Humans are accustomed to being arrogant. We take what we want and dump the wastes. We assume that the Earth will just clean up the mess and keep providing everything to us. But we are about to exceed the capacity of the planet to do this, if we have not already done so. We are about to be put in our place as just another species that cannot exceed its limits.
But if we had paid attention to the wild plants, we would have known this already. In my recently released Green Planet: How Plants Keep the Earth Alive, I describe the way the world used to be, the realm of wilderness and, in many places, huge trees. One cannot approach the General Sherman tree in Sequoia National Park, the largest living thing on Earth, and still feel arrogant. Its base is as large as a small house. Its largest branch is bigger than the biggest tree east of California. Nor can one remain arrogant in the presence of the bristlecone pines of the White Mountains of California. Though they are small, they endure cold, dry conditions. Many of them were already two thousand years old when Jesus was born.
Plants live almost everywhere on the Earth. Almost anywhere you could go, you will find plants. Tundra plants survive long winters and fierce winds; desert plants survive long periods of drought. Plants have evolved many different ways of surviving these conditions. For example, some desert plants store water; others have deep roots; others are small and complete their life cycles during the brief rainy seasons. But there is more. In the process of adapting to the different climatic conditions of the Earth, plants have created the diversity of habitats that we see: for it is the plants that make the forests, grasslands, and deserts what they are.
Plants defy our human arrogance. It is they who keep the Earth alive, and who create the habitats in which we live. If we pay attention to them, we will have a little bit more of the humility that we are going to need to survive on this planet.
Humans are just one tiny twig of the animal branch of the vast tree of life. We are the most intelligent species on the planet, but it has yet to be seen how successful we will be. We think that intelligence is the greatest adaptation. But species that have little or no intelligence have persisted for billions of years and have altered the face of the planet. Our intelligence might lead us to destruction even more quickly than it has led us to prominence, and turn out to be merely a bright flash in the long evolutionary history of the Earth.