Out on a Limb

The fossil record shows that our early ancestors were arboreal primates who, in response to a changing environment some four million years ago, gradually began to climb down from the foliage and walk upright on the ground. In her book Between Earth and Sky, ecologist Nalini Nadkarni explores how since then the human experience has been shaped by an intricate relationship with trees in terms of shelter and protection, health and healing, goods and services, play and imagination, signs and symbols, and spirituality and religion. Unfortunately, in the last twenty thousand years we have managed to reduce the number of trees worldwide by a shocking forty-six percent, and the result is a fast-approaching crisis.

Anthropogenic deforestation has multiple drivers that include agriculture, logging, ranching, mining, and urbanization, all exacerbated by population growth. Given the scope and scale of denudation it was bound to harm the planet’s atmosphere, hydrology, soil, and biodiversity; deforestation is moreover understood as a leading cause of climate change. With the unprecedented droughts and fires of today, I am much pained by the irony that a warmer and drier climate was exactly what North America’s first European settlers wanted to, in the words of Thomas Jefferson, “sensibly” engineer when they cut down many millions of trees. The idiom “be careful what you wish for” applies all too well here.

What might lie ahead? A systems analysis model published last year in Scientific Reports concluded that with current population increases, if we continue to destroy and degrade the world’s forests at the present pace, the likelihood of a “catastrophic” and “irreversible collapse in our civilization” within two to four decades is ninety percent. This grim prospect brings to mind Leonard Cohen’s unsettling line, “I’ve seen the future, brother; it is murder.” An apocalypse is not inevitable, but to avoid that endgame will take courage and commitment for which the odds, in my view, do not look good.