This is a typical advertisement by a natural gas company. I partially agree with some of these facts. Natural gas, also known as methane, is a colorless, shapeless, and in its pure form, odorless (the distributor adds an odorant to the gas as a safety measure so that people will be able to tell if there is a gas leak, or if they forget to turn off an appliance) gaseous mixture or hydrocarbon component. It is composed primarily of methane, with smaller amounts of other hydrocarbons (ethane, propane and butane). It can also contain varying quantities of carbon dioxide and other gases.

        During the majority of the 19th century, natural gas was used almost exclusively as a source of light for city streets, because there was no feasible mechanism to transport the gas into a home for heating or other uses. Even well into he 20th century, natural gas was discarded as worthless and a by-product of crude oil production. The discovery of the liquefaction method as well as the development of pipeline systems to storage, transport and distribute natural gas made it very convenient to use and allowed the expansion of its utilization. Natural gas is nowadays used for heating, cooling, cooking, production of electricity and it finds many uses in industry – pulp and paper, cement and asphalt, chemicals (such as propane, butane, ammonia and methanol), plastics, fertilizers, and petroleum refining. Today, natural gas accounts for about 25 percent of all the energy used in the United States (28 percent of the globe’s natural gas) and the world. The use of natural gas increased by 35 percent in U.S. during the last decade and is projected to continue to grow by another 60 percent by 2020.

        Natural gas fuel burns cleaner than any other traditional fossil fuel. Natural gas combustion results in virtually no atmospheric emissions of sulfur dioxide (SO₂) or small particulate matter, and far lower emissions of carbon monoxide (CO), reactive hydrocarbons, nitrogen oxides (NO_x) and carbon dioxide (about half as much CO₂ per unit energy as coal) than combustion of other fossil fuels. If methane (a simple compound) is burn completely, the principal products of combustion are carbon dioxide and water; there is no ash. Because natural gas burns cleanly, its use can be an effective means of controlling pollution. Thus, increasingly, natural gas is being used alternately or simultaneously in combination with other fuels to improve their environmental performance and decrease pollution. One particular area in which natural gas is an attractive alternative is transportation. Advanced natural-gas-fueled vehicles have the potential to reduce carbon monoxide by as much as 90 percent and reactive hydrocarbons emissions by as much as 85 percent, compared with gasoline vehicles. On the other hand, natural gas is one of the candidates to be used as energy source for fuel cells. However, methane is also one of the principle greenhouse gases that are thought to cause global warming.

        Natural gas is not a renewable resource, since there is a fixed amount of it trapped in the Earth. However, natural gas is abundant but not as abundant as coal is. Almost 99 percent of the natural gas used in the United States comes from North America. This is a sharp contrast to oil and other petroleum products, most of which are imported from overseas. But way a minute! Yes, the United States is a leading producer of natural gas but still is the world’s largest importer (from Canada). Furthermore, the world’s ratio of proven natural gas reserves to production at current levels is 66-70 years. And according to the Department of Energy, U.S. has enough proven reserves to last another 60 years and probably a lot longer. These estimates look very suspicious, though.

        To put things in perspective, let’s work directly with the numbers. By some estimates, almost half the gas that will ever be produced in this country has already been burned, and what is left is a declining rate of production not only here in U.S. but also in Canada. The proven reserves of the United States in 2000 were about 167.4 trillion cubic feet (tcf) and the consumption was 22.8 tcf (Source: Energy Information Administration). Therefore, if the current consumption trends continue, these proven reserves will be exhausted in less than a decade! Well, new discoveries of natural gas supplies might upset a little bit this calculation. If not, where’s the new gas going to come from? The major gas supplies are located in the Former Soviet Union and the Middle East. Thus, similar to oil, the expanded use of natural gas by developed nations will become increasingly dependent on the world’s most unstable regions. But, world natural gas consumption is also rising faster than that of any other fossil fuel. A simple study of natural gas consumption and reserves* reveals that if energy consumption were to continue at its present pace and natural gas were to replace oil completely in order to maintain the current level of oil consumption, and if the current consumption of natural gas were to continue unabated, then global natural gas supplies would be exhausted in about 23 years:

                945 Gboe/(27 Gb + 15 Gboe) = 23 years

        Of course, gas reserves are much difficult to assess than oil. But, on the other hand, there are also limits on how much more natural gas we can find and get out of the ground with today’s technologies. Thus, the wonder fuel may be in short supply relative to the developed nations’ energy appetite in about two decades. The energy analysts Randy Udall and Steve Andrews exposed clearly these problems in the article "Methane Madness" published in the September/October 2001 issue of Solar Today.

        Natural gas costs less than electricity, heating oil, propane or kerosene. On average, electricity costs almost four times more than natural gas. There is still, however, some uncertainty about how much yt will cost to get out natural gas from the ground in the future. Like oil, there is "easy" gas that can be produced from underground formations, and there is gas that is not so easy. Besides, energy prices in general are on the rise. Like any other commodity, energy prices rise and fall as supply and demand changes. Natural gas is no exception. Extreme weather conditions or volatility in commodity costs or market conditions can create unexpected shifts in the costs the customers pay for natural gas. On the other hand, pipeline transportation is not always feasible because of he growing geographic distance between gas reserves and markets, which increases the price for gas. Recently, natural gas prices have increased significantly throughout the entire United States. In fact, the prices has quadrupled last year and is expected to be driven even higher by skyrocketing demand for gas-fired electricity.

        Based on this, it seems that natural gas is not the wonder fuel after all, and we might be postponing the inevitable by substituting natural gas for oil. I believe, however, that natural gas should be considered seriously only for a short transition (mid-term) strategy from today’s oil-dominant energy economy to tomorrow’s economy that uses more renewable energy, such as solar power and hydrogen.