Last week, according to our crackerjack mainstream media, NASA announced that 2014 was the hottest year, like, ever.
No, really. The New York Times began its report with: “Last year was the hottest in earth’s recorded history.”
Well, not really. As we’re about to see, this is a claim that dissolves on contact with actual science. But that didn’t stop the press from running with it.
If you follow the link I gave to the New York Times piece, you will see that this opening sentence has since been rewritten, for reasons which will soon become clear. But the Times wasn’t the only paper to start with that claim, and most of the headlines are still up. The Washington Post has: “2014 Was the Hottest Year in Recorded History.” The Boston Globe: “2014 Was Earth’s Hottest Year in Recorded History.” And so on.
You can see how misleading this is. When you read the phrase “in recorded history,” you think we’re talking about a really long time—the time dating back to the first historical records in Sumeria, circa 3500 BC. (That’s what you’ll find if you look up the phrase “recorded history.”) That’s a time frame of 5,000 to 6,000 years. But in the case of the temperature record, it actually means only 135 years. Accurate, systematic, global thermometer measurements of surface temperatures go back only to 1880. That’s why the Times report, presumably after getting whacked for a wildly misleading opening sentence, changed it to: “Last year was the hottest on earth since record-keeping began in 1880.” Which is a whole lot less impressive.
That “recorded history” gaffe is even worse when you consider that during “recorded history,” in the 5,000-year sense of the phrase, there’s good evidence that the Earth has been warmer than it is today.
We don’t have thermometer measurements going back that far, but scientists can use “proxies”—things they can measure that tend to vary with temperature, such as the composition of ancient deposits of seashells, or the thickness of the rings in ancient, slow-growing trees—to get very rough estimates. These have usually shown warmer temperatures during Roman times and the Middle Ages, when “recorded history” describes wine grapes growing in Northern England and Newfoundland.
There have been a few attempts to write these warm periods out of existence—one of them being Michael Mann’s infamous “hockey stick” graph, which implausibly asserts that global temperatures remained totally flat in every century except the 20th—but these claims have been controversial to say the least.
That’s why the implication that this is the warmest year ever in all of human history should never have gotten by a reporter who knows the first thing about the science on this issue. It implies a claim that we’re pretty sure just isn’t true.
Now let’s move on to the corrected statement, that this is the hottest year since the thermometer record began in 1880. But this a very short time for gathering data about the climate and distinguishing new trends from natural variation. For example, about half of the warming that occurs in that time happens prior to 1940, before it could have been caused by human activity. This warming was probably a natural rebound from the Little Ice Age, a cool period that ended in the middle of the 19th century.
More broadly, all changes in temperature that we observe today are relatively small variations within a much larger trend on a geological time scale. We know that the earth is going through a series of freezing and warming cycles on a scale of tens of thousands to hundreds of thousands of years. And it has mostly been freezing. We’re fortunate enough to live in a cozy, warm “interglacial” period between ice ages. So we’re all staring down the barrel of the next ice age, yet we’re spending our time worrying about global warming.
But let’s say we take this hyperventilation about a few relatively warm decades seriously. Even by that standard, this latest claim is ridiculously over-hyped.
If 2014 is supposed to be “hotter” than previous years, it’s important to ask: by how much?
You can spend a long time searching through press reports to get an actual number on this—which is a scandal unto itself. Just saying one year was “hotter” or “the hottest” is a vague qualitative description. It isn’t science. Science runs on numbers. You haven’t said anything that is scientifically meaningful until you state how much warmer this year was compared to previous years—and until you give the margin of error of that measurement.
The original NASA press release did not give those figures—and most press reports just ran with it anyway. This in itself says a lot. When it comes to global warming, “journalism” has come to mean: “copying press releases from government agencies.”
But a few folks decided to do some actual journalism, and Britain’s Daily Mail reports that
the NASA press release failed to mention…that the alleged ‘record’ amounted to an increase over 2010, the previous ‘warmest year’, of just two-hundredths of a degree—or 0.02C. The margin of error is said by scientists to be approximately 0.1C—several times as much.
Pause for a moment to digest that. The margin of error was plus or minus one tenth of a degree. The difference supposedly being measured here is two hundredths of a degree—five times smaller than the margin of error. The Daily Mail continues:
As a result, GISS’s director Gavin Schmidt has now admitted NASA thinks the likelihood that 2014 was the warmest year since 1880 is just 38 per cent. However, when asked by this newspaper whether he regretted that the news release did not mention this, he did not respond.
This is not exactly a high point in the employment of the scientific method.
If we take into account this margin of error, the most we can say is that 2014 was, so far as we know, just as warm as 2005 and 2010. There is no significant difference between these years. And that gives the lie to claims of runaway global warming. As the redoubtable Judith Curry recently pointed out:
The real issue that is of concern to me is the growing divergence between the observed global temperature anomalies and what was predicted by climate models. Even if 2014 is somehow unambiguously the warmest year on record, this won’t do much to alleviate the growing discrepancy between climate model predictions and the observations.
She links to this graph which shows that observed temperatures are falling at or below the low end of the range predicted by the climate models. With every year that passes, the models predict a greater and greater increase in temperature—but the actual observations remain stubbornly flat. Curry concludes that “ranking 1998, 2005, 2010, and 2014 as the ‘warmest years’ seems very consistent with a plateau in surface temperatures since 1998.”
So allow me to suggest a more accurate first sentence to sum up this story: “In the tiny little blip of geological time for which we have accurate surface temperature records, last year was pretty much the same as 2005 and 2010, continuing a plateau of global temperatures that has lasted nearly 20 years.”
What remains of the original description of this news? Nothing but bluff, spin, and the uncritical press-release journalism that dominates mainstream reporting on the climate. It may or may not be the hottest year ever, but this is definitely in the running for the most dishonest year on record.
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