I believe that carbon pollution is a problem, and I believe we are running out of time. According to the National Oceanic and Atmospheric Administration (NOAA), the atmospheric carbon dioxide (CO2) concentration for August 2013 was 395.15 ppm. Atmospheric CO2 was 392.41 ppm in August 2012 and 390.19 ppm in August 2011. These results are not surprising, it is common knowledge that atmospheric CO2 levels are and have been rising. The big question that many have is, “Is that normal or are we causing that?” Those who do not believe in global warming can see by the global average temperature increases (here) that it is happening. What is not entirely understood is the cause and timeframe. Is it occurring over thousands of years or since the industrial revolution? Playing it safe, the likely answer is since the industrial revolution. If the data and research are accurate and atmospheric CO2 elevations are anthropogenic, then harsh realities for us and generations to follow may be approaching quickly.
There are many consequences and threats from elevated atmospheric CO2 levels that we hear about. Many of these threats have strong supporting evidence. Warming that causes ice cap melting results in sea level rise. This same warming results in ocean water density increase which contributes to more sea level rise. Sea level rise causes many problems, just to name a few: flooded cities, salt water intrusion to fresh water aquifers, and disruption of ocean currents which are crucial components to marine life, the climate, and fisheries that many countries depend on for food and income (not to say there aren’t a whole different set of environmental problems with the fishing industry). Increased atmospheric CO2 will also lead to a decrease in ocean pH (ocean acidification). This ocean acidification can result in destruction in coral reefs and ultimately extreme harm to the vast biodiversity found within coral reefs (not to mention the tourism aspect of the coral reefs which local economies depend on). Another issue with the ocean acidification is the disruption of the breakdown of ocean deposits that contain calcium ions necessary for ocean waters to absorb atmospheric CO2. In short, there are a lot of detrimental consequences to elevated atmospheric CO2.
With the aforementioned details on elevated atmospheric CO2 concentrations, this blog post will primarily discuss carbon dioxide emissions associated with the power generation industry. The image below is of Plant Bowen, one of the largest coal-fired power plants in North America with a capacity of over 3000 Megawatts (MW). It is a coal-fired power plant located near Cartersville, GA. According to the Energy Information Administration the U.S. burns approximately 50,000,000 tons of coal for electricity generation each year in these kinds of facilities. Plants like Bowen consume 1-3 train loads of coal a day; these train loads are 1-2 miles long with 10-15 thousand tons of coal on each. I have included this image to point out a few details that are typically misunderstood by the general public. The shorter (approximately 400 feet tall) parabolic-shaped towers are the cooling towers; the vapor rising from these towers is water. Most of the vapor sent to the cooling towers is condensed; what is seen rising from the towers is the fraction that does not condense. The shorter two stacks (the wet stacks) that have vapor leaving the chimneys are the only stacks being used. The vapor leaving these stacks is mostly carbon dioxide and water vapor; it is what remains from flue gas after the environmental controls such as electrostatic precipitators and scrubbers have done their part. The two taller stacks (the dry stacks- approximately 1000 feet tall) are no longer used. Not all coal-fired power plants are like this. Some do not have the shorter wet-stacks and do not scrub sulfur oxides out of flue gas. Plant Bowen has been doing this since 2007. With the addition of these environmental controls, Plant Bowen and other plants with this technology are able to remove over approximately 95% of sulfur oxides from flu gas. This is just one example of a drastic improvement associated with coal-fired power generation. It is not an example given to try to show that this is a ‘clean’ plant or an argument for the advocacy for coal. It is an example meant to show that improvements…substantial improvements…are possible.
According to the Energy Information Administration, the electric power sector emitted 2,039 million metric tons of carbon dioxide in 2012. This is about 39% of the total U.S. carbon dioxide emissions related to energy. Of this 39%, coal fired power plants generated 1,514 million metric tons, or 74% of the carbon dioxide.
Many of these figures only concern the United States. What about the entire world? There is much concern with the possibility of the United States implementing laws and regulations on carbon emissions. People worry, for good reason, that we could jeopardize our national security and the health of our economy while global carbon pollution continues.
Perhaps other less-regulated countries would follow suit to carbon pollution control. If the United States were to work towards carbon capture and sequestration and find a way to make it economically feasible, maybe other countries (with push from international governmental agencies) would also be inclined to move towards reducing carbon dioxide emissions. Carbon capture and sequestration (CCS) technology could be a way to help coal-fired power generation be a viable option in a diverse power generation portfolio. Even if coal is on its way out, carbon capture and storage may be able to help slow the increase in atmospheric CO2 in the meantime. Perhaps research and developments in CCS technology in the electricity generation industry could lead to efforts in the manufacturing and transportation industry which are other significant carbon dioxide emitting industries. Look here.
What are we supposed to do in the meantime before renewables, nuclear, and natural gas can completely take over? What if hydraulic fracturing proves to be unsafe and is banned? What if nuclear powered electricity generation is shut down because of public and governmental concern? What will happen if coal is removed from the puzzle before renewables have enough time to be developed into a solution that can generate all of the world’s electricity? According to the International Energy Agency and the Institute for Energy Research , in 2012 only 12% of electricity generated in the U.S. came from renewable resources. Data showing electricity generation quantities from different sources can be found in Table 945 here . With population increase, cost of technology, available methods, and the sluggish decision making in the United States, how quickly can renewable energy cover that separation?
Final Thoughts and Questions
There is no doubt that coal is dirty. It’s dirtier than natural gas, but natural gas extraction methods are controversial. Depending on who you ask, coal-fired electricity generation is better or worse than nuclear power generation. Renewable energy sources on a large scale will likely require vast amounts of land area and rare materials. Those are negative aspects of renewables, but they certainly could prove to be much less negative than current generation methods.
What can we do to bridge the gap between electricity generation sources now and a time where electricity is generated primarily by renewable sources? Will/should that time include nuclear power generation? Do you think that carbon capture and sequestration should be aggressively pursued and implemented on a national and/or international scale?