"impending shortage" is correct and usable in written English.
You can use it to refer to a shortage that is expected to occur in the near future. For example, "The impending shortage of oil is causing prices to rise."
The impending shortage aggravates the difficulty.
So is an impending shortage of certified teachers.
Already, the U.S. faces an impending shortage of primary-care providers.
In the last several months there have been reports in medical journals about an impending shortage of primary care physicians.
Last week the College of Law (CoL), one of the main providers of the LPC, drew attention to a possible impending shortage of rookie solicitors.
To be successful, howerver, there will need to be significant investment in developing the workforce and dealing with the impending shortage of community nurses.
Many investors in the late 1970s shared his faith that rising metal prices reflected finite supply and impending shortages.
Impending shortages of natural resources are not priced into the market, so those resources are consumed too rapidly.
But the F.D.A. isn't able to force manufacturers to produce a drug, and learning about impending shortages with little authority to alleviate them is of limited benefit.
The long-term global trend of falling commodity prices, despite growth in the world economy, is not due to the failure of markets to reflect diminishing supplies and impending shortages.
"This was the great benefit of fossil fuels in the early days: We had to invest trivial amounts, and we got this enormous return," he added Of course, theories of impending shortages have often turned out wrong, like the 1798 prediction by Thomas Malthus, the British scholar, that population growth would outstrip food production.
