It has proven politically impossible to get anywhere with #1. #3 appears to be extremely costly. Now #2, well, it is cheap, but only in a monetary sense. It has so far proven too politically costly for anyone with the temerity to try an experiment. Also, the "mitigating" approaches, #2 and #3, are seen by many as a way for "big oil" to claim we don't need to do anything about carbon emissions: "just balance the emissions with sufficient geoengineering efforts and everything will be all right." Of course, "big oil" also claims carbon emissions aren't doing any harm in the first place.

Then we need to ask the question, whose ox is being gored here? What of people who think global warming (should it be happening) is a good thing? After all, other than the lack of air conditioning, and a little political bad news called feudalism, things were pretty good during the Medieval Climate Optimum a thousand years ago, when global temperatures were about two degrees C warmer than they are right now. (Personally, I prefer a slightly cooler climate. I am living about as far south as I can tolerate already. Maybe it is time to buy land in Canada!)

The author is wise to set aside the "reduce carbon emissions" argument. There are books aplenty on the subject, and a realistic look at the Montreal and Copenhagen debacles shows just how unlikely it is that the U.S., China, India and Japan will enact any significant changes in their economies. And there is nearly nobody else who matters, in this arena, just the E.U., but they are a distant fifth place in emissions; were they to emit zero carbon starting tomorrow, the effect would be pretty small. So instead, we are treated to an interesting tour of the various geoengineering methods and their proponents.

Carbon sequestration has two flavors: chemical extraction and storage, and "getting the plants to do it". In his second chapter, Goodell presents the work of David Keith in Calgary. Dr. Keith is building a prototype chemical extraction device. A test run in the author's presence reduced CO₂ by one part per million, or about 1/3 percent of its abundance. Dr. Keith is optimistic that engineering improvements can increase efficiency to a level near 10ppm (3% of total abundance).

The machine uses cheap chemicals, but in large amounts. To reduce atmospheric carbon from the current level (380ppm) to a pre-industrial level (280ppm), you'd have to pass the entire atmosphere through an array of these machines, ten times. Let's think about this. The weight of the atmosphere is 14.7 pounds per square inch, or 1.03 kg/cm². We want to remove 100ppm of it, or a portion of 0.0001; 0.0235 oz/in² or 0.103 g/cm². Let's go metric from here.

The surface area of Earth is half a billion square kilometers. A km is 100,000 cm. The math produces a requirement to "capture" more than 500 trillion kg, or 500 billion metric tonnes, of carbon dioxide. Dr. Keith's machine converts the gas to limestone, CaCO₃. 56% of the limestone is calcium oxide, CaO, so the end result would be 1.2 trillion tonnes of limestone. Let's see, the stuff has a specific gravity of 2.7, so a cubic meter weighs 2.7 tonnes; the volume is about 440 billion m³ or 440 km³. Anybody need a second White Cliffs of Dover, or have a place to put one? Maybe we could re-fill old open-pit mines. This is the amount of carbon storage needed to remove 100ppm from the atmosphere, whether it is to yield a pre-industrial atmosphere, or to keep the next 100ppm from accumulating in the first place.

How 'bout getting the trees to do it? You don't have to tie up half a trillion tons of calcium oxide to get this one to work; the gas gets converted to cellulose. Cellulose, however, is light. Hardwoods have specific gravities in the range 0.6-0.85. Let's pick 0.7 as an average. Here, you are tying up water with carbon dioxide in a 1:1 ratio, but releasing oxygen, so 44 grams of CO₂ produces 30 grams of cellulose. This is a benefit; you "only" need to produce 360 billion tonnes of wood to take 100ppm out of the atmosphere. But the volume of that wood is greater than the volume of the limestone above, just over 500 km³. Anybody ready to plant about ten trillion trees?

Fertilizing the oceans has also been seen as a possible solution. Iron is the rate-limiting nutrient in many parts of the open ocean. Here, experiments have actually been done, but not with geoengineering in mind. Impressive plankton blooms, visible to satellites, have resulted. But you still have the volume problem. How many cubic km of diatoms and coccolithophorids do you have to produce for half a thousand km³ of them to fall to the ocean floor and stay there?

So we come to global shields, of two types. Half the book investigates the scientific, political, and social aspects of these. One method is cloud-brightening, the other is sulfate-aerosol-blocking. In the book the author reports that it takes not millions but billions of condensation nuclei to make a cloud whiter so it reflects more sunlight. Actually, nuclei of the right size require droplets just under a micron in diameter; there are about a quadrillion such droplets produced from each liter of sea water one sprays. A quadrillion is a million billion (in American numbering, anyway). It takes thousands of liters of spray to make a substantial effect over a few square km of area. So far, no experiment has been tried, because of huge fears by environmentalists.

So: sulfate aerosols. This is potentially the cheapest method. Pump a lot of micron-size sulfur dioxide droplets into the stratosphere, and they'll stay there for 3-5 years, reflecting extra sunlight all the while. I wonder what astronomers think of the idea? Globally, some $20 billion have been invested in large telescopes in the past twenty years. How many of them would be rendered a lot less useful by a sulfate haze? The primary selling point of this approach is that we're not moving half a thousand cubic km of stuff, just a few thousand cubic meters.

The numerical analyses above are my own, not the author's. In a few places, he calls some of these methods akin to bad science fiction. He also worries about military uses of geoengineering technologies. There doesn't seem to be a good way of dealing with global warming. Yet his is a hopeful book. Human nature being what it is, we are likely to do something heroic when we really need to. As usual, heroes are a vanishingly small minority, so when the true crunch arrives (such as the imminent flooding of NYC or Bangladesh), a few visionaries will likely drag the rest of the human race, kicking and screaming, into a new kind of global economy. Let's hope the death toll is less than half of humanity.

I am hopeful in another way. The Medieval Climate Optimum showed that significant warming did not heat the ocean enough to make it rise much, at least not during that 400-year warming event. The real danger is melting ice caps, the ones on land, which are Greenland and Antarctica. They didn't melt much a thousand years ago.

All kinds of dreary forecasts are based on positive feedback effects. Negative feedback seems to be less well known, or ignored. I expect a warmer total climate to produce more polar snowfall, perhaps building Antarctica faster than it is being melted at the edges. Will a warmer planet be a cloudier planet? That's a possible negative feedback effect. Nobody at present knows. There is not one "global climate model" that models clouds properly. Cloud dynamics are still poorly known.

However, I am in favor of experimentation. How are we to know the effects of nano-nucleation of clouds without actually nucleating some clouds? Macronucleation for rainmaking purposes didn't work too well, but maybe cloud brightening can be one useful tool. Maybe sulfate aerosols can be "spot applied" in the stratosphere, and maybe not. We don't know if it could be helpful, or even possible, without trying. Can iron fertilization of ocean water do any good, or do enough good? Can't know until we try. The prime virtue of all these is, if things go bad, you just stop. In short order, natural processes will eliminate the change.

Goodell makes a good analogy here, that we ought to consider carefully. We are already engineering the atmosphere, as a by-product of energy use. Geoengineering methods that attempt to gain more control of the global thermostat are akin to gardening. There is no question that a garden is not a natural landscape. But it is not entirely artifice either. It is a synergy of human planning and natural processes, a compromise between gardener and nature. We will probably never be able to "produce" a pleasant, sunny day on demand in any particular location, nor order up a centimeter of rain when and where it is urgently needed. But we may be able to modify overall probabilities, to "tilt the roulette wheel" a little. Maybe.

In the longest of long runs, we'll run out of carbon based fuels. We won't add any more carbon to the atmosphere because we won't have any to add. What kind of world will that be? Will we have had the foresight to develop truly renewable and sustainable energy-production methods? Or will it be a return to horse-and-buggy days? Will anyone still have air conditioning? How much CO₂ will the atmosphere hold by then? 1000ppm? Things could be a lot different.

Finally, a word from the other side

kw: book reviews, nonfiction, global warming, debates, debunking, polemics

It is ironic that the prior book I reviewed is a vehemently pro-global-warming polemic, and this next is just as vehemently anti-global-warming, just as polemical. The new book is Heaven and Earth: Global Warming; the Missing Science by Dr. Ian Plimer.

The author knows he has a very tough row to hoe, so he goes the proverbial extra mile (or ten): Where most books of scientific popularization have 200 or fewer references, he has more than 2,000, which he has put in footnotes rather than endnotes. I am glad. I prefer footnotes; I am disinclined to keep paging to the back of the book, and tend to read endnotes, if at all, after the rest of the book. I don't mind glancing down now and again to see if a note has more material than just a bibliographic reference.

Long before the debate over global warning, when the term "greenhouse effect" was still in vogue, I read an article in which the author stated that even if CO2 were to rise to 1% the temperature would rise no more than 4°C or 7°F. That is a lot but it not great as some claims we are hearing.

A point which Dr. Plimer makes, which he supports with this chart, is that most of the greenhouse warming that CO2 can produce has been accomplished before the amount reaches 100 ppm.


We have here a classic situation of diminishing returns. It is one point in the book that I'll treat in some detail, then follow with a more general survey. The key to understanding it is to look at the way the spectrum of CO2 changes with its amount. The following chart shows the visible and infrared spectra of oxygen, CO2, and water. These spectra are all normalized to some specific depth of the pure gas, probably one meter (though the reference doesn't say).

See how the green line for CO2's spectrum has just a few bands, and only three that are "strong"? Let us suppose that this is for one meter of pure CO2. The atmosphere has just under 400 parts per million (ppm) at present, which is one part in 2,500. That means one meter of gas is distributed in 2.5 km of atmosphere. The effective thickness of the atmosphere is about 5 km, if you allow for the rapid thinning of air with altitude. So this line is probably quite close to the actual absorption spectrum of all the CO2 in the atmosphere between the ground and space.

Now, what happens as CO2 concentration changes? I prepared a simple spectral band absorption model to show this. First, a numerical example. Let us assume that the "standard amount" absorbs 75% of the radiation at a particular wavelength. What happens when there is three times that amount? The approach is to take the proportion that is transmitted (1-0.75 = 0.25), take it to the third power to get the new transmission (0.25³ = 0.0156), and subtract from 1 to get the new absorption (0.984 or 98.4%).

I prepared the chart below for an absorption band with a gaussian shape at low concentration, shown by the lower, black line. If the amount of gas is ten times as much, shown by the red line, there is a section with nearly 100% absorption, and the whole line is wider. With each increase by a factor of ten, the absorption band widens by a smaller and smaller amount. Going from the red line to the dashed orange line, though the amount of absorbing gas increases by a factor of 10,000, the total absorption increases only by about a factor of three.
I designed this example so that the red line approximates the absorption of CO2 near a wavelength of four microns, at 400 ppm for the full depth of the atmosphere. The solid lines above that one are for 4,000 ppm (0.4%) and 4%, at which point the amount of influence CO2 might have on the atmosphere is doubled. Four percent is also the level CO2 might conceivably achieve if we burn all known fossil fuels. This would also lower atmospheric oxygen by nearly 2%; how likely is that? Nonetheless, I show, with the two dashed lines, what the absorption would be if the atmosphere were 40% CO2, and if there were nothing but CO2 in an atmosphere with four times the density of today's atmosphere; a situation 1/10th as severe as that on Venus!

One might then ask, how can it be that Venus's temperature is 500°C? First of all, Venus receives twice the sunlight that Earth does. This means its equilibrium, airless temperature would be 65°C or 150°F. The airless temperature for Earth (experienced by the Moon) is 5.4°C or 42°F. Earth's actual equilibrium temperature is about 15°C or 59°F, mainly due to water vapor.

Take a look at what water vapor (the blue line) does in the 4-line chart above. It absorbs all wavelengths longer than 10 microns, and about half of radiation longer than 1 micron. If water were a much larger amount of the atmosphere, it would absorb so much of the outgoing radiation that a much higher temperature would be needed to move the thermal radiation to a short enough wavelength to escape to space.

CO2 has a very low absorption band longer than 6 microns, which in a very thick atmosphere absorbs everything. The "valleys" between the peaks shown also "fill up", absorbing everything from about 1.5 microns on. It requires a temperature of about 500°C to overcome this absorption, for an atmosphere such as that on Venus.

This, then is the physical explanation of the "greenhouse effect". Greenhouse gases such as water, CO2 or methane allow most incoming, shortwave radiation to reach the ground. Radiation in the absorption bands of these gases just heats the gases themselves, and the air they are part of. For the heated ground to radiate its heat back into space, it must emit enough radiation to get through the greenhouse gases. The warmer the ground is, the shorter is the effective wavelength of its thermal radiation. Longwave energy absorbed by the greenhouse gases heats up those gases, and about half of that is radiated back to the ground, so the more absorption there is, the warmer the ground has to get to achieve thermal balance. Of course, all this is complicated on a real planet because much of the heating goes into producing wind, but all energy turns into heat sooner or later.

The final point on this subject is this. At the concentrations CO2 has ranged within throughout history, its greatest effect has probably never been greater than about 3 times its present value. In the distant past, it reached concentrations as great as 1% (10,000 ppm). During one such time there was an ice age! It is never likely to come anywhere close to 1% again. Now for a summary of Dr. Plimer's message.

He is called a "denier" by some, those he might call "warmists". He makes the point that a belief in global warming has become like a religion to some. No matter what people call themselves, even atheists have strongly held beliefs about something, which they hold with religious fervor. Everybody believes in something, particularly those who deny it the loudest.

The little chart above shows average global temperatures for the past 2,000 years. I deliberately went to a source different from the ones Dr. Plimer uses. If you click on it to see the larger version, you'll be able to read the reference. This prominently shows the Medieval Warming, which was warmer than 1998, the warmest year since the Industrial Revolution began in the 1800s. With this and similar data, Dr. Plimer asks the questions, "How did it get so warm in the years around 900 and 1000, when CO2 was so much lower than it is today?" and "Why were the Little Ice Age of 1400-1850 and the late Roman period before 800 so much colder?" Unless these questions can be answered, his point is that temperature is not controlled by CO2.
Then he shows the comparison graph above, on page 89. The lower half is a similar, but smoothed, chart showing the Medieval Warming and the Little Ice Age as they have been understood by climate scientists for many years. The upper chart is the infamous "hockey stick" chart produced by Michael Mann and his colleagues. This chart has been totally discredited by several scientists, but is the one used by the IPCC to base its conclusions that we are all in grave danger. Is it any surprise that Dr. Plimer and others deny there is much to worry about? or that they question the motives of the leading authors of the IPCC Report?

The structure of the book echoes its short title. The Sun (Heaven) has by far the greatest influence on weather and climate. Its variation due to the sunspot cycle and longer cycles (which periodically eliminate sunspots for 50-100 years) has a significant, well-measured effect on climate. After an introductory chapter and one on history, the Sun and influences on solar influx to Earth fill one large chapter. Other heavenly influences include cosmic rays; when the sun is weaker, its reduced magnetic field lets more cosmic rays get through, and average cloudiness increases, further reducing the amount of sunlight that reaches the ground. Cooling ensues. Warming follows a strengthened sun, amplified by a reduced cloud cover. The Maunder Minimum, a 70-year period almost without sunspots, was the coldest part of the Little Ice Age.

In his History chapter, he makes the point again and again that warming periods have been periods of increased productivity and expansion of species, and that cooling periods are marked by desertification, loss of species or mass extinction, and (in the Holocene at least) crop losses leading to reduction in human numbers. He repeats these points throughout the book, particularly in the Sun chapter, where he asks, if global warming was good for the early Romans, and even better for the late Medieval Europeans, why do IPCC scientists claim it will be bad for us?

The fourth chapter, also a long one, is "Earth". While he hits a lot of points, a big one is volcanoes. Mass extinctions seem to have occurred in sychrony with extra-large "supervolcano" eruptions that took thousands of years to burn themselves out. Each such episode produced millions of cubic kilometers of lava, and thousands of cubic kilometers of "stuff" was put into the atmosphere. A characteristic of volcanic activity is that it produces lots and lots of CO2, yet because of Sulfur oxides and solid matter also blasted into the sky, cooling is the result. By the time the cooling is over, earth processes have usually absorbed all the extra CO2 as well. But there is another, continuous source of volcanic activity, which arises in the Water chapter.

Before Water he spends a chapter on Ice, primarily the Snowball Earth period in the late Precambrian period about 700 million years ago (and perhaps another one 2,000 million years ago). Both occurred when CO2 was many times denser than it is today.

In the Water chapter he addresses the question, "Will the seas become acid?" If you measure the acidity of soda, water with a few percent CO2, it is definitely a weak acid. Not as strong as vinegar, but acid nonetheless. However, if you put almost any common kind of crust-forming rock, such as granite or basalt, in the soda, and cap it for a few weeks or months, the acidity will reduce and eventually turn to alkali. Even though granite is called an "acidic" rock, that is only with reference to basalt, which is more strongly alkaline.

Guess what forms the sea floor? Basalt. What is going on deep under the sea? For one thing, CO2 in sea water quickly hydrolyzes to bicarbonate (HCO3- ion), which is less acidic. Then bicarbonate reacts with basalt to change silicates to carbonates, except that much of it is captured by snails, clams and other growing sea critters to make their carbonate shells also. All these processes result in a sea that is distinctly alkaline.

There is a greater source of CO2 under the sea, however. The Mid-Ocean Ridge is an 80,000-km system of "spreading center" volcanism that runs through every ocean basin. The average spreading rate is 5cm/y. That results in 4 cubic km of new lava produced every year (that is 30 million tons per day). These sea-floor basalts erupt at a temperature near 1000°C. It takes a lot of water to cool them down to the 0-5°C temperature of the deep ocean. Many cubic km of water are heated continuously by this outflow. Each cubic km of lava has a lot of CO2 in it, which dissolves in the deep water. This water has been measured to have the capacity to hold a lot more CO2 than what these Mid-Ocean Ridge produces. This amount is much greater than what we are producing with all our industry. The fresh basalt reacts with some of it to keep the oceans alkaline.

A short chapter on Air challenges the entire notion of the "greenhouse effect". The radiation-in-radiation-out definition I gave above is different from what the author espouses. I don't stand with him on that one. I understand the term is a metaphor that isn't supposed to exactly equate CO2 or any other gas to the glass in a greenhouse. We all know greenhouses are more for keeping freezing or drying wind off the plants, and often have to be either heated or cooled, but they do tend to gather heat by differential radiation absorption, and this is the part of the metaphor that is useful.

In his final chapter, "Et Moi", he recapitulates his main points, and closes by asking "What if I am wrong?" Only the "wildest" of the "warmers" will claim that during the present century warming will be greater than 3°C, yet the Medieval Warming was 3°C warmer than today, with very salutary effects on all. The sea didn't wipe out coastal settlements and crops boomed. He winds up with 18 "even if" points, the last being, "Even if mitigation were as cost effective as adaptation, the public sector, which emits twice as much carbon as the private sector, must cut its own emissions by half before it preaches to us."

He started that chapter by stating, "...the greatest threat...is from policy responses to perceived global warming and the demolishing of dissent." I agree with him on this. Is he wrong, folks? Prove it. Use real data, not Mann-style "hockey stick" fraud. But I have skimmed the internet and seen mostly ad hominem fallacies against him in response to the points in this book. Their authors are a shame to the profession of science.

On Earth's failure to obey our predictions

kw: book reviews, nonfiction, global warming, policy


It is quite a paradox. After the decade of the 1990s, in which each year was "one of the five hottest of the past century!", the first decade of the 21^st Century has been disappointingly cool. A recalculation of some data indicated that 2007 may—just maybe—have been ever-so-slightly hotter than 1998, but 2008 is on track to be the "least warm" year so far since about 1992.

Climate gurus of all stripes are predicting that 2009 will be warmer. Will they have better success with their predictions than Jeanne Dixon, the famously inaccurate 'psychic' of my youth? She made a comfortable living from being right only a quarter of the time.

Climate modelers and other researchers are faced with the fact that climate is in continual flux for many reasons, most of which we are wholly ignorant. Milankovich cycles that span tens of thousands of years, Bond events of unknown cause that span a thousand or two (most recently the Medieval Optimum followed by the Little Ice Age), shorter cycles perhaps mediated by the 22-year Sunspot cycle, and trends both shorter and much longer than any of these that may relate to varying fluxes of cosmic rays: these are things we know a little about, but how many influences are as yet wholly unknown?

To those who'll react, "Isn't the Sunspot cycle 11 years?": one 11-year series has the Sun's magnetic field aligned the same direction as Earth's, while the following series it is in the opposite direction. The effects of solar flares on earth systems during a "same" series differ from flares during an "opposed" series.

My observation of the climate change debate for more than forty years is that as the (emotional) heat increases the light vanishes. I despair of pundits from any "side" of this many-faceted debate showing any reasoned restraint in my lifetime. But perhaps there is a ray of hope. Nigel Lawson (Lord Lawson, former Chancellor of the Exchequer), safely ensconced in retirement, strives to inject a rational note with his little book An Appeal to Reason: A Cool Look at Global Warming.

There is no sense pulling punches. Let's begin with his conclusion:

"...a lurch into protectionism, and a rolling back of globalization, would do far more damage to the world economy, and in particular to living standards in developing countries, than could conceivably result from the projected continuation of global warming...[It] is clear that the would-be saviors of the planet are, in practice, the enemies of poverty reduction in the developing world." (p. 106)

Though he has more than one central point, I think this is the most telling: The IPCC reports of recent years are based on various projections of the economic progress of developed and developing nations. The "hotter" cases, those that predict greater greenhouse heating of earth, are based on greater economic growth, and the "cooler" cases are based on various amounts of throttling of economic growth. Thus, the IPCC "worst case" scenario predicts that people in the developed nations will be 2.5-3 times better off 100 years from now than their great-grandparents (us) are today; for the developing nations, the figure is between 8 and 10. Their intermediate cases are based on people being perhaps "only" 75% as well off—and require cutting back our own prosperity a similar amount. So our efforts to reduce the greenhouse heating experienced by our unbelievably rich great-grandchildren entail rolling back twenty or more years of economic progress!

Looked at carefully, the IPCC predictions for the least warming ("best case") require reducing not just growth, but actually contracting the economic structure of all countries, so as to reduce greenhouse gas emissions by 70%. Think about that. It is, effectively, a rollback of Western lifestyles to the those of the 1920s or earlier, certainly before any kind of air conditioning became widespread and before most people traveled by auto rather than carriage or tram. It requires China and India, home to almost half of humanity, to halt their progress in its tracks. Precisely how likely are these things? My conclusion: ZERO.

Lord Lawson take a look at the very real reports of heat-related deaths during those hotter years in the 1990s. In one year, 2,000 people, mostly elderly, died in France. News reports that year failed to mention that the prior winter, 20,000 people, mostly elderly, died due to the cold...and that was a bit less than usual. Is the point clear? Winter is still a bigger killer than summer. At what point will they become equivalent? Perhaps that is the optimum temperature!

For those who worry that heating will truly get out of hand, the author introduces us to a few folks in the relatively new field of Geoengineering. They are working on methods to cool the planet, whether we reduce CO₂ emissions or not. Certain aerosols, for example, result in significant cooling without harming the Ozone layer (a worry that still comes up at times). So, fire a few million tons thereof into the stratosphere! With research, and luck, maybe they'll come up with something more effective and more benign than the sulfates that volcanoes routinely spread, but which come down as acids over a few years' time.

We find buried in the IPCC reports the prediction that warming is bad for some and good for others. They even phase it: a degree or two seems to do more good than harm, while four or five degrees (Celsius, of course) is expected to be mostly bad. Lawson writes, "...is it really plausible that there is an ideal average world temperature, which by some happy chance has recently been visited on us, from which small departures in either direction would spell disaster?" (p. 27). I don't think so either.

The age of Dinosaurs, which ended 65 million years ago, experienced CO₂ levels four or five times today's level, and global average temperatures as much as 18°C (32°F) greater than today. That doesn't mean the tropics baked at 50+°C, but that the poles were almost as warm as the tropics, which were only slightly warmer than they are today. All computer climate models predict 5 or more degrees of warming in the Arctic and Antarctic for each degree of equatorial warming. Canada, Siberia, and southern South America will likely be the grain belt of such a future!

Secondary threats such as rising sea level are much touted. Yet they aren't really panning out. Even the IPCC's worst case predicts at most a fifth of a meter (roughly a cubit, or 1.5 feet) of sea level rise by 2100, and then only if a goodly portion of Greenland's ice cap melts. That ice is receding a bit at the edges, but its center is thickening! Perhaps that is why, in thirty years, the sea level at the Maldives has not risen, but fallen slightly! (See N. Morner et al 2004, 'New perspectives for the future of the Maldives', Global and Planetary Change, v40, Jan 2004, pp. 177-182.)

I've been particularly bemused by the idea of carbon trading. What can it accomplish? When Al Gore pays a "carbon offset" to get a few hundred trees planted somewhere so he can feel OK about having a huge mansion and fly about in a private jet, is anything genuine actually happening? Lawson thinks not, saying, "[Buying carbon offsets] resembles nothing so much as the sale of indulgences by the medieval church." (p. 78).

He prefers we do things that might really help. Geoengineering is one possibility. Another is to learn all the climatic influences so we can make our computer models actually meaningful. Today's state of the art is miserable: "The earth's climate is determined by hugely complex systems, many aspects of which are not at all well understood. Reliable prediction is impossible." (p. 91). He favors greatly increasing research spending to bolster our understanding in hopes that this "miserable" situation will be better in the future. Yet we must remember that climate is the quintessential chaotic system. Doing something twice in a row won't always produce the same results. Too much depends on what else happened between time one and time two.

So I am heartened by his effort, but it is bittersweet. His appeal will only resonate with those who really don't need it, and be ignored by those who do.

Are we killing ourselves by degrees?

kw: book reviews, nonfiction, global warming, polemics

See my post on June 23 for background about my contention that climatic heating greater than 4°C due to CO₂ emission is implausible. I've just finished reading Six Degrees: Our Future on a Hotter Planet by Mark Lynas, an environmental activist who writes for National Geographic Explorer.

The book is well planned and well composed. Lynas has gathered all the effects we might expect at each degree C, from one to six, with a chapter for each degree. If we take the 1950s as a baseline (the author doesn't state his zero point), we're living in a "one degree world" already. The natural progress of the current cycle as outlined by Gerald Bond, that is, the "Bond Event" that began about 500 years ago with the start of the Little Ice Age, and that will run another 500 to 800 years, with a warmer middle (or at least a drier one), is likely to produce another degree of warming entirely without our help. Remember also the brief (decade or so) cooling of the 1960s and '70s. The best (not most frequent) estimate of the "human signal" in all this is half a degree or less.

Thirty-plus years ago I remember straight-line extrapolations made by scientists that warned us the year 2000 could be one or two (some said five) degrees cooler than the 1950s, and that we were in danger of continental glaciation getting started. Those fears are pretty much forgotten now. Today's fears are less likely to be forgotten, because we appear to be augmenting a natural warming cycle.

I don't want to discuss the matter, point by point. This is but one of many new books on the subject, though it happens to be the most conveniently arranged. I'll just make a few more observations as an observer with a geologic worldview.

• In my post linked above I state that the PETM some 55 million years ago was a two degree excursion. Lynas and many others state it was six degrees, and others pick various figures in between. It may have been more than two degrees, but remember it began at a point ten degrees hotter than now. The key element seems to have been release of a lot of methane from the seabed. The rate of release, during each of two thousand-year-long periods, was slightly smaller (in terms of carbon per year) than the current human output, which is growing. Methane is about twenty times as effective a greenhouse gas as Carbon Dioxide, and takes a few years to be oxidized to CO₂. Thus most of the heating was due to Methane. To me, it seems like a good idea to gather seabed methane "ice" and convert it to CO₂ before it erupts on its own...and we'd get lots of energy out of the bargain.
• More CO₂ means more acid in the oceans, making it harder for shelly creatures to make their shells, or so it is claimed. Its actual effect is to make the lysocline shallower; the lysocline—the depth below which carbonate shells dissolve—is presently 4km. In the Cretaceous, when the temperature was 15-20 degrees warmer and CO₂ was four or five times as abundant as today, the lysocline was closer to 1km depth, and shelly creatures abounded, since most of them live in water shallower than this anyway.
• Curiously, nobody talks about the "vent clams" and giant tube worms found in the deep ocean around the mid0cean ridges and their hot-water vents. They were there in the Cretaceous, too, and somehow made lots of shells even at depths below the lysocline. Just as diamonds are not stable at the surface, but slowly (millions of years) are reverting to graphite, so if you take a clam shell to a deep part of the ocean (the deepest trenches are 11km) it won't dissolve for many years. In fact, shelly creatures live in the deepest trenches today. The things that do dissolve with seeming rapidity are shells of microscopic foraminifera and radiolarians, which start out less than a millimeter across. But they don't vanish on the way down; they sink to the bottom and very slowly dissolve there.
• I keep reading about how living creatures "can't adapt" to this or that change. Yes, evolution is rather slow, but in short-lived creatures (most of our furry and feathery friends reproduce yearly or oftener) it can proceed with stunning rapidity. Let us remember that, the greater percentage of a generation gets killed, the greater the likelihood that the next generation will be substantially different from their ancestors. That is the essence of Punctuated Equilibrium, for which see the writings of Stephen Jay Gould and Niles Eldredge. Bottom line: Ten years is ten generations for a songbird or rodent. That's plenty of time for the critters to move half a continent away if needed. Only a few offspring with wanderlust need survive for a species to make a large move.
  

Author Lynas is rather pessimistic about people's willingness to sacrifice for the next generation. I tend to agree. I expect the human race of five hundred years from now will primarily be using sustainable energy, because the cheap and easy stuff we use now will be gone, and for no other reason. In part, that's also enough time for evolution to have worked on the human psyche, but in which direction I dare not hazard a guess! BUT: The larger the number of people living then, the less evolutionary change there will have been. That's a simple statistical fact.

I am in substantial agreement with about half of the conclusions in the first three chapters, and a much smaller proportion of the rest. Knowing the tendency of both living and nonliving, complex systems to "do what they want," I expect the next generation or two will live in a world about which not one of the current authors has written.

Global warming and cooling - the view from 50-plus million years

kw: opinion, global warming

Body of a Letter to my Dad: All my brothers are politically liberal, and one in particular apparently believes "Global Warming is All Our Fault". My Dad and I are more conservative. I am probably more moderate, because I believe human activity is responsible for between one-quarter and one-half of the rise in global temperatures since the 1950s. However, I do not give much credence to the gloomy predictions found in an increasing number of books and "journalism" related to the subject.

I have gathered four charts found in the Wikipedia Commons, a great resource for materials that can be used freely, as long as their source is referenced. Click on any of these images to see a larger version, typically 600-700 pixels wide.

The first chart shows a composite summary of Holocene temperatures, a weighted average of many proxies, some of which are shown in various colors, to illustrate the uncertainty of such a record. A proxy is something we can measure today, such as Oxygen isotope ratios in tree rings or clam shells, that have a known relationship to global temperature. The Holocene period, also called "Recent", is the past 11,000 years, since the end of the most recent Ice Age.

As far as I can find out, the zero-temperature-difference line is pegged to the 1980 global temperature, about a quarter degree C (half a degree F) warmer than that in 1950. First pay attention to the inset, which covers the Christian Era. This began with a bit of cooling about 100AD, then warmed toward the Medieval Optimum which ended with the Little Ice Age (LIA) that ran from the 1400s to about 1880.

On a longer scale we find that, since just over 10,000 years ago, the Holocene has been both warmer and cooler than today, but overall it has been remarkably stable, within half a degree C of the 1980s value. On a particular day of the week, a degree or two is too small to notice, but the amount of energy in a one-degree shift in global average temperature is quite significant.

The period from 4,000 to 8,000 years ago, marked "Climatic Optimum?", marks the period when agriculture and citified civilization became widespread. All of the modern grains and other major crops were domesticated during this period. Funny thing...for the past 4,000 years, these crops have been "thriving" in a somewhat cooler world than that to which they are best adapted. It may be that the "2004" temperature suits them better!

This chart's scale is too small to show the "hockey stick" graph we often see, showing just the past 2,000 years, which were extra-stable (even including LIA), followed by a one-degree uptick beginning less than 100 years ago. Interestingly, that uptick almost matches the one that occurred 8,200 years ago. One human lifetime is such a short interval...

Let's expand the scale by a factor of forty, and look at the entire "Ice Ages" record, as it was thought of until recently. These proxy temperatures are from two ice cores extracted in Antarctica; the EPICA core goes back nearly one million years. I'd hate to be the guy that counted 850,000+ dust bands!

Concentrate first on the blue line. Four glacial periods, and the end of an earlier, fifth one, plus five interglacial periods, are evident. Both the black line and the blue line show that the modern interglacial period, the Holocene, is the coolest of the four...so far. We'll get back to this later on. The most recent prior interglacial period is called the Eemian, and it began with a pulse that got as warm as five degrees C (9°F) above the 1950s zero line, for a thousand or two thousand years. The key element here is the roughly 100,000-year cycle of ice ages. Earlier on, they were more frequent, as shown in the next chart.

This chart is composed of data from several ice cores and a number of other proxies. It goes back halfway to the most recent glaciation of Antarctica, which was 12 million years ago. The primarily 100,000-year ice cycle began just over a million years ago. Prior to that, it was closer to 40,000 years. The gradually-increasing amplitude of icing events beginning 3 million years ago, late in the Pliocene era, is probably associated with the irruption of Panama cutting off the equatorial Pacific and Atlantic oceans, and their gradual adjustment to being connected only via the Southern Ocean.

The 2.5 million years prior to the Holocene comprise the Pleistocene, which began geologically when temperate-latitude soil profiles began to be interrupted by periodic glaciation. Prior to that, the Pliocene was almost always warmer than today. Now let's take one more scale expansion, to look at climate since the large Dinosaurs were wiped out and the smaller ones began to evolve into birds.

The whole prior chart fits into the blue rectangle at lower left. The bright blue scale shows that, prior to ten million years ago, the climate was, with one short exception, warmer than three degrees C (five or six deg. F) warmer than the 1950 zero line. Prior to the late Eocene, or prior to 34 million years ago, the warming, compared to today, was four to twelve (!) degrees C, or 7-22 degrees F.

Let's look briefly at the spike called PETM, in the yellowish area. This is the Paleocene-Eocene Thermal Maximum. It was apparently caused by a sudden gush of carbonic gases into the atmosphere when volcanoes began to erupt in a new area of the seabed, releasing billions of tons of methane clathrates. Methane gas oxidizes in the atmosphere to carbon dioxide, on a scale of a few decades. But here, for more than a thousand years, these two gases were put into the atmosphere at a rate that roughly equals the human-caused influx of today. So, a thousand years of excess carbonic gases caused a sudden temperature excursion of about two degrees C. That's it. And when the volcanoes cooled down, so did the planet...just as fast.

Based on all the forgoing, we can ask a few questions:

• Predictions are being made that the globe will warm as much as six degrees C (11 °F) by the year 2100AD, or around 150 years of human emission of carbonic gases. How do such predictions square with the PETM of two °C after ten centuries?
• Recent coral bleaching events have led to predictions that another degree or two of warming will cause the extinction of corals. Corals of all ages are found, including those that thrived during the "Eocene Optimum" when even polar oceans were bathtub-warm. Have corals become so fragile?
• Antarctica froze over for the first time 34 million years ago, them melted off suddenly 24 million years ago. All without benefit of people burning coal. What happened?
• It is known that many crops grow best when carbon dioxide is five times as abundant as it is today. Such levels were common in earlier times. Why would a rise in CO2 today be such a threat?
• CO2 levels during the Pleistocene have been lower than in any earlier time. This is probably due to C4 photosynthesis evolving in the Pliocene or Miocene. If there were no C4 photosynthesis, isn't it likely that Carbon Dioxide would remain at a much higher level than today?
• Based on the former questions, doesn't it make sense to talk about growing grass rather than trees to sequester the gas? Trees don't grow very efficiently at the low modern concentration of CO2 gas!
• There are many claims of extinction, perhaps of a quarter to a half of all species. (Note, "all animal and plant species" is meant. Bacteria have much wider tolerance for thermal swings) Neither the PETM nor the sudden Antarctic melting prior the Miocene caused such levels of extinction. Why the hype?
• A closer look at the second chart shows smaller wiggles that seem to cover 1,000-3,000 years each, with a height of a degree or less, mainly during the cooler, icy phases. These are harder to trace in the interglacial periods. However, Gerald Bond and his colleagues discerned eight "Bond events" since 11,000 years ago, the most recent of which is the LIA. We are in a warming phase betwen Bond events. How does this affect global warming predictions? This last is why I say our gases may be responsible for no more than one-quarter of the recent warming.

I am no "global warming denier", but neither am I an uncritical believer. As a Geologist, I am accustomed to thinking in tens to hundreds of millions of years. On such a scale, researchers (whether humans or super-roaches) of the distant future are likely to look upon our period as a mini-PETM at worst. We're going to run out of fossil fuels before we can spit out as much gas as the PETM event did. And it was a two-degree anomaly. We have no clue to what caused the ten degrees C of warming that it sat on top of!