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Energy can be defined as the ability or capacity to do work or to produce change. Forms of energy include electricity, heat, light, sound and chemical energy.
Can you imagine life without heat, light, television, cars, or computers? What if you had to cook your dinner over a fire or fetch water from a river? It might be fun for a camping trip, but you probably would not want to do it every day. But that's how life was before we discovered ways of using energy that make our lives easier.
We now realise that the things we take for granted like cars and electricity are actually having a serious impact on the world around us through the harmful gases they produce. Emissions of certain gases produced by humans have serious implications for the greenhouse effect and are causing global warming (also known as climate change).
The Intergovernmental Panel on Climate Change (IPCC), established by the World Meteorological Organisation and the United Nations Environment Programme in 1988, consists of the world's top climate scientists. The IPCC has produced three major assessments of climate change, the last of which was published in July 2001. The IPCC has confirmed that there is increasing evidence that human actions are changing the world's climate. It forecasts that, without action to reduce emissions, global average temperatures will rise between 1.4°C and 5.8°C over the next 100 years. However, the IPCC also concluded that emission reduction technology is developing quickly. There is therefore significant potential for action to cut emissions and avoid the worst effects of climate change - if action is taken now.
Concentrations of carbon dioxide in the atmosphere have increased by 31% since 1750 and the current rate of increase is greater than at any time during the past 20,000 years. By burning fossil fuels humans are adding carbon dioxide and other heat-trapping greenhouse gases to the atmosphere at a perilous rate and the Earth is heating up.
The global temperature build-up is seriously disrupting the natural balance of the world's climate. The UK Climate Impacts Programme (UKCIP) uses a sophisticated global climate model to forecast what the effects of this disruption might be over the next 100 years. Their Climate Change Scenarios report, published in April 2002, shows how the climate of the UK is already changing and how it will change even more in the future. By 2080 Scotland will have warmer, wetter winters, less snowfall and increased flooding. Sea levels are forecast to rise by as much as 60cm around Scotland, while summers may become drier and warmer and snowfall could decrease by up to 90%. In July 2003, the British Irish Council published climate change scenarios for the Scottish islands, including the Orkney Islands, the Western Isles and the Shetland Isles. The computer model used in the UKCIP scenarios had not been detailed enough to show these islands so a new model was developed. This has shown that by 2080 annual average temperatures will increase by as much as 1.8 degrees Celsius in the Western Isles, 2 degrees C in the Orkney Islands and 2.2 degrees C in the Shetland Isles. Rainfall in summer will decrease by 22% in the Western Isles, 27% in the Orkney Islands and 19 % in the Shetland Isles. Average snowfall could decrease by 89% and sea levels rise by up to 69 cm around all three islands.
Our increasing knowledge about the likely impacts of climate change makes it clear that we need to reduce emissions of greenhouse gases. We need to be more energy efficient and use alternative sources of energy to fossil fuels if we are to reduce the impact of climate change.
