Wednesday, June 26, 2013
Fossil Fuel Carbon Footprints and Global Warming
Fossil fuels are responsible for an increase in carbon dioxide in the atmosphere. Since CO2 is a greenhouse gas its presence contributes to global warming. CO2 is also a component of vocanic gases so we can't just blame fossil fuels for our problems. To help reduce our carbon footprint we can rank fossil fuels by how much CO2 they release for each Joule of energy they produce. The results for carbon (coal), octane and ethanol (oil) and methane (natural gas) are shown in the table below (source).
If we had to choose from among the fossil fuels natural gas is the best choice since it releases half the amount of carbon dioxide for each Joule of energy produced. Due to the laws of thermodynamics not all of this energy is available for use since some of it has to be wasted in our heat engines.
If we treated the choice of fossil fuel as an economic problem with the CO2 being a "cost" to the environment then to optimize the amount of energy produced while minimizing the release of CO2 the "economic" choice is natural gas. Biofuels also release CO2 into the atmosphere but we can't treat them the same way that we treat fossil fuels since they remove CO2 from the atmosphere when they are produced.
The alternative to the use of fossil fuels is energy from nuclear, solar, wind and wave sources. The last three require large areas for production since the energy density is low. Using them the cities would have to impose on the rural areas to get energy like they have done to get water in the past. Does eminent domain apply when city and state boundaries need to be crossed? National regulations are clearly needed here since nuclear energy has problems with its risks and waste.
What else can we do to reduce the nation's carbon footprint? Global warming is a problem for the entire world. We can't reduce our nation's carbon footprint by moving the "costs" of production outside the country. Transferring jobs overseas can increase the nation's global carbon footprint while reducing the footprint within our borders if we rely on countries like China whose energy comes from coal power plants. So to reduce the nation's footprint we have to look at ways of reducing our global footprint which might involve changes in our trade policy. To regain control over our carbon footprint we may need to look at doing more for ourselves at home.