Paul Krugman Shows Why the Climate Campaign Failed

By Larry Kummer – From the Fabius Maximus website

Summary: Like all of Krugman’s work, we can learn much from his latest column about climate change. See this annotated version to see how he shows why 30 years of climate crusading has produced so little policy action in the US.

Burning World in Gloved Hand

The Axis of Climate Evil“ – “Bad faith may destroy civilization”

Paul Krugman’s op-ed in the New York Times, 11 August 2017.

Krugman is a brilliant economist, with a knack for explaining technical details to the general public. He is also an insightful political analyst, albeit of the left-wing hack kind. In yesterday’s column, he shows us the latter in action — and why three decades of climate activism has accomplished so little.

It’s Not Your Imagination: Summers Are Getting Hotter.” So read a recent headline in The Times, highlighting a decade-by-decade statistical analysis by climate expert James Hansen. “Most summers,” the analysis concluded, “are now either hot or extremely hot compared with the mid-20th century.”

Krugman starts with a look at the past. Hansen’s graphs in the New York Times are what Edward Tufte calls “chart junk” in his classic work about graphics — they lack a scale for the change in temperature. All we know is that summers have grown warmer. How much? The article does not say.

For a wider perspective see this graph from the Executive Summary of the Third Draft of the Climate Science Special Report, part of the Fourth National Climate Assessment. (CCSR of NCA4). Oddly, it is not in the current Fifth Draft. It shows the hottest day in the 48 contiguous US States by year. The line has been rising since the 1960s, but remains below the levels during the long Dust Bowl. The real message here is that individual graphs can look spectacular, but no one graphic — no matter how animated — can capture the complexity of climate change.

“Extreme Hot Days Dominated by 1930s Dust Bowl.”

By Christopher Monckton of Brenchley

It is time to be angry at the gruesome failure of peer review that allows publication of papers, such as the recent effusion of Professor Lovejoy of McGill University, which, in the gushing, widely-circulated press release that seems to accompany every mephitically ectoplasmic emanation from the Forces of Darkness these days, billed it thus:

“Statistical analysis rules out natural-warming hypothesis with more than 99 percent certainty.”

One thing anyone who studies any kind of physics knows is that claiming results to three standard deviations, or 99% confidence, requires – at minimum – that the data underlying the claim are exceptionally precise and trustworthy and, in particular, that the measurement error is minuscule.

Here is the Lovejoy paper’s proposition:

“Let us … make the hypothesis that anthropogenic forcings are indeed dominant (skeptics may be assured that this hypothesis will be tested and indeed quantified in the following analysis). If this is true, then it is plausible that they do not significantly affect the type or amplitude of the natural variability, so that a simple model may suffice:


ΔTglobet is the measured mean global temperature anomaly, ΔTantht is the deterministic anthropogenic contribution, ΔTnatt is the (stochastic) natural variability (including the responses to the natural forcings), and Δεt is the measurement error. The last can be estimated from the differences between the various observed global series and their means; it is nearly independent of time scale [Lovejoy et al., 2013a] and sufficiently small (≈ ±0.03 K) that we ignore it.”

Just how likely is it that we can measure global mean surface temperature over time either as an absolute value or as an anomaly to a precision of less than 1/30 Cº? It cannot be done. Yet it was essential to Lovejoy’s fiction that he should pretend it could be done, for otherwise his laughable attempt to claim 99% certainty for yet another me-too, can-I-have-another-grant-please result using speculative modeling would have visibly failed at the first fence.

Some of the tamperings that have depressed temperature anomalies in the 1920s and 1930s to make warming this century seem worse than it really was are a great deal larger than a thirtieth of a Celsius degree.

Fig. 1 shows a notorious instance from New Zealand, courtesy of Bryan Leyland:


Figure 1. Annual New Zealand national mean surface temperature anomalies, 1990-2008, from NIWA, showing a warming rate of 0.3 Cº/century before “adjustment” and 1 Cº/century afterward. This “adjustment” is 23 times the Lovejoy measurement error.



Figure 2: Tampering with the U.S. temperature record. The GISS record from 1990-2008 (right panel) shows 1934 0.1 Cº higher and 1998 0.3 Cº lower than the same record in its original 1999 version (left panel). This tampering, calculated to increase the apparent warming trend over the 20th century, is more than 13 times the tiny measurement error mentioned by Lovejoy. The startling changes to the dataset between the 1999 and 2008 versions, first noticed by Steven Goddard, are clearly seen if the two slides are repeatedly shown one after the other as a blink comparator.

Fig. 2 shows the effect of tampering with the temperature record at both ends of the 20th century to sex up the warming rate. The practice is surprisingly widespread. There are similar examples from many records in several countries.

But what is quantified, because Professor Jones’ HadCRUT4 temperature series explicitly states it, is the magnitude of the combined measurement, coverage, and bias uncertainties in the data.

Measurement uncertainty arises because measurements are taken in different places under various conditions by different methods. Anthony Watts’ exposure of the poor siting of hundreds of U.S. temperature stations showed up how severe the problem is, with thermometers on airport taxiways, in car parks, by air-conditioning vents, close to sewage works, and so on.

(corrected par) His campaign was so successful that the US climate community were shamed into shutting down or repositioning several poorly-sited temperature monitoring stations. Nevertheless, a network of several hundred ideally-sited stations with standardized equipment and reporting procedures, the Climate Reference Network, tends to show less warming than the older US Historical Climate Network.

That record showed – not greatly to skeptics’ surprise – a rate of warming noticeably slower than the shambolic legacy record. The new record was quietly shunted into a siding, seldom to be heard of again. It pointed to an inconvenient truth: some unknown but significant fraction of 20th-century global warming arose from old-fashioned measurement uncertainty.

Coverage uncertainty arises from the fact that temperature stations are not evenly spaced either spatially or temporally. There has been a startling decline in the number of temperature stations reporting to the global network: there were 6000 a couple of decades ago, but now there are closer to 1500.

Bias uncertainty arises from the fact that, as the improved network demonstrated all too painfully, the old network tends to be closer to human habitation than is ideal.


Figure 3. The monthly HadCRUT4 global temperature anomalies (dark blue) and least-squares trend (thick bright blue line), with the combined measurement, coverage, and bias uncertainties shown. Positive anomalies are green; negative are red.

Fig. 3 shows the HadCRUT4 anomalies since 1880, with the combined anomalies also shown. At present, the combined uncertainties are ±0.15 Cº, or almost a sixth of a Celsius degree up or down, over an interval of 0.3 Cº in total. This value, too, is an order of magnitude greater than the unrealistically tiny measurement error allowed for in Lovejoy’s equation (1).

The effect of the uncertainties is that for 18 years 2 months the HadCRUT4 global-temperature trend falls entirely within the zone of uncertainty (Fig. 4). Accordingly, we cannot tell even with 95% confidence whether any global warming at all has occurred since January 1996.


Figure 4. The HadCRUT4 monthly global mean surface temperature anomalies and trend, January 1996 to February 2014, with the zone of uncertainty (pale blue). Because the trend-line falls entirely within the zone of uncertainty, we cannot be even 95% confident that any global warming occurred over the entire 218-month period.

Now, if you and I know all this, do you suppose the peer reviewers did not know it? The measurement error was crucial to the thesis of the Lovejoy paper, yet the reviewers allowed him to get away with saying it was only 0.03 Cº when the oldest of the global datasets, and the one favored by the IPCC, actually publishes, every monthy, combined uncertainties that are ten times larger.

Let us be blunt. Not least because of those uncertainties, compounded by data tampering all over the world, it is impossible to determine climate sensitivity either to the claimed precision of 0.01 Cº or to 99% confidence from the temperature data.

For this reason alone, the headline conclusion in the fawning press release about the “99% certainty” that climate sensitivity is similar to the IPCC’s estimate is baseless. The order-of-magnitude error about the measurement uncertainties is enough on its own to doom the paper. There is a lot else wrong with it, but that is another story.

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A still wider context shows another picture. America and Europe have been warming for two centuries, since the Little Ice Age ended. The IPCC’s AR5 Working Group I describes the anthropogenic part of that long warming: “It is extremely likely (95 – 100% certain) that human activities caused more than half of the observed increase in global mean surface temperature from 1951 to 2010 {link}.”

So what else is new? At this point the evidence for human-caused global warming just keeps getting more overwhelming, and the plausible scenarios for the future — extreme weather events, rising sea levels, drought, and more — just keep getting scarier. …

It’s fun to see climate activists make menacingly vague statements and support them by pointing to a voluminous reports, as Krugman does here — pointing to the 673 page-long draft CCSR. Let’s see if we can do better. The key relevant section is “4: Climate Models, Scenarios, and Projections.”

""Donna LaFramboise writes to tell me:

The head of the IPCC has written a novel in which the central character [Sanjay] is infatuated with pseudoscience and in which UFO enthusiast Shirley MacLean is presented as credible. The final installment of the Nobel Laureate Summer Reading series.

Excerpt from Donna’s Article:

As a young Hindu, Sanjay thinks about life’s great mysteries – and wonders how the soul passes from one body to another during the process of reincarnation. He consults a couple of swamis, visits a few sacred locales, and later, as a result of his meditation fame, comes to be regarded as a spiritual leader in his own right.

What kind of spirituality? The sort associated with Hollywood actress Shirley MacLean – who appears as a character in this novel, voicing lines written by Pachauri. These days, MacLean is famous for her outspoken views about extraterrestrial life. According to a recent article on Oprah Winfrey’s website, MacLean has

seen many UFOs from the deck of her New Mexico property. “I’ve seen a mothership here, and I’ve seen them at my ranch,” she says. “One famous day, a friend of mine was sitting in my hot tub out there, and three UFOs came over and hovered over the hot tub for about 10 minutes.”

…Shirley says that she believes extraterrestrials are attracted to the many crystals around New Mexico. “Crystals amplify the consciousness,” she says. “They’re attracted to that crystal amplification.”

She says she has never seen an alien but says their teaching is that the soul does not die. “The soul is everlasting, and its learning experience is lifetime after lifetime.”

In the novel, MacLean’s ideas are not ridiculed. Quite the opposite. Sanjay treats her as an intellectual equal and takes her advice. While she doesn’t mention UFOs specifically, she urges Sanjay to travel to Peru:

You won’t believe the spiritual richness of that land. God does not reside above in that place. He has actually descended on to the mountains, and you can feel his presence everywhere.

When Sanjay and MacLean meet for dinner in that country, we’re advised that a member of her entourage is “known to communicate with the spirits.”

Read: The IPCC, UFOs & Pseudoscience

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“Over the next two decades, global temperature increase is projected to be between 0.5°F and 1.3°F (0.3°–0.7°C) (medium confidence). This range is primarily due to uncertainties in natural sources of variability that affect short-term trends. In some regions, this means that the trend may not be distinguishable from natural variability (high confidence).

“Beyond the next few decades, the magnitude of climate change depends primarily on cumulative emissions of greenhouse gases and aerosols and the sensitivity of the climate system to those emissions (high confidence). Projected changes range from 4.7°–8.6°F (2.6°–4.8°C) under the higher RCP8.5 scenario to 0.5°–1.3°F (0.3° 1.7°C) under the lower RCP2.6 scenario, for 2081–2100 relative to 1986–2005 (medium confidence).”

So the report does not prophesize doom with the certainty Krugman implies. In fact, it does what activists seldom do — explicitly state the certainty of its conclusions (the IPCC’s reports also do this). We might get tolerable rise of 0.5°–1.3°F under RCP2.6 — the most favorable of the four scenarios in the IPCC’s AR5 report (it might be easy to do; see these details). On the other extreme, their worst-case RCP8.5 scenario is nightmarish but unlikely.

Paul Krugman

Paul Krugman. From Wikimedia Commons.

What becomes clear to anyone following the climate debate, however, is that hardly any climate skeptics are in fact trying to get at the truth. I’m not a climate scientist, but I do know what bogus arguments look like — and I can’t think of a single prominent climate skeptic who isn’t obviously arguing in bad faith.

A sensible person would stop reading with this pitiful attempt to delegitimize scientists who disagree with him. Only hard-core hacks write like this. Climate activists describe prominent climate scientists like Roger Pielke Sr. and Judith Curry as “skeptics”. Krugman’s description is quite mad applied to them.

Take, for example, all the people who seized on the fact that 1998 was an unusually warm year to claim that global warming stopped 20 years ago — as if one unseasonably hot day in May proves that summer is a myth.

With this science denial Krugman shows the brotherhood of the far-right and far-left. Here he vaguely refers to what climate scientists call the “pause” or “hiatus”. Hundreds of papers in peer-reviewed journals and reports have discussed this since the early ones in 2009. Scores discussed evidence showing the pause. After that was well-established, scores discussed possible causes of the pause (a debate still not resolved). Some discuss when the pause will end (with the 2015 El Nino either making a pause in the pause, or more likely ending it). Those links go to posts with citations, abstracts, and links to a sample of 150 papers about the pause.

Or all the people who cited out-of-context quotes from climate researchers as evidence of a vast scientific conspiracy.

I agree with Krugman on this, and have written several posts about it (for example, here).

Or for that matter, think of anyone who cites “uncertainty” as a reason to do nothing — when it should be obvious that the risks of faster-than-expected climate change if we do too little dwarf the risks of doing too much if change is slower than expected.

This is a creative use by Krugman of the false dilemma logical fallacy to mischaracterize his opponents. The alternatives are not a binary do nothing or something. The world faces many serious threats in addition to climate change (details here and here). We have limited resources and must allocate them wisely among these threats. Krugman does the usual climate activist trick of focusing on the fringe that denies the reality of global warming — and ignoring the serious debate about how much warming, when, with what effects. Understanding those is necessary for effective policy action.

Ministry of Propaganda


This is propaganda, characteristic of how activists have conducted their campaign to build support for massive public policy action to fight climate change. They’ve been at it since Hansen’s 1988 Senate testimony. It has not worked.

It is not too late. Climate scientists can restart the climate change debate – & win. For more information about this see putting this proposal in a wider context of science norms and the climate science literature.



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