teachers notes - HarperCollins Publishers

---

Author’s Notes for Teachers and Students

The Tomorrow Book, by Jackie French, illustrated by Sue DeGennaro (Released 1 February 2010, published by HarperCollins Publishers Australia)

Introduction: How you can change the world Think about tomorrow. Not the tomorrow you think could happen, the tomorrow that you read about in newspapers and see on TV. Think about the tomorrow you’d like to see. What would you like the world to be in twenty years? Or thirty? Or forty? The future is never what we expect it to be. When I was very young there were no TV sets, no small powerful computers, no mobile phones. Then in just a few decades, things changed in ways no one ever expected. Just one person can change the world with an invention — or by manufacturing someone else’s invention and selling it or explaining it to others so they can use it. When I was a child about six tonnes of soil was lost for every tonne of wheat grown. About thirty years ago I helped work out ways that pests and weeds could be controlled without the deadly poisons used on most farms and gardens, and how crops could be grown without digging the soil to dust several times a year. I was just one of many people doing this — but together we changed the world. You can change the world too. First you need to dream of what it can be; then you need to find ways to make that happen. Most of all, you need to believe that change can happen. Our planet faces huge problems: the world is warming, the ice caps are melting and seas are rising. Large parts of the world’s farmland may be under water within thirty years; so may many of the world’s largest cities. Climate change is altering weather patterns, making some places hotter and drier, and generating more severe storms and bushfires. Even without global warming, our world is in a mess: literally. The air in many big cities isn’t safe to breathe. Large parts of our oceans are dead: so polluted that nothing lives in them. Poisons from plastics and other dangerous rubbish are causing health

problems. Many species have died out, or are dying … I know it sounds bad. BUT … Scientists and engineers and inventors have already worked out ways to solve every problem on our planet. It’s not difficult to find these solutions, either: you’ll find most of them in magazines and books in your local library. So why aren’t governments saying: ‘Right, let’s make the world perfect — now!’? I think there are probably many reasons. Politicians are often so busy in their dayto-day work that they don’t have time to study research papers and magazines and find out what’s really possible. They are also afraid that if they try to change the world too much people may be scared, as change can be unsettling. But politicians are faced with another big problem. Some of the biggest industries on our planet — the ones that build coal-fired power stations, or make plastics out of petroleum, petrol-driven cars, or weapons for the type of war I hope will never happen — also employ enormous numbers of people. If all these people suddenly lost their jobs, they couldn’t afford to pay their mortgages or rent or buy food. The polluting factories or power stations cost large sums of money to set up, too. If our Prime Minister said, ‘Right, no more coal mining, no more coal-fired power,’ it would mean that most Australians would have to change their lives dramatically — and it would cost them a lot, personally. They might think twice about voting that government back into power. Or would they? Politicians mostly do what people want. If we all show that we want the world to change, then hopefully politicians will get the message. New ways of doing things can be introduced over years, so people have time to prepare for them. The new industries will employ people, too- possibly even more than before, as new industries take more workers to set up. And they can make the world a lot more fun. There are so many bad things we take for granted now: polluted air over our cities, few places to play and roam around, no wild animals to watch, cramped planes and traffic jams, fruit that has been stored so long before it reaches the supermarket that it’s lost its taste.

If we don’t create a new future the world is still going to change. Mostly, it will get hotter (though some parts will get colder). The air will be get steadily worse to breathe; the oceans will cover parts of the world as the ice melts; there’ll be more bushfires and wilder storms, more deserts where much of the world’s wheat and other crops are grown now. It won’t be a nice world. But it doesn’t have to be like that. Tomorrow is ours — to make and to change. Tomorrow can be very good indeed.

A few ways you might change the world 1.

Start your own business.

If you think you could run a business — do it! Maybe you can repair things, from bicycles to computers to mobile phones. My washing machine is twenty-six years old; my mobile phone is twelve years old. I just keep getting them repaired! Maybe you could create stunning clothes out of garments that have gone out of fashion, or even been thrown away. Perhaps you could make wooden furniture so beautiful that it will be kept and loved for many years by future generations. (Wood ‘locks up’ some of the CO2 that warms our planet, making it a great product to use and reuse.) Maybe you could build true solar cars (see below) or solar-powered bicycles with sidecars or gas and solar aircraft, taking people to other countries in space and comfort instead of the cramped planes we have to travel in now. You could travel in ships with sails designed so that you can take giant loads of freight to Europe in a couple of weeks, instead of the nine months it used to take sailing ships to reach there. Scientists, engineers and inventors give us new ways to do things. But the people who put those new systems into practice are just as important. 2.

Read and research.

Read magazines like New Scientist, not only to find out about new inventions, but also to discover how things work and why, in ways we never knew before. Read magazines like EarthGarden, which has articles written by people actually

practising what they preach. Articles that will show you how individuals can build their own ‘green’ houses or make their own electric cars or carts or solar-powered bicycles — using methods that you can use, too. Many of these also cost much less than ones you could buy. 3.

Dream of the future you want — and make it happen with your friends.

Find friends who believe in the things you do, who’ll work with you and support you. (Every genius needs someone to say ‘keep going’. Every person who wants to make the world better needs someone to say, ‘What you’re doing is good. Keep going.’) Don’t forget the little changes, like repairing things or making new from old, while you continue to plan and plot the big things. Always remember: the way we do things now isn’t necessarily the best way. Keep your minds and your hearts free to change, if change is needed. But most of all — have fun. Tomorrow needs to be much more fun than today. For me the best times are having lunch with my friends, cooking for them, growing food to feed us all, watching the wombats munch and the trees blossom. Long ago I worked out the life I wanted — and it’s pretty much the way I live now. I grow much of my own food, I share my world with animals, I use solar electricity to run my computer and DVD player. My luxuries are new apple trees for my garden, paintings I love or the sort of books or presents for friends that will last for 500 years. Yes, it is possible to live happily and richly without hurting the world — and even helping to cure some of the damage humans have made. This is my today, and I hope my tomorrow too.

More practical ways to change the world 1. Power The problem: Most of the world’s power comes from giant power stations. Some are run on hydropower, where water turns turbines. But we are running out of water because of decreasing rainfall and snow-fall and because there are so many of us. In some places industry is using most of the water for things like mining, and in some countries for

nuclear power stations. In other places, like much of Australia, climate change has meant there just isn’t as much rain as there was when the power stations were built. Most power stations though are run on what are called ‘fossil fuels’ — coals and oil that were once masses of minute micro-organisms in shallow seas or giant ancient forests, compressed into the fuel we use now. (Petroleum is also used to manufacture many of our plastics, like the plastic most of your computer is made of, parts of your car or furniture and even clothes.) As we burn the coal and petrol to create electricity, they release CO2. Large amounts of CO2 create a blanket effect that traps heat from the sun in the atmosphere, when it would otherwise be reflected back out into space. This blanket changes the temperatures of our world, affecting the complex interplay of wind, water, sea currents, moisture and dryness that make up our global weather. The world as a whole gets hotter, but some parts will get much colder; other parts will get wetter or dryer, and some places will get hotter in summer but colder in winter, too. There are many, many ways things that produce CO2, and other pollutants add to ‘global warming,’ too. But there are two enormous CO2 producers that make all the rest look tiny. These are cola, gas and deisel and other ‘fossil fuel’ power plants, and transport. Power plants produce about 40 per cent of global CO2; cars and other forms of transport produce about 30 per cent. If we could stop relying so heavily on ‘fossil fuels’ for power and transport we’d slow down global warming significantly. Fossil fuel power stations make the world more polluted, too, because as well as Co2, they emit various smokes and gases that turn the land and air acid and kill forests and other plants, or cause lung disease or other illnesses. Most big power stations, including nuclear ones, use enormous amounts of water, too-many farming areas across the world are desperate for water because so much is taken for cooling in the power stations. Big power plants, too, transport their electricity thousands of kilometres on vast electric grids, where about 40% of the electricty is lost. There are so many other ways to generate power, which, combined, are already efficient enough to give us the power we need. We can have local and community power plants, too, so that we don’t need to produce so much power, or

power stations that just switch on when there is a high demand for power. And if we keep working on the problem, we’ll find new and even better ways to produce, store and transmit power too.

Solutions: There are many, many ways that we can create the power we need to run our houses or tools, our factories, our cars. These are just a few of them. a) Photovoltaic power (i)

Solar panels

Photovoltaic power comes from solar panels — not the sort of solar panel that heats up water but panels that generate electricity. We’ve been running our house on solar power for more than two decades, but you can’t just swap from ‘mains’ power to solar power without spending a lot of money. Our household is designed so we use a tiny fraction of the power that most people need. We also use appliances that don’t use much power: energy efficient computers, DVD screen etc. I even use a solar oven that cooks with the sun’s heat. We don’t ‘transport’ power every far, either, so wwe don’t lose a lot. Most ‘solar’ houses, including ours, store the power in batteries so that our house has power even when the sun isn’t shining (we have enough for about two weeks). Photovoltaic solar power is best for what are called ‘stand alone’ systems — power just for one or maybe a small cluster of houses. It’s more efficient to have tiny power generators, like solar panels or wind generators on every house, or for a small group of houses, because giant power stations lose up to 40 per cent of the power they generate as the power travels along the electricity lines. In some circumstances solar may be also the most efficient system for community power stations that rely on renewable energy sources. The Bega Valley in NSW has just finished a year-long feasibility study for a community power farm — comparing solar (of various forms) and wind. They decided that the best and cheapest was solar power. But still I read (and hear) that ‘solar just isn’t a viable alternative’. People have

even sat at our table, under the solar-powered lights, eating the dinner I cooked in my solar oven (it concentrates the sun’s rays so you don’t need gas, wood or electricity — just put it out in the garden) and eating ice cream made with solar power to churn and freeze it, telling me it was impossible to live on solar power alone. Of course it is possible! And it’s also possible to be attached to your local electricity grid (which is what the power-station electricity travels on) and have solar panels. All Australian states and territories now have feed-in tariffs which vary from state to state. Systems like this mean that if you need lots of power for short periods of time you can take it from the grid, but otherwise you just use the electricity generated on your roof. (ii) Solar walls and roofs using new flexible solar technology Building and roofing panels made of solar cells have been invented, but aren’t available to buy yet. If all our roofs were made of solar panels we’d have enough power to run the house as well as store for other uses. Australian scientists at CSIRO are also developing rolls of flexible solar cells. The thin plastic cells could be attached to walls, roof, even your car. You could even wear or carry them to power a tiny air-conditioning plant to keep you warm or cool or to charge your mobile phone or power a GPS system. The cells are even thin enough to be used as windows in houses — so large windows could generate the power for a house, or the windows in an office block could power all the lights and computers there. The new solar cells are so light they could even float on water, so that we could have giant solar-generating plants on the sea. They’d even stop evaporation, so floating them on dams and swimming pools would also help our water supply. Other scientists have invented solar panels that are so thin they could be printed in much the same way as paper in a printer. We could cover every surface of our houses in solar panels! But first we need a company that will invest enough money to make them — and for that you require confidence that there will be a market for these products. Sometimes, too, the rights to these inventions are bought up by companies that have a lot of money invested in coal or petroleum so they can control what happens to them.

Solar-powered/photovoltaic fabric has also been invented — imagine if, in the future, you might fly on giant solar-powered wings, with your trousers generating enough power for small solar-powered jets to speed you along. (iii) Better solar cells Solar electric/photovoltaic cells don’t use all the energy from the sunlight that falls on them. Scientists in China and Japan studied heat-absorbing butterfly wings to invent a coating that allows solar cells to absorb about 96.21 per cent of sunlight — far more than they usually do. This coating isn’t available yet, but it’s going to make solar panels a lot more efficient, and produce much more power in a small space. (iv) Cheaper solar cells But the real problem with solar/photovoltaic cells is that they are expensive, and they may only last a few decades. (Our 30-year-old ones still produce electricity.) Canadian scientists at the University of Alberta and the National Research Council’s National Institute for Nanotechnology have invented solar panels made of plastic. They estimate that these will be 30 per cent cheaper than the ones made from metal and eventually even cheaper, so that every household or business could have a device that looks a bit like a printer — but prints out solar cells instead of paper.

b)

Biofuels

Sugar cane and sugar beet can be turned into jet fuel or bio-diesel that will run cars and trucks and power stations. The trouble is that crops like these use valuable land that could be used for food production. The world’s poor may starve while the richer countries use their land to grow their fuel. But other scientists are working out ways to make bio-diesel from algae. This would grow in shallow lakes, or even in salt water — and would trap CO2 from the air to do it. That CO2 would be released again when the fuel is used. It would therefore still be ‘carbon neutral’, i.e. it wouldn’t contribute to global warming because it would use about the same amount of CO2 that it produces. In California, they are already trialling algal ponds that collect the waste from feed-lots and turkey farms and convert it via algae into bio-diesel.

c)

Wind power

Giant wind farms have received a lot of criticism from people who don’t want to live near them, because of the high-pitched noise they make. But wind farms produce a lot of energy and they can be off-shore or in places where there are few people. The new generation wind generators are also capable of producing much lower noise levels than the old ones — the wind in the grass makes more noise than the wind generators at Australia’s biggest wind farm on hills near Ballarat in Victoria.

d)

Solar thermal electricity

Rows of mirrors focus sunlight onto water; the water turns into high-powered steam that drives turbines to produce electricity. The water can then be used again and again to create new power, unlike hydro-power where you need lots of running water. 500 power stations, each covering a quarter of a kilometre, could give us all the power we need in Australia. There is already a demonstration plant at the Liddell Power Station in NSW. It would cost a lot to set up a solar thermal power station, but less than the cost of a new coal-fired power station, and there wouldn’t be as many ongoing costs- or as much pollution.

e)

Algal diesel

Usually coal-fired power stations are an eco disaster. But just possibly they could be made much, much better. Currently there is some work being done on finding a way to use a power station’s CO2 to grow algae to process into fuel. The CO2 is siphoned from the power station and pumped into ponds where it feeds algae. It’s estimated that about 30 per cent of the algae produced has been turned into either bio-diesel or animal food. Other experiments are being performed, growing different forms of algae to make fuel, including fuel for planes, though much work is needed on this.

f)

Other power generation ideas

There are many other ways power can be generated. My husband, Bryan, built a

water wheel to give us power whenever the creek runs (which unfortunately isn’t often, these days). You can also make a tiny hydro station with the water from your house water pipes pushing a rotating ‘Pelton wheel’ to generate power. In Africa you can buy pedal-powered computers and radios and TV sets: if you want to watch TV, just get pedalling. (It keeps you fit, too!) There are many torches, radios and even mobile phone chargers that operate by being wound up and that give you a couple of hours of light or sound for the couple of minutes it takes you to wind them up. There’s wave power, deep thermal power, algal power and methane from garbage tips, abattoirs and sewerage works which can be isolated and used — either directly as gas or by burning the gas to produce electricity. [end number list B]

Things to think about: •

Try to count how many ‘alternative’ ways to produce electricity you can find (if anyone reaches over 100, email me and I’ll send you a book).

•

Hunt around your area for people who run their houses on ‘alternative’ power.

2.

•

Work out the best way to power your neighbourhood.

•

Plan the house and power system you’re going to have when you’re an adult.

Houses: Heating and cooling

The problem: Houses that need lots of energy to make them hot or cold. Most of our houses need lots of power to make them comfortable. They need to be heated in winter, cooled with air conditioning in summer. You need giant fridges to keep food cool, and electric or gas ovens to cook your dinner. Today’s houses are often very big. Australia’s new houses are among the biggest in the world — so big that often don’t leave much space to play outside — just tiny yards where the neighbours can see everything; nowhere you can have space just for yourself and maybe some animals too.

It doesn’t have to be like that.

Solutions: a)

Build houses that suit the climate — not the same style of house from Darwin to Hobart. Have you ever walked into a big old building in midsummer that was gloriously cool? That’s because in the days before air-conditioning houses were more often designed to suit the climate. (Many of those same houses would be extremely cold in winter … but if they had solar hot water stored in their roof area they could be kept warm by circulating hot water in pipes through the building). Houses in hot areas were often built on stilts, so they’d cool down fast at night. They had big verandahs to keep off the sun, palm trees in the garden to shade the windows but still let in breeze, lattice-work above the doors to let any breeze through the house too. They were built of light-weight materials so that they would cool down rapidly once the sun went down. When I was a child growing up in Queensland nearly all of the houses were suited to the summer weather — built of weatherboard, surrounded by airy verandahs — and we could play in the cool ‘under the house’ too. Then suddenly suburbs of new brick houses started springing up, much more suited to colder climates. People needed air-conditioning to keep comfortable. When I went south to my grandmother’s house, it was designed for a cold climate, with thick walls to retain the heat from fireplaces and two layers of curtains to keep the warmth in at night — as well as keeping the heat out in summer. Houses had high roofs to insulate the rooms below and most had much higher ceilings than modern houses too. We need to go back to well-designed houses that suit the climate and the individual site now more than ever before and stop building houses that may be economical to build, but not necessarily good to live in. There are many, many alternative ways to build and live in your home. Take some time now to think about whether you’d like to live in a house with any of these: •

A house built on big underground water tanks, with solar pumps and water pipes

going through every wall and under the floors. In winter the water is piped up through a roof of solar water panels that heat the water, so warm water flows through the house. The walls and the floors are warm all though winter. In summer the cold water from the underground cisterns is pumped around instead — and every wall and floor is cool. This is controlled by a house computer. If the house is hotter than 22ºC it cools it down, if it’s colder it heats it up. The water ends up in a big swimming pool, warm in winter and cool in summer. I actually know the people who live in this house — they also have vents near the floor that whoosh in air when you flick a switch so you don’t have to vacuum either, and a big wall of windows that are computer controlled so they open if a breeze is needed and shut if it’s cold. And the computer works out exactly what angle the louvre windows need to be to get the maximum breeze to flow through the house ... •

A house built around an indoor courtyard, replacing an outside yard. In winter the courtyard is covered with glass, to trap heat to warm the house; in summer it’s covered with a shade roof. Having a swimming pool in the courtyard means that breezes through the house evaporate some of the water, cooling the house down in summer; the water then condenses on the domed roof and trickles down to channels which take it back to the pool. In winter, the pool is warmed by solar hot water panels and the big area of warm water helps warm the house.

b) Changes we can make to existing houses to make them more comfortable to live in: •

Have thick curtains with linings that reflect heat in summer — pull them across in the day in summer to keep heat out, and then open them at night to let the cool air in. In winter, keep them open during the day and close them at night.

•

Have pelmets — coverings on top of the curtains that keep heat in and out too.

•

Have awnings to lower over windows in summer.

•

Insulate the walls, roof and floor, so that houses stay either cool or warm.

•

Have windows right up near the ceiling, or extraction fans in the ceiling cavity. As soon as the air outside is cooler than inside, open up all the doors and windows

(you can have security screens if you are worried about intruders) so that the house can cool down. In winter, do the opposite — open all the windows when the air outside is warmer than indoors. •

Change to solar hot water, heated by panels on the roof.

•

Leave trays of water near open windows. The evaporation will cool the house.

•

Grow trees suited to your climate. In hot humid areas you need tall trees that will shade the roof, but leave the garden below open so breezes can get through to the windows. In most of Australia, try deciduous trees — ones that are green and leafy in summer and shade your house’s roof and walls, then lose their leaves in winter to let the sunlight in.

•

Paving around your house will warm you in winter. It’ll make your house hot in summer, too, unless it’s thickly shaded by a deciduous vine like grapes, hops or kiwi fruit.

3. Bushfire Protection The problem: Houses that aren’t bushfire proof. Our house isn’t bushfire proof — I built it many decades ago, when the bushfire threat was much less than in today’s hotter, drier world. Our house could withstand a ‘moderate’ fire, but not a ‘catastrophic’ one, with the extreme winds and fierce unstoppable flames Australia has experienced in the last decade. So one day our house, deep in a valley of tall trees, may well be burnt down. And then we’ll build a house that won’t burn. How? It’ll be built mostly of materials that can’t burn, like rammed earth or bricks made from material fired at high temperatures, which won’t burn any more. And part of it will be covered by a thick layer of soil — a big mound with lots of windows. The windows will have steel or thick hardwood shutters that can be closed down if there is a fire nearby. Houses like this are cool in summer and warm in winter — the sun streams through the windows and the heat is trapped by the thick layer of earth. In summer the windows are

shaded, as the sun is higher in the sky, so the house never heats up. Think what the suburbs would be like if all the houses were underground, with just the windows opening onto the world? There’d be masses of room on top to play, to have gardens, to grow fruit trees, and much more room for animals. You don’t feel like you’re underground in houses like this because of the windows. Once you are indoors it just feels like any other house. But suddenly you have freed up almost the whole of your land to grow things and play in. Another bushfire-proof house design has a low-roofed house with what looks like a great big shed over it. The second roof helps keep the house cool in summer, but in bad bushfire weather fine wire netting can be let down to totally protect the house below from burning embers as well as a lot of the heat from the bushfire. In winter, when the sun is lower in the sky, the sun will warm the house below.

Things to think about and do: •

Find out what materials don’t burn. How many could be used to build a house?

•

Find out if there are any underground houses in your area. You may be surprised at how many are around.

•

4.

Look at magazines like Owner Builder and Alternative Technology magazines.

Plastics manufactured from petrol

The problem: Plastics based on petroleum that pollute the world and help warm it up, as well. Since 1976, plastic has been the most commonly used material in the world, for everything from clothes to car parts to TVs, computers, even to make new knees and hips and other worn-out bits of the human body. Modern plastics are mostly based on petroleum. These plastics are harder and sometimes more flexible than rubber, which is made from the sap of the rubber tree, and lighter and more flexible than metal. But they are very polluting, and often toxic as they break down, as well as contributing to global warming because they too are made from petroleum, and so release large amounts oif CO2.

Solution: Make eco-friendly ‘natural’ plastics from plants and animals, like the casein you probably ate for lunch. Casein is the protein in milk, so if you had cheese or butter or milk or yoghurt or an iceblock, ice-cream, biscuit or muffin or bread or margarine that had milk as one of the ingredients you ate casein! Plastics made from plants and rubber-like substances are the best possible solution. Plants trap carbon from the air, so when we make things from plants — as long as they last for a long time — we’re reducing the CO2 that is one of the main culprits in global warming, instead of releasing more CO2 as we do when we use anything based on petroleum. One plant that might be used to make the rubber of the future is genetically engineered dandelions. A hectare of genetically modified dandelions could produce 500 to 1000 kilograms of latex that could be used to make everything from gloves to tyres and drugs. Compared with ordinary dandelions the engineered variety produce five times as much white sap (the latex), and it stays liquid longer, making it much easier to use. Australian scientists studying lacewings — tiny winged insects — have found that lace wing ‘silk’ used to hold its eggs is tougher and stretchier than the silk from silkworms. They think it may be possible to duplicate the lacewing silk artificially by fermentation in bacteria. But there are many, many experimental forms of plastic based on everything from sewage to crab or yabbie shells. Again, these would all ‘lock up’ CO2 while breaking down into substances that won’t pollute the earth and kill living things. The Cooperative Research Centre for Sugar Industry Innovation is experimenting with making biodegradable plastic made from genetically modified sugar cane, that makes a plastic in its leaves. We could have sugar from the sap, and plastic from the leaves.

How to make your own Plastic Home-made plastics below are all biodegradable — in other words, if they get wet or buried in soil for a long time they’re going to dissolve. This is great if you just want to use your plastic once or twice, to store your food or as disposable plates or wrapping and then let it

rot — it won’t leave lots of mess, and sea birds and animals won’t eat it and die, which is what happens to lots of other plastic mess. Hard durable plastics can be made too, using everything from human sewage (otherwise known as poo) or even crab shells. But you can’t make any of these hard plastics at home or in your classroom — some need too much equipment and others might accidentally digest your teacher or parts of your school — which might not be a good idea. Making plastic from sewage, for example, needs really high temperatures — more than six times higher than you’ll get with a stove or barbecue fire. (Though you can reach these temperatures by focusing the rays of the sun, so you don’t use lots of ‘bad’ power to make them.)

(a)

How to make your own milk plastic

Milk plastic was used to make aircraft windows in World War II. Casein — the protein in milk — is made up of small amino acids with the order repeated over and over — this is called a polymer. You need: 2 cups of full cream milk (not skim milk) 3 tbsps of vinegar a saucepan a wooden spoon a sieve a bowl another 1 tbsp of vinegar a jar (For children: an adult to help you)

First of all we need to separate the casein from the rest of the milk.

Step 1. Heat the milk till it begins to bubble just at the edges. Turn it off NOW — don’t let it boil.

Step 2. Pour in the vinegar. Step 3. Stir it all around twenty times. Step 4. Wait till it’s cool! Step 5. Pour the milk through the sieve into a bowl. It should have turned into a mixture of lumps and watery ‘gunge’ — the lumps are curds and the watery stuff is whey, just like little Miss Muffet ate her curds and whey. The curds are the casein and the whey is what’s left over. (The curds can also be made into cheese, but not if you’re using them to make plastic.) Step 6. When all the whey has dripped down into the bowl, scrape the curds into the jar and add the other tablespoon of vinegar. Leave for an hour. Step 7. Tip the curds out into your hand and squeeze out all the liquid you can. You’ll be left with a whitish yellow lump. Step 8. Wash the lump under the tap, and squeeze out as much liquid as you can (again).

Congratulations! You’ve made plastic! You can press it into a mould or cut it into shapes, then let it dry. If you want to keep it for more than a few days you’ll need to paint it with a waterproof lacquer.

(b)

Gelatine Plastic

Gelatine is what sticks jelly together. All bones and other bits of animals contain gelatine and you can get it from some seaweeds and beans too. If we grow perennial beans (ones that crop for decades instead of having to be planted every year) or grow the seaweed in giant shallow pools, we’ll also be capturing CO2 from the air to help stop the planet warming up.

You need: 3 envelopes (10 g each) of powdered gelatine (from bones) or agar (from seaweed or various algae) 3 drops food colouring (you don’t really need this but it can be fun) 9 tbsps water

an old margarine or butter container scissors a metal teaspoon a wooden spoon (For children: an adult to help you)

Step 1. Put the gelatine and water in the saucepan and heat and stir till the gelatine dissolves. Now stir over a low heat for three minutes. You don’t need to boil it. Step 2. Pour into the margarine or butter container and drip in the food colouring. Stir it in with the teaspoon — be careful, as the food colouring will stain your fingers or wood or paper! Step 3. Wait! The mix will set in about an hour. Step 4. Turn out your plastic! Cut it into any shape you want. (Small coloured half moons and other shapes are fun, then you can string them together and hang them up. But if you’re going to hang them up put a small hole in each shape NOW, as they’re going to get hard over the next few days.) Step 5. Wait again! Your soft plastic will turn hard — though if it gets too wet it will soften again.

(c)

Cornflour Plastic

You need: 3 tbsps cornflour 6 drops corn or other edible oil 2 drops of food colouring (any colour) 2 tbsps water 1 freezer bag — Ziplock is good A microwave A helpful adult

Step 1. Place all ingredients in the freezer bag.

Step 2. Close up the bag then squeeze the bag to mix the ingredients — this way you don’t get mess on your hands. Step 3. Open the bag again. Step 4. Place it in the microwave oven. Step 5. Put the microwave on HIGH for 25 seconds. Step 6. Be careful — this stuff is HOT! Take it out using an oven mitt and let it cool a bit so you can handle it. Even better, leave it in the microwave for half an hour with the door open so it cools before you touch it. Step 7. Make your ‘cornflour’ plastic into any shape you want. (This stuff makes great beads — make sure you put a hole in them before they harden!) Step 8. Leave the shape a few days to dry. [end number list B]

5.

Petrol- and diesel-guzzling cars

The problem: Cars that use lots of expensive petrol or diesel and pollute as well as warm up the world … and cause traffic jams that mean it takes forever to get across a city to go to the beach.

Solutions: a) Bio-bikes It takes much less fuel to run a motorbike than a car as it’s smaller. A motorbike can easily carry two people, or three or four if you use a sidecar. A former oil driller Paul Carter set off around Australia on his ‘bio-bike’ on 23 September 2009. Betty the Bio-bike was created by students at the University of Adelaide, and runs on plant oils and animal fats that have been used to fry chips and other fast food — a way to use up polluting fats and oils as well as having low emissions. While many other people have created ‘bio-bikes’ Betty is legally registered and insured. Betty travels at about 80-90 km per hour.

b) Electric cars Electric cars don’t send out toxic exhaust smoke and, if the electricity they run on has been sustainably produced, they are pretty planet-friendly, especially if they are made of new safe plastics. Humans came to drive mostly petrol-powered cars pretty much by accident. Early motorcars were either electric or petrol driven. In 1908 Henry Ford invented ‘mass production’ — factories with giant conveyor belts along which each person did a specific job instead of building the whole car — and the price of a motorcar fell to the point where ordinary working people could afford them. Henry Ford’s cars were about half the price of an electric car when he first started selling them but the price continued to fall until it was only about an eighth of the price, although his wife bought a Detroit Electric car for herself as she found her husband’s petrol-driven cars too noisy! Henry Ford’s petrol-driven models became so popular that the electric cars were no longer made, even though they were probably better cars. Way back in 1914 the Rauch & Lang brougham car seated four people and could go at 50 kph for about 130 kilometres without being recharged. Many of today’s electric cars look pretty much like ordinary cars, but they run on electricity instead of petrol. There are many ‘hybrid’ cars around that run on a combination of petrol and electricity, but there are still very few on the roads that run solely on electricity. Most electric cars have their power stored in batteries, so they need to be recharged. If the electricity they use is from coal, the environment still doesn’t benefit greatly. But if the power comes from solar or other sustainable sources, then the car can be said to be running on alternative power. A few solar car models have their own solar panels and don’t need batteries recharged … but they rely on light to power them. Some mechanics will change your car from a petrol to an all-electric one. It costs about ten thousand dollars. Car manufacturers are also working on electric models from scratch. These also use new light materials, like plastics, and have sophisticated computer systems to make everything run as efficiently as possible, so the vehicles need less power. One new solar electric car model was made by 35 University of Sydney first-year engineering students in 2009, supervised by engineering Professor Michael Roberts. Their

‘Mango’ car is all-electric, has no heavy mechanical brakes, gear box, axles or differential. It’s so light that two people can pick it up, so it uses less power than a heavier car would, and goes faster, too. It has a 48-volt lithium battery to power the motors and a 240-volt adaptor. To recharge the battery, apparently, you just plug it in. The car also boasts a ‘regenerative braking system’ that allows it to top up its own power supply. At the time I wrote this, though, the ‘Mango’ was still just one experimental car — the students need more money to build one that can be registered and sold. At the moment solar cars either stop when the sun goes down or store power in batteries — which are both heavy and expensive. But future solar cars may store power in capacitors that are cheaper and can be built in as part of the car itself. A capacitor can be recharged in a minute or two, so you wouldn’t need to physically swap batteries — just plug the car in.

c)

Fly!

There are already jet-powered back packs that let you fly, but they use a lot of power — so much so that you can’t fly for long. But if we used solar fabric for giant wings, plus helium balloons to lift us up, we could fly wherever we wanted to go. Each family, or group of families, could have their own tiny flying ship for long journeys, but if you wanted to go to school you could just strap on your wings, harness up your balloon and fly off. Just don’t forget your grappling hook so you can grab onto the school rails and haul yourself down to earth again.

d)

Jump instead of walk or using a bicycle.

A new invention called Powerisers are springy stilts that help you leap five metres in a single bound — faster than running and about as fast as a bicycle.

6.

Water

The problem: Not enough of it The world’s population is growing: we not only need water to drink, but also to grow our food. Wealthy countries like Australia and the USA also use more water per person than

people in many poorer countries — not just in baths and showers but in swimming pools, spas and on big gardens. (A hundred years ago only wealthy homes had flowerbeds and lawns; most gardens were fruit trees, vegetables and a few plants for beauty like roses.) Once humans only used what fell from the sky — rain — or the water in creeks and rivers. Now we dam rivers; we also tap into ‘ground water’ — water that has been collecting under the ground for thousands of years, to irrigate our food crops. But once that water is used, there’ll be no more. Already many creeks and rivers and springs have dried up because the water table — the water under the ground — is lower because so much ground water has been used up and so little has been added to it. The world’s climates are also changing; in many places, especially parts of Australia, less water falls from the sky than it did several decades ago. There just doesn’t seem to be enough fresh water for everyone — and certainly not enough for maintaining healthy rivers or for wild animals in many parts of the world, too.

Solutions: a) Recycle When you have a bath or a shower or swim in your pool or flush your toilet or run a tap, you’re only ‘borrowing’ that water — the waste water (a bit dirtier now) runs away. If we clean and recycle the waste water, we can use the same water over and over again. There are ‘water recycling’ kits that homeowners can buy, but it would be more efficient if every council used the water running in their ‘waste’ pipes again and again. In many places in the world and quite a few places in Australia this recycling already happens. In parts of the world a third of water is used to cool nuclear or coal power stations. But this water, too, could be recycled, with giant pipes under the ground where the water could cool down and then be used for cooling again, instead of being stored in big ponds or lakes that then evaporate.

b) Grow plants under cover Growing fruit, grains and vegetables uses a lot of water, especially through evaporation

— sometimes about 90 per cent of the water used on a vegetable garden evaporates, while the plants only use 10 per cent. If you cover your garden with a form of shade cloth when it’s hot, plants will grow as well but lose less water. If you grow them with a covering of plastic, the water that evaporates will condense on the plastic and can be used again and again to water the plants. Scientists have already designed growing systems that could be used on Mars or the moon that use the same water over and over to grow plants and feed people … then the waste water from humans and plants is recycled. There are also sprays that can be misted onto plants, putting a protective coating on leaves so they don’t lose as much water when it gets hot. (It also makes them more cold resistant too.)

c) Trap water from the air Even when it’s very dry, there is always some water vapour in the air. This condenses as dew at night. You can trap the water vapour between two layers of plastic, and use it to water your garden — or you can let the garden find the water for you. Many Australian rainforests don’t have a high rainfall — but they do get lots of mists, and the rainforest is designed to trap the mist. Eucalypt forests have only one tree canopy, but rainforests have many layers of plants. The water condenses on the leaves, then drips off the leaves onto the ground. The more leaves, the more water. Our garden is planted in ‘groves’ with many plants grown together to protect each other from drying winds, cold, heat and also to trap moisture from each other. In very dry times here — which is most of the time — the trees growing in isolation look almost dead or do die. But the trees grown in groves look after each other. Our gardens and farms tend to be planted like European cold or temperate climate growing places, where they need to trap sunlight. But we have too much sun here. If every home garden and school and park was replanted with fruit trees and vegetables in groves, then every area would grow most of its own food, with much less water, much less work, less fuel used, fewer pesticides and herbicides (as the plants help each other with weed and pest control) … and much more fun.

For more details see www.jackiefrench.com and ‘The Wilderness Garden’, as well as ‘Backyard Self-sufficiency’ and ‘Natural Control of Garden Pests’.

d) Catch rain in tanks Most of our capital cities have quite high rainfalls, but the dams that give them their water are in areas of much lower rainfall. Many of the dams were commissioned during two wet decades (1950s and 1960s) with the engineers assuming the rainfall would stay much the same. In dry years the only water we use at our place comes from the tanks that collect rainwater and, even in 2003, when we only had 12mm of rain in ten months, we still had enough water — just — for us, the chooks, the wombats and the garden. The more tanks you have — or the bigger your tanks — the more water you can collect and store. If your roof is big enough, even a heavy mist will give you enough water for about a week, or even more.

e) Cover our water supplies Our cities’ water is stored in large dams — and a lot of this evaporates on hot and windy days. Farmers’ dams also evaporate — a farm dam can dry up in a hot, windy summer even if the water isn’t used by humans or animals. There are many inventions of varying effectiveness to cover dams and even swimming pools to reduce evaporation. Whether they’re as effective for larger dams remains to be seen.

f) Make fresh water from seawater (desalination) This is done in many parts of the world, but it uses enormous amounts of power and so helps heat up our world. And then there’s the problem of what to do with the salt and other material extracted from the water. If it is returned to the sea, the sea is too salty for fish and other creatures to live in, and we create ‘dead areas’ where nothing lives. These are also created from agriculture and fertiliser run-off, sewerage run-off and stormwater from urban areas, adding so many extra nutrients to the water that it results

in the death of many plants and micro-organisms, thus depleting the water of oxygen. It’s possible to evaporate sea water using nothing but sunlight, leaving the salt behind and collecting the fresh water, but this still leaves us with the problem of what to do with all the salt. Salts already contaminate much of Australia (having been blown inland over hundreds of thousands of years) so very few plants will grow. Some salt can be sold for cooking and preserving food, but only so much salt can be consumed — and one desalination plant can produce a lot of salt.

g)

Genetic engineering

Breeding or genetically engineering plants that need less water is possible, but at the moment most plant breeding and genetic engineering is done with a view to creating crops as cheaply as possible for food. There is some debate as to the safety of genetic engineering, and the knock-on effect of cross pollination with wild species.

h)

Stop clearing trees

When land is cleared for farming or burnt or logged, the soil becomes harder, less moisture soaks in when it rains, and the soil doesn’t store as much water. One of the reasons our dams are dry isn’t just that there is less rain — it’s because so much land has been logged or cleared that there isn’t as much water in the ground any more, to slowly seep into dams and rivers.

i) Robot farms Today’s farms usually use far more water than the plants need — up to 90 per cent of it evaporates, and chemical plant food is washed away to pollute river systems, creeks and dams, eventually killing coral reefs like the Great Barrier Reef. Scientists at the Massachusetts Institute of Technology’s Computer Science and Artificial Technology Laboratories have created a greenhouse to grow fruit and vegetables, where sensors record how much water or food the plants need and that exact amount is supplied by small robot arms and water pumps. These robot farms could recycle water, plant food and make sure plants are grown totally efficiently.

A similar ‘supply and demand’ concept is now used on many irrigation farms in Australia — sensors in the soil register how damp or dry it is, plants are tested for salts, sugars, proteins and minerals and fed according to the results. The farmer receives several read-outs a day allowing him or her to make intelligent decisions about irrigation, fertilisation and harvesting.

j) Biochar Biochar is made from burning plants using a special process. The biochar is then added to soils, but unlike ordinary plant material it doesn’t break down rapidly. Biochar is not only a good way to take CO2 from the air, but it can also help soil retain moisture and makes plant food easier for the plants to use. Biochar seems like such a good idea that some politicians think it may solve all our CO2 problems. But there have been no large trials of biochar, so that while we know that it sounds like a great idea, we still don’t know how much energy it will take to make large amounts of it, and how it will affect the soil if we use a lot of it over a long time. All good ideas need lots of testing before we try to change the world with themin case we change it the wrong way. (Coal fired power plants sounded like a great idea 100 years ago)

7. Wildlife and its world The problem: There is not enough world left for wildlife Humans are now using almost the entire planet. We are overfishing the seas, so that many species vanish; other animals are in danger of becoming extinct as we use their land to grow our crops, or chop down the forests they inhabit. Even in areas where we don’t farm or fish, we may dam the fresh water, or start bushfires that both kill wildlife and make it impossible for any that get through the fire to survive.

Solutions: a) Adapt our cities and suburbs to make them more wildlife friendly Imagine a city where every roof had a pond and grasses and other plants for birds and

animals; where more consideration was given to planting — such as wall gardens. There are many other ways to imagine your local environment in ways where wildlife can coexist. Planting more native trees, for example, brings the birds home to roost. If we gave room to monorails that moved people above the ground, fewer animals would be killed by cars, and more could cross the roads to breed or find food without being killed. Change requires imagination, as well as determination.

b) Set aside areas for wildlife — more National Parks and Wildlife Reserves I love sharing my world with wombats and wallabies, bettongs and antechinus and roos. But mostly wild animals need to be just that — wild, able to live their own lives without human intervention. There are always campaigns to increase National Park space, including organisations that buy up land from commercial interests.

c)

Control feral animals

Very few studies have been done on the impact of ‘feral’ animals on native species. In the valley where I live, at least four species have become locally extinct in the past twenty years because of feral cats, dogs and goats. The goats are turning what was once rainforest into dead dry clay gullies, and eating the grass and young shrubs that wallabies, roos, wombats and other creatures once ate. The cats and dogs eat small wild animals like bettongs and antechinus and ground-dwelling birds, and the cats are spreading a parasite called toxoplasmosis to the wombats, making them slower and more stupid and likely to die on roads or stay out in the sun when it’s too hot and dry for them to survive. Our national science body, the CSIRO, used to do a lot of research into ways of controlling feral animals — not by shooting them or poisoning them, but finding ways to stop them breeding and other solutions that don’t hurt the animals themselves. But funding and research seems to have dwindled in recent years. We need research to find out exactly how bad the problem is, people thinking of ways to help and even more people to do the work.

d) Put a LOT more work and money into fighting bushfires Most bushfires are still fought by volunteers who have other jobs, and can be expected to work for months without a break. Resources for Rural Fire Fighting services can be stretched, with sometimes tragic consequences.

e) Make farming wildlife-friendly It is possible to grow our food without shutting out wildlife, causing them to starve. See www.jackiefrench.com, and also The Secret World of Wombats, How High Can a Kangaroo Hop? and The Wilderness Garden for more information.

8. Rubbish Disposal and Recycling The problem: Lots of junk. The world is in a mess — a real mess. There are vast islands of rubbish floating in our oceans, so tightly compacted that nothing lives below them. Every city has a problem with what to do with its waste — waste that releases poisons as it decomposes or methane that adds to global warming.

Solutions: a) Repair things My washing machine has just had its 26th birthday. My grandma used the same iron she was given as a wedding present till she died at the age of 88, and her wedding present vacuum cleaner, too. In those days appliances were made to last for decades. Even sheets were handed down from one generation to the next — though the earliest ones were made of tough linen rather than the less scratchy cotton we use today. Now everything from sheets to computers are made to wear out fast so that everyone will buy new ones, and manufacturers can make more money. This is known as ‘built in obsolescence’. Magazines and newspapers and ads on TV encourage us to buy more and more items; to keep up with the latest fashion instead of choosing things we love and using

them all our lives … or at least swapping or selling them to others if we no longer want them.

b) Use less — of everything! Only buy things you need or you love. If you need to buy something, choose something that will last the longest or can be repaired.

c) Only use things that are made of materials that can be recycled You can’t buy a computer that will last 100 years, because we know that inventive humans are going to come up with better designs every year. But computers — and other things we use — can be made of material that can be recycled or will biodegrade. P.S. The best take-away food wrappers are banana leaves — you can cook things in them, use them as plates, then throw them away — or feed them to a cow or compost heap. In India ‘take-aways’ used to come in small ceramic bowls or cups of sun-baked clay — no power was used to produce them, you just threw them away after using them, and they became soil again when it rained. It is possible to make plastics that can be used for almost any purpose but that can also be recycled safely.

d) Use electric cars The bad air above our cities comes from cars and factories and coal-fired power stations. If we use electric cars instead, and have filters on our factories and power stations, we’ll have clean air.

e) Recycle sewage At the moment much of the world’s sewage ends up in the sea or is used on farmland without removing the salt and polluting metals. In some countries the recycled sewage can carry disease too. We need to recycle sewage properly, extracting the metals from it and use them again too, before using the rest as fertiliser and siphoning off the methane as fuel. One reasonably safe way to recycle sewage is to mix it with paper and other rubbish and

feed it to a special breed of earthworms. The earthworms ‘compost’ it all into soil, though this still needs to be treated to make it safe from disease and intestinal worms and other pests that might live in your body, and to extract dangerous metals and salts too.

9. Fuel Usage The problem: Planes and ships that use enormous amounts of fuel to get people everywhere, and warm up the earth as well as polluting it.

Solutions: a) Sailing ships with Oomph The age of the great sailing ships died more than a hundred years ago. Steam ships were just so much faster. But with computer technology and new stronger, lighter materials, engineers have designed new sailing ships with more efficient sails that can swoop across the oceans, with solar panels to power the ships when the wind drops.

b) Zeppelins Aeroplanes need lots of power just to get them in the air. Once they’re up there, they don’t need as much fuel. Zeppelins are giant balloons with carriages for passengers dangling below. In the 1930s, Zeppelins looked like they would take over from aeroplanes. They used so much less power that passengers had room to walk around, sit at dining tables, get up to watch the view. They felt like they were in luxury hotels. But then a Zeppelin called the Hindenburg caught alight — and a movie crew filmed the passengers falling and falling to their deaths whilst burning. It was horrendous … and it was the end of Zeppelins. The Hindenburg caught fire partly because it used hydrogen, not inflammable helium, which modern Zeppelins can use. On paper, Zeppelins seem like an ideal form of transport: they don’t need runways, and they make little or no noise in flight. But any company wishing to fly them will have to get over people’s memories — and invest a significant amount of money.

c) Green aeroplane fuel Scientists are experimenting with ‘aviation grade’ kerosene grown from algae — that green stuff that pollutes streams and dams. But this is still many years away from working.

10.

Food Production

The problem: Food that has lost its taste. The food most people eat in Australia has more salt, fat and sugar in it than ever before. Why? One reason is because a lot of our food no longer has much flavour. When you store fruit and vegetables they slowly lose their flavour, or sometimes become more bitter. Fresh broccoli is quite different from week-old broccoli, for example, which tastes more sulphuric. When kids come to our place and say they don’t like any fruit or veges I take them around the garden so they can pick their own. I’ve never met a kid who doesn’t like most of what he or she tries after that. Adults also don’t have as much time to cook. These days parents often work outside the home, and transportation to and from work takes up time. Not to mention the myriad other journeys required — to the doctor, to the supermarket, etc. Frozen food is convenient for the time-poor cook — but food loses flavour when it’s frozen, so it needs more fat, sugar and salt to make it taste okay. It’s also often cheaper to use artificial flavourings instead of real fruit, herbs and spices. (Have a look at the packets of the food in supermarkets and you’ll see that often when you think you are buying a lemon drink, or a raspberry jelly, the ‘flavour’ is made in a factory, not grown on a farm.)

Solutions: a) ‘Urban farms’

Food can be grown near where it’s going to be eaten — both to cut back on ‘food miles’ — which add to global warming via the fuel used in transporting goods, and to give people in cities greenery and animals around them. We could even have multi-storey farms, with solar-powered lights to keep the plants growing.

b) Backyard bounty Plant out your garden with good things to eat! Even a small garden can grow at least half your family’s food — and it needn’t take you more than about an hour a week to grow it and pick it — much less time than it takes to buy it in a supermarket, and more fun too. See my book Backyard Self-sufficiency. P.S. Turn your school into a food farm — you should be able to eat your school, too.

c) Cooking your own food Learn to cook at least twelve simple things that don’t take long to make, so when you’re tired you can still have a meal that tastes good fast without having to buy something ready made from second-rate ingredients and cooked in a factory.

d) Only eat real food — no additives! You think you only eat food? Look at the label on the cans and packets of what you eat — very, very few people these days eat real food. They eat preservatives and flavourings and artificial colourings and edible waxes to make things shiny and emulsifiers and thickeners and … I had better stop here or you may never eat again. A quick rule of thumb is if you don’t recognise the ingredients on the back of the packet, don’t buy it!

e) Learn to like lots of things Apparently, it takes the average human fourteen attempts to eat a new food before they know if they like it or not. So taste lots of things, over and over again. I eat feral goat because the goats here are turning the land into desert — and there is too much goat meat for the goannas and other native animals and birds to eat.

I’ve worked out many ways to serve avocado because avocado trees grow well at our place … and I cook a lot of dishes containing apples, because they grow well too. Food is too delicious to waste calories on stuff that doesn’t taste fantastic and isn’t good for you.

11. Space: The endless possibilities The problem: We’re stuck down here on earth and it’s getting crowded, too hot (or too cold) and resources are running out. There’s nowhere unknown to explore any more, except the depths of the oceans.

Solution: Go into space. Seven reasons to go to into Space 1.

It might be fun.

2.

Colonisation — the UN predicts there’ll be 9 billion on earth by 2040. It’s going to be crowded!

3.

A contingency plan in case our planet becomes uninhabitable. (Take your pick from ice ages, super volcanoes, meteor strikes …)

4.

Humans might learn to work together instead of fighting each other — we went to the moon to beat the Russians. Now we're building the International Space Station as a way to work with the Russians.

5.

Useful stuff —there are useful minerals on the moon, and on other planets.

6.

To see the universe! Orbiting observatories like Hubble Space Telescope, Advanced XRay Astrophysics Facility (AXAF), and Cosmic Background Explorer (COBE) study the stars, galaxies and how the universe works. Deep-space planetary probes and manned exploration might study other planets and asteroids and tell us more about our own world and how it was made or what it might become. Or just how wondrous the universe is.

7.

Because we’re human and it will be a Great Big Adventure! Every one of us is descended from great explorers. Humans originated in Africa and

wandered across the world, into new lands, across seas, facing weird animals and learning how to survive. Who knows what adventures are beyond the night sky? Maybe we’ll never find complex alien life elsewhere in the universe. Perhaps only the Earth has the magic combination of the correct distance from the Sun (so it is neither too hot nor too cold), liquid water, a tilted axis (so we have seasonal as well as diurnal variation) and a useful amount of gravity to have allowed a diverse range of complex, living organisms to have evolved.

The problem: It costs an enormous amount to get up into space, uses a massive amount of fuel and is dangerous. Life survives on Earth because we have a constant supply of free power from the Sun. The Sun feeds the plants (their green chlorophyll lets them turn sunlight into food). The plants feed us, or our animals. Within this solar system — the group of planets around our Sun — the Sun can still be used, both to power our spaceships (see below for examples) or to help ‘plants’ grow. But once a spaceship heads into deep space, away from our Sun, it will need something else to power it.

Solutions: a) Nuclear power At the moment long-range spacecraft — like the US-European Cassini probe now orbiting Saturn — use plutonium bricks to fuel their engines. (These tiny nuclear reactors are called Radioisotope Thermoelectric Generators or RTGs.) As the radioactive plutonium decays, it generates heat and this produces an electric current between two different types of metal. But the bricks are heavy, radioactive and inefficient, though better ones are being developed.

b) Solar sails There’s no wind in space to push a spaceship along … or is there? Solar sails are giant reflective sails — like giant mirrors. Photons of light from the Sun

bounce off the surface, giving the sail a gentle push. As long as our spaceship gets light from the Sun, it’ll be pushed along by its sails. The bigger the sails, the more push! This continues for a while after the ship leaves the solar system. There is also some research going into the effectiveness of microwave energy to propel these ships.

c) ‘Poo’ Power! Here’s a thought: What are we going to have an endless supply of on our way through the universe? Home-grown spaceship fuel … Scientists at NASA are working out how to break down human waste by heating it without oxygen. Usually when you burn faeces the molecules combine with the oxygen in the air to produce carbon dioxide and water. But if you burn them without oxygen, the molecules break their bonds and rearrange themselves into smaller molecules. First of all you get liquids then, if you burn them at a higher heat, you get gases. We could burn these gases to release energy to propel the ship or we could turn the liquids into plastics for manufacturing purposes. Scientists in Russia are working on a similar scheme — they want to use bacteria to break down the astronauts' used underwear to make methane, which could then be burnt to power the spacecraft. This method could be employed to turn other waste into more fuel.

Case Study: A country that is changing Nearly a third of the Netherlands, in Europe, is below sea level. That third is where about 60 per cent of its population lives. Most of its food is grown on the deltas of three big rivers — food to feed the Dutch population and also for export. The Netherlands is the world’s third largest food exporter (in money terms, not in kilocalories). But if the sea rises by the anticipated 65 to 130 cm within the next hundred years, most of the Netherlands would be under water too. (As will about 60 per cent of the world’s food growing areas, which use the fertile silt that floods down to river deltas world wide.) The people of the Netherlands, however, are very good at keeping back the sea. Much of their country has been ‘reclaimed’ from the sea or salt marshes. More than a thousand

years ago the people began to build their villages on man-made hills, gradually connecting them by dykes — man-made barriers of higher land to keep the sea away. From about the 13th century windmills pumped water from the farmland into artificial lakes, called polders. These days a complex network of dykes protects the Netherlands, from giant barriers to keep the sea out to smaller ones protecting farmland. These won’t be enough to protect the land if the sea rises because of the result of global warming. If the weather changes the rivers may flood more frequently, too. But in 2008 the government, scientists, businesses, universities and the people of the Netherlands began to work out an amazing plan to keep their country safe. It is going to cost about $1.6 billion a year for the next hundred years — an enormous sum of money. But much more would be lost — lives, food and money (about $350 billion lost from farm products every year) — if nothing was done. The Netherlands plan is called ‘Building with Nature’. It is seen as an exciting adventure in working out how best to live in a changing world. Instead of forcing the sea even further away, the people of the Netherlands are working out how to live with it. Some of the ideas being put into place now are: •

Floating houses that can rise and fall with floods.

•

‘Green roofs’, with plants growing on them, so that land covered in houses can still be used to grow things. Green roofs will also insulate the houses, keeping them warm in winter and cool in summer, instead of absorbing heat as tiled roofs do, and making the warming a bit worse, and the plants growing on them will help capture the CO2 that is warming our planet.

•

Floating greenhouses.

•

Floating solar-power systems.

•

Wind generators out at sea.

•

Developing and finding food plants and flowers that will grow in boggy salty land.

•

Developing giant lakes as well as giant underground storage bunkers for fresh water. When the bunkers are empty they can be used as car parks or playgrounds or sporting fields.

•

Some dykes will be made taller, but others will be demolished to allow for the

development of natural sand dunes and marshes around the rivers, that will ‘soak up’ possible floods and storm surges.

There are many, many other trials being done. Some of these may not work, but the ones that do will show the rest of the world that humans are, as ever, good at adapting to change. Humans survived far worse times in the last Ice Age — at its worst, cold and dry — about 18,000 years ago, only beginning to get warmer about 12,500 years ago. Large parts of the world were covered in ice — and when it melted many areas were flooded. It was at that time that Tasmania became an island, and the island of New Guinea separated from Australia. It’s very unlikely that we or our grandchildren will ever have to face anything as bad as that. And this time we have learned many ways to predict what’s coming and can work out what to do. The changing world is going to make us think, and plan … and that is something humans are very, very good at doing.

Conclusion: Don’t be afraid of change The more I learn about the past, the more I know that things always change. The one thing we can be sure of about the future is that it will be different from today. History also shows us how one or two people can change the world, sometimes with inventions or just by convincing others to change the way they live. Not so long ago, slavery was widespread around the world, and living standards for many were more basic than most of us today can imagine. National Parks were unheard of before the 19th century, and the fight to protect the extinction of species — from whales to Tasmanian Devils and many others between — is fiercer than ever. People fought and worked for these things to be changed. They won. They keep on winning. Always remember that no matter what, things are going to change — it’s up to us to make sure that those changes are good ones.

Tomorrow can be wonderful.

Suggested websites for further reading and research: Australasian Science magazine: www.australasianscience.com.au New Scientist magazine: www.newscientist.com ABC Online Science: www.abc.net.au/science