Energy Sciences

The environment, pollution and global warming

Energy sources are needed to keep life and civilizations developing. However, our overreliance on fossil fuels, gradual, prolonged, and increasing dramatically parallel to population growth, has created havoc in our planet. Pollution has been a constant since man discovered fire and its fuel, but habitat damage has reached dangerous levels, and global warming now forecasts times of uncertainty, chaos and destruction. Since fossil fuels have been the energy source of choice in the last two hundred years or so, we will first examine their contribution to these difficult problems.

Petroleum

Petroleum has been an accessible, efficient, and economical hydrocarbon. It has helped power our planet, diversify economies, and in many cases, improve living conditions. In spite of this, the drawbacks started from the very moment it was found; its production, transportation and usage has progressively harmed our environment and our waters. From all of these, burning the fuel we manufacture from petroleum (the main reason for which it is processed) is an alarming problem.

Carbon monoxide and dioxide (CO, CO2), and sulfur dioxide (SO2) are the most common emissions originated in the production of petroleum-derived fuels; lead is also an air toxic produced when specific types of petroleum are burned. In a previous section, we discussed how the temperatures on Earth depend on balancing the electromagnetic radiation absorbed by our planet and the re-radiation of the not absorbed light. Some of this radiation, in the form of infrared rays, helps warm our planet; another part is released past our atmosphere. When petroleum is being processed, the emissions and byproducts tend to accumulate in the atmosphere and trap the infrared rays leading to the greenhouse effect. The windows in a greenhouse trap the heat inside; the same happens in the atmosphere as the "greenhouse gases" act as windows around our planet, trapping more heat inside. This has led to what scientists call Global Warming.

SO2 also causes acid rain. Sulfuric acid ( ₂ SO ₄) forms when sulfur compounds in petroleum and its products react with water and atmospheric oxygen. This leads to precipitation with nitric and sulfuric acids. Although there is a natural-occurring acidic aspect in rain, rising levels can hurt crops and wildlife, destroy buildings, and cause respiratory illnesses and heart diseases in humans. ¹⁸

A final consideration is oil spills which tend to create environmental and habitat problems. After the 2010 Gulf of Mexico oil spill, the New York Times published a multimedia series which claim that since 1990 more than 110 million gallons of petroleum and its products have been leaked throughout the extensive network of pipelines in the nation. Around fifty percent of these leaks had occurred in Texas, Oklahoma and Louisiana. ¹⁹ In spite of this, some authors disagree on the long-term impact of such occurrences on our planet's ecosystems. ²⁰

Natural Gas

It is claimed that using natural gas as fuel does not release as many emissions as any other hydrocarbon. ²¹ The natural gas industries have also taken many precautions to prevent or dispose of gas leaks by flaring or burning it at well sites instead of releasing methane into the atmosphere, even though this process still creates CO ₂. Some of the main concerns about natural gas have to do with the impact its production will have in new areas where environment, wildlife and population are prone to be affected. The other area has to do with fracking. Fracking uses water for the mining process which is thought to diminish the available supply of water for nearby residents; at the same time, there are concerns about the pollution of underground water reservoirs since large amounts of wastewater are created in the process. Some people have also voiced their worries about earthquakes but there is no consensus about this aspect of fracking.

A shift from coal to natural gas does not eliminate the impact of fossil-fuel burning in the warming of the planet but it can be a desirable temporary step while cleaner alternatives become more accessible and inexpensive. At the same time, recent analysis and debates claim that the percentages of methane contribution to the greenhouse gases are larger than reported. ²²

Coal

Just like petroleum, coal and the availability of carbon allowed humanity to shift from wood burning, and the decimation of woods and forests, to an energy source less destructive. However, population growth and dependence on this hydrocarbon, especially for our addictive need to electricity, has brought its use to very dangerous levels.

The effects of coal extraction in the environment and atmosphere are devastating. Although coal-producing industries attempt to replant the sites, replace topsoil and return dirt and rock to the mountain tops and pits they mine, Greenpeace International reports that these projects' rate of success are very low, usually between 10-30 percent. ²³ These sites never come to be what they once were. In the case of mine tunnels, many accidents have proven their instability and caused many deaths; moreover, miners breathing coal dust in these mines can easily develop black lung disease.

Coal-firing plants release about twice the CO ₂ of oil and gas into the atmosphere, as well as SO2 and mercury (Hg); all of these add up to the greenhouse effect and global warming. ²⁴ Industries have tried to handle these emissions more effectively by cleaning the coal after it is mined, or "scrubbing" it to clean it from sulfur before it goes through the smokestacks. Research is currently addressing how to separate CO ₂ from the emissions, sequester it and later store it in a permanent underground site. ²⁵