15 November 2019

Global Warming: Some Basic Facts and Some Thoughts

This is an edited version of an essay I wrote for the Triratna Order to try to clarify the issues surrounding climate change and related problems. I have some interest in the basic idea of global warming because my education touched on it in very specific ways: I spent a lot of time at university shining light through samples and measuring what frequencies were absorbed. We can think of the atmosphere as our sample and the sun shining a broad spectrum of light through it.

One of the basic and important facts about the air in our atmosphere is that it’s transparent to visible light and thus colourless at room temperature. This is not true of all gases. Chlorine gas, for example, is greenish and opaque (at least when concentrated).

This transparency is important because it means that most of the light from the sun reaches the surface and is absorbed. Sunlight is composed of many frequencies of light. We see the visible frequencies, but we don’t see, for example, the ultraviolet. Ultraviolet light is what causes sunburn. We don’t see infrared, but we feel it as the warmth from hot things. Of course, some of the light bounces around and enters our eyes, setting off reactions that we interpret as vision. But most of it is simply absorbed.  When matter absorbs energy from any source, it heats up. Two thirds of the earth’s surface is water, which is very good at absorbing heat. So a lot of the heat generated is stored in the oceans.

Some of the light is absorbed by green things that use the energy in the light to do chemical engineering on a tiny scale, i.e. building sugar molecules one at a time from carbon-dioxide and water. A byproduct is oxygen. It took some time to evolve to use this byproduct, but nowadays we rely on being able to breathe a gas with about 21% oxygen in it. The sugars are then used in metabolism, either directly in the plant, or indirectly up the food chain by organisms that live on green things and their predators. The sunlight energy trapped in the sugar molecule is released partly as heat.

So, as a result of light from the sun reaching the earth, some heat is generated by warm things radiating and by living things metabolising.

There are different ways of thinking about heat. For example, it can manifest as movement: more heat equals faster movement. But heat can radiate as well, in which case it takes the form of infrared light (IR). So sunlight comes in, is absorbed, and heats things up a little bit, and some of that heat is radiated back into space as infrared light. Our eyes cannot see infrared, but we can feel it on our skin as a sensation of warmth. The infrared light hits our skin, is absorbed and transfers its energy to our skin, heating it up. 

Just as some gases are transparent to visible light, some gases are transparent to infrared light. Nitrogen gas (N2) is largely transparent to both, for example. But some gases are transparent to visible and ultraviolet light and opaque to infrared light. Amongst these are carbon-dioxide, methane, and water. We call these the greenhouse gases. The amounts of these gases in the atmosphere are tiny. For example, at the moment the amount of carbon dioxide is on average about 410 parts per million. That is, for a volume of 1 million litres of air, separated into its component gases, there will only be 410 litres of carbon dioxide. Tiny, really, but more than enough.

The glass of a greenhouse is transparent to visible light but opaque to infrared. Whatever is inside the greenhouse absorbs light from the sun and radiates heat which is trapped by the glass. So the interior of the glasshouse stays warmer than the surrounding air. Hence the greenhouse effect.

The same thing happens on the earth. The greenhouse gases trap heat near the surface and keep it warm. Without greenhouse gases the surface of the earth would be frozen. Greenhouse gases are essential to keeping our oceans liquid and our world livable. Billions of years ago an asteroid hit the earth and threw tons of dust up into the air, blocking the sun and it caused the oceans to freeze over almost completely. And note, that life survived this and blossomed again once things thawed out. 

The greenhouse effect was first proposed in the middle of the 19th Century. It was physically demonstrated and linked to burning of fossil fuels by the end of the 19th Century. When we burn fossil fuels one of the main products is carbon dioxide. The science of the effect is very well established and understood. No one is credibly arguing that the greenhouse effect does not exist or that it has not been adequately quantified.

We know quite a lot about the history of levels of greenhouse gases from drilling into ice and measuring the composition of gas bubbles trapped in the ice. This allows us to construct profiles over time. And these can be correlated with analysis of sediments in lakes and with records of pollen in soils (indicating what kind of vegetation was present), and with physical indications of where sea level was. Tree rings are also used to calibrate such records because trees grow faster when it is warmer.

So in a broad brush stroke picture we do understand the greenhouse effect very well indeed. We have a clear, quantitative picture of the natural cycles of greenhouse gases going back millions of years. And we can see how large-scale effects such as the average surface temperature and sea level vary according to carbon dioxide concentration.

The equation is quite simple: more greenhouse gases, more greenhouse effect; less greenhouse gases, less greenhouse effect. More carbon-dioxide in the air means more heat is trapped, raising the surface temperature and melting polar ice caps which raises the sea level. And we know that the earth is getting warmer, polar ice is melting, and sea level is rising.

To this point, everything I have said is (beyond a reasonable doubt) an accurate description of physical reality. There’s always a chance that I, personally, have misunderstood some detail, or fluffed it on the day, but the science of the greenhouse effect is very well understood and quantified. Anyone can check the basic outline because there are many available sources at many levels of detail. There is no rational dissent about the basic facts of this effect.

Another important fact is that for most of the last 10,000 years levels of carbon-dioxide have been fairly stable, rising slowly from around 260 ppm to about 280 ppm in 1800. For the next 150 years carbon-dioxide rose more steeply to 310 ppm. Since 1950 the level of carbon-dioxide has risen exponentially to about 410 ppm. 

These are average figures which vary locally and seasonally. The rise since the 1950s is occurring at a rate that is unprecedented in millions of years of ice-core sample data.  What’s more we can correlate to a very high degree of certainty that the scale and pace of the increase in atmospheric carbon-dioxide is the same as the scale and pace of humans burning fossil fuels. Given that we know the causal mechanism, we can say with confidence that current warming trends are caused by human activity, specifically by burning fossil fuels.

It is true that some natural processes, such as massive volcanism can raise atmospheric carbon-dioxide levels at a similar scale and pace, though these are usually accompanied by dust clouds that block out the sunlight. We have good records of such things since the industrial revolution and we can see that this is not a factor. The increase in atmospheric carbon-dioxide is not solely due to us, but most of it is. 

So why do people disagree about climate science?

Everyone one will be familiar with the shimmer in the air over a fire. This happens because heat causes variations in the density of the air. We’ll all be familiar with the way light bends as it goes from air into water. It can shift the apparent position of things under water by quite a distance. This can happen when light passes from a region of less dense to a region of more dense air. Hot air is less dense, which is why hot air balloons float. It is also fluctuations in the density of the atmosphere that causes the "twinkling" of star light. The warmth radiating from the earth causes the air move around. The warmer it is the faster it tends to move, and the more of it tends to move.

Weather is caused, in part, by the changing density of air. Air flows out of high pressure systems and into low pressure systems. Such air flows are sensitive to the amount of heat available. They are highly sensitive to small changes in heat. So much so, that weather is very difficult to predict accurately at the local level. With super computers we can predict the weather with over a few hundred square kilometres for about 4-5 days. But the accuracy drops from about 80% for the weather today to almost zero at 5-6 days. Weather is affected by huge numbers of variables including ocean currents, ocean salinity, cloud formations, pollutants, local greenhouse gases, vegetation, and global patterns of pressure.

Warming the earth changes the weather. We see this every year as we go through cycles of summer and winter. In fact, we see it in the difference between day and night. Large scale, long-term effects of temperature such as seasons, or longer variables, are well quantified, while small scale, short-term effects are very difficult to quantify.

We can model the complex processes involved in climate and make predictions about what will change and by how much. Such models are constantly being refined and becoming more accurate. Just as weather prediction has improved with the incorporation of real time satellite data and faster computers, so has the accuracy of climate models improved.

One of the reasons people disagree is that in the past models were cruder and disagreement was more likely. This has resolved in the last ten years or so. Nowadays, working climate scientists are largely agreed on the scale and nature of the changes that we are seeing and will see. A consensus has emerged amongst climate scientists that is reflected in documents like the various reports from the IPCC.

The dissent that I have encountered seems on the whole to come from commercial (industrial) and political rather than scientific points of view.

Political Dissent

The problem of climate change conflicts to a large extent with the prevailing political ideology. A global systemic problem cannot be addressed except by coordinated government action. But at this point in time there is a widespread feeling that we cannot trust governments to act in our best interest and a concerted effort to prevent them from doing so. This concerted effort has come mainly from politicians themselves.

This kind of dissent is not about climate change specifically. It’s about the type of governance we aspire to have for our society. People with libertarian views have become ever more vocal in arguing that government must butt out.

This kind of political discourse does not necessarily entail the denial of climate change. But where it does accept climate change, it tends to shift the burden onto individuals. Climate change in this view is the result of consumer choices and if we would only change our choices we could save the world. Industry will respond to the market, and government has no role to play in economic markets.

So there is a fundamental disagreement on the nature of the problem and the validity of possible solutions. Libertarians reject collective action on social and environmental problems. This is partly based on an essay by Friedrich A. Hayek that argued that any form of central planning inevitably leads to totalitarianism.

Of course, Hayek has been proved wrong by many nation states, with the Scandinavians being the best examples. Socialism and centralised planning do not invariably lead to totalitarianism. Centrally funded health care, for example, is considerably more fair and efficient than free market models. And pushing responsibility onto individuals ignores the role played by corporations that use monopoly (or near monopoly) power to distort markets for their own gain. 

In recent years as government have held back from the economy, corporations have consolidated most industries into three or four super-corporations that suppress competition, gouge consumers, and undermine pay and conditions for workers. Markets cannot solve our problems because the corporations that are the problem control the markets. 

Industrial Dissent

Anyone who follows the relevant news channels will know that a series of court proceedings have been initiated against oil companies in the USA in 2019. In particular, an amicus brief has been filed in the Supreme Court against ExxonMobil led by two academics, Geoffrey Supran and Naomi Oreskes. They allege that Exxon knew (see #ExxonKnew on Twitter) about the dangers of climate change but sought to cast doubt on the science, even though it was part-funded by oil companies, including ExxonMobil.

The case is based on a comparison of Exxon’s in-house communications with their public statements. There is considerable documentary evidence (available publically) that Exxon internally accepted that climate change was happening and began to plan for it in the 1980s (including plans covering exactly the kinds of lawsuits they now face). In public, however, they briefed against the facts and lobbied world legislatures to water down measures aimed at mitigating climate change. Exxon spends tens of millions of dollars each year lobbying against climate science. Interestingly, they now also portray themselves as leaders in dealing with climate change.

The situation is analogous to big tobacco companies that knew about the harmful effects of smoking, but denied the link to cancer for decades after medical research established the facts, thus delaying social changes and causing millions of deaths, but reaping huge profits.

Of course ,the oil industry has been highly politicised for over a century now. The amount of wealth involved is so vast that it distorts the politics of our globe. Oil magnates buy influence with their wealth that far exceeds the single vote that the ordinary citizen has once every few years.

Super Rich Dissent

Although this category has a large overlap with the previous one, we can state it a bit more generally. Many of the super-rich rich are enthusiastic about social change and make a great show of philanthropy. But the change they seek is external to themselves. Everything may change, except their ability to hoard wealth and the actual hoards that they have accumulated. So, for example, rather than paying their workers a living wage, they donate money to charities which help working people in poverty. This keeps workers dependent on their generosity rather than allowing them the dignity of earning a living.

The crossover is that the super-rich, the billionaires, get super-rich via super-corporations and their anti-competitive practices.

They often say that the kind of changes called for by the consensus would stifle innovation, but most living billionaires got their start in environments with much more regulation and higher tax rates. This did not stop Bill Gates or Steve Jobs from innovating in the past. It did not prevent Nokia emerging in socialist Finland, or Volvo in Sweden. Yes, the Rolling Stones did live in tax exile, but the post war tax regime did not prevent them getting rich enough to be in the top tax bracket. Innovators will always innovate because they cannot help themselves. If we were to take away the monopoly power of the super-corporations (prevent them from merging) then we would have more competition and more jobs. If competition and markets are a public good, then we should maximise them.

The super-rich suppress competition, subvert democracy, and hoard wealth that would be better placed in the hands of workers to spend in local shops. Their dissent is entirely self-serving. Real change means that they will have to give up some of their wealth and power to the rest of us. 

Media Dissent

The mainstream media generally do a poor job of reporting science. They are fixated, for obvious and understandable reasons, on the novel and exciting. The media do wait for confirmation and thus often publish stories about science that fall by the wayside. This is normal. Ideally, scientists theorise and do experiments and publish the results. Then the published results are picked apart by other scientists. Sometimes it adds to our knowledge and sometimes it turns out that either an experiment was flawed, or the explanation was flawed. This is not a flaw of science. This is the process. We have to wait for replication. And we have to be ready for our theory about why things happened to be disproved. The media short-circuit this process.

The result is that one has to fact-check the media. Or rely on trusted sources to do the fact-checking. It can be very difficult to know how to go about it. Also the media are not always truthful. Media organisations are all owned by a few super-corporations whose owners do have ideological or political agendas. The Murdoch owned News Corp owns Fox (including 27 TV channels and 21st Century Fox movies), Sky, The Wall Street Journal, New York Post, National Geographic, The Times, The Sun, and publisher HarperCollins. His newspapers may have editorial independence, but he appoints the editors based on their political views.

Media outlets have a range of approaches to climate science, but the poor way they handle science, combined with political agendas, causes problems. It is not that there is specific reason to dissent from the consensus. That is, the dissent that I have encountered in this arena was not based on rational arguments about flaws in the science. Rather, it was based on distrust of the system; on distrust of the motives of scientists. Indeed, many dissenting individuals seemed to be convinced by President Trump’s assertion that climate change is a Chinese hoax.

My own fact-checking on some media reports has been illuminating. For example, the report from Breitbart earlier this year that “500 climate scientists” had registered a dissenting opinion. On checking, only a handful of the 500 were, in fact, climate scientists. The leading voices were not scientists at all. Several worked for oil companies. Some were political activists who were focused on attacking the state (particularly in the USA). One was a journalist with no relevant qualifications. I checked this article because I saw it being repeatedly cited by those who wished to deny basic facts about climate change. 

The media thrive on fear, anger, disgust and lust. It suits them to emphasise conflict. Someone like Murdoch doesn't care about the truth; he only cares about making money. Analysis of the situation tells us that the super-rich and their super-corporations are part of the problem and they are fighting back.

Dissenting Scientists

I have only encountered one dissenter who called himself a climate scientist. But I could neither confirm his credentials nor identify his place of work. His dissent was focussed on claims about the number and strength of hurricanes hitting the USA. He claimed that hurricanes had not varied significantly from the average. As best as I can tell, he was wrong about this. Hurricanes are becoming more frequent and they are becoming stronger. 

I believe that there are some real scientists who continue to dispute climate science; to dissent from the consensus. And this is a good thing. As Richard Feynman said, “science is the belief in the ignorance of experts”. Everyone should be prepared to consider evidence that falsifies their view.  However, this dissenting group are now a tiny minority and, while we should continue to listen to them, the burden of proof has decisively shifted onto them. Extraordinary claims require extraordinary evidence.

The vast preponderance of evidence is that human activity, particularly burning fossil fuels, is causing climate change. It is theoretically possible to disprove this, but it would seem now to involve some flaw in the very nature of science and that seems unlikely.

It's Not Just Climate Change

No one seriously disputes the existence of the greenhouse effect. Very few seriously dispute the existence of global warming which is leading to global changes in the atmosphere and oceans that we experience as changing climate, extreme or unseasonal weather, rising sea-levels, and increasing numbers of wildfires. But this is not the only global problem that we face. 

Pollution is estimated to kill millions of people each year. Pollution has many sources: throw-away plastics, burning fossil fuels, spraying pesticides, farm run-off. Micro plastic particles are entering the food chain at every level. Mercury levels are so high in shark and tuna that eating too much can make us ill. The air we breathe is laden with a variety of toxins from carcinogenic particulates to acid forming oxides that cause respiratory distress and acid rain. And this is in the countries where the effects are less noticeable. In India and China the problem is orders of magnitude worse. Noise pollution is now thought to contribute to mental health problems. 

We are also witnessing the loss of natural habitats at an alarming rate at the same time as species are being pushed to the brink of extinction or over it. Vital areas of biodiversity are dying. Rainforests are being burnt. Coral reefs are being bleached. Mangrove forests are being destroyed. Flying insect populations in Europe are just 25% of what they were a generation ago. Birds that rely on insects as food are disappearing. Organisms transferred between continents go rogue in their new home and become devastating pests: rabbits, cats, and cane toads in Australia; rabbits, possums, and pampas grass in New Zealand; flatworms in the UK that eat earthworms. Or simply over-fishing in the oceans wiping out species like the North Atlantic cod. Ecologies are networks of species that have complex interrelationships. Disrupting them can have unexpected effects. 

These three problems are interrelated. They all result from humans being careless about their impact on the environment. The human population of the planet, in optimistic views, is likely to top out at around 10-11 billion. That is at about 50% more people than we currently have. Which means that there are limits to how bad problems caused by human activity will get, but that without reforms, things will get considerably worse than before. 

The worry now is the idea of the tipping point. This happens when a system is changed beyond a point of no return so that it cannot return to the natural equilibrium. The problem is that pushed out of equilibrium some complex systems begin to exhibit chaotic behaviour with unpredictable swings far from the norm. If we disrupt the atmosphere by heating it we cannot predict all of the effects, but chaotic weather will not be conducive to human thriving. 

Although much of the public discourse is focussed on climate change, and climate change is certainly an important issue, there are these other related issues. Pollution seems to be a more urgent problem, but both climate change and the ecological problems have much more severe long term consequences. 

Now What?

Our situation is a version of Pascal’s Wager. We have two choices: we can bet that the climate science consensus is right or we can bet that it is wrong. And in either case, we can win or lose the bet. That gives us four scenarios. But before looking at these, we need to emphasise that climate change is only one aspect of the problem.

Greenhouse gases are not the only product of burning fossil fuels. Pollution, in the form of sulphur oxides, nitrogen oxides, and particulates, is another major problem we face. Pollution is not simply unpleasant. It causes disease and death on a scale similar to tobacco smoking. This is also an undisputed fact. Millions of people die each year as a result of pollution related diseases. 

Another related issue to thinking about our lifestyles is the loss of biodiversity, which is increasingly being called a mass extinction event by those who study such things. The steep decline of flying insects in Europe is particularly troubling, for example, because it may cause disruption in food production if we lose pollinating insects.

Here are the choices we face:
1. If we bet that the climate science consensus is correct and accept that we need to take drastic state-level actions to combat it, then we might win the bet or lose.
1.1 If we win, then we avert a global disaster and our own possible extinction. We obtain clean air, clean water, drastically reduce waste, and shift our reliance on fossil fuels from the middle east to locally produced energy (avoiding the problem of peak oil). We protect and preserve biodiversity and the tropical rain forests. We secure our food production system. And we avoid mass migrations caused by sea level rise. 

1.2 If we lose then we invest a lot of money and look silly. But we still get clean air, water, and food, etc. 
2. If we bet that the climate science consensus is incorrect, then we eschew state-level actions and allow nature and markets to take their course. And again, we may win or lose.
2.1 If we win then current trends still continue. Which means worsening levels of pollution; rising sea levels; loss of biodiversity; worsening weather. We hit peak oil unprepared.

2.2 If we lose the bet, then climate change runs away and rapidly reaches a tipping point. Life on earth is seriously disrupted. Human civilisation falters due to widespread famine and drought. Mass extinction permanently changes all ecosystems.
In this approach we have to consider both the likelihood of the outcome and the risks associated with being wrong. The worst possible outcome is betting against the present consensus and losing; i.e., the consensus is correct and we do nothing about it. It could be the end of civilisation. If we bet with the consensus and get it wrong then the results are costly, but the outcomes will still be quite good, because we avoid the worst effects of climate change, pollution, and biodiversity loss.

The probability of each scenario is non-zero. A non-zero risk of an avoidable and very destructive catastrophe weighs very heavily on me. A non-zero risk of investing a lot and having clean air, water, and food seems attractive in any case. Betting against the climate science consensus only has bad outcomes; betting for it has some good outcomes whatever happens. 

Arguments Against

Some will argue that this scenario is too simplistic. There is a third way which involves incremental improvements in technology that will enable us mitigate or overcome climate change. This assumes that there are sufficient incentives to innovate and time to bring new technology to market. Keep in mind that the consensus is that we have about 10 years left to get our carbon-dioxide emissions under control or our grandchildren will face runaway climate change. The USA has withdrawn from the Paris Accord, is removing incentives for Green technology, and stifling attempts to implement environmental standards. Britain is about to elect a climate change denying government also, which will again remove incentives and slow progress. I’m a great fan of technology, but this approach, at this stage of the game, boils down to a bet against the consensus. 

Allied to this is the argument that we are already moving quickly enough. Saudi Arabia is converting to renewable energy sources, China is on track to meet its Paris Accord Targets, and so on. However, this argument was dealt a blow with the recent IPCC report that climate change is happening more rapidly than the average predicted by the consensus. We have less time than we thought to reduce carbon-dioxide emissions before we cause irreversible harm. This means that taking this line of least resistance is also a bet against the consensus.

One argument that I haven’t really touched upon yet is “it’s natural”; i.e., climate change is real, but it’s the result of natural changes rather than human activity and thus changes in our emissions will have no effect. This view is plain wrong. The rise in atmospheric carbon dioxide is clearly linked to burning fossil fuels. In any case, this is another bet against the consensus.

A final potential disagreement is that we cannot afford it. This doesn’t hold water. We can afford whatever we decide to afford. For example, the UK could afford £1.5 trillion to bail out the banks in 2008. We did this because the alternative was the let major banks go bankrupt and for people to lose their savings and investments as happened after the great stock market crash of 1929. Other examples are the various wars we fight. When coalition forces invaded Iraq in 2003, destroying the civil infrastructure and eventually assassinating Saddam Hussein, all based on false and faked information, we didn't pay for it out of savings. The coalition governments borrowed the money as governments have been doing since 1694 when the Bank of England was founded to fund an English war in France. What stops us at present is an economic ideology. Not only can we afford a program like the Green New Deal (first proposed in 2008) but it will pay for itself. All that is lacking is political will. The argument of affordability is another bet against the consensus.


So, yes, there are many complexities in dealing with the science that can be confusing for lay people. A little knowledge can often be a bad thing because we don’t realise how much we don’t know. And yes there are dissenting voices, coming from a variety of viewpoints, not all of which are from bad actors. And yes, there are voices joined with the consensus who are bad actors with ideological agendas. But the scientific consensus is now wide and deep. Thousands of climate scientists have now come together to assert that the scale of climate change presents an existential threat to humanity in a variety of ways. At the same time we know that millions die each year from pollution and we see alarming numbers of species either extinct or threatened with extinction. 

Yes, there is a body of dissenting opinion. And where this is genuine we should honour it. But we need not give credit to the Flat Earth Society or to conspiracy theories. We need not treat vested interests such as the super-rich and super-corporations as neutral players. We should especially identify the fossil fuel industry as a bad actor in this discussion - they are spending vast amounts of money on promoting plausible lies. 

Whatever our politics or thoughts about climate change, it will always be better to assume that the present climate science consensus is right. Assuming that the consensus is right presents us with the lowest risk strategy and generally good outcomes. Betting that the consensus is wrong can only lead to bad outcomes even if we are right and if we are wrong the outcomes will be catastrophic.

Greta Thunberg recommends not arguing with climate change deniers, but I'm not sure this is the best approach. I think there is scope for keeping the lines of communication open. People won't be persuaded by facts alone, but the facts of the greenhouse effect are not in dispute in any case.

We can continue to refine the climate change narrative: record floods, record droughts, record fires, record temperatures, record sea-level rise, record glacier and sea-ice retreat, record storms in record numbers, record pollution levels, record plastic found in the ocean and the food chain, and record numbers of species going extinct all at the same time.

is disrupting our planet and our way of life. If it is not human activity, then we can ask deniers what is it? Where climate change presents some doubts, the problem of pollution is much harder to dismiss. And if humans are causing more pollution, then why not climate change as well?  


This is a version of an essay I first wrote in Nov 2019 for the Triratna Buddhist Order. 
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