subscribe: Posts | Comments

The Holocene Epoch created America’s Delta in 7,000 years; the Anthropocene Epoch may destroy it in 400.

Too many people.

Too many people.

by Len Bahr, Ph.D.

The human-friendly Holocene Epoch began about 11,000 years ago, as Planet Earth began to warm up from the frigid Pleistocene Epoch, the last ice age, and civilization and agriculture dawned in Mesopotamia. During the last seven millennia of the Holocene, sea level rose rapidly from a level about 400 ft. lower than today and the world’s great deltas formed, including America’s Delta at the mouth of the largest river in North America.

Then, about three centuries ago, along came the Anthropocene Epoch, the age of human hegemony over all other forms of life. This dystrophic time period has seen an ever increasing ecological impact of the human species on its global ‘hood, an impact which has been indelibly engraved on the biosphere.

By the time New Orleans was established 300 years ago the Mississippi Delta Plain and Chenier Plain had reached their maximum combined aerial extent of almost 8,000 sq mi. Thanks to unintended consequences of human impacts and alterations, this incredibly productive ecosystem has been shrinking ever since, as shown in Fig.1.

Fig. 1. Area change of Mississippi-Atchafalaya River Delta Complex area.

Fig. 1. Area change of America’s Delta.

New Yorker staff writer Elizabeth Kolbert’s 2014 book The Sixth Extinction includes an excellent description of the onset of the Anthropocene Epoch. She ticks off a list of specific examples of ongoing human-caused insults to life on earth, suggesting that we’re headed for a global extinction event as consequential as the five former mass extinctions that have been documented by geologists and paleontologists.

The most recent of these extinction events followed the strike of a six mile diameter meteorite in the Yucatan Peninsula, which killed off the dinosaurs 66 million years ago, leaving less impressive terrestrial vertebrates to carry on. Kolbert notes that the phrase ‘Anthropocene Epoch,’ first used in the late 80s, is still not universally accepted — and that those who use the term disagree widely on its precise origin and triggers. In my view the Anthropocene is not only real but it began when and because humans first opened Pandora’s Thermodynamic Coal Box.

On March 2, 2017 the London Review of Books published an excellent review by Benjamin Kunkel of three books on the origin of the Anthropocene, focusing on the economic as well as the ecological aspects of this occurrence: The Birth of the Anthropocene by Jeremy Davies; Capitalism in the Web of Life: Ecology and the Accumulation of Capital by Jason Moore; and Fossil Capital: The Rise of Steam-Power and the Roots of Global Warming by Andreas Malm.

The following quotes are taken from Kunkel’s review:

…the Anthropocene condenses ‘into a single word’, as Davies says, ‘a gripping and intuitive story about human influences on the planet’.

Moore proposes that the Anthropocene be renamed the ‘Capitalocene’, since ‘the rise of capitalism after 1450 marked a turning point in the history of humanity’s relation with the rest of nature, greater than any watershed since the rise of agriculture.

Malm, a professor of ecology in Sweden, locates the headwaters of the present ecological crisis several centuries later, in the global warming set off by coal-burning industrialisation. 

But the Second Law of Thermodynamics doomed civilisation on earth to a mortal career from the start; the only question – as with a human life – is how brief and blundering the career proves.

I’m struck that neither Kolbert nor Kunkel explicitly attributes the onset of the Anthropocene and the beginning of unrestricted human population growth specifically to the exploitation of fossil fuel, although that message seems implicit in the following passages from Kunkel’s essay:

Andreas Malm’s Fossil Capital approaches these questions through a contrarian inquiry into the Industrial Revolution. Industrial capitalism effected for the first time the transition from an ‘organic’ or solar economy (in which plant life supplies power, in the direct form of firewood, or the indirect form of fodder for animals and food for human workers) to a fossil economy, defined by Malm as one predicated on ‘the growing consumption of fossil fuels, and therefore generating a sustained growth in emissions of carbon dioxide’. 

Great Britain and its colonial expansion apparently sparked the Anthropocene about 300 years ago, when the exploitation of coal dramatically expanded the global carrying capacity for Homo sapiens, setting the stage for human domination of the biosphere. The year 1776 saw: (1) the publication of Scottish economist and moral philosopher Adam Smith’s bible of Capitalism The Wealth of Nations; (2) the unveiling of Scotsman James Watt’s new and improved coal-fired steam engine; and (3) the signing of the American Declaration of Independence from Britain. Ironically, the latter manifesto was signed by a number of men of Scottish descent, including George Washington, Thomas Jefferson, Andrew Hamilton, John Witherspoon and several others.

All three events reflect the transition from a solar-based to a fossil fuel-subsidized economy in the rapidly industrializing world.

American independence was established largely without fossil fuel, while wood was still the principal energy source and building material of the new country, as symbolized by the oaken construction of the two most impressive warships of the U.S. Navy, the U.S.S. Constellation and U.S.S. Constitution. While the incipient U.S. was behind the curve in the exploitation of coal, this industrial and economic deficit was made up for by massive forest resources, New England hydropower, minerals, sugar, fur and other tradable goods. The large scale exploitation of American coal and iron deposits began a century after our revolutionary war with Mother England, as shown by this quote from Wikipedia:

The history of coal mining in the United States goes back to the 1300s, when the Hopi Indians used coal. The first use by European people in the United States was in the 1740s, in Virginia. Coal was the dominant power source in the United States in the late 1800s and early 1900s, and remains a significant source of energy.

Coal became the largest source of energy in the 1880s, when it overtook wood, and remained the largest source until the early 1950s, when coal was exceeded by petroleum. Coal provided more than half of the nation’s energy from the 1880s to the 1940s, and from 1906 to 1920 provided more than three-quarters of US energy.

Fossil carbon energy had accumulated in a solar energy ‘bank account’ of net primary production sequestered within ancient marine and freshwater swampy ecosystems during the Carboniferous Period, from 360 to 286 million years ago. Withdrawals from this account since the industrial revolution have paid the energy bill for most of the global changes wrought during the Anthropocene. These withdrawals have also increased atmospheric CO2 from about 250 to over 400 ppm since 1958.

The exploitation of coal on a global scale triggered the onset of human independence from a strict solar, or biomass economy that had previously limited our species to less than one billion people, as shown in Fig. 2,  which depicts the cumulative relationships between the global population and four successive carbon energy sources, suggesting a strong — and limiting thermodynamic connection. Consider that demographers now predict the human global population to peak at 9-10 billion by the year 2050, up from almost 7.5 billion this year. The energy cost of supporting that many humans with fossil carbon would obviously preclude reducing greenhouse gas emissions.

A simple energy-based model of population growth can be divided into four components: 1 Biomass Population – population growth due to biomass energy; 2 Coal Population – population growth due to coal; 3 Oil Population – population growth due to oil; and 4 Natural Gas Population- population growth due to natural gas

Fig. 2. A simple energy-based model of population growth can be divided into four components:
1 Biomass Population – population growth due to biomass energy; 2 Coal Population – population growth due to coal; 3 Oil Population – population growth due to oil; and 4 Natural Gas Population- population growth due to natural gas. Graphic from Peak People.

Saving America’s Delta during the Anthropocene

Thus, coping with the progressive aerial decline of America’s Delta during the Anthropocene is highly problematic, given an accelerating rise in relative sea level and a necessary reduction in non-renewable energy, as proposed in the Paris Climate Agreement, strongly supported by Obama but currently threatened by the Trump administration.

The 25 year old campaign to restore America’s Delta and to protect its two million residents from flooding is now competing for funding with efforts to offset and limit risk to humans in other coastal ecosystems around the globe. This challenge is significantly exacerbated by the current American political climate dominated by the climate change-denying GOP.

Sustainably reducing flood risk in S. Louisiana basically comes down to three stark strategies: (1) harnessing the delta-building power of the Mississippi-Atchafalaya River system to attempt to offset the progressive trajectory of landscape inundation under a no-action plan; (2) building increasingly higher sea walls, earthen levees with large maintenance and ecological costs;** and/or (3) convincing a large portion of two million at-risk coastal residents to PUHA (pack up and haul ass). This situation is further complicated by sediment limits in the river water, severe funding limits, and the politicization and suspicion of science and technology.

Option 1: delta restoration

The first option would entail re-establishing the deltaic processes that created the landscape, which would be fundamentally contingent on a massive sediment diversion program. This would require the implementation of strategic watershed management options, including sediment bypasses around lower Missouri R. tributary dams that are currently trapping about one half of the suspended sediments needed to save the delta system. This effort has been slowly gearing up for about a decade and will probably not reach full implementation for another decade, during a predictable decline in production and increase in the cost of oil and gas.

This decline will accompany the inevitable point in the future at which the energy return on energy investment (ERoEI) makes expanded oil and gas production unprofitable. Fig. 3 illustrates the relationships among the cost of oil and the use of dredged and pumped sediments to recreate marsh in America’s Delta. Arguments to use dredged and pumped sediments to rebuild landscape on a massive scale suffer from the high cost of this technique — and the fact that climate change restrictions on carbon emissions and increasing costs of diesel fuel are both on the horizon.

Sediment diversion projects use gravity, rather than diesel fuel to redistribute sediments. Success of diversion structures is primarily contingent on the volume of suspended sediments in waters of the Mississippi/Atchafalaya system, and a proposal by Kemp, et al. (2016) suggests that the volume of river sediments could be doubled by modifying a number of small dams on the Missouri River watershed. Restoration officials have inexplicably shown no interest in this concept, however. Go figure.

Fig. 4.

Fig. 3. Decreasing likelihood of offsetting landscape loss by the use of dredged and pumped sediments.

A crucial question is whether humanity can wean itself from its fossil fuel addiction before global temperature exceeds a threshold of irreversibility, triggering 6 ft or more of sea level rise (SLR) perhaps by the year 2050. Building higher levees and control structures and creating marshes with dredged sediments can buy time, perhaps a couple decades, but these actions don’t represent sustainable solutions to the inexorable problems of subsidence and SLR from global warming.

The human population is now projected to peak at 9 or 10 billion souls by the year 2050, the target date envisioned in 1999 by Louisiana state planners by which to achieve a sustainable Louisiana coastal landscape. That dream was recently discredited with the release of the state’s 2017 draft comprehensive master plan, which projects very modest benefits from a (largely unfunded) $50 billion investment.

Option 2: higher levees and sea walls (the Venice option)

It’s easy to understand the public support for protecting population centers with earthen barriers sufficiently high to recluse overtopping during storm surges. The   single project that best exemplifies this option is the $8-11 billion dollar Morganza to the Gulf (MTTG) project south of Houma, which in my humble opinion, will never be completed. Sea walls are not only expensive and high maintenance they present a moral hazard to an uninformed  public and a strong incentive for development behind the apparent safety of a levee. Once the call is made to protect landscape still above sea level with levees the ‘protected’ area will forevermore require trapped rainfall to be pumped out.

Option 3: “managed retreat,” otherwise known as PUHA

In terms of option 3, coastal evacuation to higher ground, on March 28, 2017 published an article by John Upton on managed retreat from threatened coasts. Here are some quotes:

Erosion, rising seas, ferocious storms and other coastal perils have prompted the resettlement of more than 1 million people worldwide, with an exhaustive new analysis highlighting an emerging migration crisis that’s worsening as global warming overwhelms shorelines.

Edward Richards, a Louisiana State University law professor who wasn’t involved with the new analysis, said it would be valuable for other researchers because it provides a new list of instances of managed retreat. “It’s been very difficult for any of us who are interested in this to get a comprehensive list,” he said.

The analysis showed that U.S. programs that subsidize flood insurance and promote coastal rebuilding after disasters are unusual when compared with some other regions, keeping people and property in harm’s way, even as flooding gets worse.

“We basically subsidize people to stay in the high risk area,” Richards said. “We would profoundly change the incentive if the flood insurance program provided positive incentives to relocate.”

*On April 22 published an Earth Day essay by Faye Flam that describes climate change throughout the history of life on Earth. Not a reassuring piece.

**As advocated by former Congressman Billy Tauzin, an opponent of sediment diversions.

Be Sociable, Share!
  1. Anonymous says:

    Is there a graph which illustrates the Environmentalwackoocene Era and the Gotothemoonocene Era?

  2. On April 19 published an essay by Oliver Milman on the possible pull out of the U.S. government from the Paris Climate agreement. Very sad.

  3. Kelly Haggar says:

    “Coastal Restoration: The Next Wave” will air statewide this Wed at 7 p.m. on LPB in Baton Rouge and in New Orleans on WLAE.

    The four panelists are:

    * Johnny Bradberry; Governor’s Executive Assistant For Coastal Activities/Coastal Protection And Restoration Authority
    * Denise Reed, Ph.D.; VP For Strategic Research Initiatives/The Water Institute Of The Gulf
    * Captain George Ricks; Charter Boat Captain and President of the Save Louisiana Coalition
    * Mark Schleifstein; Environment Reporter for & The Times-Picayune

    A varied audience will be asking the panelists questions. Y’all tune in!

Leave a Reply