Petroleum literally means 'rock oil'. It exists in the upper strata of the Earth's crust, and is mainly a complex mixture of hydrocarbons. Today, petroleum has transformed the world we live in. It provides the bulk of our energy and fuel requirements
In fact, petroleum accounts for 90 percent of the world's transportation requirement. It has made possible the manufacture and availability of varied consumer products, revolutionised travel and contributed to quality of life in many other ways.
Stop over at Enviroliteracy.org's section on petroleum for more information of this valuable resource and also for links on the subject. Despite being a priceless resource and central to human life on Earth today, extraction and transportation of petroleum products has a number of ecological repercussions, not all of them positive. Even though new technology has addressed some of these problems to various extents, of most serious impacts of petroleum use is on global climate change.
As a fossil fuel, its combustion contributes to polluting emissions, especially of carbon dioxide, one of the most dangerous of the greenhouse gases. Human contributions of greenhouse gases have modified the atmospheric greenhouse layer, which plays an important role in moderating global temperatures.
The future of oil production depends on demand, availability of acceptable alternatives and environmental concerns. There are fears that the production of oil globally is likely to decline in the next few years.
However, as of today, there are no viable alternatives to petroleum-based technologies that are cost-effective and likely to be adopted on a large scale. Although there is considerable research undergoing to develop new, effective energy technologies, in the short run petroleum will a major energy source.
One of the major concerns associated with petroleum use, in addition to the emissions associated with combustion of fossil fuels, is the environmental impacts associated with extracting petroleum and with transporting it. HowStuffWorks.com tells you all about how oil is drilled and refined.