Intensification the key?

Decoupling in urbanization (people), agriculture, and power

What does it mean to intensify human activity, and how can this decouple nature from environmental damage? The idea, remember, is that if we can use technology and innovation to minimize the land (and water) area we use, the rest of nature can be left alone to recover from past centuries and millennia of abuse.

Decoupling starts out “relative” and eventually becomes “absolute.” Getting there is a result of technological and demographic change.

Relative decoupling means that human environmental impacts rise at a slower rate than overall economic growth. Thus, for each unit of economic output, less environmental impact (e.g., deforestation, defaunation, pollution) results. Overall impacts may still increase, just at a slower rate than would otherwise be the case.

Absolute decoupling occurs when total environmental impacts — impacts in the aggregate — peak and begin to decline, even as the economy continues to grow.

Decoupling can be driven by both technological and demographic trends and usually results from a combination of the two.

(Source: Breakthrough’s Manifesto)

Let’s have a look at three main areas of intensification: demographic (urbanization), agriculture, and power density.

Urbanization

Human population growth is finally leveling off, globally, although there are vast differences geographically. Compare Asia with Africa, for example. Historically, along with economic growth, first the rate of population growth slows, then eventually population itself begins to decline in absolute terms. (Populations also restructure in terms of age groups.) As economies development, people also move into cities, and this radically concentrates human occupation of the land.

Cities occupy just 1 to 3 percent of the Earth’s surface and yet are home to nearly four billion people. As such, cities both drive and symbolize the decoupling of humanity from nature, performing far better than rural economies in providing efficiently for material needs while reducing environmental impacts.

Compare this level of surface impact with historic numbers:

Humans use about half of the planet’s ice-free land, mostly for pasture, crops, and production forestry. Of the land once covered by forests, 20 percent has been converted to human use. Populations of many mammals, amphibians, and birds have declined by more than 50 percent in the past 40 years alone. More than 100 species from those groups went extinct in the 20th century, and about 785 since 1500.

(Source: Breakthrough’s Manifesto)

Urbanization goes along with change in agricultural patterns (see the next section). Animal populations are directly dependent on human land use. The more land that can be left free, the better off non-human nature fares. (And it’s not just animals. The goal should be thriving resilient ecosystems with complete complements of diverse species of intact populations remaining in all relevant biological taxa, including soil microbiomes and marine microbes.)

Agricultural Intensification

Most people are familiar with the Green Revolution of the 1960s which intensified crop yields using genetic modification and intensive watering, fertilizer, and pesticides. The side effects of this transition are hardly good, but the upside is that

rising harvest yields have for millennia reduced the amount of land required to feed the average person. The average per-capita use of land today is vastly lower than it was 5,000 years ago, despite the fact that modern people enjoy a far richer diet. Thanks to technological improvements in agriculture, during the half-century starting in the mid-1960s, the amount of land required for growing crops and animal feed for the average person declined by one-half.

That means a transition of land use away from diffuse and inefficient agriculture. Along with a similar transition away from using wood as fuel, reforestation can occur at high rates in developed countries.

Agricultural intensification, along with the move away from the use of wood as fuel, has allowed many parts of the world to experience net reforestation. About 80 percent of New England is today forested, compared with about 50 percent at the end of the 19th century. Over the past 20 years, the amount of land dedicated to production forest worldwide declined by 50 million hectares, an area the size of France. The “forest transition” from net deforestation to net reforestation seems to be as resilient a feature of development as the demographic transition that reduces human birth rates as poverty declines.

How best to conserve the environment?

The possibility of intensive agriculture opens a debate between “landing sparing” vs “land sharing.” In this article, also from Breakthrough, the problem of decoupling vs harmonization becomes clearer.

Trade-offs are at the core of the debate over “land sparing vs. land sharing.” Land sparers promote high-yielding farmlands as the most sustainable form of production and argue that intensive cultivation on a small amount of land paired with land use policies that protect natural habitats allows for the conservation of larger amounts of less-productive land.

Conversely, land sharers believe in integrating conservation into agricultural landscapes. They seek to further hybridize farms and nature, even if that means diminished yields for producers and less land overall that can be left to be “wild” or for other non-commodity agricultural land uses.

The article goes on to examine the case for land sparing and high yields, arguing ultimately for the need to use data to manage tradeoffs. Interestingly, the author advocates resisting the “aesthetics” of a decision and taking yield seriously.

Aesthetic-forward assessment of farming – whether in the land-sparing or land-sharing direction – cannot be the backbone of agricultural decarbonization, conservation planning, or anything else, really.

As agricultural information becomes increasingly available, the pros and cons of different practices will become clearer. Using that information, studying it, and making decisions based on data and clear criteria will be crucial for the future of policymaking and agriculture, more broadly.

In the meantime, maintaining clear principles about what should or should not be funded, especially at the federal level, will be crucial. Specifically, USDA conservation programs ought to consider – not necessarily prioritize – yield in their assessment of practices.

Power Density

Spend any time with Breakthrough’s content, and you’ll see how much they favor nuclear energy. The reason for this is consistent with a general philosophy of intensification.

Vaclav Smil, the prolific analyst of the “grand transitions” of human evolution that have resulted in the Anthropocene, is well-known for his studies of energy and power density. The basic idea is that it matters how much land is required to produce the energy-bearing resource you need. Hint: the free Kindle sample of Smil’s book on Power Density allows you to read his opening case study of the transition from using charcoal to coke in the iron industry in Britain. There simply wasn’t enough land or forest in early industrial Britain to produce sufficient charcoal for iron needs. A transition to coke, with much greater power density, made all the difference.

A first distinction to grasp is between energy density and power density. Energy density refers to how much energy is stored in a given substance by volume or area or mass. This video gives a quick comparison of nuclear versus other familiar fuels. Nuclear is literally off the chart in comparison.

Knowing Nuclear: Energy Density of Fuels - YouTube

But energy density alone is not a sufficient measure. We need power density. Robert Bryce, an outspoken nuclear advocate (and vehemently anti-wind), discusses the difference in this video.

The Power of Power Density - YouTube

Power density is the rate of energy flow that can be generated or harnessed per unit of volume, area, or mass, and you need to know this measure because it “determines and shape and size of your power networks.”

Bryce advocates for N2N: natural gas to nuclear because these two energy sources are orders of magnitude more concentrated than corn ethanol, wind, and solar with power densities, respectively, of 0.1, 1, and 10 watts per square meter (an area measure). Natural gas, by comparison, is 1900 watts per square meter, and nuclear is 2000.

How does this translate into land use?

This video gives a brief introduction, but it doesn’t take into account all the minerals required by solar panels and wind turbines for renewables, what Bryce calls “resource intensity.”

How much land does it take to power the world? - YouTube

There’s a lot here that gets complicated fast. Still, asking these kinds of questions, and searching out the kinds of data and information needed to answer them, gives a vivid sense of the tradeoffs involved when considering human economic and power needs, land use, mineral mining, greenhouse gas emissions, etc.

I don’t think we need to become energy experts or physicists to grapple with the realities of the physical and geographic tradeoffs, whether in terms of population, agriculture, or energy.

Making decisions about how to balance these tradeoffs requires engaging not only with the science, but with the perhaps even harder ethical, political, and economic dimensions also at stake.