Can alternative energy effectively replace fossil fuels? Can you imagine a world which is covered in the blanket of darkness without any electricity to power a source that can illuminate it? This thought should intimidate you as there is a high probability that it can turn into reality in upcoming years. With rapid increase in the demand and a massive gap between the consumption and the production over the decades, it is estimated that world is going to run out of fossil fuel reserves by 2088. Petroleum reserves that constitute to 32.9% of the planet’s energy production, coming to an end in about 53.3 years. Even with great advancements in science and technology, the current state of alternative energy is not prepared to completely replace fossil fuels for the primary source of energy generation. The lack of affordability, efficiency, reliability, and most importantly, the need for breakthroughs in the process of generating energy from alternative energy sources is what allows fossil fuels to dominate the energy sector. To better understand the scope of using alternative energy sources, let’s compare the global contribution of different energy sources in the power generation. A report by British Petroleum states that about 82.6% of the world’s energy is produced by burning fossil fuels. Hydro energy and nuclear energy come next, constituting approximately 6.7% and 4.4% respectively. Other renewables such as wind energy, biogas, etc., form the remaining 2.2% of the earth’s energy. Such a high dependence on fossil fuels shows that we humans are still not fully scientifically equipped to completely replace the use of fossil fuels. Even though there are has been a significant improvement in the production of energy through nuclear, hydro, and other renewable energy, there are still a lot of hurdles to entirely rely on them. Nuclear and hydropower are two sources of energy that have the potential to replace fossil fuels in the future if they are utilized appropriately. The use of nuclear energy in the US increased from 6.6% in 2009 to roughly 20% in 2017, proposed a study by World Nuclear Association. Though some countries are trying to better avail of nuclear energy and its potential to provide carbon free energy, there are countries like Japan that have turned away from this tremendous source of energy. After the accident at The Fukushima Daiichi Nuclear Plant in March 2011, around 170,000 people were evacuated from the city due to the radioactive contamination of the land, air, and ocean waters. Due to safety concerns associated with nuclear radiations, Japan had to shut four of its nuclear power plants. This was followed by a drastic fall in its relative contribution to the country’s energy needs from 30% to just 4% by 2017. Hydroelectricity, while another carbon emission free, reliable source of energy, still cannot wholly satisfy world’s energy demands, due to geographical constraints related to successful site selection and construction of dams. Until other sources can compete with superior energy density and lower production cost of utilizing fossil fuels for energy, it is unrealistic to assume that our preferences for alternates will become a reality. Fossil fuels are highly energy dense, i.e., they produce the highest amount of energy upon being burned. For example, methane gas produces 55 MJ of energy for every kilogram that is burned, which is three times more than the energy generated from carbohydrates of the same amount. A man would have to eat 108 slices of pizza to generate 122.68 MJ of energy that could be easily produced by burning one gallon of gasoline. Comparing the prices of one gallon of gasoline to 108 slices of pizza would give a rough idea of how fossil fuels are relatively inexpensive due to their high energy density. Now, on the other hand, radioactive substances like Uranium that are used in nuclear power generation are insanely energy dense with energy density amounting to almost 500,000 Mega-Joules per Kilogram (nearly 10,000 times more than that of methane’s energy density). But the cost of producing energy from nuclear reactions (chain reactions) is also considered very high when compared to the costs associated with natural gas. After considering all these factors, it is clear that the scientific technology is not currently prepared to replace fossil fuels. This is a concerning issue as the fossil fuel reserves are gradually coming to an end. There is a need for breakthroughs and advancements in the science and technology related to generating power from alternative power sources. Development of techniques to make the power generation from nuclear energy safe is another hurdle that the scientific and engineering minds have to deal with. We have less than 50 years before the fossil fuels run out to work towards a solution and bring an end to the pollution and global warming caused by our high dependence on fossil fuels. References: British Petroleum (2011, 2013, 2014) BP Statistical Review of World Energy 2011, 2013, 2014 Available at www.bp.com/statisticalreview. Central Intelligence Agency. (2012). The World Factbook. Retrieved from www.cia.gov. EIA. (2014a). Annual Energy Outlook 2014 with Projections to 2035, DOE/EIA-0383(2014). Retrieved from www.eia.gov. EIA. (2014b). Primary Energy Consumption by Source and Sector, 2013: Monthly Energy Review Retrieved from www.eia.gov. Jones, Carla S., & Mayfield, S. (2016). Our Energy Future: Introduction to Renewable Energy and Biofuels. University of California Press, 2016, 1. Kim, Y., Kim, M., & Kim, W. (2013). 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