Open Mind

It’s the Ice, Stupid


Earlier this month the WUWT blog treated us to a bizarre post about how this year didn’t set a new record for lowest Arctic sea ice extent (it only came in 2nd-lowest), in spite of “two very strong storms.” Doubling down, they offer another post trumpeting “record Arctic sea ice growth in September.” Which makes me wonder: are those guys trying to make themselves look like idiots?

David Whitehouse (of GWPF. the so-called “Global Warming Policy Foundation”) even uses the phrase “A ten-year hiatus in Arctic ice decline?” I suspect he doesn’t know the meaning of the word “hiatus,” because the graph he shows to support this idea is this one:

It doesn’t look like a hiatus. It sure looks like it has kept going down — because it has.

He even crows about how much CO2 has increased lately, and points to the fact that the decline in the above graph didn’t get even worse! If that’s what you call a “hiatus,” you need a to get your head examined.

It’s also funny that the graph he shows is for each year’s June sea ice extent. Why June? The usual choice is September because that’s when Arctic sea ice reaches its minimum, but the annual average (using all 12 months) might be a better idea. Perhaps he chose June because it doesn’t look like the ice started disappearing faster. It also seems giddy pronouncing that the decline has been only “about 10%.”

His belief in a “hiatus” is based, not on June extent, but on annual minimum extent. But he only shows us 10 years of it:

I think you deserve some context, as in, the whole picture. Here’s the satellite record of annual minimum Arctic sea ice extent:

The red box shows what David Whitehouse shared with his readers. Cherry-picking, anyone?

Then there’s the annual average (rather than annual minimum), which I’ll compute October-through-September so this year will be complete, which looks like this:

If the red line (a lowess smooth) looks like it’s declining faster recently, that’s because it is. And yes, the increased rate of sea ice loss since then is statistically significant. And yes, this last year was the lowest on record.

We can go back even further. Walsh and Chapman combined all available records from meteorological and marine resources, from the U.S., Canada, Russia, Denmark, Great Britain, and more, to estimate sea ice extent since 1850. They came up with this:

I’ll remove the annual cycle to compute anomaly:

Then I can align the Walsh & Chapman anomalies with the satellite data anomalies, giving these annual (January-through-December) averages:

The red box in the lower right (the tiny red box) shows the time span David Whitehouse shared with his readers.

But we can go back even further. A reconstruction of Arctic sea ice by Kinnard et al. covers the last 1450 years, and gives this:

That shows just how unprecedented is the rapid, alarming, surprising, and man-made decline of sea ice in the Arctic. But David Whitehouse wants you to believe it’s nothing unusual.

The loss of Arctic sea ice is so great, so rapid, so alarming and surprising, it’s powerful evidence of dramatic man-made climate change. But folks like the contributors at the WUWT blog, and at the GWPF, keep talking about it in a vain (and rather embarrassing) attempt to downplay it. Their attempts are silly, but what’s probably stupidest is that if they really want to convince people man-made global warming isn’t a problem, they shouldn’t talk about it at all. It’s like being caught with a smoking gun at the scene of a crime, then babbling on and on and on about how you have a gun. And it’s smoking.

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