This week I completed my third stint at Mi Casita in Tres Piedras, and this time my thoughts about Aldo Leopold focused not on the distant past but the near future. Specifically, the Anthropocene.

For those of you who may not follow such things (and who could blame you?), there is an earnest discussion going on among geologists that the Holocene, the current geologic period characterized by warm temperatures, a steady climate, and stable sea levels that we’ve enjoyed for the past 12,000 years, is likely over. Here’s an excerpt from a New York Times editorial that ran in 2011:

“Among scientists, there is now serious talk that the Holocene has ended and a new era has begun, called the Anthropocene…Some species, like ammonites and brachiopods, serve as guides – or index fossils – to the age of the rocks they’re embedded in. But we are the only species to have defined a geological period by our activity – something usually performed by major glaciations, mass extinction and the colossal impact of objects from outer space…Humans were inevitably going to be part of the fossil record. But the true meaning of the Anthropocene is that we have affected nearly every aspect of our environment – from a warming atmosphere to the bottom of an acidifying ocean.”

Officially, there is a proposal in front of the International Commission on Stratigraphy (ICS) to declare the Holocene at an end. This is the formal body that makes these sorts of decisions – decisions that are not made lightly, or quickly. In other words, if the ICS decides that the Holocene is over, it’s over. And an increasing number of scientists think it is likely that the ICS will rule in favor of the Anthropocene (which my computer spell-checker recognizes, by the way). That’s because with each passing day there is fresh scientific evidence of the overriding influence of humans on natural processes with geological consequences for the planet.

I bring this up because I think it is crucial to start sorting out what worked ecologically, socially, and economically in Holocene, and what did not, and whether they will be useful in the Anthropocene. According to many scientists, one of the main differences between the two Eras will be climate stability. In the Holocene, carbon dioxide levels held relatively steady, compared to the large fluctuations that characterize most of Earth’s history, which enabled air temperatures, sea levels, and precipitation patterns to hold relatively steady as well. In the Anthropocene, say scientists, climate instability will be the norm (and may have already begun), sea levels are certain to rise, perhaps by a great deal, and average temperatures will rise above Holocene levels. Clearly, it’s going to be a different world.

Here’s a chart (the Holocene is the flat line on the right):

 A good guide to getting a grasp on the Anthropocene is Aldo Leopold. For starters, we obviously haven’t solved the riddle of what he called the “oldest task in human history” – how to live on a piece of land without spoiling it. The difference, of course, is that the task has now expanded to the entire planet. That leads directly to Leopold’s interest in ethics and what he considered to be our moral obligation to all living things on Earth. Don’t we have a moral responsibility to future generations to hand them a world enhanced by our efforts, not diminished by them? We do – which is why ethics will be a huge issue in the Anthropocene, especially to our children. That’s because the stakes of our responsibility are rising dramatically. If we fail to meet them, I’m certain we will judged as immoral by future generations.

This issue of responsibility lies at the heart of Leopold’s idea of a land ethic, of course. Here is his famous definition, from the Sand County Almanac: “A land ethic…reflects the existence of an ecological conscience, and this in turn reflects a conviction of individual responsibility for the health of the land. Health is the capacity of the land for self-renewal. Conservation is our effort to understand and preserve this capacity.”

In the Holocene, unfortunately, we didn’t adopt a land ethic very widely, despite its obvious necessity. We didn’t do so mostly because we were told by economists, business leaders, and politicians that we could have our planet and eat it too. The free market would solve all problems, we were instructed – substitutes for scarce resources would be found easily, consequences to our exploitative behavior would be minimal, technology would smooth off rough edges, and human ingenuity will take care of everything else. Except…they were wrong. And Aldo Leopold was right – which is why we need a land ethic now more ever.

Closely coupled with the idea of ethics is land health. Restoring, maintaining, and preserving (a word that will be used less and less frequently in the future, in my opinion) the basic functions of ecosystems, such as nutrient, water, energy cycles, will become increasingly critical as the Anthropocene grinds on. I suspect that securing sufficient amounts of the Five Fs – food, fuel, fiber, forage, and fresh water – will dominate the lives of billions of people in this new Era, and already do in many corners of the world. Healthy land – its capacity for self-renewal – will be vital to our survival in an era marked by rising temperatures and climate disorder.

One of the most important “land mechanisms,” as Leopold called them, for ensuring land health is the carbon cycle. When functioning properly, it captures, stores, releases and recaptures biochemical energy, making everything go and grow from the soil up, including plants, animals and people. In the last century or so, however, the carbon cycle has broken down at critical points, most importantly among our soils which have had their fertility eroded, depleted, and baked out of them by poor stewardship – as Leopold noted throughout his life (though I don’t recall him ever using the word “carbon” in this context). In the Anthropocene, the challenge of maintaining a healthy carbon cycle will be magnified, particularly by drought. To work well, the cycle needs water, but plants don’t photosynthesize well under heat stress; and they won’t perform at all if they die!

Understanding the components of land health, carbon especially, will be a full-time task in the Anthropocene. We’d had better start rereading Leopold now.

Other interests that occupied Aldo’s attention won’t be so important, however. Wilderness protection, for instance, and recreation policy – both of which occupied a great deal of his time over the decades – will be lesser priorities in the Anthropocene, possibly a lot less. Even game management (wildlife), at least as we practice it today, could also be pushed aside as a priority if things get tough for humans. Protections for endangered species in particular, I suspect, will fall by the wayside if they are perceived as obstacles to the Five Fs. Ditto with many governmental regulations, such as NEPA, if the political and economic landscape gets rocky. Leopold was not a big fan of ‘conservation by bureaucracy,’ which means he might be useful in this regard as well.

What’s timeless and what’s time-specific? What will we leave behind in the Holocene, and what will we need in the Anthropocene? What goes into the Ark, and what stays behind? These vital questions will be difficult to answer because we will want to carry as much with us into the Anthropocene as we can, much like homesteaders of yore who piled their wagons high with pianos, bookcases, and desks, only to discard them as the journey went on. In the Anthropocene, I suspect we’ll be concentrating on essentials as well – such as healthy land. That makes Leopold more relevant than ever.

Here’s  a photo of Leopold from his ranger days: