Here. The FPJ editor asked for a substantive reply to Giaever’s points, so I thought I’d take a stab – I’m afraid the response got long, but at least it’s something of an interesting tour of popular criticisms of climate science and climate change action.
Ivar Giaever won the 1973 Nobel Prize in Physics (I like the hairstyle!) for “experimental discoveries regarding tunneling phenomena in semiconductors and superconductors“. His fame in physics has translated in modern times into notoriety as a climate contrarian arguing that global warming is “ridiculous”.
Foreign Policy Journal posted this youtube clip of Giaever (colorfully titled Nobel Laureate Smashes the Global Warming Hoax) from the Nobel Laureates meeting July 1st 2015 (ah, remember the climate debates of 2015?) Commenters quickly noted the obvious, that Giaever by his own admission is not an expert in climate science – memorably claiming “I spent a day or so – half a day maybe on Google, and I was horrified by what I learned”. Also that at the same Nobel Laureate meeting 36 of Giaever’s peers (later increased to 76 laureates) signed a very different Declaration on Climate Change:
We undersigned scientists, who have been awarded Nobel Prizes… believe that our world today faces another threat of comparable magnitude… While by no means perfect, we believe that the efforts that have led to the current IPCC Fifth Assessment Report represent the best source of information regarding the present state of knowledge on climate change. Although there remains uncertainty as to the precise extent of climate change, the conclusions of the scientific community contained in the latest IPCC report are alarming, especially in the context of the identified risks of maintaining human prosperity in the face of greater than a 2°C rise in average global temperature … the world must make rapid progress towards lowering current and future greenhouse gas emissions to minimize the substantial risks of climate change.
These other Nobel Laureates don’t get quite the same internet climate fame – just to put names on a couple of them in passing, they include Brian Schmidt 2011 Nobel Prize for physics “for discovery of the accelerating expansion of the Universe through observations of distant supernovae” (“I see this issue as the single greatest threat to human prosperity, and I believe it is important for the best scientific evidence to be used by policy [makers] in making their decisions”) and George Smoot 2006 Nobel Prize for physics “for their discovery of the blackbody form and anisotropy of the cosmic microwave background radiation” (“the evidence is very strong that the major portion of climate change is man made and that continuing business as usual presents great and increasing risk to humankind.”)
FPJ editor Jeremy R. Hammond calls foul at these objections, wanting to hear answers to the substance of Giaever’s concerns, rather than criticisms of Giaever for being an outlier or a non-expert. Just because the headline reads “Nobel Laureate Ivar Giaever on Climate Change” is no reason to assume Mr. Hammond and the FPJ were trying to make some kind of appeal to authority here. All we care about are the facts. OK.
I looked around and found this article addressing some of Giaever’s claims on skepticalscience, which gives some useful context and is more polished than I’ll attempt but doesn’t address the points in this particular video clip exactly. It does however include this great xkcd comic that it seems a shame not to include again:
On to Giaever’s claims in the video clip. They are not new or novel, but they are popular and exactly the sort of thing you’re likely to find spending “a day or so on Google” – indeed this ends up being something of a tour of common (and, I’m afraid, frequently debunked and relatively superficial) complaints about the science of global warming. Here goes…
He gets rolling at about 1:46, claiming that “global warming really has become a new religion, because you can’t discuss it, it’s not proper”. Setting the tone here. Not sure whether this is the sort of claim Mr. Hammond wants addressed, but clearly this is pretty tedious name-calling; there are at least several hundred thousand pages of internet content contradicting this concern.
Giaever cites the (to him, alarming) use of the term “incontrovertible” in the previous 2007 statement on climate change by the American Physical Society, which read:
The evidence is incontrovertible: Global warming is occurring. If no mitigating actions are taken, significant disruptions in the Earth’s physical and ecological systems, social systems, security and human health are likely to occur. We must reduce emissions of greenhouse gases beginning now.
As I read it, I thought the APS clearly meant something like “conclusive” in their use of the word, rather in the vein of Stephen Jay Gould’s quote that “in science, ‘fact’ can only mean ‘confirmed to such a degree that it would be perverse to withhold provisional assent'”. Critics such as Giaever, however, felt that the term was intended to mean “discussion is not allowed”, which naturally would indeed be pretty anti-scientific. Giaever felt sufficiently moved to renounce his APS membership.
So basically a semantic dispute here – those are rarely worth spending a lot of time on. If Giaever is trying to establish that discussion is not tolerated, the extended debate just about this single term among APS members probably doesn’t support his point very well. (Needless to say, the APS avoided use of that particular term in their restatement of their climate change position last year.)
3:20: Moving on to factual matters, Giaever expresses amazement that a big deal is being made out of surface warming that only adds up to a single degree C of warming since 1880. Amusingly, he converts to kelvin so he can show it is only a 0.3% total change and therefore “amazingly stable!”
In fairness this subjective reaction is a common one and the scientific case does run against common sense here to some degree. Giaever notes that where he lives in Albany there’s as much as an 80 degree difference between annual min and max temperatures. We all commonly watch the temperature change by many degrees every day between night and day, and can barely notice a 1 degree difference. How does this add up to anything?
The answer is that 1 degree difference in daily experience is not really comparable to what a 1 degree difference in the earth’s average surface temperature means. The energy involved in the latter is rather massive. The quickest way to see this is to look at the last glacial (ice age) period, where the global average surface temperature was only about 5 degrees cooler, but the planet was quite transformed, including what would have been rather noticeable mile-thick slabs of ice across Giaever’s New York.
In particular, the state of earth’s oceans and cryosphere change a lot within a relatively small range of average surface temperature. Another nice xkcd comic summarizes this (nod to …And Then There’s Physics):
For further context, we could look at the reconstructed temperatures for the past millenium (from Pages 2K) and note that a full degree warming in the course of a century looks pretty aggressive compared to what the climate had been doing:
(source here, green dots show the 30-year average from PAGES 2k, red is HadCRUT4 instrumented temp record from 1850 on, blue just for comparison is the original hockey stick of Mann, Bradley and Hughes (1999). Graph by Klaus Bitterman.)
Giaever doesn’t think it makes sense that this amount of change would affect climate very much. The IPCC working group 2 report on impacts details a large amount of research that indicates otherwise, however. Giaever isn’t offering any counter-evidence or analysis on this point, just subjective doubt.
6:07: Notes that Antarctic temperature station data is sparse, argues “It has never been as cold on the south pole as it is right now.”
OK, maybe this is obvious, but to recap: the earth is covered in a surface ‘fluid’, and within that heat swirls around chaotically/unpredictably. This is why weather is difficult to predict. Global warming is about the global increase in energy in this fluid envelope around the earth. So, as everyone should know by this point, looking at a single location and saying “hey it’s not warming here” is not evidence that contradicts global warming. It is expected that by sheer random chance, many locations will show flat or cooling trends, despite the overall warming pattern.
Just for fun, in terms of the south pole specifically (Amundsen–Scott South Pole Station data) this paper finds “slight decreases in the temperature and pressure over the 1957–2010 time period that are not statistically significant”. Perhaps this is what Giaever or other bloggers have jumped on. Such data does not provide evidence that the south pole has “never been as cold as it is right now” (which of course is particularly eyebrow-raising if Giaever literally means “never”.)
Meanwhile, NASA GISS surface temperature index shows warming trends at all latitudes, so it’s not the case that the southern latitudes in general aren’t warming:
6:24: “Another thing that upsets me – what is the optimum temperature of the earth”. Another common, subjective reaction: why are we attached to the current conditions? How do we know that warming and climate change is bad?
The short answer is that the optimum temperature is “stable”. Human and biological systems have adapted to the relatively constant climate of the Holocene (the period since the last ice age), and so naturally that’s the conditions they’re best suited to deal with. Giaever seems to think this is a miracle: “current temperature being optimal would be a miracle”. But it’s not a miracle that earth systems have adapted as aggressively as they can to current climate – it’s survival of the fittest out there.
Meanwhile, the paleoclimate record shows alarming signs that periods of extreme climate change in the past are associated with extreme impact including reef gaps and major extinction events. For a bit of cheery reading check out some of the latest understanding of the massive Permian extinction.
7:18: Argues that you can’t measure the average temperature of the whole earth for a whole year to a fraction of a degree and have confidence in the result. This is another common one. The short answer is that the question at hand is the trend, i.e. changes in energy budget over time, and so the important thing is not that every molecule’s heat state on the planet is accurately calculated to some arbitrary precision, but rather that a global mean surface temperature (GMST) metric is consistently calculated so that we can observe trends over time.
We’re dealing with a contoured, dispersed data set and can apply statistical reasoning to such question as “is it reasonable to expect that big patches of anomalously warming or cooling areas are hiding in the gaps in our network, confounding results?” And in fact there have been some problems like that leading to discussion and correction over time. At the end of the day, the globe shows a warming pattern no matter how you slice it – rural, urban, land, ocean, by latitude etc. This contrarian viewpoint offers no logical explanation why the consistently calculated GMST metrics are all going up over time.
Giaever makes a reference to urban heat islands – the idea that the warming trend is artificially introduced by increasing urbanization around temperature stations. This again is an exhaustively studied topic and continually debunked – indeed correcting for urban heat biases is one of the reasons for the temperature record adjustments critics scream about as “data tampering” in the first place.
There are many ways statistically to analyze for such factors. For example, here’s a 2013 study that uses an independent calculation of rural site trends to assess the urban heat signal in the temperature record, “Influence of Urban Heating on the Global Temperature Land Average using Rural Sites Identified from MODIS Classifications”:
We compare the distribution of linear temperature trends for these sites to the distribution for a rural subset of 15,594 sites chosen to be distant from all MODIS identified urban areas. While the trend distributions are broad, with one-third of the stations in the US and worldwide having a negative trend, both distributions show significant warming. Time series of the Earth’s average land temperature are estimated using the Berkeley Earth methodology applied to the full dataset and the rural subset; the difference of these is consistent with no urban heating effect over the period 1950 to 2010, with a slope of -0.10 ± 0.24/100yr (95% confidence).
8:42: Giaever puts up a chart of the RSS upper air temperature measurement and repeats the “pause” claim that “for the last nineteen years, roughly speaking, the temperature has not gone up”. This is really the last, central claim the anti-AGW movement is holding onto, so just a matter of time until Giaever got to it (if his “googling” of global warming criticisms was any good.)
This, of course, is basic cherry picking. Of all of the global temperature records available, RSS is the only one showing this flat of a trend (not completely flat, as my link above shows for the last 20 years). Again a longer topic, but to quickly touch on some of the context here: RSS definitely shows a multi-decade warming trend and the flat recent period is artificially influenced by the huge El Nino spike in 1998. Measuring temperature high above the earth via microwaves is pretty difficult, and Carl Mears, the scientist actually in charge of the RSS data set, argues the surface temperature datasets are “more reliable”. We see clear, continuing warming on the surface and in the ocean, and it is warming in those places that is driving the impact we are concerned about. Another microwave sounding unit record, UAH TLT, managed by AGW contrarian Roy Spencer at the University of Alabama and also measuring the upper air, does show warming in this period. The analyzed radiosonde (weather balloon) data also shows warming in the mid-troposphere. So, this really is quite a cherry pick, and it really is extremely unconvincing evidence that “the temperature has not gone up”.
9:30: Shows the NASA GISS surface temperature data, and asks rhetorically why this shows warming when he’s “just showed you” that temperatures (according to RSS) have been flat. He strangely claims this is because GISTEMP “includes now the ocean, but for a hundred years the ocean has not been included.” Not sure where he gets this, GISTEMP has always been a global combined land and sea record because this is what NASA’s James Hansen needed to evaluate early climate models. As the site says, “The ocean data are now based on NOAA ERSST for the sake of simplicity, replacing a prior concatenation of Hadley Center’s HadSST1 and the satellite-based NOAA (Reynolds) OISST” – which hardly makes it sound like the inclusion of ocean data is new.
Giaever then veers (inevitably) into conspiracy theorist territory: “Why do you think they include the ocean? Because it’s more accurate or because they can fiddle with the data? That’s what NASA does.” Besides being a completely unsupported and somewhat reprehensible claim, this is also pretty goofy, as conspiracy theorists are quite able to believe NASA “fiddles” fraudulently with the land data just as well as they can the ocean. Not much here for evidence-based discussion. In reality, “they” include the ocean in calculating global mean surface temperature because the ocean covers about 71 percent of the surface.
10:00: “So Obama said 2014 was the hottest year ever, but it’s not true.” Giaever cites UAH (the other microwave sounding unit upper air record) which indeed doesn’t show 2014 as the hottest year, but Obama’s comment is based on the surface record (the surface being, after all, where we live.)
As an aside, the upper air measurements seem to have more of a slightly delayed response to El Nino and La Nina events, but an exaggerated response when they do. Spencer is currently projecting 2015 will “only” be the third-warmest on record for UAH, but whether the strong El Nino dominates these measurements even more to set a new record in 2016 will be a fun sideshow to watch.
11:00: Argues that CO2 increased 367 to 403 ppm since 1998, so why haven’t we seen proportional warming in that period? At this point the cherry picks are pretty shameless – 1998 was an epic El Nino which drove up temperatures dramatically. We’ve seen a lot of La Nina dominance since, which physically sponges more heat into the ocean (via surface conditions, wind/currents and coastal downwelling), and there have been many short-term periods of less steep warming in the past half-century. The big dog, ocean heat accumulation certainly hasn’t slowed at all, so there’s no evidence in the current period that the physical process of global warming via an enhanced greenhouse effect has slowed:
Giaever waxes philosophical about how if your experiment doesn’t agree with your theory “then you have to cut out the theory, you were wrong with the theory.” At this point he is rehashing the same sort of philosophical argument I examined in detail in this prior post, so no need to revisit.
13:00 or so: “Nobody mentions how important CO2 is for plant growth”. Fair to say this doesn’t get the same attention as global warming, but there is certainly plenty of discussion and research attention, including in Nature which Giaever claims “won’t talk about this”.
“They don’t talk about how good it is for agriculture that CO2 is increasing.” Well, they study it, but agriculture is affected by a lot of things including the effects of climate change which can impact whether a region remains ideal for growing a particular type of crop. From the IPCC impacts report summary again, “Based on many studies covering a wide range of regions and crops, negative impacts of climate change on crop yields have been more common than positive impacts (high confidence)“.
Giaever complains that when people talk about climate change impacts, “it’s always negative”. He seems to feel that by simple law of averages it should come out more like 50/50. But again he’s implicitly ignoring everything we know about biological systems, adaptation etc., not to mention what the actual available research is based on or what it says.
The impacts summary does refer to a variety of local positive benefits as part of the overall picture, “positive effects are expected to include modest reductions in cold-related mortality and morbidity in some areas due to fewer cold extremes” as an obvious one, also the smaller number of studies showing net positive impacts to crops mainly in high-latitude regions. But yes, generally the summary tends to come back to “globally over the 21st century, the magnitude and severity of negative impacts are projected to increasingly outweigh positive impacts”.
16:00: He’s back to cherry picking, looking at a single station in Greenland and complaining that it doesn’t show warming.
26:00: Criticizes Obama for describing climate change as a dominant challenge for future generations. Argues that we have much more pressing problems, such as the Syrian refugees, who are fleeing poverty and not global warming. Of course, ironically, some studies have looked at the links between climate change, drought, and the Syrian conflict and found:
There is evidence that the 2007−2010 drought contributed to the conflict in Syria. It was the worst drought in the instrumental record, causing widespread crop failure and a mass migration of farming families to urban centers. Century-long observed trends in precipitation, temperature, and sea-level pressure, supported by climate model results, strongly suggest that anthropogenic forcing has increased the probability of severe and persistent droughts in this region, and made the occurrence of a 3-year drought as severe as that of 2007−2010 2 to 3 times more likely than by natural variability alone. We conclude that human influences on the climate system are implicated in the current Syrian conflict.
Giaever sums up his talk with the idea that Obama is a clever guy, but just “gets bad advice”. Obama likely gets his scientific advice from a variety of places, but one would be the National Academy of Sciences, of which Giaever is apparently a member. NAS was founded by Abraham Lincoln in 1863 explicitly to advise the nation on critical questions of scientific policy. Members are elected in recognition of distinguished and continuing achievements in original research, still considered one of the highest honors in science. NAS includes a lot of scientific luminaries who have spent actual in-depth time assessing the state of climate science, leading to reports such as this one. I suspect quite a lot of them wouldn’t get caught up in the sort of confused cherry picking, misrepresentations and muddled conspiracy theories we see here.
A shame they’re not the ones getting as many internet headlines.