In “The Day After Tomorrow” (2004), a series of implacable storms plunges the planet into a new Ice Age. Can that happen overnight? No. Conditions, anywhere, won’t change in a flash. We don’t face a chilly prospect, just “day after tomorrow,” but perhaps millennia from now.
Today, we feel, we’re rather inside an enamel saucepan, adrift in a pool of lukewarm water, which we hope, won’t turn scalding, anytime soon.
It’s obvious that extreme weather events have risen dramatically in number and intensity: from dark, swirling cloud bases that hover over cities like giant, hostile spaceship to solid lakes that slop out of their shores, and crawl to the neighboring lands to biblical floods that sweep out cars to infernal tongues of flames that engulf homes.
Global warming is what it is.
But it’s nothing new. The planet has blown hot and cold since its birth, cycling through alternate periods of glacial cold and balmy interludes.
So, why sound the alarm over rising sea levels and melting ice sheets, now? That’s because what’s happening today, hasn’t happened before. The epoch known as Eocene, which began around 55 million years ago, began as a time of planetary warming. The Earth was so hot that palm trees grew in Alaska. The Antarctica had sub-tropical vegetation.
Then, it began to cool, warm, and cool again, till it went into a deep freeze, culminating in the most recent Ice Age that began about 2.6 million years ago, in the late Pliocene. And even within that period, the temperatures see-sawed between near-intolerable frigidity and toasty warmth.
Surprising as this may sound, we are, technically, still in the Ice Age—but in its milder, non-glacial phase. The glacial phase ended 11,500 years ago, marking the beginning of a relatively stable period, known as the Holocene.
Recently, a team of climatologists has reconstructed the temperature pattern, extending as far back as that period. Immediately after the glacial phase ended, studies indicate, the temperatures rose sharply. The glaciers receded. Forests erupted and spread. Then, it plateaued out, hovering, for about 5,000 years, at around 0.6 degrees Celsius above the average temperature of the last 1,500 years.
It began to plummet next, gently. But over the last 1,000 years or so, the cooling trend has hastened. It’s got colder, faster, chilling down the Earth by about 0.7 degrees Celsius below the average temperature of the last 1,500 years. The decade from 1900 to 1910 was one of the coolest patches in last 11, 5000 years.
The temperature should still have been dropping, edging us closer toward the next re-glaciation phase.
Ars Technica writes that around, 1900, however, the planet did an unexpected climactic somersault: from cooling all these years, it began to heat up, rapidly, over the past 100 years. The decade from 2000 to 2010 is one of the warmest patches in last 11, 5000 years.
With the Industrial Revolution, which began with the development of the Watt steam engine, in the mid-1700s, we began offloading greenhouse gases into our fragile atmosphere relentlessly. The results of that callousness are only beginning to show only now. The level of the most important heat-trapping gas, carbon dioxide, has reached an average daily level of above 400 parts per million, as the NYT reports, a height last reached, some 3.3 million years ago, during the mid-Pliocene.
For the rest of the Earth’s history, it’s swung between 180 parts per million in the depths of ice ages to about 280 during the warm periods between.
If we don’t reduce our carbon footprint, we could, climatically speaking, be propelling humanity back into the prehistoric times.
Assuming we did survive that, it’s what would come after that we won’t. In the next 300-odd years, we’ll have run out of coal, oil, natural gas, even wood. The excess carbon dioxide in the air would have got soaked up by the oceans and its level would’ve slowly returned to pre-industrial levels.
In about 2,000 years, the present warming trend would be a distant memory. The Earth would be entering into its naturally-induced icehouse state.
Unless we develop energy sources that would help us fend off the cold when it comes, as shown in “The Day After Tomorrow,” we’ll suffer the fate of the dinosaurs, warns a piece in M.I.T. Technology Review.