What is it?
Global Warming… Climate Change… The Greenhouse Effect. All these terms have been talked about and hotly debated in recent years but what exactly are they and what do they mean to us now and into the future? All these terms are parts of a phenomenon where a series of changes in global weather patterns are being recorded and studied. These changes from what has been considered to be ‘normal’ are happening rapidly and have different meanings and affects in different parts of the world: for some it will mean more rain in winter, for others it will be drier summers, and in yet other areas less rain overall. Longer hotter summers, longer more severe winters, an increase in the length and severity of droughts, and the increased frequency of intense weather events such as flooding, hail storms, earthquakes and cyclones are all being experienced. It is generally agreed that change and instability in global weather patterns will be the ‘new normal’.
For some years there has been conjecture around whether or not these changes are simply part of one of abnormal series of long-term, over many millennia, climate changes that the earth has experienced that has seen the climate change from wet to dry, tropical to ice age and back again, or whether these changes are actually man made. In fact, the scientific consensus is that the adverse results experienced over the last 100 years are indeed the result of human activity.
Major Reasons and History of Research
The concept of climate change is not a new one. The existence of a natural greenhouse effect was first suspected in the early 19th century when changes in the paleo climate– the climate in former geologic periods such as the ice ages – were first being studied. As far back as 1824 French scientists such as Joseph Fourier and Claude Pouillet were talking about the existence of what is now known as the Greenhouse Effect. This effect was further studied and expanded upon by Swedish scientist Svante Arrhenius who was the first scientist to attempt to calculate how changes in carbon dioxide levels in the atmosphere could lead to changes on the surface temperature of the earth.
The now-familiar term ‘Greenhouse’ was first used by another Swedish scientist Nils Gustaf Ekholm in 1901, but it was ground-breaking work, done forty years prior to Ekholm’s findings by English natural philosopher John Tyndall that brought together all the strands of earlier work done by Ekholm, Arrhenius, Pouillet and Fourier. Tyndal started with Fourier’s understanding that gasses in the atmosphere might trap heat from the sun and set out to find out which gasses these were. After careful laboratory work he identified that the presence of carbon dioxide (CO2) and simple water vapour (H2O) were able to alter the balance of heat radiation through the entire atmosphere. By the time Arrhenius was published in 1908 the rate of coal burning -one of the major sources of excess amounts of CO2 in the atmosphere -was already significantly higher than when he commenced his research in 1896.
There are many natural factors that affect the climate such as increased solar activity and events such as volcanic eruptions that emit vast amounts of greenhouse gasses such as methane, sulphur dioxide, hydrogen sulphides and CO2 into the atmosphere. We have no control over these natural but reputable scientific research lays the cause of climate change squarely at the feet of human activity, with the unprecedented growth of the human population being one of the main causes of global warming.
When serious recognition of and research into this phenomenon was beginning back at the turn of the 20th century there were nearly two billion people living on earth. In 2012, the global population passed seven billion with every one of them all needing food, heating, transport and employment. When taken into account that nearly three of these seven billion live in the developing economies of China and India it’s not difficult to understand how human activity is the major contributing factor to global warming is.
This serious upward growth of population and the unprecedented release of stored carbon into the atmosphere from burning coal began with the industrial revolution. The rise of industrialisation began in the late 18th century when the power of running water was harnessed and used to drive machinery in factories. By the middle of the 19thcentury massive amounts of carbon were being released into the atmosphere as coal took over as the main energy source. It was burned to turn water into steam to drive ever more powerful machinery to increase profits. As living standards began to increase and the cost of consumer goods began to fall due to mass production, people had more and more spending power.
By the early part of the 20th century automobile culture began to become entrenched in the USA and spread across the rest of the world after the end of WWII. By the turn of the 21st century the Greenhouse Effect had gone from theory in the time Fourier, Pouillet and Ekholm to reality today. The industrial revolution is not simply a historical phenomenon – it is being mirrored today in the industrially developing economies of India and China where the demand for cheap energy to power their expanding economies continue to grow despite some recent economic downturn.
But just what is the greenhouse effect? Simply put it is the affects felt on the surface of the planet resulting from the trapping of the sun’s radiation inside the atmosphere. This radiation then leads to heating as it is absorbed by Greenhouse Gasses. The Greenhouse gasses are primarily carbon dioxide, 82%; Methane (CH4), 9%, Nitrous oxide (N2O) 5%, and Clorofluorocarbons (CFC’s) and Hydrofluorocarbons 2%. Methane and Nitrous Oxide are mostly produced from fossil fuel production, agricultural activities such as livestock farming and from landfills and as by-products of industrial processes.
All greenhouse gasses have different properties in relation to global warming. Methane has a much shorter lifetime in the atmosphere but is more efficient in trapping radiation with an effect of being 25 times greater than the same amount of carbon over a 100-year period. Nitrous Oxide also has an enormous effect on global warming with its effect being almost 300 times that of the same amount of carbon dioxide over the same time frame. Carbon dioxide makes up the biggest percentage of greenhouse gasses in the atmosphere and is the one most directly related to human activity. The biggest contributors to CO2 emissions are the electricity and transportation industries making up more than half the emissions of CO2 with agriculture, other industries and residential and commercial use making up the balance.
It is however, the gasses found at the lowest percentage, the CFC’s that do the most damage. CFS’s, and their close cousins Halons, are organic compounds containing carbon, chlorine and fluorine and were first produced in the 1930s by the DuPont Company under the name Freon. These compounds no not occur naturally in the environment and have an active lifespan of 60 to 100 years. They were commonly used in the aviation industry and closer to home as propellants in aerosol cans, for commercial dry cleaning and in domestic and automobile refrigeration units. They have been phased out for domestic use since the IPPC (International Pollution Prevention and Control) directive in the 1990s and the signing of the Montreal Protocol saw production of new stock cease. The use of CFC’s and Halons are now prohibited in many countries since the first decade of the 21st century. Their replacements hydro fluorocarbons (HFC’s) are a little less damaging to the environment. Being less stable in the lower atmosphere HFC’s break down before reaching the higher levels of the atmosphere in the ozone layer.
Even though CFC’s make up the smallest percentage of the greenhouse gasses they are the most damaging as they deliver the ‘double whammy’ of being both a greenhouse gas and causing ozone depletion. Ozone depletion and the associated layer are two distinct phenomena that occur in conjunction with the greenhouse effect but are not connected to each other and nor do they influence one another. Ozone (O3) Ozone is a much less stable form of the more common oxygen (O2) and is found in the higher levels of the atmosphere, the stratosphere, some 15 to 50 kilometres above the surface. Ozone reacts with ultraviolet radiation and stops dangerous levels of this radiation from reaching the earth.
The widespread use of CFC’s from the end of WWII – it is estimated that it was used in up to three hundred million air conditioners, freezers and refrigerators up to the 1980’s – saw a rapid increase in the emission of these gasses into the environment. The damage is done when the CFC’s reach the upper reaches of the atmosphere. In that level of the atmosphere ultraviolet radiation from the sun causes the chemical bonds holding the CFC molecule together to break down releasing their constituent atoms. One of the atoms is chlorine. Chlorine reacts with ozone causing a devastating destruction of ozone molecules. The biggest problem with CFC’s in the atmosphere is that they are not washed back down to earth by rain and the released chlorine stays in the atmosphere to continue to wreak havoc with the balance of ozone and oxygen. Even though CFC production and use has been banned and phased out, its chemical stability means that natural repair of the damage won’t happen until at least the middle of the 21st century.
How humans have contributed to climate change.
It is generally accepted by the scientific community that human activity is the main driver for the climate changes that are now unfolding.
Clearing of forests is a major factor when considering climate change, and it is happening at an unprecedented rate around the world. One estimate is that there are more than three trillion trees on the planet. This sounds like an inconceivable number until it is considered in conjunction with another estimate that the number of trees on the planet has decreased by 46% since the beginning of civilisation. Trees are vitally important to the carbon cycle in the environment. As they grow they use the energy from the sun to convert captured carbon into their trunks and foliage acting as a ‘carbon sink’ that locks up carbon in their very structure.
Some 43% of the current trees are found in the tropical rainforests and the sub-arctic forests of the northern hemisphere, but it is the tropical rainforests, particularly the vast Amazon rainforest that are most under pressure from clearing. It is estimated that approximately 7.3 million hectares of Amazon rainforest are being lost each year with much of the felled timber simply being burned directly releasing the stored carbon into the atmosphere.
It is mostly the exotic tropical forests across Asia and South America that are in the forefront of people’s minds when considering deforestation, but recent research into global tree cover loss ranks the thinning of the sub-arctic forests in Russia and Canada as the most problematic. Deforestation in these two countries alone has accounted for over 30% of tree cover loss in recent times. Much of this loss is a direct result of climate change itself. Massive wildfires consume the forests releasing more carbon into the atmosphere adding to global warming and increasing the likelihood of hotter temperatures that in turn leads even drier conditions and to more fires.
The main human activity that has a negative impact on climate change is the seemingly ever-increasing human population. Despite the People’s Republic of China introducing the One Child Policy in the late 1970s’ the Chinese population has continued to grow from 0.9 billion in the mid 1970’s to a staggering 1.3 billion at the turn of the 21st century. Similarly, India, with just 2.4% of the world’s land area supports over 17.31% of the world’s population and has nearly 1.2 billion people. The population of the rest of the world continues to grow by approximately 83 million people per year with most of this growth being in less developed parts of the world; many countries in the developed world are experiencing much smaller population growths, with some countries experiencing a decline.
With increased population comes the need to produce more of everything: more food, more income, more housing. Other pressures that increasing human population contribute to climate change are industrialisation, the attendant demands for energy to fuel increased production and increasing pressure on agriculture and livestock production. All these factors combine and put pressure on the environment and in turn on the climate and make it difficult to reel back damaging emissions in the foreseeable future.
What are the dangerous impacts of climate change?
One of the most far-reaching impacts of the rapid climate change being experienced right now is the extinction of plants and animals. It is estimated that up to one quarter of all species will be extinct by 2050.
As a terrestrial species, it’s easy for humans to notice the impact of the warming of the land we live on but warming of the world’s oceans is a very serious threat. Oceans have responded more slowly to global warming, but research is showing that the marine environment is more sensitive to even moderate temperature change. The first threat is simply a matter of physics, warm water expands and takes up more space, meaning rising sea levels. But add to this that the world’s glaciers and ice caps are melting at unprecedented rates which is putting more fresh water into the ocean and leading to even higher sea levels, that in turn threatening low-lying coastal communities.
The most vulnerable organism in the ocean is coral. Corals are a unique symbiosis between plant and animal and lives in already quite warm water. Coral reefs provide the marine equivalent to forest cover on dry land where many species of marine animals breed. As the oceans warm, the delicate balance of tropical seas is disrupted causing corals to die off and bleach as the algae that live within the coral structure die. With no living corals reefs become warm, wet deserts.
Looking at a lush coral reef you could be forgiven for thinking that these are the most productive areas of the ocean. It is in fact the cold waters of the southern and northern oceans that are the richest with animal diversity, all because of the unimaginable numbers of krill – a small crustacean – that populate these waters providing food for many species of fish. Krill, like corals, are extremely sensitive to water temperature and recent research has shown that their numbers are significantly lower in warmer water.
As these problems weren’t enough for the world’s oceans to contend with there is another serious threat – acidification. It is not a widely known fact, but algae in the oceans are able to absorb an enormous amount of carbon out of the atmosphere. This uptake of carbon causes a chain of chemical reactions that reduce the pH balance (a sliding scale that expresses the level of acidity or alkalinity of a substance) increasing acidity. Even a small change in the pH balance can lead to major changes in coral reef formation and associated impacts on the shells of many marine creatures such as tiny plankton that are an important part of the marine food chain.
Back on land, as temperatures increase there is a higher rate of evaporation of water. This cycle means that more water is being drawn up from the land increasing soil dryness, and more water will be circulating in the lower atmosphere increasing the frequency of extreme weather events such as storms. Another factor to take into consideration is that due to generally higher temperatures much of this water will return to earth as rain rather than snow leading to even more changes in precipitation distribution – more rain will probably now fall earlier in the spring/summer cycle, putting increased pressure on ground water supplies in the hotter, drier months.
Some plants may respond well to higher temperatures. This will lead to changing climate patterns meaning that some traditional crops may not be able to be grown in some areas. But it may also mean that food production in some areas may increase due to the extended growing season and the ability to grow fast maturing crops that weren’t possible before climate change. There will, most likely, be disruptions to food supplies as earlier hot weather and longer and later snow seasons change local climates and disrupt customary farming practices.
Global health is another thing that will be impacted by climate change. As temperatures increase it is estimated that by 2050 there will be an increase of quarter of a million deaths from malnutrition and heat stress each year. Fewer people might be dying from hypothermia as the climate warms, but this will be offset by an increased number of deaths from heat stroke and more insect-born disease as vector insects such as mosquitoes increase their range.
What are the things at stake?
At stake is the very way of life for millions of people around the world have taken for granted over hundreds of years. There are two groups of indigenous people who are literally a world apart but are already experiencing the effects of climate change – the Inuit who in the icebound regions around the Arctic Circle, and the people living on low lying coral atolls such as Tuvalu in the South Pacific Ocean.
Tuvalu in the South Pacific Ocean
The name Inuit is a broad term covering a diverse group of people who have lived in the Arctic regions of Greenland, Canada and Alaska for at least a thousand years. Over this time, they have developed a finely tuned culture allowing them to live in one of the harshest and most inhospitable climates on the planet.
They have managed to survive by fishing and hunting for seal and whale, often travelling huge distances over sea ice on hunting expeditions. Recent climate change has seen an increase in animals not usually seen mostly birds and fish such as salmon, but faster melting ice has resulted in fewer hunting days each year. The winter sea ice is now thinner making hunting expeditions more hazardous. Livelihoods in the communities are changing; Permafrost is melting leading to changes in the geography and damage to buildings. The ice around inland lakes is melting allowing the water to drain into the ocean killing stocks of freshwater fish. The autumn freeze is happening later, and sea ice is floating further out to sea taking the seals which are part of the food source for both humans and polar bears further away. The changes in the Polar Regions as we experience climate change are some of the most dramatic and closely studied.
At the other end of the world, lying in the South Pacific Ocean is the idyllic island nation of Tuvalu. At its highest point Tuvalu is only 4.5 metres above sea level. Rising land and sea temperatures as a result of global warming has seen sea levels rise 5mm a year since 1993, which is nearly twice the global average. Acidification of the seawater is also playing its part with a negative impact on the growth of corals that Tuvalu is built on. It is estimated that cyclones in the region will be less frequent but more intense and Tuvalu is at a geographic juncture that sees it at the mercy of the naturally occurring El Nino cycle that governs the cycle of wet and dry seasons in the Southern Hemisphere. The future of the 10,500 population of Tuvalu and other Pacific nations continues to be closely watched by scientists studying the effects of global warming.
How can it be stopped, how can it be limited, how are we going to deal with it?
There is no magic wand that can be waved about that is going to stop climate change in its tracks. Most reputable scientific research has come to the same conclusion that to limit climate change the most effective measure than can be taken is to reduce carbon emissions. At its simplest this means directly reducing the amount of carbon emissions going into the atmosphere. This can be done but needs concerted effort by public and governments worldwide to first recognise and agree that controls need to be put into place – sooner rather than later – and secondly, by following up with effective legislation and making funds available to ensure continued compliance.
Renewable energy is a buzz-word that has been around for some time. Renewable energy sources include solar, wind and bio-fuels. Solar power has been around for some time, but it has only been relatively recently that technological advances and mass production of solar cells has brought the price down to affordable levels to make mass uptake a viable option, but it remains one of the most accessible and easily used and implemented sources of renewable energy being relatively cheaply installed and maintained. Wind power is more problematic. While it seems that wind is everywhere on the face of the planet, in reality there are very few locations that are truly suitable for commercial wind energy production. One often talked about disadvantage of large-scale wind power generation is the size of the turbines and the noise that they make. On the positive side small wind turbines can be easily installed into remote areas, particularly in developing economies. Small scale wind turbines need very little in the way of ongoing maintenance and the land below them can continue to be used for agricultural purposes. One advantage of both solar and wind power is that power generated can be stored in batteries for future use and excess power can be fed back into the conventional grid to supplement and reduce the reliance on fossil fuels generated power.
Bio-fuels are a relative newcomer in the world of renewable energy sources. They are made from a variety of sources such as corn or sugar cane, but can also be derived from algae, used cooking oils or human waste products. There are some problems with the production of bio fuels in that the raw materials required are usually used to feed people and animals. Another is the sheer quantities needed with one estimate being that for Australia to use ethanol bio fuel made from sugar cane to power cars and other road transport it would require the whole of the current crop grown with nothing left over for domestic sugar production and export. One positive to come from widespread use of bio fuels is that many of the crops that are currently used for the production of bio fuel – canola and corn – are widely grown, often in surplus quantities, and using these crops in this was would ensure steady income for many hundreds of farmers worldwide.
It is vitally important that developed nations who are striving towards reducing their carbon footprint (the amount of carbon released as a result of activities of individuals, companies or organisations) must encourage developing nations to develop and grow their economies by the use of ‘clean and green’ energy alternatives.
In developed countries we can all contribute in small ways by conserving energy. This can take the form of ensuring our houses are well maintained, installing insulation, using energy efficient light bulbs, ensuring our cars are running efficiently, and making sure that all the household appliances we use such as refrigerators and air condition units are working properly.
Global warming and climate change can be stopped. We have the means but what is lacking in many cases is the political and economic will to absorb the short-term pain of some measures to ensure long-term goals are met. These means include such measures as the introduction of carbon pricing and emission trading schemes; investment into research and development to make it possible industry to operate more cleanly and efficiently; and making sure that funds are available to ensure the enforcement of commitments made by governments. All these measures combined will ensure long-term benefits are achieved to secure a viable future for coming generations.
There are many things that each and every one of us can do to limit the impact of climate change and reduce the length of time that it will take for our planet to recover. You could try some, or all, of the following:
- Be energy efficient: Turn off your computer when it’s not being used; turn off stand-by mode on televisions and other appliances; make sure your car is good repair and drive smoothly; install energy efficient light bulbs.
- Choose renewable energy sources where possible – wind, solar, bio fuel.
- Join action groups to keep pressure on governments to meet and enforce global agreements limiting harmful practices.
- Support and donate to green groups.
- Support recycling by buying recycled products where possible
- Join up Meatless Monday – even one day a week not eating meat can have a positive impact on reducing greenhouse gasses generated by the livestock industry.
Be personally responsible by becoming the change you’d like to see. Setting a good example can help to encourage others to join in with minimising the contributing factors to climate change.