Emma Marris’ Rambunctious Garden argues our modern environmental movement’s raison d’etre, nature’s preservation in a pristine, prehuman state, is misguided. We Homo sapiens have been mucking about this planet for some 250,000 years now, leaving few spaces without our footprints. Science is accumulating evidence that suggests South America’s “wild” Amazon Basin has been sculpted by human management for well beyond 1,000 years. Mayan and some Asian tropical rainforests also prove to be longago human agricultural polycultures gone feral, further challenging a “myth of the pristine”. Where misguided preservationists won an upper hand, our own benignly neglected Sierra Nevada slopes, brush choked and densely forested, suffer monumental conflagrations. Forestry science now appreciates how ancient Californians maintained Sierra health and productivity over millennia by employing frequent, low-intensity fire.All dinosaur-crazed grade-schoolers learn bits of geologic time’s nomenclature, maybe Jurassic, Cambrian or Pleistocene. Well, geologists are mostly of a mind that we must learn another one, Anthropocene, for a new epoch named after our own kind.What sparring geoscientists can’t agree upon is just when the Holocene, throughout which humans developed agriculture, succumbed to our prolific species’ incontrovertible influence over earth’s systems.Most argue for the late 1700’s Industrial Revolution when coal combustion belched CO2 skyward and human civilization into the hydrocarbon age. Others advocate for July 16, 1945’s first atomic explosion at Alamogordo, NM, because this event’s radioactive signature will remain long-etched into Earth’s geologic record. Debate continued in last week’s Science under William Ruddiman’s lead authorship. This University of Virginia paleoclimatologist made a name for himself after formulating a plausible Early Anthropocene hypothesis that contends forest clearing and grassland plowing for agriculture which commenced 10,000 years ago, paddy rice culture’s introduction five millennia back and widespread ruminant livestock herding raised atmospheric CO2 enough to forestall an otherwise imminent ice age. He and Science coauthors contend no single “golden spike” marks the Anthropocene’s onset. Their quartet suggests we simply “acknowledge the long and rich history of humanity’s environmental transformations of this planet, both for better and for worse.” Emma Marris believes that record can be bested by embracing a “hybrid of wild nature and human management” in crafting our “rambunctious garden”. Humanity as apart from, and opposed to, nature is a myopic view of our potential to heal this Earth. Stewart Brand counsels, “We are as gods and we might as well get good at it.” –Tom Willey

Emma Marris: bit.ly/1JAd9FB | Science: bit.ly/1Fy3z1S | Earth – A New Wild: www.pbs.org/earth-a-new-wild/home/