SAN FRANCISCO, CA, DECEMBER 18, 2015 – What ever happened to the idea of “peak oil”?

Ten years ago you couldn’t avoid it if you tried. Books by James Howard Kunstler, Richard Heinberg, Kenneth Deffeyes, and others were warning that worldwide oil production would inevitably peak soon, based on analysis similar to that of celebrated geologist M. King Hubbert, who predicted, in 1956, that U.S. oil production would peak between 1965 and 1970.

Darn if he wasn’t right.

With the presumed world peak in oil production, national economies hooked on injecting oil straight into their largest arteries then began to decline. Peak oil doesn’t mean oil would disappear – half of it would still be left – just that less of it would be produced each year going forward, and shell-shocked economies would fall into a permanent state of recession as consumers battled, Mad Max-like, for every last barrel.

Except “events never play out the way one expects,” said James Murray, a speaker at a session entitled “Is Peak Oil Dead and What Does It Mean for Climate Change?” at the AGU Fall Meeting in the City by the Bay.

Technology came to the rescue, in the forms of fracking and three-dimensional directional drilling. U.S. oil production soared upward 54 percent in just five years, from 3.3 billion barrels in 2009 to 5.1 billion barrels in 2014. Although world oil production increased by only 8.5 percent in that time, it was enough to keep it from peaking.

So is peak oil now an outdated concept, or does it still lie in our future?

The latter, most experts at the AGU meeting were saying, while admitting they hadn’t foreseen the technological revolution that has allowed U.S. oil and gas production to soar over the past decade. Those resources are finite, and the cost of extracting them increases once the low-hanging fruit are picked. Oil has dropped to about $35 per barrel because oil producers, hungry for unconventional oil from tar sands and gas from shale, overproduced.

Yet they’re still not making money, said James Murray from the University of Washington. Shale oil – what the industry calls “tight shale” – “is profitable for drillers, hotels and restaurants, but not for investors,” he said. Cash flow in this sector was $10 billion in the red in 2014, even as yet more money is plowed into it from, Murray thinks, investors desperate for yields as the Federal Reserve keeps inerest rates extremely low.

Murray said the break-even price for conventional oil is $20 per barrel, but $75 per barrel for tight oil. So oil companies are drawing back: U.S. oil production seems to have peaked in July 2015, and even the Eagle Ford shale basin in Texas and the Bakken field in North Dakota are cutting back.

“The world may be close to peak oil production,” Murray concluded.

If that’s right – and at some future point it probably will be – what does it mean for climate change?

Impact on Climate

Temperature changes and fossil fuel emissions are unequivocally related.

At any time, the global average temperature change of Earth’s surface is proportional to the sum of all carbon emissions at that time. This “carbon-climate response” is 1.5 degrees C per trillion metric tons of carbon emitted – equivalent to 0.4 degrees C per trillion tons of carbon dioxide emitted.

This relationship allowed negotiators at the recent COP21 meeting in Paris to draw-up a carbon budget: the world as a whole can emit another 1,000 billion tons of carbon dioxide if its temperature change is to peak at 2 degrees C (3.6 degrees F), but only another 600 billion tons of carbon dioxide for a 1.5 degrees C (2.7 degrees F) cap.

With current world emissions of about 36 billion tons a year, the carbon budget gives the world less than another 30 years of “business-as-usual” emissions if warming is to top-out at a still risky 2 degrees C.

“We need to keep a lot of fossil fuels in the ground,” said Pete Peterson of the University of California at Santa Barbara.

David Hughes, president of Global Sustainability Research, Inc. in Calgary, pointed out that “the remaining reserves [of fossil fuels] are large, but of lower quality and require more energy to produce.” He estimated that more than 90 percent of what are known in the field as “unconventional sources” – shale gas and oil and tar sands oil – “are not recoverable.”

Hughes said IPCC’s RCP2.6 future scenario – representing the most tightly constrained fossil fuel use and leading to the least warming – “still assumes that more oil is burned than BP suggests are recoverable, and the same for natural gas, but not for coal.” (BP publishes an annual Statistical Review of World Energy.)

In fact, Hughes said, every IPCC scenario – there are four, called Representative Concentration Pathways (RCPs) – assumes more oil and gas is burned than BP suggests can be recovered. The scenario leading to the most warming, RCP8.5, actually assumes more coal is burned than is recoverable.

RCP2.6 – the scenario having the least amount of global warming – also counts on 5.1 times more uranium reserves than BP estimates are available. But it also assumes the world will have “negative” carbon emissions by 2040 – meaning drawing carbon dioxide out of the atmosphere and sequestering it.

“The only way to get to something like Paris,” Hughes concluded, “is to burn a lot less fossil fuels.”

Book author Richard Heinberg, the last speaker on the AGU peak oil panel, followed that conclusion to a point he said most peak oil theorists believe: that the future will bring a permanent recession and that “we probably can’t grow the economy while using less energy.”

“We might have to learn to get by without economic growth,” something no politician would want to hear, let alone admit, Heinberg said.

“The big problem is that we have a prioritization of economic growth above everything else.” It might be time, he said, to measure civilization’s progress in some other way, perhaps using something along the lines of the Genuine Progress Indicator or the often-mocked Gross National Happiness indicator of Bhutan.

That too may be something few politicians would want to hear or admit.