As far as we know, the Earth is a unique refuge for life. The History Channel series “Our Planet: The Past, Present and Future of Earth” is a serious yet entertaining exploration of our ever changing sanctuary. Nothing in our physical world remains static, least of all the theories of science. In the 19th century the Earth’s age was estimated at 20 million years. That estimate gradually rose to 4.5 billion.
Two of the episodes, “Global Warming” and “Life After People,” are explicit reminders of the fragility of our global ecosystem. Episode one, “How the Earth was Made,” shows that ecosystems have crashed and burned several times over billions of years. There once was a deadening ice age that extinguished all but the most primitive sea life and a million-year volcanic eruption that caused a mass extinction. More recently, 65 million years ago, a meteorite triggered the death of the dinosaurs and 75 percent of all species, according to the reading of the fossil record. Darwin’s gradual evolution was pushed sideways and back by catastrophe.
The message? The Earth is a resilient planet, situated at a perfect distance from the sun to support life, and it could continue without us, long after all human accomplishment has turned to dust. “Our Planet” is out on DVD.
