How can Science save the Earth?

Living in the modern world can be a depressing experience. It seems that as time goes on, the world becomes increasingly populated, and people are creating numerous problems every day. Each new development and invention leads to a problem that has to be solved by another development or invention.

Arguably, the world’s biggest problem is climate change. Since the invention of the internal combustion engine and the discovery of electricity, we have been changing planet Earth for the worse. Our ever increasing-demands for the combustion of fossil fuels have lead us to the brink of a global disaster, and a solution in which everyone is willing to participate must be found – very fast.

The Heating of the Earth

“Without doubt, continued increase in atmospheric carbon dioxide is one of the major environmental problems of the new decade.” These were the words in the New Scientist issue of the 17th January 1980. Now in the new century, with ever increasing energy demands and greenhouse gas emissions, the need to find a more sustainable lifestyle and curb emissions of these harmful gases is increasing, and there isn’t long until it will be too late.

What causes Climate Change

The Sun is what creates the climate on Earth. The Earth’s climate depends on how much energy the Sun gives to the Earth, and how much then escapes. The two variables that could affect this are the activity of the Sun and the composition of the atmosphere.

Climate change is a concern, because now the amount of the Sun’s energy that escapes is decreasing, due to the changing composition of the atmosphere. For the past 150 years, humans have been releasing the gas carbon dioxide into the atmosphere by combusting fossil fuels – coal, oil and gas – to supply energy. Every year our demand for energy has increased, so the amount of fossil fuels burnt has increased, and the level of carbon dioxide in the atmosphere has increased exponentially. The pre-industrial level of carbon dioxide in the atmosphere was 280 parts per million, and now it is 381ppm . Carbon dioxide is a greenhouse gas. Greenhouse gases have no effect on the Sun’s ultraviolet radiation entering the atmosphere, but absorb much of the infra-red radiation reflected off the surface of the Earth. This means that heat remains in the atmosphere, and if there is too much greenhouse gas, the Earth will warm up. There is currently an excess of carbon dioxide in the atmosphere and 2.4x10¹⁰ tonnes of carbon dioxide are released into the atmosphere each year , so the Earth will continue to warm.

Although it is obvious that humans have been the primary cause of this climatic warming, it is also true that the Sun has been very active recently. There are a large number of sunspots on the Sun which means that the Sun’s magnetic field is very strong. The stronger magnetic field deflects cosmic rays away from the solar system. Cosmic rays encourage more clouds to form, and so there is more cloud cover, which reflects the Sun’s rays. So more solar activity means first that there is more energy radiated to the Earth and second that there are fewer cosmic rays reaching the Earth, decreasing cloud cover .

Consequences

Global warming has the potential to be devastating. It could badly affect much of life on Earth.

Melting ice could raise sea levels greatly. The melting of all glaciers and ice caps could raise the sea by half a metre, whilst the complete meltdown of Greenland would raise sea levels by seven metres. A large amount of low lying land would be threatened with frequent flooding. This is particularly worrying for island communities who have nowhere to go, and evacuation plans are already on stand by. Rising sea levels could flood and render useless much agricultural land, destroy livelihoods and leave many homeless. At the same time, other places will be facing severe droughts. Wet places are set to get wetter, and dry places are set to get dryer. Melting ice could also make global warming more severe by itself, as a positive feedback effect, which means that the process will cause itself to increase. Turning white ice into dark water means less of the Sun’s rays are reflected back into space, high levels of methane – a gas 23 times more potent as a greenhouse gas than carbon dioxide – could be released from melting permafrost in boreal forests.

Global warming could be the cause of Earth’s sixth mass-extinction. Many species are being driven out of their original habitats due to warming climates, whilst others are facing extinction. Many mountain species are at risk, as they have nowhere to go. As the temperatures get warmer, they must go to higher altitudes to find a cooler habitat, but the summit is the limit. Polar bears are finding it continually harder to hunt, as the Arctic ice melts earlier in the year, meaning that they have less time to hunt seals. Half of Europe’s plant species could face extinction by 2086, and extinctions are now occurring at 1,000 to 10,000 times the usual rate. The Amazon suffered one of its worst ever droughts last year, affecting thirty percent of the rainforest. Forest fires also threaten the Amazon – previously thought to be unable to catch fire – and hold the potential for great devastation. Not only is the Amazon a beautiful place, it also converts a vast amount of carbon dioxide into oxygen, decreasing the greenhouse effect.

Time is running out, and there is much to do in order to avoid the Earth overheating catastrophically.

Bringing the Climate back into Control

Things need to change fast. Although many people are making efforts to bring climate change into control, the contributing problems are getting out of hand. It requires more than just telling people to live greener lifestyles, because those who contribute most to the problem are the ones who will disadvantage most from helping to prevent it. Part of the problem is that those who will suffer most (people in developing countries) are the ones with the least power to do anything about the matter.

Global warming, it seems, has been mostly caused by an excess in greenhouse gases in the atmosphere due to humans burning fossil fuels and carbon dioxide emissions are set to double in the next fifty years. So reducing the amount of greenhouse gases should solve the problem. Unfortunately, there are no easy ways. Before we start taking carbon dioxide out of the atmosphere, we must stop putting it in.

Reducing Greenhouse Gases

Before greenhouse gases in the atmosphere are to be reduced, the first step is to stop increasing them. Our growing demands for energy mean that more fossil fuels need to be combusted to supply that energy. Our energy demands are not set to decrease, rather to increase, so more and more energy has to be supplied. Thankfully, not all energy sources emit carbon dioxide.

Nuclear power is controversial because of its potential to go wrong. But it is becoming increasingly popular with governments, because of the threat of global warming. If there is to be a “Nuclear Renaissance”, many obstacles will have to be overcome, for example, uranium may not be mined fast enough to fuel many nuclear power stations and there are a lack of young workers since nuclear energy fell out of popularity. Some believe that nuclear power might not be as effective as renewable energy at reducing greenhouse gas emissions, but tripling the world’s nuclear energy usage would cut the projected future increase in carbon dioxide by a seventh.

As one of the windiest nations, Britain should be seriously considering wind power. Many complain that wind turbines are an ugly blotch on the countryside, but the best place for wind farms is in shallow windy areas of the sea. Offshore wind turbines can be as large as necessary, and there is no worry of obstacles which cause turbulence in the wind and reduce efficiency. England and Wales have a potential offshore wind resource of 3,200 TWh. The UK’s current annual energy demand is 407 terawatt-hours.

Other renewable energy sources include solar energy, which is more appropriate in countries with a sunnier climate, and often can be used on small scales and hydro-electric power, which provides a lot of power, although dams often cause many problems. Wave energy has been out of fashion for a long time because no efficient technology to generate wave power had been invented. However, engineer Ed Spooner has invented a new mechanism involving magnets, in which the array of magnets creates jerky motions, which are more efficient . See Fig. 1.

Oil prices are rising, and now many countries have realized the benefits of biofuels. Brazil is now the biggest producer of bioethanol, and bioethanol usage accounts for half of its total petrol consumption. Burning bioethanol is cleaner than burning ordinary petrol. The main use of bioethanol would be as fuel for cars. Half of all vehicles manufactured in Brazil are designed to run on ethanol. Ethanol can also be combined with ordinary petrol, and small but significant amounts do not require any engine modifications. Biofuels originate from crops such as corn and sugar cane. The sugar from the crops is obtained – if the crop is starchy then the starch is converted to sugar with an enzyme – and then combined with yeast. The yeast, in the process of anaerobic respiration converts the sugar to ethanol. Unfortunately, there are many possible negative consequences of planting crops for biofuels. Increasing demand for biofuels will result in large amounts of deforestation to make room for agricultural land and more intensive farming which requires more chemicals. Destruction of the rainforest and greater use of chemicals will both put more greenhouse gases into the atmosphere, which undermines the point of biofuels entirely. Hope is not all lost. The technology is in early days. There are suggestions that crops like switch grass and straw could be used. The cellulose in these plants can be converted into sugar with a different enzyme. The main advantage of these is that they could be grown on otherwise economically useless land.

China is planning a huge reforestation program. Trees convert carbon dioxide into oxygen and reduce the amount of carbon dioxide in the atmosphere. So surely planting more trees is a good thing. Phytoplankton, microscopic marine plants also convert carbon dioxide into oxygen and in much larger amounts overall than trees. The problem with planting forests is that they trap dust and prevent it from escaping into the atmosphere. The dust is what feeds the phytoplankton, and so with less dust in the atmosphere, phytoplankton numbers will decline. There is an idea that the phytoplankton could be artificially fed, but small scale experiments so far involving iron sulphate have been inconclusive and it is questionable as to whether such a “seeding” of the ocean could be carried out over a large enough scale as to make a significant difference.

Another way to reduce the amount of carbon dioxide in the atmosphere is to store it safely. This idea is called carbon sequestration. It can be as simple as trees absorbing the gas, or us physically pumping it into natural storage space. The Sleipner Gas rig uses amine to avoid having to release excess carbon dioxide into the atmosphere. Natural gas is typically produced with about 10% carbon dioxide. At the Sleipner rig, when the natural gas is extracted, the carbon dioxide is separated using amine, and then pumped back down into the crust. The porous Utsira sand where the Sleipner rig is situated is estimated to hold 6x10¹¹m³ of gas storage capacity. The Utsira sands are not a geological abnormality and there are many other cases of vast gas storage potential. The sea takes in 25,000,000 tonnes of carbon dioxide every year. It is possible to store liquid carbon dioxide at the bottom of the ocean with minimal effects on marine life. At depths of below three kilometres, the pressure will prevent the carbon dioxide from resurfacing, and it should stay in the ocean for hundreds or thousands of years. However, it would be exceedingly difficult to create such a system on a large scale, and there is a danger that it would cause complacency with regard to cutting carbon dioxide emissions. If it can be carried out entirely successfully though, it could help save the planet.

Much of the effort is at the domestic level. There are basic changes everyone can make to their home and lifestyle to save energy. Don’t leave the television on standby, dress for the weather rather than adjusting the thermostat, install good insulation and double glazing and all the other obvious adjustments one hears about every day. The European Union is now pushing for greener, less wasteful buildings. Houses will now be given an energy rating and buyers will be told how to improve their homes. Air leakage can be tested by raising the pressure in the house to about seventy-five Pascals and recording how much air has to be blown into the house to maintain the pressure. Heat loss can be measured with a thermal sensitive camera. Light is important to a house, and it is important to not have to waste too much on lighting. A normal filament light-bulb will seldom be more than ten percent efficient. Halogen bulbs are more efficient: they emit more light and use less electricity, and last two to three times as long as a filament bulb. Even better are fluorescent bulbs, which require a quarter of the electricity of a filament bulb for the same output and last ten times as long. The “Light up the World Foundation” has been selling or donating its white light emitting diodes around the world. This scheme is particularly aimed at the developing world, where kerosene lanterns – emitters of carbon dioxide and fire hazards – are in wide use. The LED lamps can run on AA batteries, or even batteries that can be recharged by solar panels, meaning zero carbon dioxide emissions.

Planetary Engineering

If we prove unable to reduce the amount of greenhouse gases, some scientists have come up with schemes to engineer the planet as means of cooling it down. However, the nature of planetary engineering means that these proposed schemes are highly controversial.

Most planetary engineering schemes involve changing the albedo (reflectivity) of the planet. One idea, proposed by Lowell Wood, is to launch piece by piece an enormous mirror of 1,000km in diameter and assemble it between the Sun and the Earth in order to reflect some of the Sun’s rays. Another idea, proposed by Edward Teller (also called the “Father of the H-bomb”), is to send millions of helium filled balloons into the atmosphere to reflect the Sun’s rays. John Latham proposes an idea to increase the reflectivity of clouds. He says that spraying clouds with salt nuclei will cause the formation of more water droplets, making clouds whiter, and increasing the amount of sunlight which they reflect.

The problem with these proposed schemes is that there could be many unforeseen side effects. The helium balloons could deprive plants of the necessary amount of sunlight for photosynthesis, for example. People will not feel so concerned about carbon dioxide emissions, so eventually another mirror or million balloons will have to be launched as climate change starts again. Greenhouse gases cause not only global warming. Acidification of rain and the oceans is another problem caused by carbon dioxide, and planetary engineering would not solve that. Most worrying of all is how much cooling we actually want. These proposals could cool the planet so much that we would have to face an ice age.

The Sun

Solar activity is now unusually high, and this contributes to global warming. However, solar physicist Nigel Weiss predicts a dramatic decrease in solar activity soon, which would temporarily solve the problem of global warming.

However, this is not an excuse to do nothing. It would help because it would give us time to solve the problem, but if we become complacent and continue emitting carbon dioxide at current levels, global warming will be even worse when solar activity returns!

Free Energy

Sean McCarthy and Richard Walshe have made the outrageous claim that they can both save the world and disprove arguably the most fundamental law of physics: the conservation of energy – energy cannot be destroyed or created, only converted.

However, McCarthy and Walshe have invented a machine involving four magnets on a wheel and a magnet opposite which is 285% efficient. McCarthy and Walshe are so convinced that they are right that they called upon the scientific community in a full page Economist advert that cost £75,000 to form a jury and assess their invention. It would save the world if it turns out to be true.

Epilogue

“I say the debate is over. We know the science and see the threat. Most of all, I say the time for action is now.” - Arnold Schwarzenegger, governor of California. On the subject of climate change, there are optimists, pessimists and activists. The optimists say that global warming is fiction, or not all that bad, whether because they really believe it or because it would inconvenience them to do anything about it. Pessimists, or doom mongers constantly alert us that global warming is a catastrophe already invoked and that we are past the point of no return. The activists warn us of the threat and then provide or use solutions to combat the problem. Arnold Schwarzenegger is one such activist. He is leading California in a great push for renewable energy, efficient cars and houses, and most of all a huge cut back in carbon dioxide emissions.

We have the technology to save the planet. It is down to intelligence, leadership and selflessness. Sir Nicholas Stern’s very recent report (31st October 2006) stated that a 1% investment now would prevent a 20% decline in global economy resulting from doing nothing about global warming, so it is not even financially beneficial to do nothing.

“To look in your grandchildren’s eyes and say: I knew that it was going to happen, but I didn’t bother to do anything about it; that would be a terrible thing.” – David Attenborough, on the TV series “Planet Earth”. With the technology we already possess we can solve the problem, and with those many more revolutionary technologies being produced, is there a single reason not to solve this potential catastrophe?

References

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