THIS POST IS PART OF OUR ANTHROPOCENE BIOSPHERE PROJECT–A SERIES OF POSTS ON ERLE ELLIS’ ‘ECOLOGY IN AN ANTHROPOGENIC BIOSPHERE‘ (ECOLOGICAL MONOGRAPHS, 85/3 (2015))

In “Ecology in an anthropogenic biosphere” Erle Ellis (2015) posited that human transformation of the biosphere is driven primarily by sociocultural causes. Forcing of global biogeochemical cycles ranks among the top of the list of side effects of such sociocultural niche construction; this post starts with a seminal paper Ellis cites on the carbon cycle by Falkowski et al. (2000), who noted that a variety of factors are conspiring to virtually guarantee continued growth in atmospheric CO₂ emissions. At the time this paper was published, over 15 years ago, atmospheric CO₂ had reached (an annual average of) 369 parts per million (ppm), nearly 100 ppm over the interglacial (pre-industrial) value of ~280 ppm. The average for 2015 was nearly 400 ppm and it is on a continuing upward ascent.

This biogeochemical forcing was sociocultural—but unconsciously, unintentionally so. Our collective consciousness has slowly awakened, ultimately leading to Paris just 2 months ago, where the COP21 (Conference of the Parties to the Framework Convention on Climate Change) pledged to drastically reduce emissions. Achieving the target of limiting warming to the 1.5^oC “tipping point,” however, requires zero emissions within 30 years, followed by negative emissions thereafter. And negative emissions implies—essentially requires—geoengineering. Sociocultural, yes—but this time conscious, and very much intentional.

So-called “geoengineering”—or as termed by recent National Research Council (NRC, 2015a, b) reports “climate intervention”— typically means either carbon dioxide removal (CDR), or albedo modification (AM). The former could entail, for example, direct air capture, or enhanced rock (silicate) weathering, whereas the latter involves ways to enhance planetary reflectivity (global shading), for example by marine cloud brightening (by injecting tiny droplets of seawater), or introducing sulfate aerosols directly into the stratosphere. The NRC considered CDR techniques of lower risk and greater benefit than the AM approaches.

A CDR technique that has spawned numerous climate entrepreneurs was inspired by the late John Martin, longtime director of the Moss Landing Marine Laboratories and an oceanographer famously known for research on “The Iron Hypothesis.” Huge regions of the ocean are high-nutrient, low-chlorophyll (HNLC) zones, meaning that they are virtual biological deserts with very little primary production, despite high nutrient levels. Martin hypothesized that the low iron levels of these regions might be limiting productivity, and he conducted experiments that demonstrated phytoplankton blooms in the wake of iron seeding. During a lecture at Woods Hole Oceanographic Institute shortly before his death he famously stated “Give me half a tanker of iron, and I will give you an ice age.”

Martin’s results ignited much subsequent research, and commercial ventures, on the effects of iron on ocean fertilization and consequent drawdown of atmospheric CO₂, research that has only intensified as humanity’s continued hacking of the Earth’s carbon cycle continues. Geoengineering in general—an approach once dismissed as an improbable path, a frighteningly futuristic “Plan B”—is now not only discussed but implicitly presumed to be a key to limiting dangerous climate change.

Once we begin to intentionally alter planetary temperature, questions not only of unintended consequences, but morally unacceptable unintended consequences enter the argument. How will albedo management affect regional shifts in monsoonal precipitation, for example? Who controls the thermostat? Indeed, in a followup comment to Falkowski et al. (2000), Falkowski and others (Chisholm et al., 2001) called ocean fertilization to the proverbial woodshed, pointing out serious risks of such technology if applied on an industrial scale. While noting that small fertilization events may be relatively innocuous in terms of ecosystem disruption, Chisholm et al. (2001) feared a “tragedy of the commons” in the wake of entrepreneurs upscaling in the race to profit from carbon credits. The more recent (2015a, b) NRC reports echoed these concerns, calling out ocean fertilization as the CDR technique most fraught with legal and ethical issues. Nevertheless, it appears increasingly evident that the geoengineering/climate intervention bus has left the station, owing in no small part to our collectively sluggish sociocultural consciousness.

Two wrongs to make it right? How much more sociocultural niche construction can the Earth System take? In last week’s post, Kiza pointed out some of the problems that might follow from Ellis’ (2015) suggestion that “To sustain nonhuman nature, it will be necessary to assist species and ecosystems in changing, for example, by translocating species” (p. 319). If anything, geoengineering goes even further, hacking not just ecosystems, but the very globe—although we must remember the interconnectedness of all systems. Each hack begets further hacking—a fact that Ellis memorializes as the “First Law of the Anthropocene”—that humans (have always, and always will) shape planetary ecology. We ARE part of nature, so let’s hope that “the better angels of our nature” prevail as we move forward in evolving cultural traits for beneficial Earth System engineering.