Billions of dollars are being invested in new power plants and manufacturing facilities on the underlying assumption that there will be cheap and abundant supplies of natural gas well into the future.But the long-range production estimates pointing to plentiful supplies might be overly optimistic, according to a Dec. 3 article in Nature, a weekly science journal.According to the article, expectations of climbing production fall in line with estimates from the U.S. Energy Administration, which figures production will grow until 2040. At the same time, prices are expected to increase gradually, but remain relatively low.However, a team of researchers at the University of Texas at Austin has been formulating their own estimates, and they’ve come to a different conclusion.As the article states:If natural-gas prices were to follow the scenario that the EIA used in its Annual Energy Outlook 2014, the Texas team forecasts that production from the big four plays the Marcellus, Barnett, the Fayetteville and the Haynesville shales would peak in 2020, and decline from then on. By 2030, these plays would be producing only about half as much as in the EIA’s reference case. Even the agency’s most conservative scenarios seem to be higher than the Texas team’s forecasts.The difference between the estimates might be accounted for by methodology, according to the article – the researchers are taking into account the sweet spots and the number of wells that could feasible be drilled in a given area.But as the article notes, the researchers have mixed opinions about their own work. One researcher said the estimates are conservative, so actual production might exceed their expectations. Another, however, said production could actually be even lower than their forecast.