Climate is what you want; Weather is what you get! – oft attributed to Mark Twain (‘though its apparently doubtful he said it).
Weather is always a local event; climate is global – it’s an average. The problem is that people remember the weather extremes they experience – not averages.
Extremes, even those experienced by other people, have obvious economic impact. Storms cause insurance company losses – and hence higher premiums. But the bigger threat of climate change comes in the creeping form of rising ‘unliveability’: droughts, heatwaves, fires, sea-level rise, etc.
The weather has changed. Measurably so in my life-time. It has on occasion been extreme. OK, so I’ve moved around the world a bit – but in all the places I’ve stayed for an extended period it was ‘common knowledge’ amongst locals that it was ‘getting hotter’. Storms have been getting stronger, too – a reflection of the extra stored energy in the atmosphere.
The temperatures in our climate are roughly distributed by frequency (i.e. how often they occur) as a normal, or Gaussian, distribution – often referred to as a ‘bell curve’. As global warming adds energy to this bell curve so surely the average temperature increases, but so does its ‘Sigma’ – meaning that there will be an increase in the extremes of temperature frequency at both ends of the graph. See: https://news.mit.edu/2012/explained-sigma-0209 for a better understanding of why this might be important in climate change.
Climate change is not just a recent ‘discovery’. The planet may have been warming since the start of the Industrial Revolution. Indeed it may have started with the event of mankind’s use of fire.
A warning for the scientists in the audience: I’m about to possibly oversimplify the mechanism of global warming through analogy!
Imagine the earth as a cup of coffee. If we wanted to keep that coffee hot we’d put it in a vacuum flask. Right?
Why? Because the vacuum flask prevents heat-loss.
Heat has only three ways of moving.
1.There is conduction (hold a metal bar – put one end in a flame and wait – your end will soon get hot! The energy has travelled through the metal. We call this conduction). It’s not particularly fast, nor can it deal with a large amount of heat (the metal would melt!).
2. Heat can also travel by convection (remember the coffee? In the cup the surfaces are surrounded by air – some heat is conducted to the air molecules on the surface, and so energised, they expand to become less dense than the surrounding air [as in a hot air balloon], thus they rise taking the coffee’s heat with them – and are replaced by cooler air which then goes through the same process). This is also a not particularly fast way of moving heat (think of the hot air balloon rising) but can work at at all temperatures.
3. The third way heat can move is by radiation of light (typically Infra-Red). The heat energy, as photons, can now travel at the speed of light – even across a vacuum. Not only is it capable of moving a great deal of heat quickly, it works at all temperatures (think of the Sun). Vacuum flasks are typically mirror-coated on the inner surface of the outer container that forms the vacuum cavity around the inner receptacle. This is done to minimise the escape of infrared radiation – to reflect it back to from whence it came (the hot coffee).
Now, think globally. The Earth, in its orbit around the sun, is surrounded by ‘space’ which is a very good vacuum and hence a pretty good insulator (i.e. maybe one gas molecule per cubic metre – possibly fewer). So the Earth cannot shed any heat into space via the mechanisms of conduction or convection – just like with the coffee in the flask.
Fortunately we are not encapsulated in a mirrored enclosure – so we can shed excess heat via radiation. However, we are encapsulated (and live) in an atmosphere that contains a growing presence of CO2. CO2 readily allows the transmission of ultra-violet and visible light – but it effectively restricts the flow of infra-red light by a process of absorption and re-radiation. Importantly re-radiation can take place in any direction.
A photon of Infra-red (a quantum of light energy) that collides with a CO2 molecule is absorbed, it then has a 50% chance of being re-radiated back toward the Earth. Obviously it has an equal chance of being radiated out toward space – but then it too will likely collide with another CO2 molecule, and the process repeats. This chance process repeats on and on till the 480 km (vertical) of atmosphere is transited and the Infrared photon can escape into space. It is worth noting that even at the speed of light this can take some time.
Whilst the atmosphere only contains a tiny fraction of CO2 (currently 416 ppm) there are going to be a very large number of these CO2 collisions (of the order of 10 to the power 30 or more). But in the time it took for that to happen, the escaping photon’s energy contributed to the ‘temperature’ of the thin layer of atmosphere that we live in (the lower 3 or 4 km). This makes all of our weather.
The lower 4kms are the climate we experience – only jet pilots and mountaineers experience much above that.
The climate has always been of interest to those of a scientific inclination. There is an excellent timeline to be found here https://www.co2.earth/1820-1930-fourier-to-arrhenius
Jean-Baptiste Joseph Fourier (Joe to his friends) was the mathematician who invented Fourier Analysis (The notion that you can define any wave form – or repetitive pattern – in terms of an array of pure sinusoids: a fundamental and a number of its harmonics. A truly useful technique, the basis of much modern technology). Joe clearly understood waves, then.
The nature of the Sun (a gigantic Hydrogen-fuelled fusion reactor) is that it radiates the energy from this reaction as light waves, or photons as they might be more readily understood – some of which reach the Earth (we call it sunlight). It is a broad spectrum of light including the very short and invisible wavelengths (X-Rays and Ultra-violet light), through the visible (Violet, Indigo, Blue, Green, Yellow, Orange, Red) and then longer still to the again invisible (Infra-red and radio waves). Once the received energy of the short-invisible and visible light has been absorbed by various surfaces (roofs, roads, rocks, etc.) it is typically re-radiated as Infra-red, and therein lies the problem.
FUN FACT: If you cut the Earth in half – and look at the flat bit (a circle) it is the equivalent area of the Globe that is receiving the Sun’s energy 7 X 24. Each square metre receives about 1367 watts of incoming solar radiation as measured in space at the edge of our atmosphere (referred to as the Solar Constant – so-called because it varies by less than 0.2% over the typical 11 years of the solar-cycle). Each square metre reflects about 1107 watts of energy immediately back into space. The area of that circular Earth is 2πR – The Earth’s radius (R) is 6378.1 km. So, doing the arithmetic we get an area of: 2.55634 X 10 to the power 15 (that’s 25 followed by another 14 0’s!) expressed in square metres. Multiplying that by 259 watts (the difference between the energy that arrives and then immediately leaves, per square metre) makes for a very large number (6.6209206 X 10 to the power 17) Watts, say 66 with 16 additional zeros. That’s how much energy is available to warm us up.
Joe Fourier who was, as we know, good at Maths, was also a keen observer of the physical world and, importantly, he noted that the Earth’s atmosphere is what enabled it to be warmer than it otherwise would be, given its average distance from the Sun (1 AU=149,598,000 km). Without the greenhouse effect the Earth would be a seemingly lifeless, frozen planet – as it was (possibly more than once) during the so-called Cryogenian period some 650 Million years ago. It is thought that this so called ‘Snow ball earth’ came to an end when various volcano’s belched vast quantities of CO2 into the atmosphere, triggering the first greenhouse period. So the ‘greenhouse effect’ wasn’t an invention of Fourier’s – merely an explanation. Joe’s work on heat was also progenitor of a very important branch of Physics – Thermodynamics.
John Tyndall, in the latter part of the 1850’s, identified the unique properties of CO2, and water vapour, that enable their role in the insulatory aspect of the atmosphere. Svante Arrenhuis then proved that Water vapour was not significant, as its cycle time is short and circular (it heats and cools in equal measure, in a relatively short time frame). Arrenhuis then went on to calculate the effect of doubling CO2 in the atmosphere (coal burning was already beginning to add measurable CO2!). This indicated – before the end of the 19th Century – that the doubling of the concentration of CO2 in the atmosphere would raise the global average temperature by 5 to 6°C. At that time CO2 (from recent Ice core data) was about 290 parts per million (ppm) – it is presently 416 ppm and we have experienced a temperature rise of around 1.3 deg C. Sadly, his conclusion was soon challenged by Ångstrom (a then more famous scientist) and consequently not accepted. However, given the limited modelling tools and data Arrenhuis had to hand, his prognosis was remarkable and not significantly different to our actual experience.
For more information on the various gases that contribute to the greenhouse effect see: https://scied.ucar.edu/longcontent/greenhouse-effect
Scientists generally regard the later part of the 19th century, the start of the ‘Industrial Revolution’, as the point at which human activity started influencing the climate. But one study brings that date back toward the 1830s (the beginning of the ‘coal’ age?). The Australian study, published in the journal Nature, in 2016, drew on a record of tropical sea surface temperatures dating back to 1500, captured in fossilised corals and tiny marine organisms. “The findings suggest the climate system responds to greenhouse gases quicker than thought” said the authors, “with consequences for understanding future climate change.”
Ocean warming is the hardest thing to directly experience – unless you’re a coral reef – and yet it is also ‘the elephant in the room’ – a very large elephant at that. Oceans play a BIG role in climate change – they store a lot of energy – and move it around the planet in ways that were not fully understood until the late 20th century. It’s also where 93% of the energy that lands on the surface of the Earth ends up! (see https://www.carbonbrief.org/scientists-clarify-starting-point-for-human-caused-climate-change ).
Despite the above, it is fair to say that suspicions of human-induced climate change (global warming) began to grow at the beginning of the 20th Century. See https://www.ipcc.ch/site/assets/uploads/2018/03/ar4-wg1-chapter1.pdf This article also contains an excellent diagram (FAQ 1.1 Figure 1) that explains the flows of energy into and out of the atmosphere. Interestingly they chose to use data corrected for the curvature of the Earth rather than Solar Constant – but it has no net effect on the the outcome. Global warming is still the result! The picture represents the so called zero-dimensional climate model – which is more than accurate enough to tell us what is going to happen – global warming!
Indeed, on its 100th birthday, in 1959, the Physicist Edward Teller warned the US Oil Industry about global warming. (https://www.theguardian.com/environment/climate-consensus-97-per-cent/2018/jan/01/on-its-hundredth-birthday-in-1959-edward-teller-warned-the-oil-industry-about-global-warming ) an excellent article by Benjamin Franta – well worth the read.
It would be fair to say that whilst Teller had indeed got his maths right – he hadn’t engaged much of his considerable intellect into fully fleshing-out the climate impacts and their consequences for humanity, or the economy. He pointed to where that work might be done – but given his audience was the oil industry there was no enthusiasm for the task. So tempus fugit…
The thing is – Teller was eerily prescient – he was working with scientific facts (and forecasts based on conservative estimates of future behaviour). All of which, it turns out, were about spot-on.
Other scientists did take note of Teller, or had already suspected CO2 as a warming agent (the ‘greenhouse effect’ – following the work of Fourier and Arrenhuis). Indeed, scientists like Charles David Keeling, of the Scripps Institution of Oceanography, was the leading authority in establishing the global atmospheric carbon dioxide (CO2) record. A record he started in 1958 and that to this day bears his name ‘ The Keeling Curve” which is now maintained by The National Oceanic and Atmospheric Administration at Mauna Kea, Hawaii.
With various satellites and terrestrial climate recording systems, we now have a very much more comprehensive view of the world than even Teller could have imagined. We can now see the weather everywhere – we can see the climate in detail. So now with enormous volumes of data with which to model the Earth’s climate and its susceptibility to variables, there is no shortage of ‘facts’.
However, the problem with ‘facts’ is that they require reasoned analysis. And as my favourite Australian, Clive James, observed: ‘You cannot reason someone out of a position they did not reason themselves into’. So facts, sadly, don’t always have the ‘cut through’ that is necessary to effect an appropriate response to climate change from the ‘general public’.
It is arguable, and there is much evidence to support, that the oil industry (and the coal and gas industries – and their friends) have been funding a global campaign of mis-information aimed at delaying the only sensible response to the facts of climate change/global warming i.e. urgent de-carbonisation in an attempt to take atmospheric CO2 back to (choose a period you’d like – I’d suggest pre-industrial times) say 280 Parts Per Million?
OK, Europe would be colder. The North Pole would be year-long surrounded by extensive ice formations – so no Western Passage. But on the good news front Australia wouldn’t be in such drought, bushfires would be infrequent and the Earth’s flora and fauna wouldn’t face extinction – beyond the normal Darwinian ‘improvement plan’ that is.
In some ways the oil industry’s campaign of mis-information was made easier by the plethora of data, improved modelling and theories that have sought to truly capture the mind-melting scale and complexity of global climate. Each new ‘fact’ – irrespective of its inconvenience – alienating one or more of the ‘general public’. In many ways we might have been better served with less science, less data and much more emotion!
The oil industry (and to a lesser extent the coal and gas industries) has long understood the power of aspirational marketing. Once you’ve appealed to someone’s emotions – they’ll stop reasoning. It is this, more than anything, that drives the unholy trinity of: oil industry, car manufacture – and the ‘general public’ – leading to resistance to change.
Interestingly, many early cars were electric. In fact, at one point in the early 1900’s the majority of cars registered in New York were electric. The oil industry naturally preferred car builders to specify gasoline (petrol) engines but had first to solve the disparity between the easy-start convenience of electric cars and the crank-handle start required by petrol engines. It was, ironically, by the adoption of batteries and small, high torque starter-motors that petrol cars were able to get closer to the convenience of electric cars – and without the performance blunting penalty of heavy lead-acid traction batteries.
Having solved this problem, the car industry, still in its infancy, was able to promote the automobile as a ‘freedom machine’ liberating owners to explore as they wish. The resulting explosive growth of the car industry – and manufacturers responses to the related scaling challenges – set the pattern for all Industrial growth globally. This exacerbated the climate crisis we were already in.
The Advertising Industry, itself in its infancy, took to this opportunity with such memorable ads as the ‘Jordan Playboy’ https://images.app.goo.gl/DHtZZuDNsPoFv6q8A – a car that not only promised the kind of freedom one might experience on horseback, but that was the first ever to particularly target women (who in the 1920’s were aspiring to the kind of freedoms that had been the exclusive domain of men). It turns out that notions of freedom and excitement are equally popular with both genders – and being emotions they are processed in advance of any rational thought. Things like noise, thrills and power all connect with the emotions.
Such emotions are heightened in youth, so our aspirant young selves were easily sold on the appeal of a ‘freedom machine’. The advertisers then carefully cultivated their marketing to reach into other emotions, through the all-conquering weapon of ‘status’, that easily outlive youth. Appeals to logic were rarely made – and even more rarely successful.
Thus smitten by the addictive charms of automobiles, the ‘motorists’ of the world made the oil industry so rich that it could ‘buy’ whatever influence it felt was needed to overcome any threat to its existence. The oil industry, through a number of consolidations, was then further able to build a buttress against a persistent threat. The threat of fossil-fuelled climate catastrophe.
A threat that is now being realised.