PLANET EARTH - THE 3RD MILLENIUM

Part 1: Energy on Earth

Fifteen billion years ago the universe was born in a Big Bang of explosive radiation. The stuff, the matter, the dust created in that explosion made the billions of galaxies and stars and planets that populate our universe. The radiation created in that explosion still powers all of the activities of those galaxies and stars and planets.

One of the most interesting of the planets is a small one called earth which has proved a nurturing cradle for a rare activity in the universe -- life.

Planet Earth has been orbiting a medium sized star out near the edge of the Milky Way Galaxy for about four billion years. During that long period, life on earth has blossomed into a stunning variety of forms, not the least of which is the one most likely to create new opportunities in the future, human beings. Very recently, at the beginning of the third millennium, earth has begun making waves in the noosphere, that is, in the universe of intelligence.

It is time to record the progress on planet earth and to speculate about its future. First we look at the energy that powers the earth. There are two kinds of energy in the universe, one of which is well-known on earth and the other glimpsed only in fits and starts.

The well known energy is the energy of thermodynamics, the physical energy needed to do work. Work means moving a force through a distance. Scientists measure this kind of energy in calories or watts or BTUs (short for British Thermal Units). The energy needed to do work is best summarized in two laws first described toward the end of its second millennium by a young French engineer named Nicholas Sadi Carnot.

The first law of thermodynamics says that energy cannot be created or destroyed. In other words you can’t get something from nothing. You can change energy from one form to another, but in every energy change you end up with the same total amount of energy that you began with. As some put it, there is no free lunch.

On the other hand, the second law of thermodynamics points out that in every energy change there is always a loss. In every energy change some useful energy gets changed into random heat energy. This random heat is useful only for warming the universe. This concept of the inevitable heat loss in all energy changes is called entropy.

So what is the situation on earth? Earth gets most of its usable energy day-by-day from its sun, about 173 quadrillion watts of high-quality solar radiation.

Almost half of that radiation is changed into heat energy, warming the air, the water and the earth. 23% is used to evaporate water and 30% is immediately sent back into space as low-quality random heat wave radiation.

A very small percentage of that solar energy, about two one-hundredth of 1 percent, is captured by the green plants of earth and converted into stored chemical energy by the process of photosynthesis. In photosynthesis (using light to put together chemicals), green plants bring in carbon dioxide and water from air, water and soil. They use the energy of sunlight to convert these two low-energy chemicals into a high energy chemical, sugar. This high energy chemical has been used by plants and animals for four billion years to power all of their life activities.

About ten thousand years ago humans learned how to make that process of photosynthesis better serve their purposes. In what scholars call the agricultural revolution, humans in Asia, Africa, the Middle East and South America learned to select certain seeds from wild plants, to plant, nourish and then harvest the grains and fruits. In this way they could make available larger amounts of energy, store some of this energy and use it to feed many more humans than before. Populations of humans multiplied.

Much earlier in what is called the Carboniferous Period on earth, about 300 million years ago, an interesting thing happened that was to have profound importance to human populations just a few hundred years ago. Some of the plants and animals living in that Carboniferous Period did not use up all of the energy they captured in photosynthesis. When they died the energy still contained in their dead tissues was not used by some other living creature, but instead was buried under sand and water and rock. Slow decay followed but these once-living chemical tissues held on to a great deal of that sun-captured energy.

Humans discovered some of these stored treasures of energy in the days of the agricultural revolution. They did not begin to make use of them in very large quantities, however, until just a few hundred years ago in what is called the Industrial Revolution.

These energy treasures from the distant past are stored in chemical forms called fossil fuels. The most important fossil fuels are coal, oil and gas. These fossil fuels were brought up from under the ground and under the oceans and used to power new machines that could do much more work and do it much faster than animal or human muscles. This industrial revolution began in the 19th century and reached its most advanced point in the just completed 20th century, the last century of the second millennium on earth.

As with the agricultural revolution, the industrial revolution brought a large increase in available energy for human use and because of this a large increase in human populations. Like the agricultural revolution, it also brought new ecosystem problems. Here in China for instance, as well in as many other countries on earth, they have large supplies of coal. They use this coal to heat their homes, cook their food, power their factories and to make electricity.

Unfortunately this burning of coal, while it releases the needed energy, also produces waste products of carbon dioxide and other unwanted chemicals, some of which pollute the air above China. Some of these unwanted chemicals move across political boundaries to affect climate and life activities in other countries of Asia and indeed around all of earth. Unfortunately, the same thing happens in Europe, Africa, North and South America.

Besides coal, the fossil fuels oil and gas power most of the world’s transportation vehicles and are increasingly being used to generate electricity. Earth has very great stores of fossil fuels but not unlimited ones. Besides the serious problems of pollution, eventually fossil fuels will become more scarce and more expensive.

Still another problem. Many scientists and environmentalists think these waste gases will significantly change the climate on earth, warming it by a few degrees in the next century. Climate change of only a few degrees may not sound like much but it could result in major changes in rainfall patterns, plant and animal populations, ocean levels, agricultural productivity, disease, health, wealth and poverty for millions of people in all countries on earth.

Since fossil fuels provide by far the greatest portion of the energy used by humans on earth this means we have serious problems in this the 21st century. Here are some ways we may be able to solve them.

One direction: Scientists and engineers are developing new ways of using the sun’s energy that are renewable, that is, do not rely on fossil fuels. Falling water for one. This is one of oldest of the renewable ways that uses the energy of water lifted into clouds by the sun, after it falls as rain and flows in rivers back to the sea.

Agricultural societies tapped falling water energy to grind their grain and to power early factories. Modern societies use the same energy to create large amounts of electricity. Wind. During the agricultural revolution humans learned to tap the energy of the wind to power sailing ships. Countries like Holland used the energy of the wind to pump sea water and thus to reclaim land from the sea.

In modern times when the wind blows, the blades of newly designed windmills turn rotors in electrical generators that produce electricity. Wind farms like these are going up in California, in Denmark, in India and China and in many other advanced and developing countries on all the continents of earth.

Farmers have long used solar energy to dry their crops and cure their animal meat and skins. New solar ovens cook meals and bake bread, and new solar panels on rooftops use the sun’s energy to heat water. Panels like these are also rapidly becoming common in Russia, in China, in India and Japan in the United States and Canada, indeed all over the world.

Experimental solar energy projects like this one in the California desert near Barstow are capturing the sun’s energy in molten salt which in turns boils water which turns generators to create electricity. New fuel cells use hydrogen as an energy source and produce only water as a waste. They are rapidly coming to commercial use in space satellites, homes, buses and automobiles. New research is developing miniature fuel cells that may replace small batteries in the coming decades. Of course, it should be noted, that hydrogen is not a primary energy source on earth. It may end up one of the most useful ways to deliver energy but hydrogen itself must be obtained by extracting it from water or from natural gas and to do this takes energy that has to come from somewhere else.

Some think the most promising of the renewable energy options are these photovoltaic cells that convert the sun’s energy directly into electricity. Already photovoltaic cells are powering earth satellites and communication equipment on, under and around spaceship earth. They are now being commercially developed and sold to individual consumers as well as to industrial ones.

Still another promising renewable source is called biomass. Waste grass clippings, sawdust, weeds, brush, animal wastes, seaweed, algae scum all have large amounts of stored energy still present in their plant tissues. Humans are working on novel ways to tap that stored energy. Some of it can be directly burned to power electrical generators. New techniques using genetically engineered bacteria can turn the wastes into ethanol, a good fuel for transportation vehicles. Genetically engineered fungi can break down wood cells and save energy needed to make paper.

All of these new forms of directly converting solar energy to useful work, renewable energy, provide only a small portion of the world’s total energy supply as the 3rd millennia begins, There will probably play a larger role in the coming decades and centuries. All of these solar forms of energy capture and conversion, like other energy capture and conversion forms, do have unwanted side effects,

One of the largest rivers in the world, for instance, is the Yangtze River that flows through China. The energy carried by this river is very great. China is right now building the largest dam ever built, the Three Gorges Dam, to try to capture and use some of this energy, as well as prevent the catastrophic floods that the Yangtze has caused in past years and centuries.

As side effects, however, the Three Gorges Dam will also require the relocating of more than a million people and bring about the destruction of thousands of priceless ancient monuments. It might lead to the extinction of some species of plants and animals, and no one can be certain it will not silt up in time and never produce all of the energy or the flood protection it is being built to achieve.

Even the seemingly benign wind and solar panel methods have unwanted side effects like bird destruction, excessive land use and toxic chemical use and distribution. In addition, the solar alternatives (except for hydroelectric) have a major drawback—they only work when the sun is shining or the wind is blowing.

The one energy choice on earth that has the fewest side effects is not a source at all, but an idea and a technology. The idea is simple. To do more with less. To do more work with less energy. To improve efficiency. The technology is varied. Green plants are on the average 1% efficient in changing solar energy into chemical energy. New agricultural technology, including bioengineered plants, is improving that efficiency, getting more food from less sun.

New industrial technologies, light bulbs, electric motors, internal combustion engines, storage batteries, steam boilers, insulation materials, plastics, metal smelting, mining machines, high speed trains, communication lines, computers, these and the thousand more inventions of the industrial world are being made more efficient every day, making them able to use less energy to produce more results.

Of course, the population on earth is also increasing, and the poor people of earth are getting richer as well. This means that despite the rapidly increasing efficiencies of agricultural and industrial machines and devices, there will still need to be substantial new energy sources developed. More people means more mouths to feed and more desires to satisfy. Fortunately it also means more hands and more minds to take up the twin challenges of improving efficiency and of developing new energy sources.

Solar energy, stored as fossil fuels or renewed daily as wind, sun and water power, is not the only source of energy in the universe, or on earth. One important source that is just in its infancy on earth is the same source that earth’s sun and all of the other stars in our universe use. This is the most basic energy of all, the energy that holds together the smallest things in the universe, atoms. The energy inherited from the Big Bang. On earth it comes in two forms, geothermal energy and nuclear energy.

Geothermal energy is the energy still trapped in the center of the still-cooling planet earth. This energy is used by some unusual recently discovered living creatures in the depths of the ocean to power their life activities. It is also used by humans in many places on earth to heat homes and factories and to generate electricity. Nuclear energy comes in two forms, fission and fusion.

Scientists on earth figured out how to use nuclear fission to produce useful energy in the middle of the 20th century, in the middle of the most destructive war in human history, World War 2. In nuclear fission, engineers tap the energy of the atom that is stored in very heavy atoms like uranium and plutonium. They do this by bombarding these heavy atoms with high speed particles until they break apart. This starts a chain reaction that breaks more heavy atoms apart ... and more and more and more.

If you let it accelerate you get a very destructive explosion as happened to end that second World War. If you control the chain, as is done in nuclear energy plants around the world today, you get useful heat which is used to boil water, which is used to create electricity.

Here, too, there are side effects and trade-offs. On the positive side, nuclear energy does not contribute to global warming, nor does it pollute the air, earth or water with any gaseous emissions. Nuclear energy also is not dependent on weather or climate. Unlike most renewable energy options, nuclear power works night and day, rain or shine.

On the negative side, nuclear plants generate dangerous radioactive wastes that must be safely stored or buried. They also are potentially vulnerable to thefts that could put highly radioactive materials in the hands of terrorist groups. Also, any time you deal with energy changes of large magnitude destructive things can happen as they did in the latter part of the 20th century at Three Mile Island in Pennsylvania and much more seriously at a place called Chernobyl in present day Ukraine.

No technology is without risk however. The very greatest risk would be to not provide enough new energy for future societies, because that would result in catastrophic increases in world-wide unemployment, poverty and violence.

New designs for nuclear power plants make major future accidents extremely remote. So much so that many scientists, along with an increasing number of environmentalists, economists and concerned citizens think that all things considered the best option for the 21st century may be to increase the use of nuclear energy to provide what is called the “base load” of electrical generation that can then be supplemented with renewable energy sources, like windmills, solar voltaic panels, biofuels, etc. This combination of nuclear power with renewable energy could also be used to produce hydrogen for fuel cells that could power most of our transportation. In this way we may be able to stop using any fossil fuels for energy production by the end of the 21st century.

There is one final wild card in future energy production. Instead of getting energy from the breaking apart of large atoms, nuclear fusion gets energy from the fusing together of small atoms like hydrogen and helium. This is the same process the sun and other stars use.

As a source of useful energy on earth nuclear fusion is still but a promise. Humans have worked out ways to use nuclear fusion as an explosive device but as yet they have not been able to use it to produce electricity. Once they do solve the problems here many scientists think nuclear fusion will be the primary source of energy for the next millennium and like the sun itself this energy source will be safe, inexhaustible, and cheap.

And full of surprises! For remember, the sun and the other stars are the ultimate source of all the energy and all the matter in the universe. This universal solar radiation comes from the innermost heart of matter. It is the source of all the energy on earth. It is also the source of all the matter on earth. Perhaps once humans discover more of the secrets of the sun (and the other stars) they will be able to enter more fully into the other energy field, the most renewable and efficient of all, the noosphere, our universe of intelligence.

One of their scientists seemed to have a glimpse of this other energy field when he noticed a few years ago that ... ”We are made of dust and the light of a star.”