The Best Australian Science Writing 2013

by Jane McCredie

  So, as a general principle then, his argument centres around the idea that efficiency actually increases, rather than decreases consumption. And that’s what’s become known as the ‘Jevons Paradox’. It’s also sometimes referred to as the ‘efficiency dilemma’ and it’s one of the major reasons why striving to be energy efficient in the modern world so often ends up as an exercise in pedalling faster, rather than moving ahead.

  Dr Miles Park from the Faculty of the Built Environment at the University of New South Wales explains it like this:

  When you buy these new ‘eco-efficient’ products, it can change your behaviour. This is referred to as a ‘rebound’ effect, whereby there’s the psychological thinking that ‘Well, this product is saving me energy’. So therefore you may be inclined to leave the lights on longer, or perhaps you’ve bought a new eco-efficient car so you’ll drive further and more frequently.

  Walk inside the modern house and it’s easy to see what Dr Park means. Newly constructed dwellings are now built with energy-efficient lighting but whereas a room used to have, on average, just one ‘inefficient’ incandescent light bulb, today the fashion is to have as many energy-efficient globes as the ceiling space will allow – or the bearers in the roof will hold. I visited a beach house in the fashionable Sydney suburb of Avalon not so long ago that had more than 40 downlights in the open-plan entertainment area alone! At night time the ceiling looked like a planetarium. You could have mapped your path to another galaxy just by sitting at the breakfast bar and looking up.

  And lighting is just the beginning of it: we build more freeways and overpasses in order to make our traffic flow more efficiently, only to end up with an increase in vehicle usage and eventually even greater levels of congestion. Then there’s the internet. The web was meant to herald the age of the paperless office, but in reality the online environment has vastly increased the flow of correspondence between people, resulting, in turn, in an increase in energy costs from the electricity required to run the world’s computers and servers. And to make matters worse, an awful lot of the digital correspondence that’s sent between offices often ends up being backed up on paper anyhow.

  But there’s also another problem with computers: the faster they’ve become, and the greater their capacity, the more applications we’ve found for them, which means more usage, which, in turn, means more energy consumption. It’s now estimated that information communication technology (ICT) infrastructure accounts for around 20 per cent of the energy consumed in the standard modern office.

  ‘It’s certainly the case that our information and communications technology devices are chewing up more and more energy and there’s a huge effort in the community, in the computer and electronics community, to reduce that amount of energy, to look for lower energy and more efficient devices,’ says Dr David Skellern, a former head of the technology research organisation National ICT Australia Ltd (NICTA). ‘But inevitably, as we have more and more systems connected, we are going to see an increase in the amount of energy that’s used.’

  In 2007, a study by the tech research company Gartner found that ICT accounted for around 2 per cent of total greenhouse gas emissions. That doesn’t sound like much, but put into perspective, that’s round about the same percentage as emissions from the aviation industry. And Lachlan Andrew at the Centre for Advanced Internet Architectures at Melbourne’s Swinburne University says all the relevant indicators are pointing upward.

  The most recent figure I’ve heard is about 15 per cent annual growth in the energy consumption of the internet. Another figure that I’ve heard is around 6 per cent or so in total due to e-commerce type activities, which includes things like buying a book online. Now, you don’t have to physically travel to a bookshop, but that book is in fact being shipped to you. If you consider all the packaging costs and suchlike, the energy cost of buying a book online is often more than driving to the bookshop and buying the book yourself.

  The solution seems obvious enough: consume less. But encouraging less consumption is always going to be easier said than done in affluent countries like Australia and the United States. It shouldn’t be, but political considerations do get in the way.

  To show you what I mean, I need you to shut your eyes. Shut them tight. I mean really tight. OK, you might have to peek a bit in order to read what I’ve got to say, but only a little bit. Now, imagine a politician running for election on a campaign platform based on cutting back. Not slicing away at the size of the national deficit or the public service, but forcing voters to seriously cut back on the gadgets and good stuff that we as a society of consumers just love to have. Imagine a campaign message that said to voters that they needed to spend less time on their computers and other digital toys. Or that for the sake of the planet and future generations, they should rip out almost all of the mood lighting in their home, and be content to have just one bathroom in the new house they’re building. Or better still, imagine advising people that perhaps they could get by with just one giant flatscreen plasma television in their home, not one per room.

  It’s just not going to happen, because it’s a message that none of us want to hear. The future is meant to be about more, not less; and besides, aren’t we already doing our bit for energy efficiency by turning off the lounge-room light once a year in support of Global Earth Hour?

  In summary, weaning people off at least some of their gadgets is never going to be easy in a world that’s saturated with advertising and where the term consumer has now begun to replace the word citizen. Part of the answer is always going to have to be about thinking smarter and trying to reduce energy usage without inadvertently stimulating greater demand.

  So what sorts of initiatives could work? Well, I thought about it for a long while and couldn’t come up with any myself, so once again I turned to David Skellern for help.

  ‘There are sophisticated ways in which you can save energy,’ Skellern assures me, and the example he gives involves motor vehicles. Manufacturers, he says, are experimenting with systems that connect the engine management of a car to the outdoor environment. ‘If we knew, for example, when a light was going to turn on or off, a traffic light, and we let the computer in the car determine that we’re actually going to be in a braking mode, then it could change the whole energy system in the car to save energy,’ explains Skellern. ‘And the savings are not trivial. General Motors has recently estimated that you might save 15 to 20 per cent, or something of that order of magnitude, by being able to alter the energy usage in the car during a braking circumstance.’

  And Lachlan Andrew and his colleagues at Swinburne University have also been researching ways in which the efficiency of personal computers can be improved, without getting people’s backs up. ‘Computers can run much faster at a peak speed than they often need to in quiet times,’ says Andrew.

  And so one of the things we’re looking at is optimally controlling the speed at which computers run, so that they’re only running as fast as they need to at a given time. And this can save a lot of energy in the quiet times, but still give reasonable performance in the peak times when it’s really needed.

  It’s a noble cause, but Dr Andrew is well aware that it’s also a difficult one to realise, given human nature. ‘It’s a very fine line to tread,’ he agrees.

  It’s important the user experience not be significantly harmed by the techniques we’re introducing. It’s important that the user experience be as if computers were running at full speed all the time. But at the same time, if people aren’t aware of the resources that are being consumed, then we run the risk of encountering Jevons Paradox, which says that if we make something more efficient, then it becomes cheaper to provide, and so the total amount of energy that is used in the system might actually increase as a result of energy-saving measures. Many people are concerned that is happening with IT already. If we make computers more efficient, then it’s going to dramatically increase the amount of computing that’s done, which will potentially increase the
total amount of energy consumed.

  And around we go again.

  Human induced

  Moving parts

  Home-making

  Alimentary thinking

  Emma Young

  It’s been a tough morning. You were late for work, missed a crucial meeting and now your boss is mad at you. Come lunchtime you walk straight past the salad bar and head for the stodge. You can’t help yourself – at times of stress the brain encourages us to seek out comfort foods. That much is well known. What you probably don’t know, though, is that the real culprit may not be the brain in your skull but your other brain.

  Yes, that’s right, your other brain. Your body contains a separate nervous system that is so complex it has been dubbed the second brain. It comprises an estimated 500 million neurons – about five times as many as in the brain of a rat – and is around 9 metres long, stretching from your oesophagus to your anus. It is this brain that could be responsible for your craving under stress for crisps, chocolate and cookies.

  Embedded in the wall of the gut, the enteric nervous system (ENS) has long been known to control digestion. Now it seems it also plays an important role in our physical and mental well-being. It can work both independently of and in conjunction with the brain in your head and, although you are not conscious of your gut ‘thinking’, the ENS helps you sense environmental threats, and then influences your response. ‘A lot of the information that the gut sends to the brain affects well-being, and doesn’t even come to consciousness,’ says Michael Gershon at Columbia-Presbyterian Medical Center, New York.

  If you look inside the human body, you can’t fail to notice the brain and its offshoots of nerve cells running along the spinal cord. The ENS, a widely distributed network of neurons spread throughout two layers of gut tissue, is far less obvious, which is why it wasn’t discovered until the mid-19th century. It is part of the autonomic nervous system, the network of peripheral nerves that control visceral functions. It is also the original nervous system, emerging in the first vertebrates over 500 million years ago and becoming more complex as vertebrates evolved – possibly even giving rise to the brain itself.

  Digestion is a complicated business, so it makes sense to have a dedicated network of nerves to oversee it. As well as controlling the mechanical mixing of food in the stomach and coordinating muscle contractions to move it through the gut, the ENS also maintains the biochemical environment within different sections of the gut, keeping them at the correct pH and chemical composition needed for digestive enzymes to do their job.

  But there is another reason the ENS needs so many neurons: eating is fraught with danger. Like the skin, the gut must stop potentially dangerous invaders, such as bacteria and viruses, from getting inside the body. If a pathogen should cross the gut lining, immune cells in the gut wall secrete inflammatory substances including histamine, which are detected by neurons in the ENS. The gut brain then either triggers diarrhoea or alerts the brain in the head, which may decide to initiate vomiting, or both.

  You needn’t be a gastroenterologist to be aware of these gut reactions – or indeed the more subtle feelings in your stomach that accompany emotions such as excitement, fear and stress. For hundreds of years, people have believed that the gut interacts with the brain to influence health and disease. Yet this connection has only been studied over the last century. Two pioneers in this field were American physician Byron Robinson, who in 1907 published The Abdominal and Pelvic Brain, and his contemporary, British physiologist Johannis Langley, who coined the term ‘enteric nervous system’. Around this time, it also became clear that the ENS can act autonomously, with the discovery that if the main connection with the brain – the vagus nerve – is severed the ENS remains capable of coordinating digestion. Despite these discoveries, interest in the gut brain fell until the 1990s when the field of neurogastroenterology was born.

  We now know that the ENS is not just capable of autonomy but also influences the brain. In fact, about 90 per cent of the signals passing along the vagus nerve come not from above, but from the ENS.

  The second brain also shares many features with the first. It is made up of various types of neuron, with glial support cells. It has its own version of a blood-brain barrier to keep its physiological environment stable. And it produces a wide range of hormones and around 40 neurotransmitters of the same classes as those found in the brain. In fact, neurons in the gut are thought to generate as much dopamine as those in the head. Intriguingly, about 95 per cent of the serotonin present in the body at any time is in the ENS.

  * * * * *

  What are these neurotransmitters doing in the gut? In the brain, dopamine is a signalling molecule associated with pleasure and the reward system. It acts as a signalling molecule in the gut too, transmitting messages between neurons that coordinate the contraction of muscles in the colon, for example. Also transmitting signals in the ENS is serotonin – best known as the ‘feel-good’ molecule involved in preventing depression and regulating sleep, appetite and body temperature. But its influence stretches far beyond that. Serotonin produced in the gut gets into the blood, where it is involved in repairing damaged cells in the liver and lungs. It is also important for normal development of the heart, as well as regulating bone density by inhibiting bone formation.

  But what about mood? Obviously the gut brain doesn’t have emotions, but can it influence those that arise in your head? The general consensus is that neurotransmitters produced in the gut cannot get into the brain – although, theoretically, they could enter small regions that lack a blood–brain barrier, including the hypothalamus. Nevertheless, nerve signals sent from the gut to the brain do appear to affect mood. Indeed, research published in 2006 indicates that stimulation of the vagus nerve can be an effective treatment for chronic depression that has failed to respond to other treatments.

  Such gut-to-brain signals may also explain why fatty foods make us feel good. When ingested, fatty acids are detected by cell receptors in the lining of the gut, which send nerve signals to the brain. This may not be simply to keep it informed of what you have eaten. Brain scans of volunteers given a dose of fatty acids directly into the gut show they had a lower response to pictures and music designed to make them feel sad than those given saline. They also reported feeling only about half as sad as the other group.

  There is further evidence of links between the two brains in our response to stress. The feeling of ‘butterflies’ in your stomach is the result of blood being diverted away from it to your muscles as part of the fight-or-flight response instigated by the brain. However, stress also leads the gut to increase its production of ghrelin, a hormone that, as well as making you feel hungry, reduces anxiety and depression. Ghrelin stimulates the release of dopamine in the brain both directly, by triggering neurons involved in pleasure and reward pathways, and indirectly, by signals transmitted via the vagus nerve.

  * * * * *

  In our evolutionary past, the stress-busting effect of ghrelin may have been useful, as we would have needed to be calm when we ventured out in search of food, says Jeffrey Zigman at UT Southwestern Medical Center in Dallas, Texas. In 2011, his team reported that mice exposed to chronic stress sought out fatty food, but those that were genetically engineered to be unable to respond to ghrelin did not. Zigman notes that in our modern world, with freely available high-fat food, the result of chronic stress or depression can be chronically elevated ghrelin – and obesity.

  Gershon suggests that strong links between our gut and our mental state evolved because a lot of information about our environment comes from our gut. ‘Remember the inside of your gut is really the outside of your body,’ he says. So we can see danger with our eyes, hear it with our ears and detect it in our gut. Pankaj Pasricha, director of the Johns Hopkins Center for Neurogastroenterology in Baltimore, Maryland, points out that without the gut there would be no energy to sustain life. ‘Its vitality and healthy functioning is so critical that the brain needs to have a direct and
intimate connection with the gut,’ he says.

  But how far can comparisons between the two brains be taken? Most researchers draw the line at memory – Gershon is not one of them. He tells the story of a US army hospital nurse who administered enemas to the paraplegic patients on his ward at 10 o’clock every morning. When he left, his replacement dropped the practice. Nevertheless, at ten the next morning, everyone on the ward had a bowel movement. This anecdote dates from the 1960s and while Gershon admits that there have been no other reports of gut memory since, he says he remains open to the idea.

  Then there’s decision-making. The concept of a ‘gut instinct’ or ‘gut reaction’ is well established, but in fact those fluttery sensations start with signals coming from the brain – the fight-or-flight response again. The resulting feeling of anxiety or excitement may affect your decision about whether to do that bungee jump or arrange a second date, but the idea that your second brain has directed the choice is not warranted. The subconscious ‘gut instinct’ does involve the ENS, but it is the brain in your head that actually perceives the threat. And as for conscious, logical reasoning, even Gershon accepts that the second brain doesn’t do that. ‘Religion, poetry, philosophy, politics – that’s all the business of the brain in the head,’ he says.

  Still, it is becoming apparent that without a healthy, well-developed ENS we face problems far wider than mere indigestion. Pasricha has found that newborn rats whose stomachs are exposed to a mild chemical irritant are more depressed and anxious than other rats, with the symptoms continuing long after the physical damage has healed. This doesn’t happen after other sorts of damage, like skin irritation, he says.