BY: Joan Baxter
On a balmy, overcast August day, I stood at Port Joli Head in the Kejimkujik Seaside park on Canada’s Atlantic coast, nibbling on delectable little beach peas, staring out over the windswept beaches of white sand and rounded weathered grey stones, and at blue waves exploding white against magnificent rocks of granite as the ocean waters nudged relentlessly at the southern shore of Nova Scotia.
Just offshore, fat seals lounged on rocky islands, ensconced there like complacent and over-indulged Roman emperors. I envied them their thick layers of blubber that allowed them to slip happily in and out of the frigid crystalline waters, for their ability to live without a single thing but their own thick coats and their seal brains. And being in the national park, they didn’t need to worry about human predators as they lazed about on the rocks. They completely – almost insolently – ignored the human beings gaping at them through binoculars.
The park’s interpretive signs informed hikers that 18,000 years ago this area was covered by a sheet of ice three kilometres thick, and the land mass we now call Nova Scotia extended fifty kilometres out to sea. As the ice slowly retreated about 13,000 years ago, the sea level rose and the waters crept ashore, swallowing up land, even as the land itself was rising, heaving a sigh of relief as the weight of the ice diminished. That was naturally-induced climate change, caused by minute alterations in the earth’s tilt in its orbit that have brought about cycles of ice ages and periods of warming. Such change is gradual, happening over thousands of years. Life forms can adapt to the changes by evolving or finding new niches in which to live.
But that has not always been the case in our planet’s history. Between about 440 and 65 million years ago, there were five Great Extinctions, each of which wiped out the majority of the species on earth at the time. Scientists believe these were triggered by cataclysmic events — giant asteroid impacts and the eruption of flood basalts when molten rock bursts through the earth’s surface — that involved the release of enormous amounts of dust and sulphur dioxide into the Earth’s atmosphere. But it was the dramatic climate change the cataclysms invoked that caused the great extinctions.
Today, we’re in the middle of what is called the Sixth Great Extinction. The cataclysmic event causing it? We, the people. Human beings. Homo sapiens sapiens, literally “wise or knowing humans”. Continue reading Climate change and “wise” human beings — will our species rise to the challenge?