Fuel, SUV's and Global Warming
During the last decade, the automotive industry and many environmental agencies, such as the EPA and Friends of the Earth, have been involved in a heated debate over the regulation of emissions standards from light-duty trucks (SUV’s). While the Friends of the Earth, an international environmental activist organization that uses grassroots techniques, has worked hard to get the federal government to raise fuel economies and emission standards for SUV’s, the automotive industry has been more than willing to produce mass quantities of gas guzzling machines. According to the EPA and other environmentally concerned groups, without tighter federal government regulation of greenhouse gas emissions from SUV’s and other light-duty vehicles, global warming will quickly ensue and lead to such major environmental issues as global climate change. As a result, automakers must weigh their decision between meeting the ever-increasing demand for light-duty trucks or realizing the imminent threat that their products have on the environment, and doing something about it.
It is important to define greenhouse gases and describe which gases are emitted from light-duty trucks and SUV’s. According to the EPA’s Global Warming Website on emissions¹, some greenhouse gases are naturally occurring, such as water vapor, carbon dioxide, methane, nitrous oxide, and ozone. Some unnaturally occurring greenhouse gases include hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6), which come from other industrial processes(1). All of these gases are capable of absorbing heat from the earth’s atmosphere, but some gases have a much greater propensity to trap heat in the atmosphere than others, resulting in warmer climatic temperatures over time. SUV’s typically release these naturally occurring greenhouse gases into the atmosphere and scientists argue that these gases are slowly raising the earth’s temperature. For example, according to the EPA, the nitrous oxide released froman SUV traps 270 times more heat per molecule in the atmosphere than carbon dioxide(1). When nitrous oxide increases in the atmosphere, more heat is trapped in the atmosphere and unnecessarily contributes to the earth’s natural greenhouse effect.
While standards have been developed to curb these emissions since 1970, it wasn’t until 1993 that standards were placed on evaporative emissions for light-duty trucks as well as tailpipe emissions. Evaporative emissions were suspected as being equally responsible for contributing to the increased amount of hydrocarbons and oxides of nitrogen in the atmosphere. According to an article in Atmospheric Environment:
Evaporative emissions are divided into five types: Diurnal, which are the emissions when the vehicle is at rest which occur due to ambient temperature changes over a typical 24-h period; Hot soak, which is driven by residual engine heat once a warmed-up engine is parked and the engine is...