The world needs to start making alternative energy sources a priority for a number of reasons. “Alternative energy refers to energy sources that have no unintended consequences such as fossil fuels or nuclear energy” (“Alternative Energy”). Alternative energy sources collectively provide only about 7% of the total world energy supply (McLamb). Although fossil fuels are cheap and abundant, can help a country's economy, and can be extracted with relative ease, they have many disastrous effects (“Activity 3 – Fossil Fuels – The Pros and Cons”). The burning of fossil fuels emits dangerous substances that damage our ecosystem. Carbon dioxide, a major greenhouse gas, is emitted (McLamb). Greenhouse gases cause global warming to progress (McLamb). The effects of global warming include the melting of the polar ice caps causing sea levels to rise. This causes a change in the composition of the surrounding water (McLamb). Pollution from burning fossil fuels also harms living plants and animals (McLamb). Fossil fuels will become increasingly difficult to extract as time goes by (“Activity 3 – Fossil Fuels – The Pros and Cons”). Even though scientists have found a way to control pollution, it is very expensive (“Activity 3 – Fossil Fuels – The Pros and Cons”). It will also become more difficult and dangerous to extract fossil fuels as companies like Exxon and Marathon are forced to drill deeper to obtain more oil (“Activity 3 – Fossil Fuels – The Pros and Cons”). This will increase fuel costs (“Activity 3 – Fossil Fuels – The Pros and Cons”). There are many alternatives to fossil fuels that can provide sustainable energy. Nuclear energy provides 6% of the world's energy (McLamb). Nuclear energy is harvested by printing valuable resources into cars and electricity when they are needed to produce new materials and power medical research equipment (“Activity 3 – Fossil Fuels – The Pros and Cons”). Humans need to start caring about the future of the Earth and start using renewable energy sources regularly. Works Cited "Activity 3 - Fossil Fuels - The Pros and Cons". SEAI. The Sustainable Energy Authority of Ireland, n.d. Web. 15 November 2013. “Alternative Energy.” – Wind, solar, hydroelectric and other alternative energy sources for home energy. Np, nd Web. November 13, 2013. “Alternative Forms of Energy.” Advantages of recycling. Np, nd Web. November 13, 2013. Karthik, Natayani. "Alternative forms of energy". iBuzzle. Np, 04 Oct 2011. Web. 13 Nov 2013. McLamb, Eric. “Fossil Fuels Versus Renewable Energy Resources.” Global Ecology Network. Ecology Communications Group, September 6, 2011. Web. November 12. 2013.