Science magazine

PNAS: Peer Review or Old Boy Network?

by Marlo Lewis on September 23, 2009 · 1 comment

in Global Warming

On February 25, 2009, Dr. James Hansen of Columbia University’s Earth Institute and Dr. John Christy of the University of Alabama in Huntsville testified on “Scientific Objectives for Climate Change Legislation,” before the House Ways and Means Committee.

Dr. Hansen is probably the world’s most influential scientist in the climate alarmist camp. His 1988 congressional testimony, which projected significant increases in global temperatures over the next two decades, gave birth to the warming movement.

At the Ways and Means hearing, Christy testified that datasets he and his colleagues have developed contradict the climate model hypotheses and surface temperature records on which alarmism rests. His leading example was the discrepancy between Hansen’s 1988 model forecasts and actual temperatures as measured by two independent satellite monitoring systems.

christy-observations-vs-hansen-1988-models1

“GISS” A, B, and C are Hansen’s 1988 global warming model projections. “A” and “B” are model projections assuming business-as-usual emission levels similar to what happened (actually a bit lower than what occurred). ”C” is a model projection assuming drastic CO2 cuts. ”UAH” and “RSS” are, respectively, the University of Alabama in Huntsville and Remote Sensing Systems satellite records.

Christy comments:

All model projections show a high sensitivity to CO2 while the actual atmosphere does not. It is noteworthy that the model projection for drastic CO2 cuts still overshot the observations. This would be considered a failed hypothesis test for the models from 1988.

 Ancient history, you say? Maybe, but Christy also compared the IPCC Fourth Assessment Report’s (AR4) climate model warming projections with actual temperature data.

christy-observations-vs-ipcc-models

The red and orange lines mark the upper and lower bounds of 95% of the global warming projections calculated by 21 IPCC AR4 models for multi-year segments ending in 2020. The blue and green lines show temperature trends calculated from the UAH satellite record and the U.K. Hadley Center surface temperature record, respectively.

Christy comments:

The two main points here are (1) the observations are much cooler than the mid-range of the model spread and are at the minimum of the model simulations and (2) the satellite adjustment for surface comparisons is exceptionally good. The implication of (1) is that the best estimates of the IPCC models are too warm, or that they are too sensitive to CO2 emissions.

By now you may be wondering what any of this has to do with peer review at the Proceedings of the National Academy of Sciences (PNAS). Patience, grasshopper.

At the hearing, Hansen declined to address Christy’s critique of model sensitivity assumptions on the merits. Rather, he asserted that climate sensitivity is “crystal clear,” and advised the Committee to ask the National Academy of Sciences (NAS) to produce a report and accept its verdict as “authoritative.”

Now, if you’re like me, you probably assume that the National Academy insists on the most rigorous standards of peer review for PNAS, the organization’s flagship publication. But an article in the current (19 September 2009) issue of Science magazine (subscription required) suggests otherwise.

The article, “PNAS Nixes Special Privileges for (Most) Papers,” reports that:

National Academy members, as elite scientists, could shepherd their own work through peer review with less vetting than at other publications by “contributing” a paper. They could also “communicate” a paper on behalf of colleagues who had not been elected to the academy’s august ranks.

The article goes on to explain that:

In practice, “communicating” a colleague’s paper meant that a member lined up referees to review it before PNAS ever saw it. This increased the chance of a favorable reception — and looked suspiciously like cronyism to outsiders.

Because of that perception, PNAS announced last week that it will end the “communicated” option for submitting papers by July 2010. However, Science reports, “The move will not affect the privileges of academy members to line up reviews before they submit their own papers to PNAS …”

I don’t know about you, but my college GPA would have been higher had I been allowed to ”line up” friends to grade my term papers and tests. And wouldn’t it be nice if, during job performance reviews at work, we could “line up” allies to decide whether we deserve a raise and a bonus?

Science further reports that the “rejection rate for communicated or contributed papers that reach the PNAS is a few percent, whereas the rejection rate for standard submissions is 80%.” Membership doth seem to have its privileges at the National Academy.

Having spent a few years in institutions of higher learning, both as a student and a teacher, I have seen how our alleged bastions of academic freedom breed conformity and group-think. 

First, there’s the quest for tenure. A young professor serious about his career dare not challenge the methodological or ideological pieties of his colleagues, lest they deny him the coveted job security he seeks. And if the acolyte makes it into the ranks of the tenured, he will think twice about offending colleagues with whom he may be stuck for decades, and he’ll take care not to jeopardize his department’s research contracts and grants by offending the political pieties of grantmakers in Washington, D.C.

Most people admitted into the august ranks of the National Academy will have been shaped by the conformity mills that our institutions of higher learning have become. Moreover, once ensconced in the club, they will be loathe to offend other members, many of whom may have voted to admit them in the first place.

So it should come as no surprise that “the rejection rate for communicated or contributed papers that reach the PNAS is a few percent, whereas the rejection rate for standard submissions is 80%.” 

Even apart from these considerations, cronyism seems to be a significant problem in climate-related research. The IPCC reports are collections of literature reviews in which the lead authors often review their own work. Statistician Edward Wegman noted in his assessment of the infamous “hockey stick“ reconstruction of global temperatures (which allegedly proved that 1998 was the warmest year of the past 1,000 years) that “authors in the area of paleoclimate studies are closely connected and thus ‘independent studies’ may not be as independent as they seem on the surface.” 

So when National Academy member James Hansen declines to debate John Christy on the merits, and instead advises Congress to let the NAS decide the scientific basis of climate legislation, he is actually asking Congress to let the old-boy network to which he belongs call the shots.

That Hansen would proffer such self-serving advice rather than debate the core issue on the merits is reason enough to be skeptical of the science he espouses.

Policy Peril Segment 4 – Sea Level Rise

by Marlo Lewis on August 3, 2009 · 5 comments

in Global Warming, Odds & Ends

In An Inconvenient Truth, Al Gore warns that global warming could raise sea levels by 20 feet, and he implies that this could happen quite suddenly–in our lifetimes or those of our children.

Specifically, on pp. 204-206 of the book version of AIT, Gore warns that if half the Greenland Ice Sheet and half the West Antarctic Ice Sheet melted or broke up and slipped into the sea, some 100 million people living in Beijing, Shanghai, Calcutta, and Bangladesh would  “be displaced,” “forced to move,” or “have to be evacuated.”  Is there any truth to it?

Today’s clip from CEI’s film Policy Peril: Why Global Warming Policies Are More Dangerous Than Global Warming Itself, again features Dr. Patrick Michaels of the Cato Institute, former Virginia State Climatologist, author of several superb books (most recently, Climate of Extremes: The Global Warming Science They Don’t Want You to Know), and prolific blogger on World Climate Report.

Here are my previous posts in this series:

To watch today’s video clip, click here. To watch Policy Peril from start to finish, click here.

The text of today’s excerpt immediately follows. It includes some graphics from the film and footnotes to the pertinent scientific literature.

Dr. Patrick Michaels: This even as there is a purported large melt of ice from Greenland. It turned around — the thermohaline circulation became stronger. [1] 

Narrator: Hmm. These facts are inconvenient only for the makers of An Inconvenient Truth. But who can forget the scenes where a 20-foot wall of water rolls across the world’s coastal communities. In the book version [of AIT], Gore says, “If Greenland melted or broke up and slipped into the sea–or if half of Greenland and half of Antarctica melted or broke up and slipped into the sea–sea levels worldwide would increase by 18 to 20 feet.” Reality check! How much ice is Greenland shedding?

Dr. Michaels: The actual loss of ice from Greenland is about 25 cubic miles per year. [2] Now, if that seems like a lot, there are about 700,000 cubic miles of ice on Greenland. The loss rate is four-tenths of one percent of its ice mass, per century. I didn’t say per year. I didn’t say per decade. I said four-tenths of one percent per century. [3]

Narrator: That translates into how much sea-level rise?

Dr. Michaels: If you take a look at the IPCC’s latest volume, by the year 2100, they have two inches of sea-level rise resulting from the loss of Greenland ice. Not two feet. Not 20 feet. Two inches! [4] That’s the “consensus of scientists,” okay. Whether or not we believe in consensus science, that’s what they say.

Narrator:  Gore says global warming could melt half of Greenland. Is that plausible?

Dr. Michaels: The United Nations [IPCC] projects that if we raise carbon dioxide to four times the background level–that would be about 1,100 parts per million, right now we’re at about 385 parts per million–and maintain that for 1,000 years, that Greenland would lose about half its ice in a millennium. [5] Now, we don’t have enough fossil fuel to maintain that concentration for 1,000 years.

Narrator: Gore also says half the ice sheet could break off because of “moulins.” For me, this was the scariest part of  An Inconvenient Truth. Moulins are cracks that channel meltwater from the surface of the ice sheet to the bedrock below. By lubricating the bedrock, moulins could destabilize the ice sheet, Gore says. [6]

moulin

Well, a recent study in Science magazine lays that fear to rest. A small meltwater lake poured down a moulin at a flow rate exceeding that of Niagara Falls. [7] Yet, Science magazine reports, “For all the lake’s water dumped under the ice that day, and all the water drained into new moulins in the following weeks, the ice sheet moved only an extra half meter near the drained lake.” [8] An extra half meter. [9]

Notes

[1] The thermohaline circulation “became stronger.” Dr. Michaels (Pat to his friends] just finished debunking Gore’s claim that ice melt from Greenland will inject enough fresh water into the North Atlantic to disrupt the thermohaline circulation (THC, a.k.a. oceanic “conveyor belt”), which most scientists–though not Richard Seager of Columbia University’s Lamont-Doherty Earth Observatory–believe is responsible for Europe’s mild winters. There was a brief scare about THC shutdown a few years ago when Bryden et al. (2005) reported that the Atlantic branch of the conveyor belt slowed by 30% between 1957 and 2004. But one year later, Richard Kerr of Science magazine reported on new data showing that the Bryden study was a “false alarm.” In fact, Dr. Michaels says, alluding to Boyer et al. (2006) and Latif et al. (2006), the THC became stronger. The Center for the Study of Carbon Dioxide and Global Change reviews Latif et al. (2006) here, and reviews many other THC studies. I discuss Gore’s warming-causes-cooling fantasy on pp. 11-12 of my April 2007 testimony before the Colorado Republican Study Committee.

[2] The estimate of 25 cubic miles of Greenland ice loss per year comes from Luthcke et al. (2006), a study summarized here on NASA’s Web page.

[3] Greenland has approximately 3 million cubic kilometers of ice. To convert cubic kilometers into cubic miles, you multiply the number of cubic kilometers by 0.2399. Hence, Greenland has about 719,000 cubic miles of ice. It is losing about 25 cubic miles of ice per year, which translates into a rate of 2,500 cubic miles per century. 2,500 is 4/10ths of 1% of 719,000.

[4] In the IPCC’s mid-range emissions scenario (A1B), Greenland ice loss contributes between 1 centimeter (cm) and 8 cm of sea-level rise in the 21st Century; in the IPCC’s high-end emissions scenario (A1FI), Greenland ice loss contributes between 2 cm and 12 cm per year (IPCC AR4 WGI, Chapter 10: Climate Change Protections, Table 10.7, p. 820). Translating into inches, Greenland ice loss contributes between 0.4 and 3.1 inches in mid-range A1B emissions scenario and between 0.7 and 4.7 inches in A1FI high-end emissions scenario.

[5] Pat here refers to Ridley et al. (2005), as reviewed in Chapter 10 of IPCC AR4 WGI, on p. 830. The figure below shows what the researchers project would happen to Greenland’s ice if carbon dioxide concentrations increase to four times pre-industrial levels and stay there for 3,000 years.

greenland-ice-melt-ipcc-751

[6] Gore’s photograph and diagram of moulins come from Zwally et al. (2002), published in Science magazine.

moulin-diagram

In AIT, Gore animates the diagram so that the ice sheet begins to break apart at the E.Q. (equilibrium) line. This is thoroughly misleading. The E.Q. line of an ice sheet is the elevation at which glacier melting and snow accumulation are equal. Above the E.Q. line, snow accumulation exceeds ice melt; below it, ice melt exceeds snow accumulation. The E.Q. line is not a fault line or fissure in the ice.

More importantly, Zwally et al. (2002) is not evidence of an impending ice sheet crackup. The researchers found that moulins associated with summer ice melt accelerate glacial flow, but only by a few percent. For example, the flow rate of one outlet glacier increased from 31.3 cm/day in winter to 40.1 cm in July, falling back to 29.8 cm in August, increasing annual movement by about 5 meters. Apocalypse not!

[7] In a study updating the Zwally team’s research, Joughin et al. (2008) found somewhat more glacier acceleration associated summer ice melt and moulins. However, the study’s bottom-line conclusion is pointedly non-apocalyptic:

Surface-enhanced basal lubrication has been invoked previously as a feedback that would hasten the ice sheet’s demise in a warming climate. Our results show that several fast-flowing outlet glaciers, including Jakobshavn Isbrae, are relatively insensitive to this process . . . Our results thus far suggest that surface-melt enhanced lubrication will have a substantive but not catastrophic effect on the Greenland Ice Sheet’s future evolution.

[8] In a companion article (cited in this Policy Peril excerpt), Science magazine reporter Richard Kerr quotes Pennsylvania State University glaciologist Richard Alley on moulin-induced ice sheet lubrication:

“Is it run for the hills, the ice is falling into the ocean?” asks Alley. “No, it matters but it’s not huge.”

 Kerr goes on to observe, as noted above, that an entire 4 km-long, 8 m-deep melt-water lake disappeared down a moulin in about 1.4 hours–at an average rate of 8,700 cubic meters per second, “exceeding the average flow rate of Niagara Falls.” Yet, despite all the water dumped under the ice that day and all the water drained into new moulins in the following weeks, the ice sheet moved only “an extra half meter near the drained lake.” 

[9] To put the extra half meter of glacial movement in perspective, consider that the Greenland Ice Sheet extends 2,530 kilometers (1,570 miles) North-South and has a maximum width of 1094 kilometers (680 miles) near its northern margin.

In a segment of Policy Peril immediately following today’s film excerpt, Pat also discusses studies in Science magazine indicating that the West Antactic Ice Sheet (WAIS) is more stable than scientists previously believed. The researchers found that outlet glaciers drag debris under the ice that piles up into “wedges.” These hidden land forms then prop up and stabilize the ice shelf.

 stabilizing-wedges 

The significance? Scientists once worried that sea-level rise of just a few feet could lift the WAIS off its island moorings, hastening its break up and demise. However, as Anderson (2007)  reports in Science magazine, in a review of Anandakrishnan et al. (2007) and Alley et al. (2007) and their discovery of  stabilizing land forms under the WAIS, “At the current rate of sea level rise, it would take several thousand years to float the ice sheet off its bed.”

A more recent study by Pollard and DeConto (2009), reviewed by the Center for the Study of Carbon Dioxide and Global Change, concludes that “the WAIS will begin to collapse when nearby ocean temperatures warm by roughly 5ºC.” How long would that take? 

In a companion article, Huybrechts (2009) estimates that, “The required ocean warmings, on the order of 5ºC, may well take several centuries to develop.” He asserts that “such an outcome could result from the accumulation of greenhouse-gas emissions projected for the twenty-first Century, if emissions are not greatly reduced.” His source here, however, is simply the IPCC report with its questionable assumptions about climate feedbacks and sensitivity. Huybrechts continues:

The implied transition time for a total collapse of the West Antarctic ice sheet of one thousand to three thousand years [in Pollard and DeConto (2009)] seems rapid by Antarctic standards. But it is nowhere near the century timescales of West Antarctic ice sheet decay based on simple marine ice-sheet models. 

And one to three thousand years is certainly nowhere near the years-to-decades innundation of the world’s coastal communities that Al Gore conjures up in An Inconvenient Truth.