TOWARDS THE END OF HIS LIFE, James Baldwin wrote a meditation on the polymorphous nature of human sexuality and the irrational fears awakened by it. For its title, he chose an old, possibly apocryphal phrase used in ancient maps to mark the region where America would one day be discovered: “Here Be Dragons.” For what are dragons but potent symbols of our deepest anxieties (and farthest hopes)? Some are ancient, others are new. None is as novel or as unprecedented as climate change, if only because there is nothing imaginary about its effects.
Governments have been talking about reducing greenhouse-gas emissions for almost three decades, from the Rio Earth summit of 1992—on the whole, to very little effect. Some fifty percent of the carbon dioxide released into the atmosphere since the Industrial Revolution was added after 1990. Currently, the best estimate—provisional like all estimates—tells us that if global warming is limited to 1.5 degrees Celsius, there is some chance of avoiding the worst. Above this, large swathes of the natural world will cease to exist. As it happens, this state of nature is not very old—a mere twelve thousand years or so, when the last glaciation ended and the current interglacial began. Homo sapiens is much older than that, but most of the achievements we associate with our condition date from the Holocene: agriculture, cities, states, culture in the sense of artifacts, writing, art and the built environment.
It seems all but certain that global warming will go well above two degrees—quite how high no one knows yet. A popular response—because it doesn’t involve changing anything as fundamental as our dependency on fossil fuels—is the exhortation to plant more trees. This is because trees sequester carbon by absorbing carbon dioxide. Burning them releases it, which is why the scale of forest fires in the Amazon basin last year garnered headlines. Planting trees is regarded as a painless way of doing, or appearing to do, something about climate change. In the relatively empty forests of the boreal zone, logged intensively for timber, this presents few difficulties. But in some temperate and most tropical forests, the problems are of a different order. They are much more diverse and fragile to begin with, and exposed to a much greater range of pressures. Global warming magnifies these problems; planting trees does nothing to offset them. In some cases, it transforms a natural landscape into something artificial and dead.