Beneath the fads, the fashion, the loud headlines, media threats and intimidating claims lies a totally rational story; the bare science of a shifting environment that, once explained, is simply irrefutable. You can be skeptical about going on a blind date or about eating Indian food before said blind date, but you can’t be skeptical about the fact that humankind has and is having a definite and permanent effect on the climate of our planet. That’s naivety at its worst.
In this blog post and the next, we’ll be taking a journey through the fancy terms thrown around by the media and redefine them to yield a totally new and more scientifically accurate understanding. We’ll come to appreciate what’s normal (historically speaking) and what definitely isn’t in terms of climate variability. We’ll also take a closer look at Earth’s atmosphere in order to get a better perspective on how our relentless and ruthless industrial activities are able to cause such significant global-scale changes in weather patterns and climate.
And so, let’s begin…
Weather and Climate: The Difference Between Them And So Help Me If You Don’t Remember This!
You know what sand is, you know what clouds are and you definitely know a week old breakfast burrito when you smell one. We know all of this because we are exposed to it just about every day (maybe not the burrito, but point made). And yet, in spite of the fact that we are directly exposed to weather and climate all the time, very few people actually know the difference between them.
That ignorance ends today!
Weather is the day-to-day expression of the atmosphere as it is experienced on the ground. It’s the warm sun beating down upon the beach, it’s the rain on your parade, it’s the tornado relocating your house and it’s the humidity causing you to sweat like George Bush Junior’s publicity team during a press conference. The weather encompasses a great variety of atmospheric parameters and they include things such as wind speed, wind direction, temperature, humidity and precipitation. All of these come together to either put a skip in your step or to totally ruin your day.
Climate, on the other hand, describes the average weather characteristics of a region over a minimum period of 30 years. Texas is hot and prone to severe thunderstorms in summer; New York is balmy and mostly clear in autumn, Cape Town is pissy and freezing cold in winter and Seattle is just pissy and freezing cold all year round. THAT’S what the climate is.
It makes my eye twitch when I hear people saying: “The climate is great today!”
Imma stab a bitch!
Climate Change Lost In Translation
“Climate Change™” has become celebrity verbiage to such an extent that I felt the need to add capitalize the first letter of each word even though it’s grammatically incorrect to do so. Al Gore has used climate change so much in his political campaigning in the past that he really should have trademarked it. And so, climate change has become so easily tossed about by the media that few people truly understand what it is anymore. It’s almost as though it has become totally divorced from its original and true meaning. The consequence of this and of the sensationalism with which the media presents its information on the science of climate is that the lay man and woman will look outside their window, see an unseasonably cold, wet, hot or windy day, blame it on climate change and become convinced that the end is nigh. You can catch these people on National Geographic Channel’s “Doomsday Preppers.”
Climate change is a complex concept because it pertains to the long-term characteristics of Earth’s atmosphere and the atmosphere is incredibly complex. It consists of several sort-of distinct layers, a multitude of parameters, countless variables and infinite outcomes based upon the precise interaction and behavior of these variables. This is why the weatherman doesn’t always get the forecast spot on: not because he or she is an idiot, but because true accuracy in that job is about as impossible as an adrenalin spike at a dentures convention.
And so, climate change is something that should be treated with great humility and reverence. Even I am reluctant to make any broad or sweeping statements with regards to climate change and I have a Masters Degree in Atmospheric Science.
Now that we know the difference between weather and climate and can appreciate that one day of unseasonable weather doesn’t mean the apocalypse is upon us, we can FINALLY get around to discussing exactly what climate change is. We can also meet its celebrity cousin, global warming, because believe it or not these two are NOT the same thing.
What IS Climate Change?
Climate change is a lasting shift in average global weather patterns and characteristics. This shift is also significant enough for us, our fancy equipment and, of course, Mother Nature to notice it and it usually takes place over a time period of decades to millions of years. What causes the climate of Earth to change?
All sorts of things actually!
Climate change has, historically, been caused by factors that range from variations in solar energy and plate tectonic activity to volcanic eruptions and meteorite strikes. Any one of these can cause local climate to change over varying periods of time. For example, a particularly violent and belchy volcanic eruption can release enough gas, dust and ash into the atmosphere to create gorgeous sunsets halfway around the world and deflect sufficient sunlight to cause very slight global cooling. It might not be much and the degree of cooling may be more isolated to the regions surrounding the eruption, but it is by definition climate change.
Changes in land surface type – what covers the crusty portions of our globe – can also lead to climate change. Dark verdant forests soak up sunshine like the delinquents from Mötley Crüe soaked up Jack Daniels, whereas concrete jungles, with all their reflective shiny surfaces sends sunshine right back where it came from. This changes the heat characteristics of the land, which, in the long term, has an impact on climate. So, climate change, in the traditional sense of the word, refers to any shift in local or global climate and it is caused by a myriad of factors. Climate Change™ on the other hand is believed to be the cause of the anthropogenic emissions of greenhouse gases.
Wait!! Come back!! I swear I can explain! It’s not as difficult as it sounds!
Greenhouse Gases: Baking the Lower Atmosphere Since, Like, Ever
The word “anthropogenic” quite simply means of human origin or to be generated by human beings. So, anthropogenic emissions of greenhouse gases would be those generated by human-related activities such as those clearly shown in the above picture.
Now what the hell are greenhouse gases?
Our atmosphere is composed predominantly of nitrogen (78,09%), oxygen (20,95%) and argon (0,93%). The remaining fraction consists of a soup of other trace gases, many of which are “greenhouse gases.” Carbon dioxide and water vapor are two super important ones; methane, sulfur dioxide, ozone and nitrous oxide are others. Molecules of these gases absorb the thermal energy emitted by the sun and they then re-radiate this energy as heat in all directions, including down upon our little heads. The effect this has upon the lower atmosphere is to warm it. This is why it’s referred to as the “greenhouse effect,” since green houses, which aren’t actually green at all, are purposefully built to achieve this same effect and in doing so provide a warmer growing environment for plants and flowers that would otherwise die from the cold.
In the absence of greenhouse gases, sunshine would pass through our atmosphere as per usual, except it would hardly be absorbed by the air at all and as a result, tits would be frozen off around the world. In fact, the greenhouse effect is a vital atmospheric process for life on Earth because without it, the average surface temperature of our planet would plummet by an approximate 30°C or 60°F. So, whatever average temperatures you’re used to in winter, knock off another 30°C or 60°F. You may as well live in Antarctica. Even midday at mid-summer in the tropics would warrant a warm sweater and a scarf. So, greenhouse gases are good! But, too much of a good thing is definitely bad, as tequila repeatedly demonstrates to me every Saturday night.
Thank God for amnesia or else I’d remember not to drink tequila every Saturday night.
Anthropogenic climate change is the change in global weather patterns and characteristics that have arisen as a direct result of human activity: our factories, our refineries, our agriculture, our motor vehicles and more.
Stay Tuned for Part 2
We’re getting there! Now that we understand the terminology and the concepts behind weather, climate, climate change and the greenhouse effect, we’re finally ready to discuss anthropogenic climate change and just why the skeptics out there – the people who tell you it’s all a hoax – are full of the proverbial.
I’m almost certain this kid knew the answer and, at the expense of one mark, decided this joke was too good to pass up on.
For those enquiring minds who really do want to know the answer…
Saturn is one of the largest planets in our solar system, in mass and size. It is known as a gassy giant because of its penchant for Mexican cuisine. I’m kidding. Because it is so massive and its gravity so great, that everything from giant space rocks to gass molecules were drawn in towards its centre at the formation of our solar system, approximately 4.5 billion years ago. If Saturn was just a little bit bigger (“a little bit” being an approximation for a whole lot), the intensity of its gravitational pull would have generated the central pressure and heat necessary to initiate nuclear reactions. And THIS would have made Saturn a star! The same applies to Jupiter, which is also a flatulant giant.
So, in other words, Saturn and Jupiter are failed stars… or that is what my astronomy professor always referred to them as.
Saturn’s rings are composed of orbiting particles of rocks and ice, some no bigger than snowballs and others the size of a bus, according to NASA’s fun cosmology website. Each of these particles, gargantuam and minute, are by definition moons, all in gentle orbit around the giant planet. They share this orbit with 63 other more “traditional” moons, the largest of which is the aptly-named Titan.
While it is unclear as to why all of this orbiting debris has accumulated into almost perfect geometric circles around the planet, the answer is suspected to lie in gravity. Over the many millions of years subsequent to the formation of the solar system (or seven days subsequent to creation), each particulate, snowball, moon and hunk of rock has had the time to settle into a position that reflects, in part, the force of attraction between itself and its giant parent planet. One might suspect that the larger, heavier particles will be arranged in belts closest to the planet, while the lighter and less dense particles will be in belts further away.
And you might suspect this because the force of attraction between two objects is proportionate to their respective masses and disproportionate to the distance between them. In other words, the heavier you are, the more attractive Earth finds you, which is why your bathroom scale groans every morning. You can refer to this spectacular blog entry for elucidation on this point: Gravity And The Laws of Attraction, Somewhat Revised.
This is precisely what I thought, but the picture is more complex than that. Each particle in orbit around its central giant – each particle of dust and each bus-sized space rock – is travelling at a certain speed. And while gravity acts to pull these particles in towards Saturn, they continue along a path that is perpendicular to it, rather than careening inwards. The force that propels these “moons” forward is called the centripetal force and you would have experienced that as a child when you were flung off a merry-go-round, because your douchebag brother seemed to think the word “stop!” meant “faster!”
Saturn’s rings are therefore organised into belts of particles that are travelling at different velocities. I have a very helpful reader to thank for this relevation and you will find his comment below.
And so, this gasy giant finds itself swathed in many beautiful, carefully arranged rings all consisting of particles, rocks, snowballs and moons travelling at varying velocities; trapped in an eternal dance around itself. Here’s something else: so does Jupiter and Neptune! The only difference is that the two latter planets’ bridal trains are thinner and far more translucent and so Saturn, with its ostentatious display, has become the planet in our solar system famed for its rings.
I’ve been nominated for these blogger award thingy’s before and admittedly, while I’ve graciously accepted them, I haven’t taken the time to follow through on all the things you have to do… you know… tell friends, thank your nominator, climb Mount Everest, drink a gallon of chocolate milk, etc.
Is it because I have bad manners? No. I save those for the bedroom. Mostly it’s because I am terribly short of time and would rather spend what time I do have on writing more blogs and drinking beer. However, this occasion is different because I think we can have a little fun with this one.
For those of you who aren’t familiar with the WordPress blogosphere and these blogger awards, here’s how it works:
You get nominated by some random stranger (usually a fellow blogger) for a totally made-up award that comes with ABSOLUTELY no monetary compensation: in this case, the Dragon’s Loyalty Award. In fact, it comes with no compensation whatsoever. Not even a badge or a ribbon.
What’s the point of such an exercise? These awards are the blogging equivalent of a Mexican wave of credit and recognition. One person nominates you because you’re awesome and you repay them by thanking them and nominating 15 of your own favourite blogs. You pay it forward just like Haley Joel Osment who is weirdly fat and hairy these days.
All of this is finished off by answering some questions or presenting some facts about yourself, as if anyone cares. To be honest, it was this part of it all that really sealed the deal. I’ve been writing this blog for over 18 months now and I liked that the Dragon’s Loyalty Award presented me the opportunity to tell you, my wonderful readers, a little more about the human being behind Why? Because Science.
RIGHT! It’s that time of the evening! Who do I regard as deserved of this play-play award?
Seemed Like Good Science: http://seemedlikegoodscience.com – because Christopher Reeve is one of the best humans I have met and he writes like a veritable god. Also, he shares his name with the original Superman.
Jimmy Eat World: http://jimmyeatsworld.com – for those who want to live vicariously through someone else’s spectacular travel adventures. Jimmy is also a SERIOUSLY talented photographer.
11 Things You Might Not Have Known About the Author of Why? Because Science
I’m a girl. You’d be shocked by how many people assume I’m a dude.
I love clouds, stars, birds and weather. It’s a miracle I don’t walk into more lampposts and road signs.
I hate it when people leave the tap running when brushing their teeth or washing their face.
I love cats. I would own 10 if they didn’t do things like poop and require feeding.
I am a tumbleweed. I absolutely love travelling.
I think Mila Kunis is arguably one of the fittest of human specimens on the planet. Her and my current girlfriend. Here’s hoping this won’t require editing in the next few months.
I believe there’s nothing a good glass of red wine can’t solve. Now, imagine what you can do with a bottle!
I find people with poor oral hygiene gross.
I am a total sucker for love songs. Squishy, cheesy, toe-crinkly love songs.
Guilty pleasure: bubble wrap and dubstep music. And white cheddar popcorn.
I am in love with science writing. THAT you already knew.
Your Questions Answered…
What’s your favorite game of all time? Not your second or third favorite but your favorite game ever.
7 minutes in heaven.
Oh you meant COMPUTER game? Of course you did. You’re a total nerd.
Quake. Because I like turning zombies into chunky kibbles.
Where was your favorite place to go as a child?
The dank, fragrant pine forests on the slopes of the mountain I grew up on. We called the forest “Terabithia” after the novel by Katherine Paterson.
Who do you look up to the most in life?
My brother. He’s really tall.
What’s your dream? Doctor, Lawyer, Serial Killer, Etc…
You caught me on a good day! Last night’s dream was particularly entertaining. It involved a shower and an aesthetically pleasing human being. In terms of life goals, I want to be a science writer and I want to be happy, both of which I have achieved. I’m now working on the becoming stinking rich part…
Have you ever farted in the middle of a crowd of people and blamed it on someone else? Be honest people…
I’m a girl. Girls don’t fart.
Name 5 things you want to do before you die.
See the aurora lights
Publish a book that is well received
See the Grand Canyon
Be happy in love (check!)
Who’s your favorite Author?
Bryce Courtenay, Sarah Waters, Wilbur Smith, John Irving, Terry Pratchett, Steven King, Haruki Murakami, James Herbert, Neil Gaiman, your mother.
What’s your favorite comic book series?
I may be a nerd, but I draw the line at comic books.
If you could have any super power what would it be? Would you use your powers for good, or evil?
I’d choose telekinesis because:
(1) You could keep your talent subtle enough to avoid too much attention. If you’ve ever watched X-men you’ll know that humans with special powers get branded “mutants” and are shunned by society.
(2) It’s two-for-the-price-of-one: If I wanted to fly, I could simply move myself through the air.
(3) I’d never have to get up for the remote control again.
I suspect that I’d use my powers for fairly benign means… I might try to impress the odd person and make a disgusting amount of money out of it. But two out of the seven deadly sins isn’t bad.
If asked what colour Earth’s sky is, you wouldn’t be unforgivably wrong to answer that it’s blue. A more correct answer, however, would be “it’s blue, sometimes”.
Earth’s sky is black at night and grey in overcast weather. It’s brilliant crimson, orange and yellow at sunset, and a sultry blend of indigo, violet and pink at dawn. Around noontime on clear days, it’s white at the horizons and on brooding, stormy days, when there is a promise of severe thunderstorms and hail, it can be slate grey with a slight tinge of green.
The sky is many colours. It’s only sometimes blue. Ever wonder why? Doesn’t matter, I’m going to tell you anyway and what better place to start than by shedding some light on… light!
What Is Light?
What we know as light really only represents a fraction of the full spectrum of energy radiated by the sun and the other stars in our Universe (and other possible Universes). Visible light is the narrow range of electromagnetic energy that can be seen by humans and is responsible for illuminating our world in a cacophony of beautiful colour. It’s made up of teensy particles called photons (think photography, meaning “light”), which, unlike gas molecules, don’t float about arbitrarily bumping into the sides of objects like pong balls. Rather, photons travel in waves, just like nausea after some bad Chinese.
Waves are awesome for more than just surfing. They have all sorts of physical properties that, once understood, give us the key to understanding the behaviour of sound and light and our perceptions thereof… such as the colour of the sky!
Like, Wave Properties, Man
Any (serious) surfer will tell you that waves have many properties, including height, amplitude, energy, frequency and wavelength. These are all measurable quantities that can be applied to ALL kinds of waves, including energy and sound waves. For this particular topic, however, we shall be focusing on a property called frequency.
The frequencyrefers to the number of waves that occur in a given time period. So, imagine you’re sitting on a cliff that faces out to sea. In a period of one minute, you count every wave crest that passes your direct line of sight. The number of crests you count per minute is the frequency. Sounds pretty simple doesn’t it? Now try counting the light waves that are bouncing off your dad’s horrible Hawaiian shirt. Obviously you can’t. We can’t see light waves, or sound waves for that matter, but we CAN perceive the differences that arise as a result of differences in their frequency.
Sound waves with a high frequency (refer to the above diagram with the squiggly lines) are perceived by our ears to be high-pitched. Like the sound your wife makes when she gets mad at you for leaving your cheesy socks next to the bathroom sink. Sound waves with a low frequency are perceived by our ears to be low-pitched, like Barry White’s crooning. Similarly, light that travels at a high frequency is perceived by our eyes to be blue or violet and light with a low frequency, as red or orange. In between, you’ll find green and yellow. Together, they all make up the gay flag!
As it was initially explained, visible light represents a mere fraction of the full range of energy produced by our star. The “electromagnetic spectrum” may sound like a horribly complex term, but you’ve actually met most of the members of the family! Let’s take a look… Take a deep breath. It’s not complicated. I believe in you!
The Electromagnetic Spectrum
The squiggly line in the middle represents the size of the wavelengths of the various “kinds” of electromagnetic energy, from the low energy radio and microwaves (that you use to heat up your TV dinners) to the high energy X-ray and Gamma rays (that you definitely don’t use to heat up your TV dinners).
Slap bang in the middle of this diagram, you will see the blue box titled “visible”. This is visible light and it refers to a range of energy frequencies that account for all the colours we see and, in general, the light that illuminates our world.
Now, as we move to the right of the spectrum, the waves become more energetic and the frequency increases. Electromagnetic radiation becomes ultraviolet and then X-ray, as is used in medical diagnostic technology to reveal your bony insides. Finally, at the high-frequency end of the electromagnetic spectrum, we get gamma radiation, which is so ridiculously energetic that a minute’s exposure would either incinerate you, or cause such terrible mutation of your cells that you’d turn into Joan Rivers.
Thankfully, the gamma radiation produced by the unending nuclear fusion reactions in the heart of the Sun doesn’t quite make it to the Sun’s surface and so, our little planet is safe. Earth’s ozone layer also manages to deflect much of any high-energy radiation that heads our way from other locations in the universe, except for small amounts of UV light, which can cause sunburn and melanoma, amongst other kinds of skin cancers.
But, how on EARTH does this all link back to the colour of the sky?
By understanding how the frequency of visible light determines its position on the colour spectrum, we are given the key to understanding the colour of the sky!
Why Is The Sky (Sometimes) Blue?
When visible light reaches our planet, it encounters all the trillions of molecules of gas, water and other particulates that are so abundant in the atmosphere. While the majority of the spectrum can travel through this veritable obstacle course unscathed, blue light is unlucky enough to be of the perfect wavelength or “size” and so can’t help but collide with all these molecules and particles.
It’s like trying to roll a marble (blue light) tennis ball (green light), skateboard (yellow light), bicycle (orange light) and car (red light) through a car park FULL of marbles. Which one do you think it going to have the greatest difficulty getting from A to B without being deflected off its path? Blue light obviously and as a result, it gets scattered off its original course, which is what we see when we look up at a blue sky. This effect is known as Rayleigh scattering and is named after the obnoxiously titled English physicist, John William Strutt, 3rd Baron Rayleigh Peacock Eminent La-di-da.
In reality, more than just blue light is scattered. A little bit of violet and green and even red light is scattered, too. But it’s predominantly blue that has fender benders across the daytime sky. If you throw a teaspoon of violent, green and red into a bucket of blue paint, the resultant colour will still be blue. This all changes, however, as the sun carves its path across the sky, drawing inexorably closer to the horizon…
Red, Orange and Yellow Sunsets
From our perspective, the atmosphere at the horizons is thicker owing to the oblique angle at which we are looking at it. The following two diagrams illustrate this point beautifully, saving me a fair amount of wind…
In the first image, the length of the path the sunlight travels to reach the little sunbathing dude, as denoted by the black arrow, is much shorter than in the second image, when the sun sits on the horizon. This longer distance means that by the time the light finally does arrive at the dude’s eyeballs, all the blue light has been scattered out, leaving only the low-energy frequency light: reds, oranges and yellows. This is why sunsets look like sex-on-the-beach cocktails.
It’s also why they inspire cocktails… and sex on the beach.
Interestingly, at midday, the light travelling to us from the horizon still needs to claw its way through a thicker layer of atmosphere. While this light IS scattered red light, its mixture with all the blue scattered light from the rest of the sky causes the one extreme end of the colour spectrum to meet the other, effectively cancelling each other out. The resulting colour is white. In other words, at the horizons, all members of the visible colour spectrum are reunited, leaving you with *drumroll* white light.
Why Are Some Sunsets More Spectacular Than Others?
Discounting the sunsets you watched while totally baked on that good shit your cousin somehow smuggled in from Canada, the more spectacularly hued sunsets can be attributed to the composition of the atmosphere.
The more particles there are in the sky, be it dust, pollution, smoke, water vapour or the workings of a local volcano with indigestion, the more aggressive the scattering and the more enhanced these effects will be. This explains why there is nothing more beautiful – implications aside – than a sunset over a horribly polluted sky.
Cloudy With A Chance Of Green
There is a strange greenish tinge to the sky that can sometimes develop just before a severe thunderstorm drops its load. It’s especially noted with powerful storms that are able to form large hail and tornadoes. I’ve heard two theories explaining why this happens, but it would seem that the jury is still out on which one is more correct:
Severe thunderstorms typically occur during the latter half of the day and especially towards sunset. These kinds of thunderstorms also form very high cumulonimbus towers and the abundant water vapour within these clouds sends blue light scattering like skittles on a waxed floor. With the sunset throwing red scattered light on the blue underside of the clouds, the resultant visual effect can be a greenish tinge, as you can see in the picture above.
The other explanation is that the presence of large hailstones within a thundercloud can actually scatter light whose frequency is slightly lower than the standard blue. What colour comes next after blue? Green of course, hence the greenish otherworldly tinge. I prefer this explanation since it’s more awesome.
Having said all this, a greenish sky is not a sure-fire indicator that a tornado is on the way, as is a popular myth amongst the residents of Tornado Alley. But it does indicate the presence of a very tall convective storm, which you can pretty much bank on ruffling a few leaves. Maybe even relocating a cow.
Class Dismissed: Your Take-Home Message
The sky appears to us in a myriad of colours throughout the day and it all comes down to the fact that visible light has multiple personality disorder. Whichever colour you do see is a result of that particular frequency of light being scattered more effectively than the others. But our foray into the physics of light has explained more to us than just the hue of the sky… it has also revealed just how many fascinating things wave properties account for, from the pitch of your irate wife’s voice to Indian Ocean tsunamis.
I intend to explore both of these in good time, but in the meanwhile…