What Cancer Can Teach Us About Arctic Sea Ice
In a September 8 Daily Mail story, tabloid journalist David Rose, who’s long played fast and loose with climate change facts, was at it again, championing the “record return” of Arctic ice cap this year, while completely ignoring the long-term warming trend—that summer sea ice has declined by 40 percent since satellite tracking began in 1979.
As he has in the past, Rose cherry-picked the global warming factoid he needed to arrive at his point, while ignoring the big one that would have led readers in the opposite (and correct) direction. His story has spawned even more climate deniers’ claims that global warming is over and that we’re entering an era of global cooling.
Let’s take the key assertion in Rose’s piece: that from 2012 to 2013 Arctic sea ice grew by 60 percent, thereby disproving global warming, and disprove its enduring relevancy.
Because of weather variability (weather patterns, ocean cycles, etc.), ice loss can fluctuate, sometimes wildly, on a year-to-year basis, but the long-term prognosis for Arctic sea ice has been, and will continue to be, terminal.
Consider this: If you’ve ever spent time around someone with Stage 4 cancer, you’ve probably seen her have the occasional great day, during which her energy level was high and she was feeling like her old self. But this short detour into good health was just that—a brief sidestep. This person still had terminal cancer, and had one good day sprinkled throughout all the terrible ones.
This is basically what happened with this year’s Arctic sea ice. Yes, Arctic sea ice averaged 2.35 million square miles in August 2013. Yes, this is 60 percent bigger than the low of 1.32 million square miles recorded in September 2012. But this occasional great day isn’t indicative of the big-picture narrative.
Also, in turning a blind eye to this long-term prognosis, Rose failed to mention the fact that, because of a statistical principal known as “regression to the mean,” climate scientists largely saw the increase in Arctic sea ice coming.
Mean regression is the idea that if a measured data point—in this case sea ice—is extreme in one year, the next time that same data point is measured it will probably be less extreme.
Confused? Consider another analogy: In a season-opening victory over the Baltimore Ravens, Denver Broncos quarterback Peyton Manning tied an NFL record by throwing for seven touchdowns. The last year a QB threw that many touchdowns in a single game was 1969. Chances are, in his next game, Manning won’t throw for nearly as many scores. Most likely, he’ll revert (regress to the mean) closer to his career per-game touchdown average, which is 1.9.
So, given that 2012 set a record for lowest sea ice coverage, it is only logical that 2013 would not set another record low.
“Even if this year ends up being the sixth- or seventh-lowest extent, what matters is that the 10 lowest extents recorded have happened during the last 10 years,” said Walt Meier, a glaciologist with NASA’s Goddard Space Flight Center, to Nature World News in late August. “The long-term trend is strongly downward.”
The key phrase in Meier’s assertion being “long-term.”
Whereas weather can best be described as atmospheric conditions over a short period of time, climate is how the atmosphere behaves over long periods of time.
And, no matter what the year-to-year cherry-pickers like Rose pronouce from their climate-denying soapboxes, the long-term prognosis for Arctic sea ice is fairly dismal, with some scientists predicting an ice-less summer within a decade.