Global warming is the greatest crisis facing the environment. The average surface temperature of Earth is predicted to increase by between 1.1oC and 6.4oC by 2100, depending on which climate change scenario occurs. If emissions were stabilised at year 2000 levels, the average temperature would still rise by around 0.6oC by 2090-2099.
As shown in figure 1, different regions will warm by different amounts. This figure is taken from the Third Assessment Report (TAR) of the Intergovernmental Panel on Climate Change (IPCC) summary for policymakers (download IPCC report).
The recent warming has largely been caused by the burning of fossil fuels on a massive scale, to meet rising energy demands and also by land use changes. Electricity and transport demands are predicted to grow enormously during this century, requiring the consumption of ever increasing amounts of environmentally damaging fossil fuels. The carbon dioxide emissions produced from burning these fuels will therefore also continue to grow and contribute to damaging climate change.
We need to act now to avert the worst consequences of our actions. We must develop more efficient and cheaper, carbon neutral energy technologies, then implement them on a global scale.
In addition to the threat of global warming, there are other reasons to develop renewable energy technologies. Recently, concerns over energy security have gained prominence around the world. The need to import fossil fuels from a variety of foreign countries has led many people to contemplate more predictable sources of energy supply. Also, recent massive increases in fossil fuel prices, especially oil and gas, have focused minds on the need to develop alternative energy sources. It is obvious that there are many reasons to develop and implement renewable energy technologies. For more information see the references at the bottom of this page.
Of all of the so-called alternative or renewable energy sources, solar has the most advantages and fewest disadvantages of any of the potential sources of energy. Key advantages of solar energy include:
But current solar photovoltaic panels (that generate electricity directly from sunlight) are relatively inefficient at converting light into electricity. Solar panels also remain far too expensive, which prevents their use on a significant global scale. If we could develop far more efficient and cheaper solar photovoltaic panels we could use the vast potential of sunlight to generate electricity in every country of the world, greatly reducing the emissions of greenhouse gases.
Want to find out more? Other pages on the website provide information on climate change (and the theory behind it), energy use, solar energy and photosynthesis.