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Climate Change
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Click on the links below to have some of your climate change questions answered
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Why do we need to use less energy?
Why do we need to know how much CO2 we produce?
Why is CO2 emissions a problem now, when we have been burning coal for centuries?
What are governments doing to reduce emissions?
Aren't big carbon emitters ignoring the Kyoto targets?
How can the UK meet the Kyoto targets?
Why do some countries have high green house gas emissions than others?
Where does this leave Britain?
What about CO2 offsetting? Can't we just plant trees?
Is there anything I can do?
Why do we need to Use Less Energy?
Every time we switch on a light or turn on the central heating, or even eat a hot meal we use energy. Whatever kind of fuel we use, whether we burn it directly or indirectly by buying electricity generated from fossil fuels (coal, oil or gas), we are releasing Carbon Dioxide (CO2) into the atmosphere. CO2 is one of the main gases that contributes to global warming, which is now scientifically recognised as a real threat to today's climate. This doesn't just mean warmer summers and milder winters: global climate change is responsible for there being more floods, storms and droughts around the world than ever before.
Over the past 20 years, scientists have gathered conclusive evidence temperatures have been rising sharply since the start of the industrial revolution, and that mankind is the main cause of global climate change:
The graph above, which has been produced by the Intergovernmental Panel on Climate Change (IPCC) shows how global average temperatures have risen over past 1000 years: most of the change has been in the past century as the world industrialised and population has grown rapidly. From fluctuating in a narrow band around 0.5°C below the average 1990 temperature, it has started to rise sharply and is most likely to be between 1.5°C and 5.5°C above current temperatures by 2100.
This would have a catastrophic effect on the earth, with widespread melting of glaciers and ice-sheets, and a highly probable rise in sea level that could lead to the inundation of countries such as the Netherlands and Bangladesh. Latest scientific concern is focused on melting ice lowering salinity in the North Atlantic Ocean, that could lead to the reversal of the "Great Atlantic Conveyor" - better known as the Gulf Stream. If this were to happen, we could find that temperatures in NW Europe, including Britain, fell by up to 10°C, despite temperatures elsewhere in the world rising.
Why do we need to know how much CO2 we produce?
Recent years have seen a huge rise in the number of abnormal weather events. These have included summer droughts, flooding in Yorkshire, the Severn Valley and East Sussex, and even a number of small tornados in Southern England. Meteorologists agree that these exceptional conditions are signs that Global Climate Change is happening already. Scientists agree that the most likely cause of the changes are man-made emissions of the so-called "Greenhouse Gases" that can trap heat in the earth's atmosphere in the same way that glass traps heat in a greenhouse. Although there are six major groups of gases that contribute to Global Climate Change, the most common is Carbon Dioxide (CO2).
Carbon Dioxide is a global problem, but the countries that produce the greatest amount per person are in North America, Europe and Australasia. If Carbon Dioxide reductions are to be made, the lead has to be taken by people living in these countries. Most Carbon Dioxide in these countries comes from burning fossil fuels, such as coal, gas and oil to heat buildings (including homes) and transport. Of course, Carbon Dioxide is also given off by all living things, but in general plants capture as much as animals and micro-organisms generate. In contrast, Carbon Dioxide produced by burning fuel adds to the gases in the atmosphere and cannot be captured by plants.
Why are CO2 emissions a problem now, when we have been burning coal for centuries?
It is quite true that we, in Britain, have been burning coal for several hundred years, but Carbon Dioxide emissions each year have risen sharply since 1900. These higher levels cannot be taken out of the atmosphere by growing plants and form the major component of the Greenhouse Gases giving rise to climate instability. The five principal components of CO2 emissions come from:
- Solid Fuels, including coal, peat, town gas (created from the coking of coal) and an allowance for net combustion of wood in excess of that absorbed by new planting of wood for fuel;
- Liquid Fuels, mainly oil, but with a little LPG;
- Natural Gas, typically from the North Sea
- Flare Gases, associated with oil production, refining and methane from landfill; and
- Cement Manufacturing, where CO2 is given off a by-product of the process creating lime.
The graph below, based on data from the Carbon Dioxide Information Analysis Center of the Oak Ridge National Laboratory, shows graphically how much higher emissions are now compared to a century ago:
Data based on long term trends collated by G. Marland, T. A. Boden and R. J. Andres of ORNL
Emissions peaked about 1960, and appear to have been on a gently downward trend over the past 20 years. However much of the reduction in energy consumption over the past two decades has been due to two non-recurring features:
- the "dash for gas" in power generation, with old coal-fired stations being replaced by more efficient gas-powered stations; and
- a steady erosion of the UK's manufacturing base, with many industries closing factories to be replaced by plants in the Far East.
Although emissions from coal have steadily declined since 1987, those from oil have not. They remain stubbornly fixed at around 55 million tonnes of carbon (MtC) per annum. Although cars have generally become considerably more fuel efficient, we are all driving more miles, and newer cars are typically bigger, heavier and better equipped with energy consuming accessories such as air-conditioning. With almost one third of emissions due to the transport sector, much more needs to be done in this area.
Natural gas emissions have risen from nothing half a century ago, to around 55 million tonnes of carbon. Gas is widely used by industry and commerce as well as for power generation and to heat our homes, partly because it is seen as being the cleanest fuel. However there are only limited supplies in the North Sea, and the UK is already beginning to import some gas to make up for seasonal shortfalls - typically in winter when demand is highest. Much imported gas comes from politically unstable regions, so there is a real risk that in future supplies may not meet demand, and the UK will have to fall back onto its coal reserves. The risk was highlighted in January 2006 when a dispute between Russia and the Ukraine led to a reduction in gas supplies to much of Western Europe. Although some gas can be imported in liquid form (LNG) the associated carbon dioxide emissions are significantly higher due to liquefaction and transport energy use.
The chart also shows how external events can affect greenhouse gas emissions. The deepest dip relates to 1926, the year of the General Strike. But there is also a smaller dip in 1984, when the UK miners' strike cut consumption of coal by power stations.
The chart only looks at Carbon Dioxide emissions, and not at total energy use. This has risen much more sharply than emissions, partly because of the switch from high-carbon fuels (coal and heavy fuel oil) to lower carbon fuels (natural gas), but also because an increasing proportion of UK electricity has come from nuclear energy. If the UK is to reduce its dependence on nuclear energy, especially as its older power stations close between now and 2020, then it really has to invest more money in both energy efficiency and renewable energy.
What are Governments doing to reduce emissions?
Governments across the world have met in a series of Climate Change Conferences and set targets for the reduction of emissions of CO2 from burning fossil fuels. The main international agreement is known as the Kyoto Protocol, under which certain industrialised nations agreed to a cap on their emissions of CO2.
Under Kyoto, the EU committed to reducing average CO2 emissions from the 15 member states by an average of 8% below 1990 levels by then period 2008-12. The UK Government accepted a higher Kyoto target of 12.5% savings and at one stage set itself an even tougher non-binding target of cutting emissions by 20% by 2010. Although most European countries have been working hard towards achieving their Kyoto targets, they only came into force in 2005 after Russia ratified the agreement.
Aren't big carbon emitters ignoring the Kyoto targets?
It is true that some large emitters of CO2 in the developing world, notably China and India, were not set targets under Kyoto, and that Australia and the USA have refused to ratify the protocol, despite signing it initially. Nonetheless, countries expected to make over half the savings have implemented the protocol, and it is expected that the follow-on agreement will include most of the large developing countries. In all, over 150 countries have ratified the agreement.
Please follow this link for a list of countries that have signed the Kyoto agreement (PDF file, 15K) including the amount of CO2 emitted by all main countries in 2002.
How can the UK meet the Kyoto targets?
The best way of reducing CO2 emissions is by using less energy and - just as importantly - getting best value from the energy that we do use. But as well as doing this, it helps to know just how much Carbon Dioxide we are using. This web page includes a simple calculator that should help in calculating your own CO2 emissions. All figures apply to the UK and are based upon official Government figures from the Department of Environment, Food and Rural Affairs.
Why do some countries have higher Greenhouse gas emissions than others?
There are three main reasons why some countries use more energy per person than others:
· Climate
· The level of industrial development
· Energy taxes.
Carbon Dioxide emissions also depend on how electricity is generated.
Many people are aware that the USA is the world's largest producer of Carbon Dioxide. This is partly because it has the highest material wealth in the world, in total and on a per person basis. But it also suffers from a relatively extreme continental climate, with bitterly cold winters away from the coast and blisteringly hot summers. Much energy is used in heating and cooling buildings. Americans are also famous for their love of the automobile. Petrol (gasoline) is, by European standards, very cheap, and many American cities are widely spread out, causing inhabitants to drive long distances to work or to shop.
It may be a surprise to see that Canada has a lower Carbon Dioxide output per inhabitant, even though it is even colder than the USA. In part, this is due to lower summer temperatures requiring less air-conditioning, but Canadians also generate more electricity from non-polluting sources (hydro) and pay higher taxes on petrol and have begun to impose high insulation standards on new buildings.
After the USA, the two highest Carbon Dioxide emitters are Australia and Norway. Australia is particularly hot, requiring cooling, and much of its electricity comes from cheap opencast coal, which produces the most CO2 level per unit of electricity. Norway is contrastingly cold, but also once had an extensive coal industry.
If Norway is a high emitter, then Sweden is relatively low for an even colder developed country. This too is largely due to its choice of fuel for electricity - in Sweden's case a mix of hydro-electricity, biomass (from forest wastes, often in combined heat and power schemes) and nuclear energy. 49% of Sweden's electricity comes from renewable resources, and the Swedish government is committed to increasing this to 60% as it phases out nuclear power over the next few years. Swedes have also employed superb levels of insulation in buildings since the 1930s, meaning that homes are snug and affordable in the very worst winters.
France is another European country with a lower than expected Carbon Dioxide output per person. The French climate is relatively temperate, but the real reason is that around 70% of its electricity comes from nuclear power.
Looking across the rest of the world, two areas stand out: the Middle East, with quite high emissions, and Africa with low ones. In the Middle East energy - oil - is very cheap and temperatures are high year-round: this has led to rapid growth in energy demand in recent years as buildings have benefited from air-conditioning and people have started to make even quite short journeys in air-conditioned vehicles.
In contrast, sub-Saharan Africa has many of the world's poorest countries, including Chad, which boasts the lowest per capita emissions in the world. Demand for energy remains low, despite the climate, and in rural areas much of the energy used comes from burning wood. This has led to problems associated with deforestation and desertification: if the environment is to be safeguarded then, at least in the medium term, African CO2 emissions are likely to have to rise.
Where does this leave Britain?
Our national emissions remain well above the world average, although not dissimilar from much of Europe. Although they have fallen in recent years, this has largely been as a result of a rapid change from coal to gas for electricity generation. We could, and should, do a lot more to reduce our energy use and encourage the development of truly renewable resources - only 1.7% of our electricity comes from renewable energy.
The UK will only be able to reduce its Carbon Dioxide emissions is ordinary people do their bit as well as Government. As an individual, there are a number of things that you can do.
What about CO2 offsetting ? Can't we just plant trees?
 One way of reducing Carbon Dioxide (CO2) in the atmosphere is to capture the gas and store it (sometimes known as sequestering the carbon). This can be done most easily by planting trees, which absorb CO2 and convert it into woody biomass, which will not be released into the atmosphere for many years.
This is superficially a very attractive way of saving carbon, and a number of companies have been set up to plant forests with the specific purpose of taking carbon out of the atmosphere. However there are a number of problems with this approach: one is to ensure that the carbon captured in this way stays as wood and does not return to the atmosphere within a generation or so, for example by chopping down and burning the forests. The other, more serious complaint, is that there simply is not enough land to plant all the trees that would be necessary to sequester all the necessary carbon.
The UK's Forestry Commission has calculated that as a rough guide, the carbon sequestered by half a hectare of woodland over one rotation can compensate for the CO2 emissions associated with car fuel consumption during an average driver's lifetime. This may not sound like a large area, but with 30 million motorists in the UK, three-quarters of the land area of Britain would have to be planted with trees permanently to make car use alone carbon-neutral. And given that CO2 emissions from transport are roughly equal to those from homes, a similar area would be needed to make up for energy used in British homes in an average lifetime.
Many of the companies originally set up to plant trees have realised that this cannot be enough on its own, and so also invest in energy saving measures and renewable energy sources to offset carbon dioxide emissions from their customers. Buying carbon offsets from one of these companies can still be an environmentally good thing to do to ameliorate the effects of CO2 emissions from, say, an aircraft flight. Our free CO2 calculator will help you estimate amount of CO2 that you may need to offset in this way.
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Is there anything I can do?
Over a quarter of the CO2 produced in the UK comes from the fuel we use in our homes. By insulating our homes, controlling the way we use our heating and using other appliances sensibly we can have a major impact on the amount of energy and CO2 used. (And with another quarter of British energy used by motor cars, we can also help reduce the risks from global climate change by avoiding unnecessary car trips, using public transport, cycling or walking whenever possible.)
The average household can cut at least £100 a year off their fuel bills without losing either warmth or comfort by simply using energy efficiently and effectively, and at the same time make a considerable reduction in CO2 emissions.
Visit the Carbon Workout to find out how or take a look at Act on CO2 at Home and Act on CO2 when Traveling or contact your local Energy Efficiency Advice Centre by calling 0800 512012 |
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