Burning Buried Sunshine: Human Consumption of Ancient Solar Energy

Jeffrey S. Dukes1
Climatic Change volume 61, pages 31–44 (2003)

Fossil fuels developed from ancient deposits of organic material, and thus can be thought of as a vast store of solar energy from which society meets >80% of its current energy needs. Here, using published biological, geochemical, and industrial data, I estimate the amount of photosynthetically fixed and stored carbon that was required to form the coal, oil, and gas that we are burning today. Today's average U.S. Gallon (3.8 L) of gasoline required approximately 90 metric tons of ancient plant matter as precursor material. The fossil fuels burned in 1997 were created from organic matter containing 44 × 1018 g C, which is>400 times the net primary productivity (NPP) of the planet's current biota. As stores of ancient solar energy decline, humans are likely to use an increasing share of modern solar resources. I conservatively estimate that replacing the energy humans derive from fossil fuels with energy from modern biomass would require 22% of terrestrial NPP, increasing the human appropriation of this resource by ∼50%.

Dukes's article has singlehandedly done more than any other source to shape my thinking on energy, finite resources, renewables, and the fundamental failure of economic markets to rationally price production. Largely toward pessimism.

The buried lede is that we're consuming petroleum and natural gas at 5 million times their rate of formation. In about 200 years we'll have drawn down an inheritance accumulated over 400 million years, effectively accounting for bank withdrawals based on the cost of printing cheques written against it.

As cheap energy is presumed for all economic productiion functions, and cost accounting ignores natural capital, this is a tremendous bias at the very core of all market pricing mechanisms. The system is based on a lie.

The numbers also reveal just how rocky the process of moving off fossil fuels will be, whether that's a planned sustainable migration to renewable/carbon-neutral sources or something more catastrophic. The magnitudes involved are tremendous, specific qualities of energy sources hugely significant, and glib expectations that a few windmills, solar panels, and dams scattered across the landscape will be sufficient tremendously naive. (Of other renewable options, only geothermal offers any plausible scale, much of which is already exploited. And there's the troublesome prospect of nuclear power.)

Author Vaclav Smil (see below) describes oil wells as punctiform. They are literally holes in the ground from which modern civilisation has spouted, more effectively than any djin pouring forth from a lamp. Renewable resources are (mostly) expansive: they capture or harness energy diffusely incident over vast areas, measured in watts per square meter.

The paper pairs well with deeper contexts. Ironically, petroleum apologist Daniel Yergin's The Prize (1992) does a phenomenal job of conveying just how completely transformative oil was for humanity. Vaclav Smil's Energy and Civilization (2018) quantifies the impacts and mechanisms of past energy transitions. The economic piece has yet to be written, though Herman Daly, Nicholas Georgescu-Roegen, Robert U. Ayres, and Steve Keen have provided significant bits. Possibly Mariana Mazzucato's work on value also.

My current hopes are mostly looking at : geothermal, can scale quickly, and involves the knowledge of the oil industry.
Almost no land use, and a huge reserve of energy. I'd say it is a long term 'transitional' carbon free energy

@temsa Geothermal is an excellent option: dispatchable (unlike wind and solar), clean, minimal environmental impact (unlike hydro), and small footprint with high capital utilisation (unlike most other renewables).

The bad news is that much available capacity worldwide is already utilised, or off-limits (e.g., national parks or other wilderness preserves).

Utilisation of lower-yield resources, as in the Salton Sea field, is a possible growth path, though others strike me as more promising.

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