Denier Denier Denier …

It wasn’t that long ago that Nature Climate Science published a paper using the word “denier” to describe those in denial of global warming. Anthony Watts was all up in arms about it, with not one, not two, but three posts expressing outrage.

Hotspot Data

In the last post we discussed the “Northeast hotspot.” It’s a region of the Atlantic coast of North America where sea level rise has accelerated in recent decades, identified by Sallenger et al.

Sea Level Rises … Tisdale Falls

A reader asked whether we might take a look at a recent post by Bob Tisdale on WUWT. Let’s do that, shall we? Incidentally, Tisdale has since created another post on WUWT on the same subject, which is: a paper by Sallenger et al. showing that sea level has recently accelerated in a region of the Atlantic coast, a region they call the “Northeast hot spot,” or NEH.

Open Thread and Interesting Article

There’s an interesting article from Popsci, well worth a read. It includes this quote from Katharine Hayhoe:

When I get an e-mail that mentions my child and a guillotine, I want to pull a blanket over my head.

Evidently the fake skeptic strategy of denying the science isn’t working, so they’re using other tactics.

Sea Ice Update

I’ve said it before and I’ll say it again: one of the strongest evidences of global warming is the dramatic loss of sea ice in the Arctic. Northern hemisphere sea ice has taken a nose-dive recently, which has caused some speculation in the blogosphere that we might be headed toward a record-shattering melt season.

The Light of Day

Anthony Watts has posted a story about an Oregon State University instructor, Nickolas Drapela, who has been dismissed from his job. Watts hosts a lengthy piece (by Gordon Fulks) which accuses OSU of intolerance, raises the spectre of Lysenkoism, and suggests that Drapela was dismissed because “Drapela is an outspoken critic of the theory of Anthropogenic Global Warming, the official religion of the State of Oregon, the Oregon Democratic Party, and Governor John Kitzhaber“.

I’m not sure which is greater, the pity that the scientific issue of global warming has been so politicized by those who want to prevent us from doing anything about it, or the irony that one of their strategies is to accuse others of politicizing the issue. In a move I find almost incomprehensible, Watts also linked to a slide presentation by Drapela. It’s astounding.

CO2 Sanity

Not too long ago a post at WUWT examined the most often-used data set for atmospheric CO₂ concentration, from the Mauna Loa atmospheric observatory. The post itself is just a curve-fitting exercise, but the author doesn’t make outlandish claims about the significance of his conclusions. What’s disturbing is some of the reader comments, especially from those who don’t want to believe that the CO₂ increase has been caused by human beings.

Annual Cycle of CO2

The question arose, whether the size of the annual cycle in atmospheric CO₂ concentration has been changing recently. We’ve previously shown that it increased several decades ago, but has it increased or decreased more recently than that?

Big Difference

Tim Curtin’s paper in TSWJ isn’t the first time he’s mis-applied the Durbin-Watson test in order to justify rejecting a regression of physical variables (he substituted regression of the differenced values, after which he found the regression not statistically significant). He also does so in this precursor, in which he explicitly states (regarding his first regression)

… the Durbin-Watson statistic at 1.313, which is well below the benchmark 2.0 …

I don’t see any other interpretation than that he was using two (in fact, two point zero) as his critical test value, which we have already mentioned is completely wrong.

Curtin claimed that the absence of autocorrelation is required for valid regression, which is also wrong. Nonetheless he uses that claim to justify requiring regression be performed on differenced variables. Curtin isn’t the first (and won’t be the last) to claim that regression of climate variables like global temperature should be done using differenced variables. For example, a recent commenter on RealClimate by the handle “t.marvell” did the same, justifying it by insisting that global temperature was not a stationary time series. Of course it’s not stationary — it shows a trend!

Neither of those individuals seems to understand the impact that first-differencing has on regression analysis, especially when the causal relationship we’re interested in has to do with the trends which are present. Let’s give that some consideration.

Why I Must Speak Out about Climate Change

Over thirty years ago, James Hansen was lead author of a scientific paper titled Climate Impact of Increasing Atmospheric Carbon Dioxide. They estimated that doubling the amount of CO₂ in the air would raise global temperature about 2.8 degrees (C, equal to about 5 degrees F). They projected that from 1980 to 2010, earth would warm a little more than 0.4 degrees C. High northern latitudes, however, would warm at a much faster rate. We would likely see the start of melting of the great ice sheets in Antarctica and Greenland. They further suggested that we could start to lose much of the sea ice in the Arctic, which might even open the Northwest and Northeast passages.

That was over thirty years ago. What has happened since then?