Tag Archives: global warming

Global Warming Canaries, Anyone? A short intro to why most scientists are worried about climate change…

The current state of arctic sea ice (see graph below) sends a chill down my spine.

Image

So what it says is that the ice is melting furiously, and looks like it’s not yet slowing down even though the days have started to draw in.

However, any scientist will tell you that no single data point can be used as evidence of global warming, there are simply too many fluctuations for anything to be concluded over anything but the longest timescales. We cannot simply look at the mean temperature for a hot year and say, there you go, global warming!

Now, the issue is, there are well-known cycles over pretty much all timescales – this pretty much undermines all serious attempts at prediction.

So, what to do? Well all is not lost; there are still some clever little leading indicators we can look at to give us that sobering wake up call.

#1:  CO2

Firstly, we know CO2 concentration is up, no doubt or argument, this can be seen in the famous Hawaii data above, complete with the seasonal ‘breathing’ by global plant-life. The argument is about whether the greenhouse models that say this will result in warming will turn out right. I honestly don’t know, but I wouldn’t even have to wonder if the CO2 levels weren’t going up, would I?

#2: A Record Breaking Rate of Record Breaking

Secondly, rather looking at averages or ‘new records’, we can look at the frequency of records. So rather than saying, “we just had the hottest summer ever in some parts of the US, there’s the proof” we can look at how often records are set all over the world – hottest, coldest, wettest, dryest and so on. This approach creates a filter; if it shows there are more records being broken on the hot side than the cold side, could this be an indicator? I hope not, because there are.

Again, it could be part of a long-term cycle that could bottom out any time now. But on the other hand, if it was going the other way, I wouldn’t have to hope, would I?

#3: Sea Ice

Now the sea ice. The sea ice is another proxy for temperature. The reason it’s interesting to climatologists is because it is a natural way to ‘sum-up’ the total warmth for the year and longer; if ice is reducing over several years, it means that there has been a net surplus of warmth.

CryoSat – The European Space Agency’s Sea Ice Monitoring satellite launched in 2010 – (Image credit ESA)

Today we are seeing a new record set for minimal northern sea ice. And not only is there less area of ice, but it is thinner than previously realized and some models now suggest we could be ice-free in late summer in my lifetime.

Now if that does not strike you cold, then I didn’t make myself clear. This is not some political posturing, not some ‘big-business’ spin, nor greeny fear mongering. It’s a cold clean fact you can interpret for yourself, and it could not be clearer.

So is it time to panic?

Well it can still be argued the melting is part of a cycle, it could of course reverse and hey, no biggy. After all, what does it matter how much ice there is?

Well, yet again, I hate to rely on the ‘hope’ that it’s a cycle. Because if it continues, the next effect will be felt much closer to home…

Sea Level

Sea level is the ultimate proxy for warming. Indeed, sea level change can be so serious, maybe it is the problem rather than the symptom. If the ice on Greenland and Antarctica melt, the rise in sea level would displace hundreds of millions of people and change the landscape so dramatically it’s a fair bet wars and famine will follow. Now that is serious.

So have we seen sea level rise? Well, yes. Here’s the plot:

Now, it looks pretty conclusive but hold the boat. Some say’s it’s proof of warming but not everyone agrees. It’s true it could again be a cycle. Also, the sea level rise is fairly gradual; what people are really arguing about is whether we should expect it to speed up. If temperature goes up a few degrees it could go up 5 or 10 times faster. The speed is the issue. Humanity can cope if the level goes up slowly enough, sure, countries like Tuvalu will be in big trouble either way, but countries like Bangladesh and cities like New York and London will only be in real trouble if the rate increases.

Actual Canaries

Canaries taken into mines in order to detect poisonous gases; the idea being they would suffer the gas faster than the people and if the canary dropped, it was time to vacate. Do we have systems that are hypersensitive to climate change?

Yes! There are many delicately balanced ecosystems that can can pushed over a tipping point with the lightest of touch. Is there an increase in the rate of species loss, or an increase in desertification? Yes!

We can also look at how far north certain plants can survive, how high up mountains trees can live or how early the first buds of spring arrive.

Again, these indicators fail to give solace. Everywhere we look we see changes, bleached coral, absent butterflies, retreating glaciers.

The conservative approach is to ascribe these changes to the usual cut and thrust of life on earth; some take solace from the fact that humankind has survived because we are the supreme adapters and that the loss of species is exactly how the stronger ones are selected.

Yes, we are great at adapting, however, to kill any complacency that may create, consider the following: for humans just ‘surviving’ is not the goal, that’s easy, we also need to minimize suffering and death, a much tougher aim. We’ve also just recently reduced our adaptability significantly by creating ‘countries’. Countries may seem innocuous, but they come with borders – and mean we can no longer migrate with the climate. Trade across border also needs to be of roughly the same value in both directions.  While some countries will actually see productivity benefits from global warming, most will not, and without the freedom to move, famine will result. Trade imbalances mean inequality will become extreme. The poorest will suffer the most.

So for now changes are happening, and advances in agricultural technology are easily coping; however, because ecosystems are often a fine balance between strong opposing forces, changes may be fast should one of the ropes snap.

Conclusion

Looking at the long history of the earth we have seen much hotter and much colder scenes. We have seen much higher and much lower sea levels. We are being wishful to assume we will stay as we have for the last 10,000 years. It may last, or it may change. Natural cycles could ruin us. And mankind is probably fraying the ropes by messing with CO2 levels.

Can we predict if we are about to fall off of our stable plateau? No, probably not. But is it possible? Heck yeah.

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If you liked this, you may like these earlier posts on the subject of global warming:

  1. What does the earth’s history tell us about climate? And how can we find out if our house will be one that sinks should sea levels rise? Find out here!
  2. Can we  change the planet’s dangerous behavior? Read my call for a study in mass behavior.

Hysteresis Explained

Hysteresis (hiss-ter-ee-sis). Lovely word. But what on earth does it mean?

Hysteresis is one of those typically jargonny words used by scientists that instantly renders the entire sentence if not lecture lost on its audience. Sure, you can look it up on wikipedia, but you may die of boredom before you get to the point, so I am going to explain it here.

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Hysteresis on the way to school

Let’s go for a walk. Let’s say we are ten years old and we are walking to school. The route is simple. The school is a few hundred yards down the hill on the other side of the road. Now consider the question: at what stage do we cross the road? Immediately? Or do we walk all the way to opposite the school before crossing – or somewhere between?

Assuming there are no ‘official’ crossing points, I bet you cross immediately, then walk down the far side of the road.

How can I make this prediction? Well, I assume that crossing the road requires there to be no traffic, so if there is no traffic as you start the journey, it is a good time to cross. If there is traffic, you just start walking down the road until a gap appears, then you cross. This strategy allows you to cross without losing any time. If your strategy had been to cross at the school there is a real risk you will need to wait, thus losing time. So it turns out the best strategy to avoid any waiting is to cross as soon as you can.

So now picture your walk home. Again, it makes sense to cross early on. The result is that the best route to school is not the same as the best route from school. This is an example of hysteresis – or a ‘path dependent phenomena’.

Hysteresis  everywhere

The dictionary will drone on about magnetism and capacitance and imaginary numbers. A much nicer example is melting and freezing of materials – some substances actually melt and freeze at different temperatures. This shows that the answer to the question: “is X a solid at temperature Y?” actually depends – on the path taken to that temperature. Just like what side of the road you are halfway between home and school will depend on whether you are coming or going.

It seems to me that falling asleep and waking up also bear some of the hallmarks of hysteresis; although they could be considered a simple state change in opposite directions, they feel very different to me – I  seem to drift to sleep, but tend to wake to alertness rather suddenly.

Now think of a golf club in mid swing. As the golfer swings, the head of the club lags behind the shaft. If the golfer where to swing in reverse, the club head would lag in the other direction – thus, you can  tell the direction of movement from a still photograph. We can therefore say the shape of a golf club exhibits hysteresis – and again you see see why it is so-called “path dependent”.

This logic can be taken further still – wetting is not the opposite of drying and likewise heating is rarely the inverse of of cooling. Let’s imagine for example that you want to make a chicken pie warm on the inside and cool on the outside. This is best done by warming the whole pie and then letting it cool a little. The temperature ‘profile’ inside your pie thus depends not only on the recent temperature but has a complex relationship with its more distant temperature history. This particular point is somewhat salient at the moment as we ask the question: is the earth heating up? 

So what?

Good question. I’m not a fan of jargon, and hysteresis is not a word I hope to need to use in my smalltalk. However, you can see that it encapsulates a rather specific and increasingly important concept that is pretty hard to replace with two or three simpler words; thus it passes my test of “words a scientist should understand that most don’t”. Please let me know your own additions to such a list!

 

 

Could Google Earth Show Sea Level Change Impacts?

I just finished reading Storms of my Grandchildren by James Hansen – it is basically an alarming presentation of evidence that not only is climate change affected by humans, but that the changes could indeed be dramatic and soon. While the author warns of effects more extreme than the ‘consensus’ of the IPCC, he argues very credibly. It is worthwhile to note that in achieving consensus, any group needs to ‘normalise’ opinion (i.e.  compromise).

The IPCC cannot say “all is well”, as there is undeniable evidence that it isn’t, and they are, after all, a bunch of tree huggers (said with love!) .

However, it cannot say “ban all coal” either, because it would render itself at odds with governments, and find the party invitations will dry up sharpish. The IPCC said what it had to say from day one: there is a massive risk of disaster and we need to find a pragmatic way forward that does not punish any sector too harshly.

It also appreciates that it needs to gradually adjust the Zeitgeist. Each report will get more draconian, not just because the evidence is getting stronger, but because the audience is softening up with time. Of course, this public opinion inertia takes up time, which is exactly what we haven’t got.

James Hansen, is therefore now acting as a representative for those who feel the urgency is lacking. He accepts that his invitations to the Whitehouse may have got lost in the post of late, but he is gathering a following and starting to get heard.

Anyway, on to my point. While reading the book, I realized not only the lack of action against climate change, but also the lack of action to prepare for it.  I read up on what various people are thinking (including the IPCC take), and I was wondering how much the individual can do.

In a slump of morbidity (you read the book, you may have one too), I wondered how my town may look if sea levels does rise a few meters. It is not too hard to trace out the new shoreline, but it did make me think I could write a program that could plug into Google Earth in which you could dial in the sea level and take a look.

Initally I thought I might get lucky with new sea views to look forward to – then I realize my house would be completely unaccessible and my local town would be gone, along with my friends and also most of the roads…

Perhaps I should start saving for a nice big boat?

PS. Feed your obsessive-compulsive side – take a regular look here: http://arctic.atmos.uiuc.edu/cryosphere/ . Is this a good canary in the coal mine? I hope not! There is an alarming dip the last few days – (today is Dec 23, 2010) –  tell me it was a blip! Did I mention looking at this daily will lead to the complete abandonment of statistical sense and every blip will be a crisis? I mention it now…

What exactly is temperature? Ever wondered?

We take it for granted. We understand it. It is obvious what temperature is. Cold, warm, hot…obvious.

But how many of us have asked the next question: what is the real difference between a hot stone and a cold one? The answer is interesting and helps us to realise that measuring temperature is much trickier than we tend to suppose.

Over many hundreds of years, many clever people have devised lots of experiments to understand what temperature is, I hope in this article to round up the facts!

Temperature and Energy

For much of history, there were only a few sources of heat – the sun, fire, lava and of course the warmth of living creatures.

People were puzzled by what created it, but it was immediately obvious that it had one consistency – whenever it had the chance, it flowed – put something hot next to something cold, and the heat would flow.

Of course you could argue that it was the ‘cold’ that flowed (the other way), but there were no obvious sources of ‘cold’. While ice was clearly cold, it was not a sustainable ‘source’ of cold the way a fire was.

It was also noted that heat melted things – like fat or butter and that it make some liquids (like molasses) thinner. It could even boil water and make it ‘vanish’. The mechanisms for these were unknown and a source of fascination for early scientists.

Early experimenters noticed that gases would increase in volume upon heating, and that compressing gases would cause them to heat up. They also investigated other sources of heat, like friction, (rubbing your hands together).

It was the work with gas that led to the big breakthrough. Boyle and Hooke, as well as Edme Marriotte, working in the 17th century, realized that the temperature of a gas would increase consistently with pressure, and like-wise, decrease consistently with pressure. This sounds unremarkable, until you note that you can only decrease pressure so much…

Once you have a vacuum (no pressure), you should have ‘no temperature’. Thus their observations implied that there really was a limit to how cold things could get, and predicted it was around -275 Celsius. They were of course unable to cool anything that far simply by expanding it because heat always flows into cold things, so to achieve this you need much better insulation than they had available.

So they had a big clue in the search to understand what temperature is, but still no explanation.

It took until 1738 until another great scientist moved us forward. Daniel Bernoulli realised you could use Newton’s (relatively new) laws to derive Boyle’s temperature-pressure relationship. He basically asked: what if gas was made of a large number of very small billiard balls flying around crashing into everything? What if pressure was just the result of all these collisions? Using this theory he realised, for the first time I think, what temperature truly is.

Source: Wikimedia Commons

It turns out that his model equated temperature with the speed of the billiard balls. A hot gas only differs from a cold gas in the speed of the molecules flying around. Faster molecules crash with more momentum and thus impart more pressure. Squashing the gas into a smaller volume does not give them more speed, but means more collisions each second, so higher pressure.

This is a pretty serious finding. It basically says ‘there is no such thing as temperature’. There is only lots of little balls flying around, and their number and speed dictate the pressure they exert, and there is no ‘temperature’.

If we put a thermometer into the gas, what is it detecting then? Great question.

It turns out that solids are also made of lots of balls, except, instead of being free to fly around, they are trapped in a matrix. When a solid is exposed to a hot gas,  it is bombarded by fast flying atoms. When a solid atom is hit, instead of flying off, it starts to vibrate, like a ball constrained by a network of springs.

So the ‘temperature of a solid is also a measure of speed of motion, but rather than linear speed it’s a measure of the speed of vibration. This makes a lot of sense – as the solid gets hotter, the balls are going literally ‘ballistic’ and eventually have enough speed to break the shackles of the matrix (aka melting).

Source: Wikimedia Commons

So this model of heat as ‘movement’ not only explains how gases exert pressure, but also explains how heat flows (through molecular collisions) and why things melt or vaporise.

More importantly, it shows that temperature is really just a symptom of another, more familiar, sort of energy – movement (or kinetic) energy.

Energy is a whole story of its own, but we can see now how energy and temperature relate – and how we can use energy to make things hot and cold.

Making Things Hot

There are many easy ways to make things hot. Electricity is a very convenient tool for heating – it turns out that when electric current flows, the torrent of electrons cannot help but buffet the atoms in the wire, and as they are not free to fly away, they just vibrate ever faster, ‘heating’ up.

Another way to heat things is with fire. Fire is just a chemical reaction – many types of molecules (like methane, or alcohol) contain a lot of ‘tension’, that is to say, they are like loaded springs just waiting to go off. Other molecules (often oxygen)  hold the ‘key’ to unlocking the spring, and when the springs go off, as you can imagine, it is like a room full of mousetraps and ping-pong balls – and all that motion – means heat.

Making Things Cold

Manipulating energy flows to make things cold is much trickier.

One way it to just put the thing you want to cool in a cold environment – like the north pole. But what if you want to make something colder than its surroundings?

Well there is a way. We learned earlier that gases  get hot when compressed – it turns out they do the opposite when decompressed or ‘vented’. This is the principle that makes the spray from aerosol cans (deodorant, lighter fluid, etc) cold. So how can we use this? First we use a compressor to compress a gas (most any gas will do); in the process it will warm up, then you let it cool down by contacting it with ambient air (through a long thin copper tube, but keeping it compressed), then decompress it again – hey presto, it is cold! Pump this cold gas through another copper tube, inside a box, and it will cool the air in the box – and hey presto, you have a refrigerator.

Measuring Temperature

Before we had thermometers, temperature was generally estimated by touch.

However this is where temperature gets tricky. Because the temperature we feel, when we put our hand on the roof of a car is not really the temperature of the car, it’s really the measure of energy flow (into our hand), which relates to the temperature, but also relates to the conductivity of the car.

This is why hot metal feels hotter than hot wood, why cold metal feels colder than cold wood – the metal, if at a different temperature to your hand, is able to move more heat into you (or take more heat away) faster than wood can. Thus our sense of temperature is easily fooled.

The ‘wind-chill factor’ is another way we are fooled – we generally walk around with cloths on, and even without clothes we have some body hair – therefore, we usually carry a thin layer of air around with us that is nearly the same temperature as we are. This helps us when it is cold and when it is hot – however, when the wind blows it rips this layer up and supplies fresh air to our skin – making us feel the temperature more than usual. Also, because our skin can be damp, there can be evaporative effects which can actually cool you below the air temperature.

Scientists have long known that we cannot trust ourselves to measure temperature, so over the ages many tricks have been developed – can the object boil water? Can it freeze water? A long list of milestone temperatures was developed and essential knowledge for early scientists – until the development of the lowly thermometer.

It was noted that, like gases, solids and liquids also expand upon heating. This makes intuitive sense if you think of hot molecules as violently vibrating – they push one another away, or at least if the charge  (electric charge is what holds these things together) is spread just a little thinner, adjacent molecules will have slightly weaker bonds.

The expansion of liquids may only be very slight, and if you have a big volume of liquid in a cup, the height in the cup will change only very slightly, but if its in a bottle with a narrow neck, the small extra volume makes a bigger difference to the level. This principle is used in a thermometer – it’s just a bottle with a very narrow and long neck. The bigger the volume and the narrower the neck, the more sensitive the thermometer. Of course the glass also expands, so it is important to calibrate the thermometer – put it in ice water, mark the liquid level – then put it in boiling water and mark the new level. Then divide the distance between these marks into 100 divisions – and hey presto! you have a thermometer calibrated to the centi (hundred) grade (aka Celsius) scale. Now you know where that came from!

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So that is temperature explained in a nutshell.  If you enjoyed this article you may enjoy my related article on energy.

Good reading for anyone wanting to be more energy efficient…

I am busily researching a series of articles on energy, and thought htis article deserved an immediate link…
http://www.environmentmagazine.org/Archives/Back%20Issues/September-October%202008/gardner-stern-full.html

Skeptics vs Deniers

There is a growing movement, grassroots in nature, but starting to connect, called the skeptics community.

Who exactly are they? Are they people who are starting to uncover the truth – that most world governments are a sham and that secret societies control our every move? Do they deny the holocaust and suspect 9/11 was a complex plot?

No.

A skeptic is merely someone who needs to be convinced of things through reason, rather than one who accepts things on some-one’s say-so.

Simple!

So what is a global warming ‘skeptic’?

Climate science is complex, and consensus opinion is that man’s activity has led to increased greenhouse gas emissions which are likely to reduce outgoing radiation and thus lead to a net shift upward in the temperature of the Earth’s delicate surface. Yes, there are other possible causes, yes, the models contain assumptions, and yes, some fools have fabricated data to look cool. It is also true that many respected scientists will not say it is a cast iron ‘fact’.

So that is the scene – and there seem to be a few types of stakeholders:

  • the ‘global warming denier’
  • the  ‘global warming skeptic’
  • the regular ‘skeptic’
  • and lastly, the gullible!

A ‘global warming denier’ has come to mean someone who does not think the evidence stacks up enough to warrant concern, or worse, thinks it is all a giant conspiracy.

A ‘global warming skeptic’ has come to be somewhat synonymous with a denier, but perhaps without the conspiracy angle. However, many are just people who are on the fence – they are often very smart, and don’t just believe what they are told, but on the other hand, they are easily misled, as there is just so much misinformation out there. They may be the ones who say “I heard the jury is out…” rather than actually looking at evidence.

Some legitimate scientists have foolishly allowed themselves to be given this label, just because they debate some small details (like the rate of heating, or the likely nature of socio-political impacts). These scientists are then lumped with deniers. Tough luck to them.

I found this is some random folder on the 'net. If it's yours, please let me know, I love it! Update: it looks like it may well be from thisisindexed.com - click it to link - nice one Jessica Hagy!

Now a true skeptic will weigh all evidence according to the following principles:

  • is it logical?
  • does it conflict with other strong theories? If so, is it strong enough warrant a change to your previous understanding?
  • is there independent corroboration?
  • do the proponents have a  proven track record (credibility)?
  • is there any incentive by stakeholders to twist the facts?

This describes most good scientists, so its not a bad thing.

In the case of global warming, most true skeptics who have looked closely at the evidence and weighed it appropriately, agree that there is real cause for concern.

But yes, we skeptics will always retain just a little doubt, because you just never know…

Energy Explained in One Page

Ok, so we all want to be good to the environment. The first step to doing this, as is often the case – is to understand the main characters in the story – and possibly the biggest character in the story in Energy.

However, energy is such a very vague concept, so where do you go to learn more? Do you have to do a physics course?

I don’t think so, and to test my theory, I have tried to explain energy as briefly as I can in this post.

Energy 101

Energy is what makes the world go round. Literally. Every neuron that sparks in your brain, every electron that fires down a wire, every molecule burning in a fire, carries with it a sort of momentum that it passes on like a baton in a complex relay race. The batons are flooding in all directions all around us and across the universe – they are energy and we have learned how to harness them.

The actual word “Energy” is a much abused term nowadays – because energy is used to represent such a disparate range of phenomena from heat to light to speed to weight, and because it seems to be able to change forms so readily, it is cannon fodder for pseudo-scientific and spiritual interpretation. However, you will be pleased to hear that it actually has a very clear (and consistent) nature.

I like to think of energy being a bit like money – it is a sort of currency that can be traded. It takes on various forms (dollars/pounds/swiss francs) and can be eventually cashed in to achieve something. However, just like money, once spent, it does not vanish. It simply moves on a new chapter in its life and may be reused indefinitely.

§Energy currencies:{1}Matter is energy(see footnotes) {2} Radiation {3} Chemical energy {4} Thermal (heat) energy {5} Compression energy {6} Kinetic (movement) energy {7} Electrical energy

To illustrate the point, let’s follow a ‘unit of energy’ through a visit to planet Earth to see what I mean. The [number] shows every time it changes currency (see the key on the right).

The energy starts off tied up in hydrogen atoms in the sun [1]. Suddenly, due to the immense pressure and heat, the nuclei of several atoms react to form a brand new helium atom, and a burst of radiation[2] is released. The radiation smashes into other nearby atoms heating them up so hot [4] that they glow, sending light [2] off into space. Several minutes pass in silence before the light bursts through the atmosphere and plunges down to the rainforest hitting a leaf. In the leaf the burst of power smashes a molecule of carbon dioxide and helps free the carbon to make food for the plant [3]. The plant may be eaten (giving food ‘Calories’), or may fall to the ground and settle and age for millions of years turning perhaps to coal. That coal may be dug up and burned to give heat [4] in a power station, boiling water to supply compressed steam [5] that may drive a turbine [6] which may be used to generate electricity [7] which we may then use in our homes to heat/light/move/cook or perhaps to recharge our mobile phone [3]. That energy will then be used to transmit microwaves when you make a call [2] which will mostly dissipate into the environment heating it (very) slightly [4]. Eventually the warmed earth radiates [2] this excess of heat off into the void where perhaps it will have another life…

This short story is testament to an enormous quantity of learning by our species, but there are some clear exclusions to be read into the story:

  • Energy fields (auras) or the energy lines in the body that conduct the “chi” (or life force) of Asian medical tradition
  • Energy lines on the Earth (aka Ley lines)
  • Negative or positive energy (as in positive or negative “vibes”)

These energy currencies relate to theories and beliefs that science has been unable to verify and thus they have no known “exchange rate”. Asking how many light bulbs can you power with your Chi is thus a nonsensical question, whereas it would not be for any scientifically supported form of energy. And since energy flows account for all actions in the universe, not being exchangeable would be rather limiting.

Where exactly is Energy kept?

This may sound like s strange question, we know Energy is kept in batteries, petrol tanks and chocolate chip cookies. But the question is, where exactly is it stored in those things?

Energy is stored in several ways:

  • as movement – any mass moving has energy by virtue of the movement, which is called Kinetic Energy
  • as matter – Einstein figured out that matter is just a form of energy, and the exchange rate is amazing – 1g = 90,000,000,000,000,000 joules (from E=mc^2)
  • as tension in force fields

That last one sounds a bit cryptic, but actually most of the energy we use is in this form –  petrol, food, batteries and even a raised hammer all store energy in what are essentially compressed (or stretched springs).

What is a force field? Why on earth did I have to bring that up?

All of space (even the interstellar vacuum) is permeated by force fields. The one we all know best is gravity – we know that if we lift a weight, we have to exert effort and that effort is then stored in that weight and can be recovered later by dropping it on your foot.

Gravity is only one of several force fields known to science. Magnetic fields are very similar – it takes energy to pull a magnet off the fridge , and so it is actually an energy store when kept away from the fridge.

The next force field is that created by electric charge (the electric field). For many years this was though to be a field all on its own, but a chap called Maxwell realised that electric fields and magnetic fields are in some senses two sides of the same coin, so physicists now talk of ‘electromagnetic’ fields. It turns out that electric energy (such as that stored in a capacitor) consists of tensions in this field, much like a raised weight is a tension in a gravity field. Perhaps surprisingly, light (as well as radio waves, microwaves and x-rays) are also energy stored in fluctuations of an energy field.

Much chemical energy is also stored in electric fields – for example, most atoms consist of positively charged nuclei and negatively charged electrons, and the further apart they are kept, the more energy they hold, just liked raised weights. As an electron is allowed to get closer to the nucleus, energy is released (generally as radiation, such as light – thus hot things glow).

The least well known force field is the strong ‘nuclear’ force. This is the forces that holds the subatomic particles (protons) together in the nucleus of atoms. Since the protons are all positively charged, they should want to repel each other, but something is keeping them at bay, and so physicists have inferred this force field must exist. It turns out their theory holds water, because if you can drag these protons a little bit apart, they will suddenly fly off with gusto. The strong nuclear force turns out to be bloody strong, but only works over a tiny distance. It rarely affects us as we rarely store energy with this energy field.

Now we understand force fields we can look at how molecules (petrol, oxygen, chocolate) store energy. All molecules are made of atoms connected to one other via various ‘bonds’ and these bonds are like springs. Different types of molecules have different amount of tension in these bonds – it turns out coal molecules, created millions of years ago with energy from the sun, are crammed full of tense bonds that are dying to re-arrnage to more relaxed configurations, which is exactly what happens when we apply oxygen and the little heat to start the reaction.

The complexity of the tensions in molecules are perhaps the most amazing in nature, as it is their re-arrangements that fuel life as we know it.

What exactly is Heat then?

You may have noticed that I did not include heat as a form of energy store above. But surely hot things are an energy store?

Yes, they are, but heat is actually just a sort of illusion. We use heat as a catch all term to describe the kinetic energy of the molecules and atoms. If you have a bottle of air, the temperature of the air is a direct consequence of the average speed of the molecules of gas jetting around bashing into one another.

As you heat the air, you are actually just increasing the speed of particles. If you compress the air, you may not increase their speed, but you will have more particles in the same volume, which also ‘feels’ hotter.

Solids are a little different – the atoms and molecules in solids do not have the freedom to fly around, so instead, they vibrate. It is like each molecule is constrained by elastic bands pulling in all directions. If the molecule is still, it is cold, but if it is bouncing around like a pinball, then it has kinetic energy, and feels hotter.

You can see from this viewpoint, that to talk of the temperature of an atom, or of a vacuum, is meaningless, because temperature is a macroscopic property of matter. On the other hand, you could technically argue that a flying bullet is red hot because it has so much kinetic energy…

Is Energy Reusable?

We as a species, have learned how to tap into flows of energy to get them to do our bidding. So big question: Will we use it all up?

Scientists have found that energy is pretty much indestructable – it is never “used-up”, it merely flows from one form into another. The problem is thus not that we will run out, but that we might foolishly convert it all into some unusable form.

Electricity is an example of really useful energy – we have machines that convert electricity into almost anything, whereas heat is only useful if you are cold, and light is only useful if you are in the dark.

Engineers also talk about the quality (or grade) of energy. An engineer would always prefer 1 litre of water 70 degrees warmer than room temperature, than 70 litres of water 1 degree warmer, even though these contain roughly the same embodied energy. You can use the hot water to boil an egg, or make tea, or you could mix it with 69 litres of room temperature water to heat it all by 1 degree. It is more flexible.

Unfortunately, most of the machines we use, turn good energy (electricity, petrol, light) into bad energy (usually “low grade heat”).

Why is low grade heat so bad? It turns out we have no decent machine to convert low grade heat into other forms of energy. In fact we cannot technically convert any forms of heat into energy unless we have something cold to hand which we are also willing to warm up; our machines can thus only extract energy by using hot an cold things together. A steam engine relies just as much on the environment that cools and condenses water vapour as it does on the coal its belly. Power stations rely on their cooling towers as much as their furnaces. It turns out that all our heat machines are stuck in this trap.

So, in summary, heat itself is not useful – it is temperature differences that we know how to harness, and the bigger the better.

This picture of energy lets us think differently about how we interact with energy. We have learned a few key facts:

  1. Energy is not destroyed, and cannot be totally used up – this should give us hope
  2. Energy is harnessed to do our dirty work, but tends to end up stuck in some ‘hard to use’ form

So all we need to do to save ourselves is:

  1. Re-use the same energy over and over
  2. by finding some way to extract energy from low grade heat

Alas, this is a harder nut to crack than fission power, so I am not holding my breath. It turns out that there is another annoying universal law that says that every time energy flows, it will somehow become less useful, like water running downhill. This is because energy can only flow one way: from something hot to something cold – thus once something hot and something cold meet and the temperature evens out, you have forever lost the useful energy you had.

It is as if we had a mountain range and were using avalanches to drive our engines. Not only will our mountains get shorter over time but our valleys will fill up too, and soon we will live on a flat plane and our engines will be silent.

The Big Picture

So the useful energy in the universe is being used up. Should we worry?

Yes and no.

Yes, you should worry because locally we are running out of easy sources of energy and will now have to start using sustainable ones. If we do not ramp up fast enough we will have catastrophic shortages.

No, should should no worry that we will run out, because there are sustainable sources – the sun pumps out so much more than we use, it is virtually limitless.

Oh, and yes again – because burning everything is messing up the chemistry of the atmosphere, which is also likely to cause catastrophe. Good news is that the solution to this is the same – most renewable energy sources do not have this unhappy side effect.

Oh, and in the really long term, yes we should worry again. All the energy in the universe will eventually convert to heat, and the heat will probably spread evenly throughout the universe, and even though all the energy will still be present and accounted for, it would be impossible to use and the universe would basically stop. Pretty dismal, but this is what many physicists believe: we all exist in the eddy currents of heat flows as the universe gradually heads for a luke-warm, and dead, equilibrium.

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Ok, so it was longer than a page, so sue me. If you liked this article, my first in a series on energy conservation, you might like my series on efficient motoring.

Please leave a comment, I seem to have very clued-up readers and always love know what you think!

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§ Footnotes:

[1] Matter is energy according the Einstein and the quantity relates to mass according to E=mc^2 (c is a constant equal to the speed of light).

[2] Radiation (like sunlight) is a flow of energy, and energy content relates the frequency according to E=hf (h is the Planck constant).

[3] Chemical energy – the most complex energy, a mixture of different tensions in nuclear and electromagnetic force fields.

[4] Thermal (heat) energy- this is really just a sneaky form of kinetic energy [6 below] – small particles moving and vibrating fast are sensed by us as heat.

[5] Compression (or tension) energy – while compressed air is again a sneaky form of kinetic energy [6], a compressed spring is different – it’s energy is more like chemical energy and is stored by creating tension in the force fields present in nature (gravity, electromagnetism and nuclear forces).

[6] Kinetic (movement) energy

[7] Electrical energy – this energy, like a compressed spring, is stored as stress in force fields, in this case electromagnetic force-fields.

Climate change solutions: mass behaviour simulation

Saving our planet from catastrophic climate change might require an unprecedented mass co-ordination of all the people on our lonely little planet.

However, it requires co-ordinated sacrifice, the west are living unsustainably, the east have not had their fair share yet, Africa is unmanageable… how will we pull it off?

Pondering this issue, I am sure none of the experts will have any good prediction of how people will behave – when will the zeitgeist be strong enough to allow governments take the massive steps required? When will china be satisfied that they have pulled up their living standards enough such that it would be fair for them to sacrifice too?

With such imponderables, it seems to me, we might gain some insight if we can create on on-line simulation, a ‘game’ if you like, with a large number of participants, each with their own minds, their own priorities, their own feeling of what constitutes justice.

In this game, some would be wealthy, those that had benefited from the industrial revolution, the slave trade, etc, etc, and fiercely protective of their way of life, many more would represent the 3rd world, the developing nations, the disenfranchised, the war-torn…

These people would thus all live in a 2nd-life style world in which carbon emissions are sure to cause catastrophe (no-one knows when!) but carbon emissions are associated with the luxuries used by the people. Will people be able to co-ordinate themselves to reduce overall emissions? Or will they each take the ‘every man for himself’ route, ensuring that the fit survive, but perhaps with a lower total survival rate?

Could such a game be set up?

It would require a committed community of computer experts (which exist) and a committed community of environmentalists (which also exist) – but do they overlap?

How could we go about trying to make this happen?

Extrapolating your way

There is a very powerful scientific reasoning tool that I use, that, it occurs to me, I wasn’t actually taught… the simple art of extrapolation.

Most people have a pretty good idea of what extrapolating is – its where you look at a trend and predict what will happen if that trend persists. 

For example, if I said it took me 6 months to save £500, I can use extrapolation to predict how long it will take me to save £2000; its something we do all the time – yesterday I was driving down from Bristol, I could count off the the miles, and knowing the distance, I could predict if I would make it for dinner (I didn’t).

Scientists use this too. A good example is the way we can calculate the temperature of “absolute zero” by looking at the volume of a balloon as you heat it up. If you had a balloon at 25C, and you heat it to about 55C its volume would increase by about 10%. What does that tell us? It tells if we cooled it, it would eventually have no volume – and that this would happen at around -275C (-273.15C actually) – absolute zero.

Of course, the method relies upon assumptions – usually the assumption that the trend will continue in the same way (people often use the term “linear” to represent relationships that form straight lines when plotted on a graph).

What if the relationship is non-linear? For example, if little James is 5 feet tall when he is 10, how tall will he be when he is 20? Clearly he won’t be 10ft tall – that is because the relationship between height and age is “non-linear”.

Most of us are smart enough to extrapolate without knowing the jargon, but when the relationships get complicated a bit of maths and jargon can help.

For example, if we want to examine the population of bacteria in a petri dish, or the spread of a virus (or a rumour) through a population, our mental arithmetic is not always up to it. Luckily, some scientists have realised even these complex affairs have some predictability and although “non-linear”, they can still be modelled – graphs can be plotted and extrapolations made.

If this interests you, I refer you to books on epidemiology; I will move onto another sort of extrapolation – one used to check people’s theories by identifying ‘impossible’ extrapolations.

Let’s say, for example, that the want to predict  how the obesity epidemic will progress in the coming decades. If the media says obesity in a certain group increased from 14-24% between 1994 and 2004, and then goes on to predict that obesity will therefore reach 34% by 2014, does this withstand scrutiny?

Never mind that the definition of obesity may be faulty (BMI), never mind that they are extrapoliting from 2 data points – let’s rather ask if the linear trend is justifiable. This can be done by extrapolating the prediction to try to break it. 

If the model is right, obesity will go on increasing and soon enough 100% (or more!) of the population will be obese. This is clearly wrong – obesity is not likely to get everyone – vast swaths of the population are likely to be immunised to some extent against obesity due to active lifestyles and good dietary educations, or perhaps its in their genes, the lucky things. 

The truth will of course be more complex – the first group to become obese will be the most vulnerable, so an increase from 14-24% may incorporate that group, but each successively 10% will be harder fought.  All this is enough to suggest the predictions made for 2014 are doubtful, and those that go further are downright shameless. But it doesn’t stop them

I am sure you can think of other suspicious trend-based predictions, like those for peak-oil or global warming. They could do with some improvements, so get to it!