At present, most of our electricity and heat come from burning fossil fuels, such as gas, coal, and oil. This produces carbon dioxide gas, which builds up in the earth’s atmosphere. This build-up acts like the roof on a greenhouse, trapping the heat inside—the so-called greenhouse effect.
Other greenhouse gases, including methane and nitrogen oxides, also contribute to the greenhouse effect. The result is global warming. Average temperatures at the earth’s surface are gradually rising, causing CLIMATE CHANGE and rising sea levels.
Also, our dependence on oil as a fuel means that supplies are becoming scarcer, and production is likely to decline in the coming years. We might already have reached PEAK OIL – the point when new oil fields cannot match the production from depleted reserves, and the oil begins to run out.
On a more local level, energy efficiency helps to lift people out of FUEL POVERTY – the situation when people are forced to spend a disproportionate amount of their household income on fuel for heating and other domestic uses.