Bishop Hill Hansen at the LSE
May 21, 2013 Climate: Sceptics Climate: other Reader Danny Weston sends this report of James Hansen's lecture at the LSE last week.
On Friday the 17th James Hansen came to speak at the London School of Economics (LSE), on “Itinerant farming to White House arrests: A scientist’s view of the climate crisis”.
The venue was completely packed and I wasn’t sure initially if I would even get in. There were hundreds of people, already buzzing with excitement before Hansen began his talk.
As expected, Hansen put the frighteners on, emphasising that immediate action was required to stymie anthropogenic CO2’s allegedly noxious effect on our environment. His presentation was littered with continual emotive references to, and pictures of, his numerous grandchildren, showing them gradually growing up. This was important because Hansen is now pushing the line that whilst climate catastrophe is not imminent, it is “in the pipeline” and the victims will, apparently, be our grandchildren. The reason we’re not seeing imminent catastrophe now is because of “climate inertia” and we should be worried because there are further “tipping points” to come after which “we could lose control”. I’m sure all of this sounds familiar.
Furthermore, he was also playing the victim card, detailing his interactions with the Bush administration and presenting himself as a hard pressed and isolated scientist working against the grain. He claimed that the 30% reduction in the NASA climate budget during this period was a result of him having gone to the New York Times claiming that NASA had censored him [1].
He went through all of the standard alarmist memes with almost no qualification or caveats to speak of. Regular readers of BH and other sceptical blogs will be familiar with all of them – TSI not being a factor in affecting the climate, “unprecedented melt” in Greenland (for which he showed this [2] image, with no mention of these [3] issues), both Arctic and Antarctic “death spirals” (showing a graph for each, with a single curve sloping precipitously downward at an ever faster rate), ocean acidification, coral bleaching and so on.
“Extreme weather” of course had a central place in the presentation. He claimed that there were now “more extreme forest fires” and of course highlighted Hurricane Sandy. He said that droughts were also getting worse and tried to illustrate this anecdotally by claiming to have noticed changes in the migratory behaviour of the monarch butterfly in North America (also giving him another opportunity to reference his grandchildren).
He then moved onto more political aspects of his views, leading with a slide quoting himself thus:
“Our parents did not know that their actions could harm future generations. We will only be able to pretend that we did not know.”
This led into a discussion of “intergenerational justice”. During which he made a number of bizarre claims and statements. These included:
- Extolling the virtues of France’s dash to nuclear power (no mention of the issue of nuclear waste whatsoever, nor the fact that both the UK and Germany regularly rely on French nuclear power).
- Answering a questioner who raised the issue of national debts as possibly being more important than “green” spending, he claimed that attacking the deficit rewards the government, helping them to grow bigger.
- Praising Bill McKibben for “getting the Sierra Club to join him” and “thousands of people” to surround the Whitehouse for the anti-Keystone pipeline demonstration. This is bizaare because Hansen was there himself – with all 50 attendees [4]
- Then of course there was the boilerplate “there is a well funded [fossil fuel] effort to prevent the public from understanding the issue”.
During the Q and A session as I listened to one questioner after another identify whichever activist group or green lobbying special interest group they were from, I truly felt like I was alone in enemy territory. I almost backed out and let my fear get the better of me. But I kept putting my hand up regardless – I felt Hansen’s scaremongering could not go unanswered and if it wasn’t by way of putting points and questions to him then it was going to have to be heckles.
Shortly before the mike came to me, one of the activists in the audience pointed out that he [Hansen] was only preaching to the choir, saying that it was important to get people from ‘outside the choir’ to attend such events and asking how.
That was my in. Hansen responded to her that it was very important to get people from ‘outside the choir’ in to such talks but didn’t know how.
The mike came to me and I stood up and laid into him. I said that he was high on the hyperbole and hysteria and low on the facts. Most of the people there would unfortunately take him at his word and not look any further so I said I felt obliged to point out that most of his claims were highly controversial and some were flat out wrong and that I’d be happy to go through them with him there and then and debate him.
The crowd then turned on me, exploding in incredulity.
I stated that my question to him was that if he truly wanted people from ‘outside the choir’ to get involved then what on earth did he expect to happen when he continually pushed the line that there was an enormous well funded “denial” campaign, painting anyone who dared express a sceptical thought as being in bed with the fossil fuel industry.
After several hostile exchanges with the crowd immediately around me and a bit of back and forth between myself and Hansen, he finally got around to (not) answering my question. His response was very odd. He went through the hackneyed nonsense about science being based on scepticism (the implied syllogism here being that he was a scientist, therefore also a sceptic). He then said that he had debated Richard Lindzen previously. He said (referring to Lindzen) that it was “hard to win against an articulate guy”. He also – bizzarely – claimed that Lindzen had been shown to be wrong again and again and that he [Hansen] would no longer have any kind of debates, public or otherwise, with Lindzen or others because Lindzen “like other climate contrarians” – apparently – “even when he has been shown to be wrong on so many occasions, just shifts to another point to pick on”.
Following the talk I ended up being collared multiple times outside the lecture theatre. Thankfully a few people backpatted me and saying “very brave”, and a couple whispered to me conspiratorially “I’m outside the choir too”, but plenty were wanting to argue. I was happy to oblige.
I want to say thanks here by the way to the one kind chap who sided with me and argued with the attendees outside. What was particularly depressing though was further confirmation of the general pattern of ignorance that many of the alarmist footsoldiers appear to exhibit. There genuinely is no variation in my experience and over the last seven years or so during which I’ve argued with hundreds face to face since I fell from grace and became a CAGW sceptic. It is abundantly clear that they all get their talking points from the same limited insular group. I’d be interested to know if other BH readers have had a similar experience – commonalities include ignorance of CO2’s direct effect following a logarithmic decay, the importance of climate sensitivity and strong positive feedbacks to the alarmist case and similarly, their importance to the typical sceptic’s position (they always seem to have an utterly cartoonish impression of sceptics having never having before met one in real life), not understanding that the temperature data of 1880 or before may not necessarily be comparable to that in 2013, not knowing that regular measurements of CO2 have only been taken since 1958, not knowing that Venus’s climate is driven primarily by atmospheric pressure and proximity to the sun rather than CO2 and so on.
All in all a thoroughly depressing experience.
[1] http://www.nytimes.com/2006/01/29/science/earth/29climate.html?pagewanted=all&_r=0
[2] http://www.nasa.gov/topics/earth/features/greenland-melt.html
[3] http://wattsupwiththat.com/2013/03/21/greenland-ice-melt-overestimated-due-to-satellite-data-algorithm-issue/
[4] http://wattsupwiththat.com/2013/02/13/keystone-xl-nasas-james-hansen-risks-arrest-again/
Reader Comments (107)
Correction
For an ECS of 2.0C equilibrium would be reached after 185 years in 2065, 15 years late.
EM, Thank you for you response.
However, let's return to Eric Gisen's original comment:
"A half-doubling is sqrt(2), and we have just reached that point. Depending when you start (1950, not 1800), there is about 1C rise. That should rule out climate sensitivity above 2C."
He is essentially claiming that the equilibrium senstitivity is less than 2. Since the transient sensititivity is necessarily lower than the equilibrium sensitivity, your answer remains unresponsive to the original comment.
On the other hand, if you really wanted to counter his argument, you could have pointed out that the relationship he was really getting at is delta T is proportional to ln(C/Co).
Thus, he shouldn't have just doubled the observed temperature rise to get to the maximum equilibrium sensitivity, he should have divided by ln 1.4 (C 40% greater than Co), which if he accepts an observed rise of 1 deg, would give about 2.8 for the equilibrium senstitivity to doubling. Of course, the observed rise is only about 0.75 deg, so that takes us to an equilbrium sensitivity of about 2.2, without accounting for any lag. The proportionalily is for equilibrium, the observed rise may include a factor due to lag.
That is why I was trying to get you to be specific on what you meant by "lag".
John M
Thank you. You put it better than I ever managed.
I used the radiative forcing formula ( delta T = 5.35 * ln(C/Co) / 3.7 ) once before to assist another commenter's confusion between log and ln, but the resulting torrent of ridicule rather discouraged further debate.
For anyone else interested, this is the calculation for the direct warming to be expected due to an increase in atmospheric CO2.
ln(C/Co) is the natural logarithm of the relative change in concentration; 5.35 is a constant of proportionality; 3.7 is the change in wattage needed to change the temperature by 1C.
This gives an ECS due to CO2 alone of just over 1.0C/doubling. Any secondary forcings then have to be accounted for separately.
"Any secondary forcings then have to be accounted for separately."
Actually, secondary forcings are accounted for in the more usual protrayal of "instantaneous forcing" and temperature rise.
It is described here.
http://en.wikipedia.org/wiki/Radiative_forcing
The original question was not just about the temperature rise due only to CO2 increase, but rather, in the context of capping the totalsensitivity based on the current rise in CO2 levels and temperature. I put it in the form of ln(C/Co). The Wiki article says a doubling of CO2 should give a temperature rise (sensitivity) of 3 degrees, but you can assume any sensitivity and back-calculate what the current temperature rise should be based on that sensitivity and a value of C/Co.
Either way, the question still stands, why is the temperature rise lower than calculated by the ln(C/Co) relationship. If it is due to "lag", what is the "lag"?
For example, if the lag is 20 years, we should be using the CO2 level from 20 years ago, and not the current measurement. But what is the "lag" and what evidence is it based on?
John M
The equation I gave you is for the direct effect of CO2. The radiative forcing section (5.35*ln(C/Co) derives from laboratory measurement of the infrared emission and absorbtion behaviour of CO2 and is the increased radiation in watts reaching the surface as a direct result of increased CO2. The total sensitivity includes other effects such as cloud cover and water vapour, and cannot be derived directly from the radiative forcing equation.
The problem with going from TCR to ECS is that the system does not respond as a whole to increased energy input. The troposphere responds to a change in radiation within days. The land surface reaches a new equilibrium temperature in weeks and sea surface temperatures in months. The upper 700 metres of the ocean respond over years to decades. The deep ocean may take centuries and the thermohaline circulation up to a millennium.
The key parameter determining the time to equilibrium is the total heat capacity of each system. The atmosphere has a low heat capacity, so it takes only a small amount of energy to produce a temperatue change and the temperature can vary by tens of degrees in one day.
The top 2 metres of the oceans has the same heat capacity as the atmosphere and shallow water can change temperature over similar time scales. With mixing, surface heating warms the upper 700M and the rate of temperature change is much slower.
The deep oceans and the thermohalone have even greater volume and heat capacity, so the rate of temperature change is slower again. Indeed, the deep ocean warming is only just fast enough for our current technology to measure it, and will take a considerable time to reach any equilibrium. Melting of glaciers and ice sheets absorbs considerable latent heat without any temperature change at all.
As a simple analogy, take three similar saucepans on similatr hotplates. Fill one pan with water, 1/2 fill the second and fill the third with ice. The 1/2 full pan will boil first after heating fastest. The full pan will show a slower rate of heating and boil after twice as long. The pan of ice will stay at 0C unchanging until the ice has melted and will only then begin to warm.
You are corrct that the temperature changes observed to date is due to CO2 released over the last 150 years. The atmospheric and sea surface heating reflect recent CO2 levels. Deeper water temperatures reflect a degree of heating seen when CO2 was lower and have not caught up yet. Ice melt shows that the system is out of equilibrium, but, while it cam be measured and used to calculate the energy absorbed, it cannot give direct temperature information.
What past CO2 content are we seeing the effect of? It varies depending where you look. What is the lag? Again it varies depending where you look.
These are not simple questions, which is why there are no simple answers. An overall figure for ECS is unlikely to be less than 1, because CO2 alone produces that, and no large negative forcings have been observed. Calculating an upper limit requires complex calculation and some aspects rely on estimates of climate behaviour with their own uncertainties.
The short timescales of ECS estimates based on recent records makes me less certain of their validity because of their built-in tendency to underrread. The paleo based estimates allow tens of millennia for even the most gradually responding parts of the system to equilibrate.
Ectopic Man : ... the direct effect of CO2 ... derives from laboratory measurement of the infrared emission and absorbtion behaviour of CO2 and is the increased radiation in watts reaching the surface as a direct result of increased CO2
This I take it is the 'back-radiation' theory, ie the idea that CO2 emits the longwave it absorbs - in all directions, some of which strike the earth's surface ?
A rival theory is that the IR warms the CO2, and, as the oceans are typically warmer than the lower atmosphere, this slows the cooling of the oceans into the atmosphere.
Can either or both of these claimed effects be measured?
Tomcat
The back radiation is measurable in the lab and by direct Earth observation. The outward longwave radiation (OLR) spectrum measured by satellites shows the expected bell curve of infra-red (IR) radiation from Earth's troposphere, with reduced radiation at the several wavelengths absorbed by water and ozone. There is also an intensity drop of 50% at the main absorbtion wavelength of CO2, around 13 micrometres, which would be expected if CO2 were absorbing and reradiating.
You can also directly detect the downward radiation. A simple £10 IR thermometer pointed at a clear sky will show a temperature due to downward IR. If you have an IR spectrometer, this will show that the wavelength matches the same CO2 absorbtion/reradiation detected in the OLR.
Dr Roy Spencer discussed this in a recent post on his website.
Some of the energy absorbed by the CO2 does increase the troposphere temperature, but is the sea surface typically warmer than the air? The balance reverses between day and night, and seasonally.
I haven't encountered your second theory before, and would need a more detailed description of the energy flow pattern it predicts. In principle the energy flow could certainly be looked for, but I do not know if it has been observed. It would show as a slight imbalance in the daily and seasonal oscillation. This would happen under either theory, but you would need to know how their predictions would differ before being able to distinguish between them.