Denialism Heats Up
Opponents of the science behind global climate change have latched on to two recent developments in their ongoing efforts to claim what’s happening isn’t happening. First is a counter-intuitive fact: Antarctic sea ice has reached a new historic maximum. How can ice in the ocean around Antarctica be increasing if the earth is growing hotter? Second is a claimed statistical lull in the rise of global land temperatures, leading Britain’s Daily Mail to confidently proclaim, “Global warming stopped 16 years ago, reveals Met Office report quietly released… and here is the chart to prove it.”
Are the climate change deniers right? Can we sleep soundly now? Let’s take a closer look.
First, on the matter of the “Met Office report”, one released “quietly” (so as apparently to not draw attention to the truth behind the global warming hoax). Putting the claims into context, the Daily Mail has long been a champion of climate science opposition. That doesn’t make them wrong, but it does seem to make them partisan.
Their claim is that a recent “report” shows “The world stopped getting warmer almost 16 years ago,” and this “ ‘plateau’ or ‘pause’ in global warming has now lasted for about the same time as the previous period when temperatures rose, 1980 to 1996. Before that, temperatures had been stable or declining for about 40 years.” This report “was issued quietly on the internet, without any media fanfare, and, until today [Oct 13], it has not been reported.”
There are so many false statements and implications there it’s hard to know where to begin. First, there was no “report”. Britain’s Met Office regularly releases compilations of weather and climate data, and did so in early October as it always does. The Met Office itself responded to the Daily Mail article this way:
Firstly, the Met Office has not issued a report on this issue. We can only assume the article is referring to the completion of work to update the HadCRUT4 global temperature dataset compiled by ourselves and the University of East Anglia’s Climate Research Unit.
We announced that this work was going on in March and it was finished this week. You can see the HadCRUT4 website here.
Any implication there was an attempt to coverup or play down an embarrassing “report” is clearly false. But what about the substance of the data? What did the most recent temperature recordings show?
To the right is the “chart” (actually, it’s a graph) which the Daily Mail claims is “proof” that global warming “stopped” sixteen years ago. Notice a few things here; we’ll come back to all of them. First, it shows monthly readings for the period 1997–2012. Second, there are large peaks in 1997 and 2006, and large valleys in 1999–2000 and 2007. Third (this is the one the Daily Mail really likes) the average temperature at the beginning of the time period is the same as at the end (do you suppose this is the reason the particular time interval was selected?). Fourth, these temperatures are relative to something — “tenths of a degree above and below 14°C world average”.
Where did that “14°C world average” temperature come from? It has its origins in the way climate scientists measure world average temperatures, by picking a baseline from which to judge changes. The graphic here claims the temperatures graphed are “above and below” the “average”, but do note they are all actually “above” — the bottom of the graph is at 0 and the top is at 0.9. The standard used — 14°C — was the average baseline temperature for the period 1940–1980. These dates are important. Remember the Daily Mail article claimed that temperatures had “risen” from 1980 to 1996 (implying that was the whole basis for claims of “global warming”) and that temperatures had been “stable or declining for about 40 years” before that — in other words, from 1940 to 1980.
Here is a graph of global temperatures since 1880, showing the features described by the Daily Mail. (It’s clickable, so you can see it full-size.) The entire Daily Mail graphic comprises the tiny plateau in the upper-right-hand corner of the graph. The steep rise from 1980 to 1996 is the “previous period when temperatures rose,” and the relatively stable era from 1940 to 1980 serves as an arbitrary baseline used by climate scientists to track changes in global temperature.
Note that the trend is clearly upward, for more than a century — with short-term random walks up and down, yes, but there is no mistaking a very long-term, very clear — and rapidly accelerating — trendline. Seen in context of the full dataset, the very short plateau of the last few years is nothing unusual as part of the complete upward movement. Compare it, for instance, to a similar “plateau” around 1990, or another one around 1960.
In fact, nine out of the ten hottest years on record have happened since the year 2000, as part of this “plateau” that the Daily Mail claims is “proof” that the world has stopped warming.
The Daily Mail made no attempt at trend analysis, but concentrated instead on short-term noise. As if to stress that random chatter, they presented monthly averages, and chose a particularly warm year — 1997 — as the starting point, and a relatively cooler year — 2011 — as the endpoint (2011 was “only” the ninth warmest year on record). The peaks and valleys even within that short timeframe show that any given temperature reading will be encountered multiple times as the random noise of temperature readings are tallied. It is very easy to pick an arbitrary timespan with similar beginning and ending temperatures, display the chaotic readings between those points, and claim that the trend has “stopped”.
Using a cherry-picked short span like this is similar to using stable temperatures in Chicago between May 1 and May 7, and using that to “prove” the weather doesn’t get warmer when comparing December to August. And making a point out of the 1940–1980 baseline is like saying that if we compare May’s temperatures to those from March, we needn’t realize it has been warming since December.
All told, the Daily Mail article proves nothing other than the scientific incompetence of the people working at the Daily Mail. But what of the news concerning Antarctic ice? Surely that is of more concern to climate scientists? The Daily Mail article was no more than fraudulent use of statistics. The news from Antarctica is a far more complex story.
Summer in the Northern Hemisphere, of course, is winter in the Southern. We’ve been hearing for years that the sea ice around the North Pole is shrinking, setting progressive records for the least amount of frozen North we’ve ever seen. As the announcements are made, deniers like to remind us that Antarctica still has plenty of sea ice around it. Of course, the argument happens at the height of Southern winter, and the year’s maximum extent of antipodal ice.
This year, the stakes are higher. In the North, this summer marks a record low for Arctic ice — 50% below the 1979–2000 average. You can see in the map on the right the record low level of ice. There is open sea in places there has not been open sea since before the last ice age.
In the north, the situation is fairly simple. The Arctic is an area of open sea surrounded by land. If the temperature of the air and water rise, the ice melts, and the surrounding land prevents water from flowing in to modify the temperature in either direction. What happens in the Arctic, stays in the Arctic.
The story in the South is different. In many ways it is the reverse of the North, and not just because of the reversed seasons. The continent of Antarctica is land, surrounded by water. Oceans on all sides circulate and mix from latitudes closer to the equator. The sea ice surrounding the continent melts almost completely every summer, aside from a few protected places such as the Ross Ice Shelf. When sea ice forms in the winter, it isn’t a solid sheet; it’s a collection of large and separate floating chunks. This matters.
This winter, Antarctica is surrounded by a record expanse of sea ice, roughly 5% more than average. (The image to the left is clickable to see it full-sized; you have to look close to see the line that shows the difference between the current maximum and the average maximum.) The difference in the change is thus far less than the change in the north. Still, it is a record. Does this mean the south is cooling, while the north is warming? Does it mean the two balance out, and thus the Earth’s temperature is remaining fairly constant?
No. In point of fact, the winter sea ice around Antarctica is at a record high because the Earth is warming, and because of other things humans have done to the planet. There are several effects involved, since the situation, as I said, is complex.
First, the ozone layer above the South Pole has been severely impacted by human air pollution. The ozone layer acts as a blanket to help keep heat in (as well as keeping ultraviolet radiation out). With the ozone significantly depleted at the South Pole, heat is radiated into space, and the air temperature over the continent tends to go down.
Farther from the continent, the air and water is warmer. And it is getting warmer still, because the Earth is, in fact, heating up. Warm air is less dense than cold air. This sets up strong winds from the south (cooler than normal because of the depleted ozone layer) toward the north (warmer than it was because of global warming) and these strong winds push blocks of sea ice away from the continent. At the same time, warmer air can hold more moisture than cooler air. There are more frequent storms now than there used to be above the waters surrounding Antarctica, and they are more severe, dropping more snow into the frigid water, which freezes into more sea ice.
All told, this means the moderate expansion of sea ice we’re seeing around Antarctica is caused by human-influenced global climate change, rather than being evidence against global warming. It’s happening because the Earth is getting warmer, and because of other things we’re doing (such as depleting ozone).
The verdict here? Both of these newly-popular memes from climate change deniers mean something other than what the denial industry wants them to mean. Both are evidence of the continuing, and worsening, of global warming. One has to wonder whether the earth’s climate would cool, at least a little, if only the science deniers didn’t produce so much hot air.
- Another Daily Mail Fail: Met Office Politely says, “Bugger Off you bloody, blithering Barmpot!”
- Lying With Statistics, Global Warming Edition
- Report: Global warming stopped 16 years ago
About dcpetterson (186 posts)
D. C. Petterson is a novelist and a software consultant in Minnesota who has been writing science fiction since the age of six. He is the author of A Melancholy Humour, Rune Song and Still Life. He lives with his wife, two dogs, two cats, and a lizard, and insists that grandchildren are the reward for having survived teenagers. When not writing stories or software, he plays guitar and piano, engages in political debate, and reads a lot of history and physics texts—for fun. Follow on Twitter @dcpetterson