We can do a similar calculation for natural gas and coal: at our current consumption rates, natural gas will last us around 62 years and coal will last us around years [1,6]. Nonetheless, the point remains that fossil fuel resources are finite and, based on the calculations above, will not allow human societies to flourish for timespans longer than years. There are significant national security concerns related to depending upon and financially supporting these politically volatile nations, some of which have links to terrorist networks.
Fossil fuel use is also unsustainable for our health and the safety of the environment. For example, emissions from coal-fired power plants include particulate matter and mercury, and are responsible for respiratory illness and premature death especially in vulnerable populations like children and the elderly [8].
Due to the Clean Air Act, the United States has instated more measures to regulate pollutants than developing countries. Unfortunately, coal plant emissions are not just local, meaning that longer-lived pollutants like fine particulate matter, mercury, and cancer-causing chemicals get transported from countries with poorer air quality standards to other areas of the globe [9].
Further, coal has a considerable hidden cost associated with economic, health, and environmental impacts. It is estimated that the combined cost of mining, transportation, processing, and combustion to the United States alone can range from billion to over billion dollars annually [11].
In other words, we pay a high price for coal in the form of health care costs and higher taxes but coal appears cheap only because the price is not directly on our electricity bills. If we account for these hidden costs, coal-generated electricity is three times more expensive than what we pay directly and suddenly renewable sources of electricity are economically competitive with coal [11]. Human fossil fuel use is also contributing to global climate change: burning fossil fuels produces the greenhouse gas carbon dioxide as a byproduct.
There is increasing evidence that the carbon dioxide produced from burning ancient fuels is accumulating in the atmosphere faster than the land and oceans can take it up. Sustainable energy is derived from resources that can maintain current operations without jeopardizing the energy needs or climate of future generations.
The most popular sources of sustainable energy , including wind, solar and hydropower, are also renewable. Biofuel is a unique form of renewable energy, as its consumption emits climate-affecting greenhouse gasses, and growing the original plant product uses up other environmental resources. However, biofuel remains a major part of the green revolution.
The key challenge with biofuel is finding ways to maximize energy output while minimizing the impact of sourcing biomass and burning the fuel. Even with resources that are both renewable and sustainable, like wind and solar power, an important question remains: Is sustainable energy the solution to our energy and climate needs?
In addition to the biomatter conundrum , not all sustainable solutions can be used in every situation. In the U. How do we ensure this energy fairly provides for other regions, like the Northeast? Furthermore, disparities in regulations and target goals can create a problem where the best place to produce energy may not have the public interest or infrastructure necessary to support it.
For example, a windy state may struggle to pass legislation for financing the construction of turbines, while its neighbor may be eager for a nearby source of clean energy. How do we navigate such situations in a way that allows consumers to get what they want, no matter where they live?
It will take more to support widespread adoption of renewable and sustainable resources than technical knowledge alone. They can also occur during distribution, for example in oil spillages from tankers that pollute beaches and kill wildlife; or on combustion, which generates atmospheric pollutants such as sulphur dioxide and oxides of nitrogen that are detrimental to the environment and to health.
Fossil fuel combustion also generates very large quantities of carbon dioxide CO 2 , the most important anthropogenic human-induced greenhouse gas. The majority of the world's scientists now believe that anthropogenic greenhouse gas emissions are causing the earth's temperature to increase at a rate unprecedented since the ending of the last ice age. This is very likely to cause significant changes in the world's climate system, leading to disruption of agriculture and ecosystems, to sea level rises that could overwhelm some low-lying countries, and to accelerated melting of glaciers and polar ice.
Nuclear power has grown in importance since its inception just after World War II and now supplies some 7 per cent of world primary energy. A major advantage of nuclear power plants, in contrast with fossil fuelled plants, is that they do not emit greenhouse gases. Also, supplies of uranium, the principal nuclear fuel, are sufficient for many decades — and possibly centuries — of supply at current use rates. However the use of nuclear energy, as we shall see, gives rise to problems arising from the routine emissions of radioactive substances, difficulties of radioactive waste disposal, and dangers from the proliferation of nuclear weapons material.
To these must be added the possibility of major nuclear accidents which, though highly unlikely, could be catastrophic in their effects. Although some of these problems may be amenable to solution in the longer-term, such solutions have not yet been fully developed.
Extracting energy from fossil or nuclear fuels, in the course of providing energy-related services to society, generates significant environmental and social impacts.
These impacts are greater than they need be because of the low efficiency of our current systems for delivering energy, converting it into forms appropriate for specific tasks, and utilizing it in our homes, machinery, appliances and vehicles. An important way of mitigating the environmental impacts of current fuel use is therefore to improve the efficiency of these systems.
Over the past few decades, significant efficiency improvements have indeed been made, but further major improvements are feasible technologically — and are, in many cases, attractive economically. Of course, not all energy sources are of fossil or nuclear origin. The renewable energy sources, principally solar energy and its derivatives in the form of bioenergy, hydroelectricity, wind and wave power, are increasingly considered likely to play an important role in the sustainable energy systems of the future.
The 'renewables' are based on energy flows that are replenished by natural processes, and so do not become depleted with use as do fossil or nuclear fuels — although there may be other constraints on their use. The environmental impacts of renewable energy sources vary, but they are generally much lower than those of conventional fuels. However, the current costs of renewable energy sources are in many cases higher than those of conventional sources, and this has until recently retarded their deployment.
All these considerations suggest that in creating a sustainable energy future for humanity during the coming decades, it will be necessary:. These three general approaches will be explored further, and in greater detail in the remaining sections of this course. Making the decision to study can be a big step, which is why you'll want a trusted University. Take a look at all Open University courses. If you are new to University-level study, we offer two introductory routes to our qualifications.
You could either choose to start with an Access module , or a module which allows you to count your previous learning towards an Open University qualification. Read our guide on Where to take your learning next for more information. Not ready for formal University study?
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