Category: ClimateOpinion

Cars – what do we do about them? Part 1: the challenge

I’ve never liked cars. I think that may go back to my parents getting a car when I was 10 and me failing to get the silver badge on the Rail riders club. But, while I’ve long since got over that, I have found through my life that my dislike of cars has taken many forms. Cars made me sick. They still do, especially petrol and diesel cars, which smell. I disliked having to run the gauntlet of the “scary road” when walking my children to school. That was the local rat run, where cars, trying to get quickly over the main road, would not always pay attention to crossing pedestrians. Even back in the 1990s I cared about the environment, about air pollution and climate change and my moral attitude that “cars are bad” was a wonderful way of hiding the more honest truth that I was scared of driving. Eventually, when I was about 40, I did get a car – briefly, for four or five years. My parents in law had given us their first edition Prius. I did get over my fear, and stopped gagging when I filled it with petrol. The first year we had it, I drove it 1000 miles. The final year we had it, I drove 3000. The garage mechanic, who took the £570 from me that the last service cost, thought we could keep it going for years. Two weeks later, thieves stole the catalytic converter and I naively let the insurance company write it off: in hindsight a big mistake. For a while I used a car club, until they replaced my local automatic car with a manual, which really didn’t appeal to someone who doesn’t really like driving. Actually, the only time I have enjoyed driving was the summer when I hired an electric car.

All this is to say, I am never going to be the biggest fan of cars. So it was strange that I got so upset with several people (including a close friend) posting memes on Facebook about how all cars should be banned. I, probably the one who has driven fewer miles than anyone else in the discussions that ensued, was the one seemingly defending cars, while the other people – passionate environmentalists who had had cars in the past, argued they should be banned. One person, not a personal friend, told me that I “should know better” and that my defence of cars shows that I couldn’t be a real climate scientist. Ever since then, I’ve been thinking about the question of cars, learning the facts, considering the challenges that we, as a society have to rise up to and how we can begin to do so.

Today, I saw an almost identical meme posted by another friend. But that friend came from a very different perspective – the perspective of someone who likes cars, and sees environmentalists as trying to take them off him. You see, what upset me when the environmentalists posted was not really about cars. It was the fact that I recognised the memes they posted, because I’d seen them before. I’d seen them on the walls of people who deny climate change, of people who don’t want climate action. Exactly the same memes. And I’m cynical enough to think that people on both ‘sides’ of this are being manipulated by powerful, evil forces who want us to fight each other, rather than them. When I put those memes through a reverse image search, I was not surprised to see that the earliest instances of them were from Russia.

But, that’s a topic that deserves a whole essay of its own. Today, I want to talk about cars.

I want to start with the case against cars. If you like cars, then please try to hear this neutrally. If you dislike cars (all, or just electric or just petrol), then I’m sorry I’ve missed your other reasons. First, cars use up a lot of land. The car infrastructure takes up a huge amount of space – roads, driveways, carparks, service stations – all cover land with concrete and tarmac. Concrete and tarmac can’t hold flowers that feed the insects. And one of the reasons we get so much poo in our rivers is because the concrete and tarmac surfaces can’t absorb heavy rainwater (and heavy rain is more intense now because of climate change), so when it rains, the drains overflow and our Victorian sewage system leaks out into the rivers. Now, there are many solutions to that – but when I see front gardens concreted over to create drives, I do feel sad.

Roads full of cars – parked and driving (though in the morning rush hour near me this distinction is not always clear) – are dangerous for children and the elderly. Ironically, many parents solve this by driving their children to school, creating a vicious circle. Cars emit particulate air pollution – both from their exhaust (especially when diesel), and from their tyres (especially when they are heavy) – and recently, in London, a girl’s death from asthma was directly linked to the air pollution from vehicles outside her home. Cars kill people. In the UK, 1300 people a year die due to a car and 26000 are seriously injured. That’s 8 times as many as those who die or are injured in knife crimes. And cars require energy, and specialist materials: to build, maintain and use. An electric car’s battery is typically around 50 kW hr. That’s similar to what my house uses in the summer in a week – and the country needs to increase its electricity generation just to meet housing demand. A petrol or diesel car is releasing not only carbon dioxide, but also other dangerous gases into the environment, and oil refining requires many of those rare metals that the batteries use, too. All cars require steel production – a process that inherently requires huge amounts of energy, and which, when made from ore, rather than recycled, also release carbon dioxide as a chemical by-product of its production. Petrol use puts money into the hands of dictatorial countries that produce it. Electric battery production is often supported by unsafe, and unfair working conditions of miners. Cars – both electric and petrol – catch fire sometimes. Petrol is explosive. Electric battery fires are very hard to put out. And finally, when the car reaches the end of its life – whether a real one or through the choice of its owner (or, indeed through the act of a few thieves after its catalytic converter), the car needs to be recycled: a process that itself uses energy.

I completely understand why many of my friends come to the conclusion that we shouldn’t have cars at all. They argue that electric cars are only slightly better than petrol cars: many of the arguments above apply to both, and that we’re not coming to real solutions while we think that simple replacement will solve the problems. And, in many ways they are right. We can’t simply replace existing petrol cars with electric cars and “solve” the environmental problems. But, before I expand their perspective, I want to consider other perspectives.

Many people, in the lives they lead now, need a car. There are even some people who enjoy driving a car – with my experience in the electric car, for the first time I had some sense of how that could feel. Let’s start with the obvious end: for someone who is disabled in some way, a car provides essential independence. For someone with autism, it could provide an essential safe and quiet space, while public transport is overwhelming. For someone with a weak immune system, it keeps them from the viruses and bacteria that could kill them. For someone with a trade, or medical, job that requires bringing equipment to customers, or moving rapidly to different patients, a car gives them the necessary speed and flexibility. We also need road infrastructure – if only for for fire engines and ambulances! We can stretch this further: in some places, and for some vulnerable people, public transport is frightening or dangerous. Women are attacked and harassed on public transport. So are teenage boys. And gay couples. And ethnic minorities. Even if these cases are rare, it is important to recognise that it may be much easier for some groups to use public transport than for others. And then, in the imperfect world we really live in, public transport in most parts of this country (away from London and a handful of other large cities), is extremely poor. It’s unreliable, expensive, infrequent, only goes down certain major routes so very inflexible, and often overcrowded. You wait in poor quality areas that offer almost no shelter from the British weather, for random periods of time, usually to stand, squashed against strangers, on the journey itself. Even in London, overcrowding is prevalent, and public transport provision is unequal between the North and South of the river – and most of the country feels frustrated that the investment is only going to London.

There are arguments against many of these. We can make some choices: My family consciously chose to live in a smaller house where we could walk to work and school, rather than a larger house that would require a car commute. You can pay for a lot of train journeys for the price of a typical car service and annual insurance costs – let alone the down payment of a car. When car owners say public transport is expensive, it is because they’ve written off in their calculations the cost of the car itself. And, of course, more people die in car crashes, than are stabbed on public transport. But I don’t think these arguments help people: I think they dismiss people’s very real concerns. They also feel a bit like the “metropolitan elite” knowing what’s best for the poor people, or men dismissing the fears of women. Most people don’t have the luxury to think deep thoughts about living a sustainable life – they have a real job which may or may not be near their real house, real responsibilities, real local public transport situations and they’ve made the best decision they can.

Because, fundamentally, the choice we as individuals make really doesn’t matter in itself. What matters is the world that society builds. Now, the choices we make can influence the society that is built – in a capitalist society, where we spend our money matters, and the death of night trains in the 1990s and their resurrection in the 2020s were both caused by demand changes because of the financial choices of individuals. And maybe sometimes the choices we make influence our friends and family to consider if they can do things differently and that can ripple out to a ‘tipping point’ in society behaviour. But, mostly, we need to build a society that makes it easier. And that’s because we as a society needs to have fewer cars between us – but that doesn’t mean that any one individual must sacrifice to the point of making their own life difficult.

As individual households we can consider: how many cars do we need: 2, 1, 0? If we need one or more cars, can we make them smaller? Is an electric car better than a petrol one (I will do a separate thing on this – it depends how much you drive)? Is the car we use day-to-day necessarily the same vehicle as the one we take on a two week holiday (if not, can we have a smaller car, or shared car, or no car for day to day)? Can we share a car we need – but not every day – with our neighbours? But we shouldn’t feel guilty if the answer is “right now, I need a car”, and we shouldn’t feel arrogantly superior if the answer is “right now, I don’t need a car”.

But as citizens in a democratic (ish) society, we can think about other questions – how do we support politicians who will encourage improved public transport and cycle routes? How do we build communities where people can walk to the shops and schools? Can we subsidise through our taxes the infrastructure of high quality public transport before the demand is there? How do we make public transport more pleasant? Can we create more options around shared cars?

I fundamentally believe we should not be shaming people for using cars. We should be building infrastructure that means that for most people, not using a car, or sharing a car, is easier, cheaper and more fun. That will more effectively reduce the number of cars on the road, than any amount of shaming.

[I realised that the blog I wanted to write – with the numbers about electric cars vs petrol cars – will have to wait as a part 2… to come, when I have time]

But what do we do about it?

I’ve done a lot of travelling recently – mostly by train, but also one flight, which I feel guilty about (but I’ll get onto that later). And on these journeys I have on several occasions talked to the person sitting next to me. At some point in the conversation, they ask me what I do. And when I say I observe climate change, they light up and we have a deep conversation. Several of these serendipitous conversations have been with grandmothers, worried about the world their grandchildren are growing into. Our conversations go well beyond the science – although they want to know about the science too – and fundamentally they come down to ‘what can I really do?’

These conversations have been clarifying my own thinking about what society needs to change. This is not a subject I have any expertise on, so here I write in a personal, rather than professional, capacity. But it is a subject I think a lot about. Of course, there are many other resources on the practical options, and I’ll try to link to them later (although I’m too tired to search them all now). What I want to discuss here is a more general perspective.

Climate change is real, and more serious than most people realise. Even if you consider yourself well-informed, you are probably underestimating the speed and scale of the changes that are coming (unless you’re panicking, or feeling like it’s too late and we’re all doomed, in which case you may have a different distortion). I have recently been to a large number of climate conferences – and I have found myself in tears during scientific presentations, especially one on melting glaciers in the Alps. The scientist presenting showed pictures of their measuring station in the Alps – and how their institute had been monitoring the glacier in the same spot for 150 years. This summer, the glacier broke off and their station disappeared forever. Something in the way that was presented, in the visual images, made me cry. But the other presentations were telling a similar story – rapid heating of the oceans, sea level rise displacing millions of people, ocean acidification, polar ice caps vanishing, ocean circulation patterns changing, rapid increase in the ferocity and frequency of storms, drought, heatwaves, and so on. We also have less time than we think. Governments are talking about 2050, but what we do in the next 5 years will have massive, long-term impacts – at the world’s current fossil fuel burning rate, we’ll reach 1.5 degC warming in 4-8 years. We need to stop using fossil fuels, now.

But this is terrifying, and most of us feel helpless. I feel helpless, too. But terror is not a good emotion for action – terror leads to our flight or fright response – we either ignore the danger, or we get angry. I fear that when scientists like me keep talking about the problem, and activists keep doing their stunts to force us all to take notice, we’re all reacting with a flight or fright response. (I do, however, understand why activists are doing their stunts and I am going to keep talking about the problem).

There are things we must do as individuals, things we do as communities and things we do as a society and through our governments. Each of us has a different set of background challenges, and a different set of skills and abilities – so we each have different responsibilities. How do we work out what our personal responsibilities are? I know some people who will take a perfectionist attitude. It is true that if we fairly share the remaining ‘carbon budget’ to get to 1.5 degC between the population of the Earth, then we cannot eat meat, chocolate, coffee or dairy products (produced as they are now) more than once or twice a month. We cannot fly, ever. We cannot own a car per family – we should be sharing our (electric or hydrogen, small) cars with our neighbours. We have to buy less stuff (electronics, clothes, …) , especially stuff with short lifespans. (I haven’t double checked all this, so treat details with caution – my point here is the principle, not the detail). Ideally we’d be generating our own electricity with our roof solar panels and capturing rainwater for flushing our toilets or growing our vegetables.

Those kinds of changes are hard. Sometimes impossible. I’m sure each reader (I think I get readers) will have read that previous paragraph with a combination of guilt, fear and perhaps anger (because you can’t do that) and pride (for the ones you are doing better than others). A perfectionist mindset hits other ‘ist’s. It is ableist (harder to do without a car if you are disabled), racist (harder to do without flights if you have family on another continent), classist (harder to make changes if you’re poor and if we stop buying things jobs are lost), pits city vs countryside (our country has a huge public transport issue outside a small number of big cities). And yet, it is needed. We’ve actually missed our chance to do this slowly and gently over a few decades – because of active, intentional misinformation campaigns in the last decade of the 20th century and the first decade of the 21st. Does that make you feel angry? It does me.

So, what can we do? The first thing I think we must recognise is that most change has to come from our governments and the decisions they make. The main problems are from the way society is structured – the choice of building materials, the way steel and concrete are manufactured, the way fossil fuels and sustainable energy, and different farming methods are taxed and/or subsidised, the accessibility of public transport, and availability of alternative options to cars and flying. We as individuals are not without influence (we can influence through our votes, our participation in democracy and/or activism, our influence in our jobs and even our choice of jobs, where our pensions are invested, …), but we need action at state levels.

Our individual actions are also important. Not so much because we actually as individuals have any significant impact on the planet, but because we as individuals can have a lot of impact on other people. We must look out for environmental tipping points because of the risks they pose to us, but we must also look out for social tipping points, because of the opportunities they provide. We’re social creatures and we all want to be doing what everyone around us is doing (think about covid mask wearing norms in different countries, and/or sectors within countries and how they tipped from (almost) ‘no-one’ to (almost) ‘everyone’ and back to (almost) ‘no-one’ as we followed laws and, more importantly, followed those around us. In my childhood bicycle helmet wearing was rare, now it’s very common here). When we change our behaviour, we influence those around us.

I think the hope society has, is in a non-linear growth of pro-environmental behaviour and choices. And in later blogs I want to explore that further. I’m also wondering about setting up some discussion forums – online and in person somewhere near Kingston/Teddington – next year to allow people to talk and ask questions. (If I have the energy, I’m going to discuss the importance of not burning out as individuals next).

Genesis, the Wizard and the Prophet

The Fall of Adam and Eve as depicted on the Sistine Chapel ceiling, Michelangelo

This post is very much opinion / faith / personal views. If you want to stick to facts, see my climate change lessons. It is also inspired by two books I’ve recently read: The Wizard and the Prophet by Charles Mann and Ishmael by Daniel Quinn. I recommend both books – one biography, the other fiction. The first helped me put the second into perspective as a “Prophet story” (ironically, Ishmael uses the term “prophet” in a way that links more to the “Wizard” viewpoint, but both, roughly, recognise the same dualism). It also has some ideas I got from “The Human Planet: how we created the Anthropocene” by Simon Lewis and Mark Maslin (I recommend that one too, and I know Mark).

The first chapter of Genesis tells a very different story to the story that follows in Chapters 2-4. Chapter 1 (and the first three verses of Chapter 2, to be pedantic) tell a story of a world and universe that “God saw was good” and that was created for humanity. Chapter 1, verse 26 (almost perfectly repeated again in verse 28 to really bring the message home) sums it up with:

Then God said, ‘Let us make humankind in our image, according to our likeness, and let them have dominion over the fish of the sea, and over the birds of the air, and over the cattle, and over all the wild animals of the earth and over every creeping thing that creeps on the earth.’  NRSV Anglicised, my emphasis in bold.

In this story there are already cattle and humankind’s dominion (farming?) is a blessing.

In chapters 2-4 there is a different story being told. Here Adam eats of the “tree of knowledge of good and evil” after the serpent tells Eve: “… for God knows that when you eat of it you will be like God, knowing good and evil …”. Being like God, humanity can choose which animals and plants get to live, and which get to die – and that curses humanity to be farmers. “… in toil you shall eat of it all the days of your life; thorns and thistles it shall bring forth for you, and you shall eat the plants of the field. By the sweat of your face you shall eat bread until you return to the ground…”

Just to emphasise the point, in Chapter 4, Abel, the sheep herder, is brutally murdered by Cain, the farmer. When God calls up Cain for this, Cain asks: “… am I my brother’s keeper?” – the farmer has rejected the herdsman, taken his land to farm, and killed his brother without care for his brother’s livelihood (life). Again, God curses Cain: “When you till the ground, it will no longer yield to you its strength…” But then God protects Cain and builds everything that follows on him and his descendants.

The argument in Ishmael is that this is the story that the ancient, herding and gathering Semites told to explain how the northern farming tribes burnt their pasture to turn it into farmland that quickly disintegrated by over-farming – so they burnt more, killing their “brother”. In farming, humans make the choices about what species live and which die, and humans go out to search and kill (plants, animals, other people) to limit competition, and not just for the immediate purposes that hunter-gatherers kill (food, safety, maintaining/gaining territory). The farmers are “like Gods, choosing good and evil” rather than like animals living in accordance with the hunter/prey relationship. In that argument, the Hebrews, who wrote the story down and were descendants of the original Semite story tellers, could no longer understand this story, as they too had abandoned herdsman lives for farming and “civilisation”, but they recognised it as their story, so wrote it in their creation. The first (probably later-written) chapter, in contrast, is the creation myth (I don’t necessarily treat a myth as “untrue”, depending on how you define “true”!) of a civilisation (the Hebrews) that sees humankind’s destiny as owners and controllers of the land as a blessing rather than a curse.

In “The Human Planet”, there is supporting evidence for these ideas. Farming started on a large scale around 10’000 years ago in different locations, including the “fertile crescent” (modern day Iraq, Syria, Lebanon, Jordan, Israel, Palestine and Egypt), but that this was a “progress trap” – farming made people’s lives worse: they had to work longer hours, they were more at risk of starvation when a harvest failed, life expectancy decreased as diseases increased (cross-over from animals and having people living closer together). But once you start on the journey of agriculture, it is very difficult to go back. Later, we, the descendants of those early farmers, fell and jumped into further “progress traps”: globalisation 1 (Europeans to Americas), the industrial revolution and then globalisation 2 (modern life). In each of these progress traps, life got harder for most people in the short term, then easier in the longer run – and with it we got/took yet more control over (and, unfortunately, because we didn’t manage it well, created damage to) nature. We have become more and more like Gods making decisions of who and what is good and who or what is evil, and now we control the whole planet.

In Ishmael the two cultures have divided, with the majority of the planet following the path of the “Takers” – societies that control nature. Only a few “Leavers” (hunter/gatherers and small scale herdsmen) remain. In Ishmael, Quinn encourages us to believe that only the “Leavers” are living in accord with the fundamental laws of nature. He makes some points that I don’t agree with – we have (possibly) managed to get on top of population since he wrote it, and by feeding people and educating women, rather than by letting people starve (I don’t like the suggestion in Ishmael that we should leave, or even encourage, people in poorer countries to die because that’s more “natural”!).  I also don’t think his “Leavers” were quite as pure as he makes out – or as unsophisticated (Lewis and Maslin describe how the early American tribes also cut down large amounts of the rainforest and possibly altered the climate in so doing). But overall, I think he’s absolutely right – that it is our cultural assumption that we are meant to rule the world, that has been extremely damaging – for that world, and also for ourselves.

In this, he is proposing the worldview of the “Prophet” in the “Wizard and the Prophet” book. If ever-increasing technology has caused the problem, and if our “ruling” over nature has only made everything worse, then we should stop with the technological fixes and move to a more localised, small scale production: organic farms that bring nature back into our food supplies, small, supportive communities and a fundamental shift in our lifestyle so that we can become more in tune with nature (even if we don’t give up all of our “civilisation”).

The Wizard worldview, according to Mann, is very different: it says that the solution to our poor management of the world is good management of the world. We should accept that we are now running the world, whether we should have done or not. Wizards wouldn’t usually put it like this, but basically: the fruit of knowledge of good and evil has been well and truly eaten over and over again in the last 10000 years and we cannot go back into the Garden ever again because we have been cursed. Even God has recognised this, which is why he still protects Cain, even after his murder of Abel. Given that we do rule the earth, we can no longer relinquish our control, and maybe now we are at the beginning of the wisdom necessary to control it well. We shouldn’t give up just as we have learnt that wisdom, instead we should harness our technology to save the world, rather than to harm it. We should build carbon sequestration units, install windmills and LED lighting, build hydrogen and electric vehicles, limit our farming to small areas of intensive farming and manage the rest of the land for wildlife and biodiversity.

I find myself curious about both approaches. I have a lot of sympathy with the Prophet/Leaver viewpoint, but I wonder if we no longer have time to wait for a complete shift in human philosophy. I wonder whether a Wizard/Taker approach may buy us that time and whether it just feels a more feasible shift in a world that is so dominated by “Taker” thinking. I know, however, I have friends who strongly feel that we can shift humanity towards a more natural life.

I’ve always found Genesis 1 consoling and Genesis 2-4 disturbing. Perhaps it’s time to accept that that may be because of my cultural conditioning and, as so often in my faith, I’d be better to sit with the disturbance than take refuge in the consolation! Maybe Jesus’ biggest challenge – far more challenging even than loving our enemies – is to consider the birds that do not sow and reap and the lilies that do not spin. Almost none of us have taken that particular statement literally!

 

Climate History: Fourier, Tyndall, Arrhenius and Callendar

Image of Svante Arrhenius, from Wikipedia.

I still have some science to cover – but I’d like to take an aside and write something about the history of our understanding of the climate science.

Joseph Fourier, in 1820, was the first person to realise what the very simple calculation that I described in Climate Lesson 4 that calculates that the temperature of the Earth “should be” much colder than it is. Blackbody radiation would not be fully understood for another 80 years, so his calculation was based on somewhat different premises, and you can read those for yourself (in old-fashioned French) in his paper. He recognised that somehow the incoming radiation must make it through the atmosphere easily, but that the outgoing radiation from the Earth would be blocked in some way by the atmosphere.

Tyndall’s experimental equipment from Wikipedia

In the 1850s, John Tyndall was able to measure the amount of heat absorbed by different atmospheric gases and he concluded that the “Greenhouse effect” that Joseph Fourier had surmised was dominated by water vapour absorption and that carbon dioxide had a smaller, but observable heating effect too.

Svante Arrhenius, in 1896, published a significant paper “On the influence of Carbonic Acid in the Air upon the Temperature of the Ground” (available in full here – this one is in English). In this he calculated that doubling the amount of carbon dioxide in the atmosphere would lead to a temperature rise of around 4 ºC.  I’m amused by how he starts his discussion section with “I should not have undertaken these tedious calculations if extraordinary interest had not been connected with them…” The extraordinary interest was to understand the causes and effects of natural climate variations during and between ice ages, but he already realised:

“The following calculation is also very instructive for the appreciation of the relation between the quantity of carbonic acid in the air and quantities that are transformed. The world’s present production of coal reaches in round numbers 500 millions of tons per annum … Transformed into carbonic acid, this quantity would correspond to about a thousandth part of carbonic acid in the atmosphere …

In a later book he would go on to say that burning coal would have a positive effect on the planet as it would stop the next ice age and would allow more crops to grow (I assume as he was living in Sweden, that he could only imagine warming in a positive way). He did, however, think it would take a 1000 years for humanity to double the carbon dioxide in the atmosphere – he assumed a linear, rather than exponential, increase in our burning of coal (we are on track to have doubled it in 150 years).

[The IPCC AR5 report (see page 82 in the Technical Summary) in 2013 stated that the “Equilibrium Climate Sensitivity” (impact of a step doubling of CO2 in the atmosphere and the planet going into equilibrium thereafter) is “likely between 1.5 ºC to 4.5 ºC”.]

But Arrhenius’s paper was met by a strong criticism by Knut Ångström. Ångström, and his assistant “Herr J Koch”, were doing absorption experiments with carbon dioxide and realised two things that seemed to suggest problems in Arrhenius’s work. First, they changed the amount of carbon dioxide in glass tubes and measured how much infrared radiation was absorbed. Their measurements suggested that carbon dioxide absorption saturated very quickly, meaning that very quickly all the infrared was absorbed and increasing the amount of carbon dioxide made no difference beyond this point.

Even more convincingly, they also showed that water vapour had absorption bands that overlapped the carbon dioxide bands – meaning that those wavelengths were already completely absorbed by water vapour.

This time – around the turn of the 20th Century – was a time when there was a real “greenhouse gas debate”. These two excellent scientists were arguing about confusing evidence and an incomplete and necessarily highly simplified conceptual model of the Earth system.

The assistant Koch’s observations actually didn’t show that there was no difference in absorption as the carbon dioxide was increased – he saw a 0.4 % decrease, which Ångström dismissed as trivial. (Modern calculations suggest he should have seen a 1 % decrease, and this suggests that Koch and Ångström underestimated their uncertainties). 

Arrhenius published a long response (this time in German) to explain why Ångström was wrong – he apparently (I haven’t been able to access the full text) correctly realises that Ångström was oversimplifying his analysis – the spectral bands of water vapour and carbon dioxide do not fully overlap (we also now know carbon dioxide absorption is not fully saturated), but most importantly, the atmosphere is not like a single thin sheet of glass – it has layers, and while the lower layers may mostly absorb the infrared, the outer layers are drier (less water vapour) and the atmosphere itself emits thermal infrared radiation.

Other scientists seem not to have noticed, or understood, Arrhenius’s 1901 paper, and the assumption that Ångström had proven Arrhenius wrong limited research in this area for many decades. Furthermore, there was growing recognition that the Earth itself could, and would, regulate any increase in carbon dioxide by absorbing it mostly in the ocean, and, with any that the oceans didn’t absorb, in increased growth of trees, peat bogs and so forth. The Earth would sort itself out, there wasn’t that much coal anyway and we weren’t (then) burning it fast enough for there to be a problem. (We now know that there are limits to that absorption too – I’ll come back to that).

It was Guy Stewart Callendar who, in the 1940s and 1950s, revitalised the Arrhenius ideas. He, as a hobby, started compiling temperature measurements since the 19th century and started to see an upward temperature trend (we now know that trend was not based on the relatively low increase in carbon dioxide, but on natural effects). To understand this he re-investigated the absorption of carbon dioxide and newer observations that provided more detailed spectroscopy of carbon dioxide absorption; he started to make a coherent model of the atmospheric effect. His papers influenced scientists to start systematic measurements of carbon dioxide in the atmosphere (although he also got a lot of criticism). Charles Keeling started taking Mauna Loa observatory measurements in 1958 as a response (see my earlier blog on that).

Now my opinion on all this: I’ve been reading climate sceptic blogs and webpages and many of them gleefully say that “the first climate alarmist Arrhenius, who was an amateur scientist, was proven wrong by the much better scientist Ångström…” In this they are misunderstanding the whole scientific method (and confusing Ångström with his father). Both Arrhenius and Ångström were good scientists who were working on limited information, poor models and experiments that were in their very early days. Both made mistakes of understanding – but both also showed new concepts that were essential pieces of the jigsaw that more recent scientists have put together. Most importantly – this argument is over – we now understand what neither of those scientists understood, we have better observations of everything from the absorption spectra of carbon dioxide and water (using similar  experiments to those of Ångström and Koch, but with more sophisticated analyses) to the atmospheric composition and we have models that split the atmosphere into far finer levels than Arrhenius imagined, and which also include clouds and atmospheric circulation (that he couldn’t include).

Oh, and as a personal note, when I was at Imperial College in the mid 1990s, I won both the Tyndall and the Callendar prizes. It’s nice to be building on their work!

Aside on climate politics and tobacco

This blog is my opinion.

I am intentionally separating the science of climate change from a discussion of the politics and what we should do about it. Too often, people have conflated the two. I think Al Gore talking about climate change was one of the most damaging decisions ever (and he should never have got a Nobel Prize). Because, and particularly in the USA, people who disagreed with his suggested solutions to the problem, chose to argue with the science, rather than the politics. I think they didn’t understand the difference between different types of “truth”. (I wrote a lot about different types of truth in 2016 and the 2nd-5th posts on this blog are about that). I believe politicians and all of us should be grappling with (and that includes arguing about) what we are going to be doing about climate change. We should not be arguing about whether anthropogenic climate change is real or not.

I am trying to give a faithful and honest account of what I understand about climate change in my lessons. The science is not perfectly known and there are some very big unknowns – for example how positive cloud feedback is – but just because we don’t know everything doesn’t mean we know nothing. The science of climate change will advance and with that advance it will become ever more possible to understand the detail of what’s happening, but we already know the main point: anthropogenic climate change is putting human civilisation as we know it at risk. We either have to stop it (mitigation) or we have to adapt to it. Or perhaps a bit of both.

But we’ve only fully understood this for about 20 years. We’ve had hints before that, and the hints have got stronger and clearer over time, but the clear picture we have now is very recent. I think there are parallels with how we learnt about – and then reacted to – the dangers in tobacco which it’s useful to draw.

The first scientific study on the dangers of tobacco was in 1791. John Hill did a clinical study that showed that snuff users were more likely to get nose cancer. A debate about tobacco in the Lancet started in 1856. In 1889 Langley and Dickenson do the scientific studies that start to explain why nicotine is dangerous. They start modelling the processes by which nicotine effects the cells in our bodies. In 1912 the connection between smoking and lung cancer is first published. The first large-scale scientific analysis of that connection was in 1951. In 1954 the Readers Digest published an article about this and that article contributed to the largest drop in cigarette sales since the depression. In 1962 the British Royal College of Physicians published a report saying that the link was real and in 1964 the US Surgeon General did the same. Cigarette adverts were banned on tv in 1965. Cigarette smoking was banned on the London underground in 1984 – but not for health reasons, instead because a dropped cigarette may have contributed to a fire at Oxford Circus. A comprehensive review about the dangers of passive smoking came out in 1992. Over time more and more things are banned – no smoking zones are introduced in pubs, advertising has bigger warnings …. and eventually in 2003 tobacco advertising is banned in the UK and in 2007 smoking in workplaces is banned in England. Now, 12 years on, I think most of us consider this normal. [I got these dates from an interesting document online: http://ash.org.uk/information-and-resources/briefings/key-dates-in-the-history-of-anti-tobacco-campaigning/]

In 1964 the evidence was clear. We didn’t understand everything – we didn’t understand all the effects of passive smoking, we weren’t quite sure about how a mother smoking affected the fetus in her womb, we didn’t know the link between smoking and cervical cancer or heart disease… but we knew it was dangerous and we took our first steps towards changing it. We had to change people’s attitudes, we had to get people to change how they did things, we had to make smokers uncomfortable on long-haul flights. And people sued the tobacco firms and they fought back – and often won – court cases. It was a long journey that often didn’t go what we now, in hindsight, see as the right way.

I think in climate change we reached that 1964 moment with the publication of the first IPCC report in 1990. There was a lot that that report didn’t know – just like the 1964 tobacco and health reports didn’t know everything either. But equally, it was the first clear report that the problem was real.

If it follows a similar timescale, and I think human nature is such that that’s a good first approximation, that would put climate change in 2020 in the same place as tobacco smoking in 1994. That’s the year some individual organisations made voluntary changes – like Wetherspoons introducing smoke free areas in their pubs, and Cathay Pacific introducing smoke free long-haul flights. It’s also the year that the tobacco companies lost their court battle to stop the warnings being printed in big font on their cigarette packets. There were signs that the numbers of smokers were dropping and British Rail had banned smoking a year earlier – to 85% approval. But there were still 8 years to go before smoking was banned in workplaces – and it probably would have felt too much back then. (I remember being pleased to have a smoke free area in the pub and I didn’t question that the rest of the pub still allowed smoking, I just held my breath walking from the bar to the place I was sitting).

I think that if we’re doing the voluntary stuff now, and the legal stuff catches up with us in 5-10 years – we’ll probably end up ok. But we all need to be talking about this and saying that we want to live in a world where burning fossil fuels seems as old fashioned, unhealthy and odd as smoking in British pubs does today.