Doomed to repeat the past?
Did the dinosaurs die out because of global warming? Well, sort of.
In an op-ed in Sunday’s Seattle Post-Intelligencer, Peter Ward, a University of Washington professor of biology and earth and space sciences, takes a look at climate change through the unlikely lens of paleontology. Ward points out that prehistoric volcanic eruptions released enough carbon-dioxide into the atmosphere to radically alter the planet’s climate, resulting in serious ecosystem disturbances and extinctions. Here’s Ward:
I can show that at least 11 times in the past 250 million years, bouts of global warming have produced successive mass extinctions — two in the late Permian Period, three in the Triassic, two in the Jurassic, two in the Cretaceous and two in the Tertiary. A new paradigm is now apparent: Global warming has thus caused the majority of mass extinctions in our planet’s past, including the most catastrophic of them all, the Permian mass extinction.
Luckily for us, we’re not likely to soon face large-scale volcanic activity of the sort that caused major extinctions. And greenhouse gases released because of human activities are also not likely to result in catastrophes comparable to those Ward describes. Still, the heat-trapping potential of our human-generated carbon-dioxide is serious enough that, for instance, we could face signficant disruptions in agriculture.
Here’s Ward again:
At the rate of current rise of [carbon-dioxide] caused by human as well as natural causes combined, we will be at the same level that created the temperatures allowing Eocene palm trees in Washington in less than a century. Our future appears to look like our past.