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Thursday 22 July 2021

An odd theory about oil.

 Some fuels, like peat, coal, and perhaps oil may be derived from the fossilised remains of plants and animals. Standard wisdom says all the oil and coal that we find is organic, and so must have originated with organisms.

This is testable in some cases: we can certainly find plenty of fossils in coal, confirming that coal was formed when dead plant and occasional animal matter was buried in a swamp under the right conditions. We can see peat, brown coal, black coal and anthracite, and we can show that these are always found in sedimentary rock. We call these energy sources fossil fuels because we regard them as a form of buried solar energy, fossilised sunshine.

Every so often, a scientist comes up with what sounds like a totally crackpot idea. That is, in terms of what other scientists believe, it is a crackpot idea. Alfred Wegener wanted people to accept the idea of continents moving, and people dismissed him as an eccentric or a fool. Louis de Broglie made the crazy suggestion that electrons might really be waves, and almost failed to get his doctor’s degree because of it.

Wegener died without recognition, though his theory of continental drift (which we now know in an amended form as plate tectonics) is standard stuff in your textbooks. Louis de Broglie was luckier, because Albert Einstein heard about de Broglie's strange idea, and suggested gently that de Broglie might in fact be correct, and de Broglie lived to see the electron microscope (which treats electrons as waves) become a standard laboratory tool.

Wegener’s case is a bit more typical, for few ‘crackpots’ get an easy time of it. More than that, most of the crackpot ideas turn out to be wrong. Yet without those strange ideas, science would never grow. Thomas Gold had to comfort himself with that thought, each time a geologist sneered at his ideas about where oil comes from. That, and the knowledge that scientists can change their minds.

Scientists usually work with a particular paradigm until evidence arises to make the old paradigm unacceptable. There have been many failed paradigm shifts, because scientists are only swayed by the evidence. When the scientists proposing a change are as astute and capable as the late Thomas Gold was, people need to ask themselves what evidence they should look for, either to support or refute the paradigm shift that Gold offered.

Gold was a famous physicist, one of three astronomers who worked out the steady-state theory of the universe, which has now been replaced by the Big Bang theory of the origin of the universe. He lived to see that theory overthrown, and now he was attacking an older, and more deeply accepted theory. He could not accept that our world’s hydrocarbons are biogenic, made by living things.

When we first discovered petroleum, said Gold, it was close to the planet’s surface, and chemists then thought that the only place you found carbon chemicals was in living things. They even named carbon chemistry organic chemistry, because it was the chemistry of organisms. Oil was made of organic chemicals, so obviously it had to come from organisms.

Now we know that comets contain ‘organic’ chemicals, and so does Jupiter. Nobody argues that the methane on Jupiter came from giant Jovians breaking wind, and nobody assumes there are little green people all over the comets, producing the organic stuff there. If we were to discover oil today, said Gold, we would never be so silly as to claim that it came from plants and animals, not with the knowledge we have now of other bodies in the solar system.

The geologists sneered at this. How much oil has been found in igneous rock? they asked. Gold accepted this question cheerfully. Not a lot, he said, because geologists are set in their ways, and they only drill for oil in sedimentary rock, where the oil sometimes gets trapped as it rises to the surface. He had, he claimed, extracted 12 tonnes of hydrocarbons from granite in Sweden, most of it coming from dolerite veins that have intruded into the granite from below. The veins either weakened the granite, or carried the hydrocarbon with them, he said.

The Arabian Gulf oil fields, according to Gold, have no common features at any depth, except that they are over an area of great seismic activity. This area contains 60% of the world’s recoverable hydrocarbons. From the mountains of south-eastern Turkey down to the Persian Gulf, the plains of Saudi Arabia and the mountains of Iran, there is a continuous band of oil-fields, but nobody can find an adequate supply of source rocks to account for the oil that is there.

There is simply no ‘coherent geology’ beneath the surface to explain why the oil is found there, he said. The rocks are of all types and all ages, with nothing in common. But they are all rich in oils, and the oils are chemically identifiable, right through the area. They must have a common origin, said Gold, but some of the rocks are fifty million years younger, and were formed when the climate, the biology, everything in the area had changed. According to Gold, there is just no way the oil could have come from the rocks that have formed since life evolved.

In other places as well, we find oil provinces that stretch much further than any surface geological features. The only thing that is common is the deep seismic activity.

Then we come to Gold’s other problem: where did the living things that supposedly formed the oil get their carbon? If they got it from carbon dioxide in the air, through photosynthesis, there could not have been enough for life to keep going. So, said Gold, there must have been a continuous supply of carbon compounds for life to keep going. On his calculations, the earth’s atmospheric CO2 must have been replaced 2,000 times in the past 500 million years.

The source of our hydrocarbons, he suggested, is about 150 km below the surface, seeping upwards when it can. Look at Indonesia, he said, where the movement of the Australian plate is causing activity below the surface, and there are huge oilfields. Look at California, where two plates are separating. Look at the match-up between seismic activity and oilfields in the rest of the world, he said.

It was true, he said that we often find petroleum in sedimentary rocks, but that, he said, was merely because we have a paradigm that says that we should look in sedimentary rocks, and so we only drill oil wells in sedimentary structures.

We were trapped in a 19th century paradigm, he said, one that held, until well after Friedrich Wöhler synthesised urea and William Perkin synthesised the first organic dyes in 1856, a paradigm that is reflected in the very name of the science that Perkin initiated, organic chemistry.

Back in the 19th century, as people began to drill for oil and use it, they naturally assumed the carbon compounds were organic, formed from living things. Even Pluto has hydrocarbons, but where did Pluto’s methane come from? There are no swamps or cows on Pluto, yet there is methane there. These organic chemicals come from a distinctly non-organic background.

Just for now, the oil companies have not been rushing to take up exploration leases on the world’s granite belts. In the future, we might just see a paradigm shift that leads them to do so, but even then, the oil would still be fossilised sunshine in a sense, for all of the solar system’s other hydrocarbons must have had their origin inside the sun, or some other earlier star, and the stored energy in them is derived from a star’s nuclear furnaces.

That leaves me wondering about the Yarrabubba asteroid: might it have smashed into a large deposit of inorganic oil? The best answer: more research is needed. Science often says that.

Friday 2 July 2021

A changing climate

Jens Galschiot’s installation
‘Unbearable’ in Copenhagen.

 In the savage illustration on the left, the J-curve skewering the polar bear reflects the graph of the unstoppable rise of atmospheric carbon dioxide, and the curve is made from lengths of oil pipe. Sometimes, art and politics go together very well.

Did you know scientists knew about global warming, well before we usually think? Today, reputable atmospheric scientists everywhere are certain that human activity is driving the modern changes in our climate, but in 1950 it was just a curiosity. Of course, ‘global warming’ is a bad description, so we call it ‘climate change’ now. Under any name, it’s the same beast, the same looming disaster, and we knew about it, two thirds of a century ago.

Nobody denies that the Earth is getting warmer, because the evidence is there, and it was apparent in 1950, when George Kimble reported in Scientific American that the northern limit of wheat-growing in Canada had moved northward some 200 to 300 miles (call it 400 kilometres), adding that farmers in southern Ontario were experimenting with cotton. While cotton seems not to have taken off there, he reported another trend that continues to this day, the northward retreat of the permafrost:

In parts of Siberia the southern boundary of permanently frozen ground is receding poleward several dozen yards per annum.

Was it a cycle? Kimble said the Domesday Book featured 38 vineyards in England in 1086, in addition to those of the Crown. He pointed also to the Greenland colony which was frozen out, back around the mid-1400s and other evidence that climates change. He looked at Biblical evidence on the distribution of date palms to show that conditions in 1950 were much those of Biblical times, providing a picture of a climate that fluctuates around a mean. Maybe the trends were all just part of one of those cycles.

Mind you, the knowledge that humans are to blame is even older, because the whole thing had been predicted. The problem before was that there was not a lot of hard science in the arguments, which come down to logic, reason, careful modelling—and interpretation that was likely to be biased by a generous serving of self-interest. That changed in the last ten years.

Before ‘global warming’, climate change was called ‘the greenhouse effect’. In cold climates, a greenhouse is a glass shed which lets sunlight shine in, where much of the radiation is absorbed and changed to heat. Glass is less transparent to heat, but a greenhouse does more than trap warmth that way: it also holds a body of warm air around the plants, and protects them from wind-driven evaporation. So while we still speak of ‘greenhouse gases’, it is rare to hear anybody mention the greenhouse effect these days, even if the term goes way back to those early predictions.

Still, 1950 wasn't when it all began. In the 1820s, Joseph Fourier realised that heat-trapping might occur. In 1896, Svante Arrhenius reminded us that both water vapour and carbon dioxide were ‘greenhouse gases’ (escaping that bad analogy is hard) and so water and carbon dioxide would play a role in making the planet warmer. 

He also considered changes that might be happening, and consulted Arvid Högbom, who just happened to know all about carbon dioxide sources and sinks. Carbon dioxide was coming from life forms when they breathed, from volcanoes, and from humans burning fossil and other fuels. The human additions were minimal, perhaps one part in a thousand was added by the burning of coal, and there were probably checks and balances. 

Let's say 1896, OK? I mean, that was the story, I thought, but in late March 2019, a circular from Rush Holt at the American Association for the Advancement of Science (AAAS, of which I am a member) drew my attention to Eunice Foote:

Let me add one interesting historical note that is not widely known. In 1856 at the AAAS Annual Meeting, the work of Eunice Foote was presented, showing that carbon dioxide is a heat-blanketing greenhouse gas that in the atmosphere could warm the Earth. This was years before the work of the men usually credited with the finding (Tyndall in England and Arrhenius in Sweden).

Well, that broke into my weekend a bit. Foote’s short piece in The American Journal of Science and Arts in 1856 begins on p. 382, and says: “An atmosphere of that gas [carbonic acid, CO2] would give our earth a high temperature …”

Arrhenius thought it would take 3000 years to double the atmospheric CO2 levels, if ever, but such a doubling would raise world average temperatures by 5 to 6°C. In 1896, when Arrhenius did his calculation, the CO2 level was around 290 parts per million: in 2021, the value was estimated at 420 parts per million: we had travelled almost half of the projected distance in just 125 years. Now look at the angle of that pipe, the one skewering the bear!

To Europeans in the 1890s, the warming effect seemed nothing to worry about, because nobody had stopped to consider the cascades, the flow-ons that might be driven by that rise in temperature. A German chemist, Walther Nernst, even asked if it would be feasible to set fire to uneconomical and low-grade coal seams, so as to release enough carbon dioxide to warm the Earth’s climate deliberately!

In the 1990s, global warming was in much the same position that “continental drift” had been in, a generation earlier, with some of the scientists arguing furiously, even when they agreed on the main principles, and as in the puzzle of the wandering continents, the key evidence was right there. Mind you, when I covered the 2002 Spring Conference of then American Geophysical Union, there were no nay-sayers there. The problem is that so long as people can get away with saying “global warming”, we are once again stuck with a bad label, just as the early 1960s saw us hung up on “continental drift”.

The cost of disagreement and bickering is much higher with climate change. It mattered not at all if people disagreed about plate tectonics (except, perhaps, that it makes tsunamis like the 2004 Indian Ocean tsunami easier to understand), but under any name, global warming is likely to be a major disaster for humanity, and any delay has the potential to cost lives. To understand this, we have to accept some puzzling propositions.

The formation of sea ice in the northern Atlantic is probably what stops Dublin’s and New York’s ports being iced-in each winter. This is because the sea ice is largely free of salt, leaving a residue of cold brine that drives a current known as the Conveyor, which in turn drives the Gulf Stream. The Gulf Stream takes warm water from the Caribbean and swirls it up around the North Atlantic, contributing to fogs and breaking icebergs loose, but keeping northern ports warm and open, even in winter.

Just as the prion proteins of mad cow disease have more than one stable form, so do weather patterns, and if the weather once drops into a new stable pattern, we may not be able to bounce it back to where it started. Then again, as northern Europe freezes over, the fast-melting glaciers will be replenished, lowering sea levels. The increased snow cover will also increase the reflectivity of the northern hemisphere, and that may cool the planet down a little. We just have to hope it does not trigger a new stable pattern that happens to be an ice age.

The changes that might follow the breaking point are hard to predict. They are unlikely to be spectacular and major, and will probably act stealthily, when infrastructure, port facilities and cities are flooded, or when agricultural land is lost, either by being covered by the sea or as a result of drastically changed rainfall patterns.

If any significant amount of rock is exposed in Antarctica, this could lead to a low pressure zone over the icy continent that could change weather patterns around the world. It hasn’t happened yet, but we need to learn from history. Ten years ago, no politician would take a long-term view and force the changes needed in the next thirty to forty years, when most of them are elected for a mere three to four years, after which they have to face the voters again.

It’s easier to bleat plaintively that there is no real agreement among the scientists yet (even if there is), or that some eminent scientists believe in other explanations (they aren’t all that eminent: just look at where the funding of these “scientists” comes from). That load of bollocks saves the politicians from having to act—and the honesty of scientists in saying that they cannot be sure just how things will go wrong allows devious short-term opportunists to prate that “the scientists don’t know…”

Politics is a marvellous human discovery. It is a pity that politicians have yet to discover humanity and consider its prospects. It is likely that politics, dithering, duck-shoving and shilly-shallying will make this disaster happen. So long as the electorate value their comfort right now over the comfort of their grandchildren, they are doomed.

We must care about the young: they are delicate. I will turn to how the young develop next.