Gross withdrawals of gas from wells were down by nearly 2 percent in April 2016 compared with the same month in 2015.

At the same time, gas consumption is rising, with deliveries to industrial customers and electric power producers sharply up.

Cheap gas has accelerated the structural shift away from coal combustion in electricity production while encouraging the expansion of more gas-intensive industrial processes.

In the short term, the developing imbalance between production and consumption was masked by an unusually warm winter in 2015/16.

Mild weather cut residential and commercial heating demand for gas and left the market carrying unusually high stocks by March 2016.

But the mild weather was at least partially down to the presence of El Nino in the Pacific. As El Nino fades and is replaced by La Nina, the winter of 2016/17 will almost certainly be colder, boosting gas demand.

Declining output while consumption is increasing is clearly unsustainable. As President Richard Nixon's chief economic advisor Herbert Stein wrote: "If something cannot go on forever, it will stop."

In the medium term, there will have to be more oil and gas drilling to stabilize gas production and meet growing demand, and that requires higher prices for oil, gas and hydrocarbon liquids.

Futures prices are already anticipating a tighter supply-demand-stocks balance at the end of next winter. Futures prices for gas delivered in March 2017 have risen 31 percent from $2.50 to $3.28 per million British thermal units.