‘Polar Extremes’ – Why the past is a warning
The Earth’s poles are warming. That’s not exactly news.
But the history of the warming and cooling cycles in the Arctic and Antarctic over the past 650 million years may provide clues for what our immediate future holds climate-wise, as detailed in a new “NOVA” documentary premiering this week on PBS.
In “Polar Extremes,” a two-hour special premiering Wednesday, Feb. 5 (check local listings), paleontologist Kirk Johnson takes viewers back in time with the help of footage from remote locations and 3D graphics of long-lost landscapes to expose the secrets of the planet’s polar past, when alligators lived in a subtropical forest in the Arctic, dinosaurs roamed at a temperate South Pole and glaciers deposited strange fossils in Death Valley.
The film paints a picture of an Earth with no polar ice and much higher sea levels, as evidenced by seashells found in a Virginia quarry 90 miles from shore. Polar ice samples indicate carbon dioxide levels in the atmosphere three million years ago were 400 parts per million, just below today’s 410 ppm, a number that figures to go higher as the ice continues to melt.
“I think one of the big take‑home things,” Johnson explained to a recent gathering of journalists in Beverly Hills, Calif., “is that even though things happened millions of years ago, they are relevant to what is going to happen in the next few decades. So the fossil record gives us a menu of future planets to choose from, and we can see things that have happened in the past that are things that will happen in the future. And, really, the question is not if, but how long is it going to take and how dramatic it’s going to be.”
Johnson adds that there is still much we don’t understand about what may happen, but he says if past is prologue, humanity has a major challenge ahead of it.
“The challenge is really one of moving culture in that direction,” he says. “And, of course, it’s a political issue, because this is probably the first actual issue that’s genuinely global. Every single one of the 7.7 billion people on this planet will be affected by this climate change thing, so it is going to be tremendously political because it impacts everybody, not just scientists.”