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Global Warming   Global warming, also called climate change, is the greatest burden on our moral behaviour: global warming is rapidly pushing life on Earth to extinction and we are responsible for it happening. A few years ago global warming was speculation. Now we see it happening all around us, from melting Polar ice caps, dissolving permafrost, increasingly serious regional storms, to changes in wild animal behaviour. Only a few simple organisms might survive the impending disaster. Global warming is a greater threat to life than global nuclear war. Contents What is Global Warming? Cause of Global Warming The Greenhouse Effect Carbon Dioxide Evidence for Global Warming Global Warming Unleashed Cataclysms in the Offing Biosphere Wipe-Out Can We Stop Climate Change? Morality Appendix 1: Proof of the Impossibility of Slowing Global Warming Appendix 2: Getting Rid of Carbon Appendix 3: The Main Greenhouse Gases Appendix 4: Kyoto Links to Web Sites About Global Warming What is Global Warming? Global warming is an increase in the average temperature of Earth's air and sea. Earth's climate naturally slowly changes over thousands of years. It alters in response to changes in solar activity, Earth's orbit around the Sun, volcanic emissions, and other natural phenomena. Of particular concern with the present climate change is that it is happening very fast, too rapidly for species to adapt to changing conditions. Consequently, global warming will wipe out millions of species. Global warming has been simmering scientifically since the late 1980's and now it has boiled over into public and political awareness internationally. Cause of Global Warming The consensus among climate scientists is that Earth's climate has warmed during the last century and most warming is man-made. Humans have changed the composition of the atmosphere by increasing its concentration of greenhouse gases, gases which increase the temperature of the sea and land. (See Appendix 1, below: The Main Greenhouse Gases.) The Greenhouse Effect The greenhouse effect powers global worming. The land and sea absorbs most of the Sun's heat reaching Earth. The heat then passes to the atmosphere and is lost into outerspace. However, some of the heat in the atmosphere gets trapped by certain gases and remains next to Earth's surface. This trap is called the greenhouse effect. The greenhouse effect is natural. Without it Earth would be too cold for life to evolve the way it has. One of the first people to apprehend the greenhouse effect was Frenchman Jean-Baptiste Fourier in the 1820's. He coined the analogy with a greenhouse. The window panes of a greenhouse are like Earth's atmosphere. They allow the Sun's warmth in but prevent some of it getting out, raising the temperature of the greenhouse. Carbon Dioxide Several gases in the atmosphere take part in the greenhouse effect and global warming is largely due to the gas carbon dioxide. Carbon dioxide is the most abundant greenhouse gas humans release and they have released hundreds of billions of tonnes of it into the atmosphere. Eighty percent was released by burning fossil fuels, that is coal, oil and gas. Most of the rest was released by humans destroying forests and secondly by other man-made land-use changes. The concentration of carbon in the atmosphere has increased by about a third since pre-industrial levels (that is since 1750) and most of that has happened in the 20th century: 275 ppm (parts per million) pre-industrial revolution. 360 ppm in the 1990's. 380 ppm now and rising at 2 ppm per year. Currently humans annually release 22 billion tons of carbon dioxide and other greenhouse gases into the air. All these gases contribute to global warming. Evidence for Global Warming Temperature - average global temperature is higher. Snow cover - global snow cover has decreased by ten percent since the 1960's. Permafrost - it is thawing. Arctic - sea ice has thinned by 40 percent in recent decades and parts of the ice sheet are disintegrating. Inland glaciers - are melting from the Alps to the Himalayas. Sea level - average sea level rose 10 - 20 cm (4 - 8 inches) in the 20th century. Coastal areas - more are flooding annually and many shorelines are receding inland. Rainfall patterns - more frequent and intense droughts across regions of Africa and Asia and recurrent and heavier rainfall across the mid northern hemisphere. Species - the distribution and behaviour of many species are changing. Global Warming Unleashed Climatologists thought climate change was a slow process. But in the last few years climate scientists realise that the climate can increase rapidly in abrupt and steep steps. Computer simulations of global warming for the 21st century indicated a future average temperature increase of one to six degrees Celsius. Now revised estimates put the average increase in temperature at ten degrees Celsius - minimum - within 200 years. Even a moderate temperature rise will raise the sea level and seriously change weather patterns. A ten degree rise is staggeringly high and portends grave consequences. It can trigger cataclysmic events: Melting of the Greenland Ice Sheet. Thawing of the permafrost. Conflagration of the entire Amazon rain forest. Release of methane hydrates. These events are mechanisms that can rapidly accelerate global warming into unbridled global devastation, within the next 200 years. Cataclysms in the Offing Rising Sea Level A rise in sea level over six metres (20 feet) due to melting ice caps and a warming sea (water expands as it heats) will flood and obliterate lowlands. The United States as well as Bangladesh will suffer. Millions of people and animals will be forced to move to higher land or die. Species that cannot migrate will go extinct as they drown. Gulf Stream Switch-off The Gulf Stream (also know as the Atlantic Conveyor) is a major current in the Atlantic between the Caribbean and Europe. It conveys 20 times more water than all the rivers on land. Within its body of water it carries heat and distributes it to the atmosphere across the globe. Without the Gulf Stream much of Europe would be as cold as the same latitude in Canada, where virtually nothing lives because of the freezing conditions. Unfortunately, the Gulf Stream can shut off swiftly and permanently by ice cold water from the melting Arctic and the Greenland Ice Sheet colliding with it. If this happens, North-west Europe would suddenly be thrust into an uninhabitable Arctic climate. A mass die off of most fauna and flora in Europe would be inevitable and millions of people would be forced to migrate south causing massive civil conflict and destruction to wildlife. The change would not be confined to Europe but impact other parts of the world because all parts of Earth's climate are connected. Greenland Ice Sheet Meltdown The ice sheet covering Greenland is melting. The Greenland Ice Sheet is Earth's second largest ice cap and contains about 10 percent of the world's fresh water. It could take over 100 years to melt completely but once started it cannot stop. Melting would raise the sea level at least six metres (over 20 feet). The sea will engulf lowland coastal areas where countless creatures and billions of people live, including cities like Shanghai, London, New York, Mumbai and Sidney. Permafrost Melt Earth's warming atmosphere is melting the permafrost. Permafrost is ground a few inches below the surface that is normally constantly frozen solid, although the top few inches can thaw in summer. Circling the globe, mostly in the far northern hemisphere, it occupies up to a fifth of Earth's land surface. In some places it is around 1,000 m (3,000 feet) thick. Scientists predict a major thawing by 2040. The permafrost contains enormous amounts of carbon dioxide and methane that will be released into the atmosphere, massively adding to global warming and precipitously speeding up further warming. Amazon Conflagration Climate change could dry up the Amazon rain forest turning it into one huge combustion holocaust. It will release vast amounts of carbon into the atmosphere (trees are made mostly of carbon) suddenly driving up global warming. The majority of animal and plant species live in rain forests. So when the Amazon is destroyed most terrestrial species on Earth will die with it. Ocean Death The surface of the sea absorbs carbon dioxide from the air above it. Increasing amounts of carbon dioxide in the air will turn the oceans into a dilute acid (carbon dioxide plus sea water makes carbonic acid, HCO3) and most marine life will perish - from microscopic plankton to coral reefs and whales. Chemical processes gradually incorporate the carbon dissolved in the sea into rock, thus removing it from the sea. Sea creatures start this process by taking up the carbon and building it into their bodies. Ultimately they die, fall to the bottom and the immense weight of water overhead compresses them with their carbon over aeons into rock. Without this process, when sea-life disappears, carbon will saturate the sea. Carbon in the air will no longer be able to dissolve in the sea, will build up in the atmosphere and accelerate more global warming. Methane Hydrates Release Methane hydrates are vast quantities of methane gas stored under the sea floor frozen like ice. There could be trillions of tonnes of it. Rising temperatures in the sea will trigger its release to surge up as methane gas into the atmosphere. Earth's warming climate will get an abrupt gigantic boost from this gas, several times more powerful as a global warming gas than carbon dioxide. Global warming will be uncontrollable and unstoppable. Biosphere Wipe-Out How will global warming leave the Earth? The cumulative effect of all these cataclysmic events when they happen will be a climate change that destroys the biosphere: the realm of all living things (between the atmosphere above and the lithosphere of rock below). Without the Arctic ice, creatures dependent on it will die off. As the jungles dry up most land species on Earth will vanish. The oceans and almost all life in them will be dead. Virtually all life on Earth will come to an end; only some micro-organisms adapted to live in extreme environments will survive. Can We Stop Climate Change? We cannot stop climate change. Even if we act promptly and effectively global warming will continue. Once changes to large bodies, like the oceans and ice caps, are set in motion they take hundreds of years to slow down and stop. Nevertheless, some people hope to avoid the worst scenario: global warming accelerating so fast that it is impossible to slow. But can we slow global warming significantly? Politicians say we can reduce global warming without giving up our standard of living or aspiration for a higher standard. This is false because slowing global warming depends on: The amount of global warming fuel (oil, wood, etc) that humanity uses. But humanity continues to use fossil fuel worldwide and shows no sign of seriously limiting its usage, despite knowing about the dangers of global warming. The number of people on Earth and its rate of increase. But humanity's population is 6,500,000,000 and increasing fast without control. New technology saving us. But new technology is a reverie; it does not exist (for instance see Carbon Capture, below) and probably could not be delivered in time if it were invented. Enormously costly and widespread unpopular economic changes. But no one is going to give up anything unless the other guy/country does first. If everyone else is polluting, no individual or country will put themselves out or pay vast sums to constrain themselves. Everyone will pollute the air freely to the last gasp. It is the ultimate tragedy of the commons. The last point is the really big stumbling block when trying to control global warming. Each of us has evolved biologically to behave in our individual self-interests. This behavioural adaptation helped our forebears to survive on the plains of east Africa, where our species evolved. Try as we might, humanity cannot divest itself of this biological imperative, even as we topple on the edge of the global warming cliff into oblivion. Also see Appendix 1 (below): Proof of the Impossibility of Slowing Global Warming. Morality Given that global warming is upon us and we cannot stop the coming catastrophe, what is the outcome for animal ethics? The many periods of the evolution of life on Earth fall into several distinct aeons, each lasting hundreds of millions of years. Anthropocene, meaning human life, was coined recently to describe just the last tiny fraction of evolution: the brief, couple of hundred years of human existence - the period when humans have so thoroughly devastated the biosphere. After hundreds of millions of years of evolution we have arrived at the Anthropocene. An animal species is just beginning to comprehend life and the universe. Ironically, on the point of this extraordinary leap in knowledge, understanding and wisdom, the animal species in question is committing suicide and taking all life with it. A billion years from now, when Earth has recovered a flourishing biosphere, an intelligent and ethical life may re-awaken. Or it may awake on another planet. Meanwhile on Earth it is the end of ethics. Appendix 1: Proof of the Impossibility of Slowing Global Warming Proof 1 Fifteen to twenty-five percent of carbon emissions that we put into the atmosphere comes from motor vehicles. Severely cutting back on motoring would therefore contribute significantly to slowing global warming. Even though it would have no influence on slowing global warming generally, selling your car next month and giving up driving would be an enormous personal contribution. But you are not going to sell your car and stop motoring. No one else will, so why should you? Thus if no one (and this applies to countries too) is going to make a commitment, how can we stop global warming? Proof 2 Similarly, having one less baby when deciding to start a family would make a far greater contribution to slow global warming. In your baby's lifetime it will emit as much carbon as you in your lifetime. Thus by having this baby you double your carbon output (actually you would have to have two babies, taking account of your partner). But you are not going to stop having a baby because of this. Nor will anyone else. So how can we slow global warming if we do not make sacrifices. Conclusion There is no technological quick fix to slow global warming. Therefore we all have to alter our lifestyles drastically. But no one will do this. So the biosphere is destined to perish by a global warming caused by humanity. Appendix 2: Getting Rid of Carbon Human society is heavily dependent on the use of fossil fuels. To reduce emissions of carbon dioxide and other greenhouse gases in order to slow global warming we must transform the way we power the global economy. To reduce greenhouse gas emissions people can: Cut the demand for energy. Change energy production methods, for instance switch to non-carbon fuels like solar, nuclear or wind power. Improve energy efficiency of devices, for instance improve fuel efficiency of cars. Block greenhouse gases entering the atmosphere, for instance employ filters to trap man-made emission of carbon dioxide. Capture carbon, that is remove carbon from the atmosphere (see Carbon Capture, below). Carbon Capture Global warming might be slowed by removing carbon dioxide directly from the atmosphere by capturing it and converting it into another compound. A natural way to do this is to plant vegetation, for instance forests. The plants take carbon dioxide in the air and incorporate the carbon into their bodies. However, even global reforestation would not be sufficient to counter present carbon dioxide emissions by humanity. Another idea for slowing global warming is to remove carbon from the atmosphere. Carbon might be removed by fabricating some kind of carbon dioxide absorber and then the absorbed carbon could be buried underground. Another possibility is constructing giant mirrors in space to deflect the Sun's rays from Earth's poles to keep the poles cold and prevent further melting of the polar ice. Motorists could pay for the technology by adding a few cents tax on the price of petrol. But all three of these ideas are presently wishful thinking science fiction. Appendix 3: The Main Greenhouse Gases Here is a round-up of the most important gases that contribute to global warming. Earth's atmosphere is almost entirely: Nitrogen - 78 percent Oxygen - 21 percent Some gases other than nitrogen and oxygen in Earth's atmosphere trap heat from the Sun and are called greenhouse gases. Some occur naturally in varying amounts and others are man-made. They include: Water vapour - less than 4.0 percent Carbon dioxide - less than 0.035 percent Methane - less than 0.0002 percent Nitrogen oxide - minute quantity Once in the atmosphere greenhouse gases remain there from about ten years to thousands of years, depending on the gas. Water vapour This is water in its state as a gas. It is normally invisible but you can feel it as humidity in the air and see it as clouds in the sky and steam from your boiling kettle and hot bath. It is the most effective gas for retaining the Sun's warmth (holding about 60 percent of Earth's natural greenhouse gas warming). You can feel the warmth noticeably when comparing cloudy versus clear nights; clouds trap the Sun's heat. Its chemical formula is H2O, that is it consists of particles made up of two atoms of hydrogen and one atom of oxygen. Carbon dioxide A colourless, odourless gas. There is relatively little carbon dioxide in the atmosphere (0.035 percent) but it is the most important greenhouse gas after water vapour and the most important man-made greenhouse gas. Human activities have released more carbon dioxide into the atmosphere than any other gas and it contributes most to man-made global warming. About 80 percent of the carbon dioxide people add to the atmosphere currently comes from burning fossil fuel (coal, oil and gas). Most of the rest comes from land use, such as clearing forests, agriculture and ranching. Because of the importance of carbon dioxide climate scientists take it as the standard for comparing the global warming potential of gases with each other. Carbon dioxide is set as one unit. The time taken for an amount of carbon dioxide to disappear from the atmosphere is 200-450 years. Plants are built largely from carbon. Plants remove carbon dioxide from the atmosphere to build their bodies from it. Fossil fuels (coal, oil and gas) were originally mainly plants, which is why burning fossil fuel releases large amounts of carbon dioxide into the air. Conversely, by growing plants (for instance forests) you can remove carbon dioxide from the air. Animals get their carbon by eating plants and incorporating plant carbon into their bodies. When animals and plants decay or burn, their carbon combines with oxygen and is released into the air as carbon dioxide. Its chemical formula is CO2 (ie particles consisting of one atom of carbon and two atoms of oxygen). Methane A colourless and odourless gas. Its atmospheric concentration has more than doubled since the industrial revolution (ie post 1750). It has about 20 times the global warming power of carbon dioxide. Time taken for an amount to disappear from the atmosphere is about 12 years. Numerous human activities produce methane, for instance it is produced at coal mines, gas and oil wells and it evolves from decomposing garbage landfills. Like carbon dioxide, it is a natural by-product of the decomposition of once living creatures. (Animals and humans also produce it in their guts. Farting cattle (1.3 billion worldwide) have been seriously questioned as a factor contributing to global warming. It is claimed that 90 percent of New Zealand's greenhouse gas emissions comes from it's 40 million sheep. For livestock numbers worldwide see Livestock Numbers Worldwide.) Chemical formula is CH4 (ie it consists of particles with one atom of carbon and four atoms of hydrogen). Nitrous oxide Produced by natural processes and human activity, for instance agriculture (released by fertilisers), industry and fossil fuel burning. There is little in the atmosphere but it lasts 100 times longer than carbon dioxide and its global warming potential is hundreds of times greater. It is the same as 'laughing gas', administered by dentists as an analgesic. Its chemical formula is N2O (ie it consists of particles made of two atoms of nitrogen and one atom of oxygen). Other Gases Some gases in the atmosphere are entirely man-made, generated by industry. Although they exist in the atmosphere in minute quantities they are nevertheless powerful greenhouse gases contributing to global warming with lifetimes from a few years to tens of thousands of years. Among these greenhouse gases are the halocarbons: groups of gases containing chlorine and fluorine, like chlorofluorocarbons (CFC's) and hydrochlorofluorocarbons (HCFC's). Appendix 4: Kyoto Kyoto is an international agreement signed in the Japanese town of that name. Kyoto legally binds industrialised countries to slow global warming by reducing greenhouse gas emissions over the course of a decade by five percent below 1990 levels. However, the proposed cuts are too small to make any significant difference to reduce the affect of global warming. We must stop carbon dioxide emissions all together within the next 50 years if we are to prevent serious harm from climate change. Links to Web Sites About Global Warming Pew Center on Global Climate Change Europa: climate change United Nations Framework Convention on Climate Change Intergovernmental Panel on Climate Change (IPCC) WWF - about global warming. US Environmental Protection Agency: global warming © 2004 Roger Panaman All rights reserved