Thanks so much for this show and all the pioneering work you bring to your audience, Alex!

There is a reason why Ecoshock should rely on actual scientists when you interview people on scientific issues like climate sensitivity. I was giving talks in 2008 on how the IPCC is underplaying global warming, but Wasdell's analysis is way off base. James Hansen -- not someone to play down the risks of climate change -- has looked at the paleoclimate data on climate sensitivity (which, by definition, includes all known and unknown feedback effects) and comes up with ~3ºC, which is far less than Wasdell's figure.
http://www.columbia.edu/~jeh1/mailings/2012/20120508_ClimateSensitivity.pdf

Wasdell was brought up in the comments of RealClimate.org and Gavin Schmidt (Hansen's replacement at NASA) said of Wasdell's theory:

[Response: you have seen the problem right away. ESS (Earth System Sensitivity) is only relevant to the very long term change in CO2, not the value today, or in 2050. We could have a huge overshoot and then come back down by 2300 and few of the additional effects will have made themselves felt (not that I would recommend that course of action). More specifically, the SPM is very focussed on the relatively near term, and is broadly correct, Wasdell’s piece is neither. – gavin] - See more at: http://www.realclimate.org/index.php/archives/2014/02/unforced-variations-feb-2014/comment-page-7/#sthash.eTLdAXke.dpuf

The bottom line is there are non-scientists that claim there is no such thing as global warming and there are non-scientists that say they understand climate sensitivity better than trained climate scientists. They are both wrong. Let's promote the views of those that know what they are talking about. +3ºC sensitivity is bad enough!

I've checked out Hansen's paper regarding sensitivity that Mr Miller refers to. Here is the text from the intro:'Our best estimate for the fast-feedback climate sensitivity from Holocene initial conditions is 3 ± 0.5°C for 4 W/m2 CO2 forcing (68% probability)'- this statement excludes slow feedbacks. In fact Hansen states in the paper ‘It is difficult to assess the speed at which slow feedbacks will become important in the future, because of the absence in paleoclimate history of any positive (warming) forcing rivalling the speed at which the human-caused forcing is growing’ Gavin Schmidt argues that the fast feedbacks are the only relevant ones over the short term, essentially ignoring the slower positive feedbacks (for example, the thawing of the land and sub-sea permafrost in the Arctic). Clearly, the current models are considerably underestimating the changes in the Arctic region, particularly the volumetric loss of the sea ice and signs that the methane and carbon dioxide emissions due to melting permafrost are gathering some momentum - tipping points - which could have considerable bearing on the sensitivity value this century.

Wasdell is quite rightly drawing our attention to the a very dubious carbon budget metric which assumes that none of these slower positive feedbacks will come about within the near future - I very much agree with Wasdell that this is a foolish premise for the basis of our strategic response to climate change. Whether one agrees with Wasdell's Earth Sensitivity value or not (and by the way in that same paper referenced above, Hansen places great store in using the paleo-climate record to help derive the Earth Sensitivity value), the truth is that the current predictions are based on the lower bound value of Earth Sensitivity with the real figure being greater than 3, probably significantly greater than 3. And as Wasdell makes very clear, the Earth's ability to deal with Greenhouse gases was very different in the Holocene than in the current Anthropocene (viz: degraded carbon sinks etc). And taking Hansen’s point, there is nothing in the paleo climate record to match the pace at which we are adding carbon dioxide and its equivalents to the atmosphere.

Just because a sensitivity of 3 is ‘bad enough’ should not mean that we use it.

When do slow feedbacks speed up? When they are in the Arctic. The climate sensitivity of the Arctic methane clathrates is a perfect example. Emissions are speeding up. Natalie Shakova spent 10 years in the Arctic watching the methane dramatically increase with under 1°C rise. She says everything is anomalous. Gavin Schmidt sat in front of his computer for ten years working on "models" that ignore slow feedbacks. He says its nothing is happening.

Everyone should read this (especially people who are focussed on climate change and/or peak oil)- Meadows is so clear and unassailable.

"...hunger, poverty, oil depletion, climate change—are not in themselves problems; they are symptoms. The problem is continued material growth in a physically finite world."

"Our society has moved into the rapids phase.

Climate change is an example of this. There was a period where we had some possibility of influencing future climate by our decisions about the use of fossil fuels. I think that time has passed. Climate change is increasingly dominated by a set of feedback loops—like the methane cycle and the melting of Arctic ice sheets—which are beyond human control. They have come to be the drivers of the system. The dominant drivers of the system are not people sitting around trying to reach a consensus about which of several different possible outcomes they most prefer."

http://churchandstate.org.uk/2015/11/growing-growing-gone-reaching-the-limits-an-interview-with-dennis-meadows/

The 10,000 Year History Of Climate Models:


https://www.reddit.com/r/collapse/comments/3tsxx8/how_the_ipcc_is_fucking_us_over/

Alex: while I generally enjoy your shows, I was very annoyed by 4 things in this one. In approximately increasing order of irritation:

1. In the first minutes, you said something about Ecoshock seeking to provide "scientific proofs." You probably didn't mean that; whether or not you did, you should understand that "proof" in this context--empirical science generally and Earth system modeling particularly--is a *very* bad usage, and a "red flag" in some quarters. The term "proof" is only legitimately applied to deductive arguments: David Hume (and predecessors going back to at least Sextus Empiricus) demonstrated rather convincingly why it's inappropriate to empirical (and especially inductive) ones. Worse, "proof" tends to especially wildly overestimate certainty when applied to ESMs and paleoclimate (point#=4 in next comment, due to your 4096-character limit on comments). So please don't apply that term in this domain--it makes you sound foolish.

2. You really should have pointed out that Wasdell has no formal credentials in this domain (did I miss that?) and furthermore is regarded (by folks who *have* the formal credentials) as, at best, controversial. That point has been made by Dan Miller above, so I won't repeat it. That doesn't imply (much less "prove" :-) Wasdell is wrong, it just implies that his claims shouldn't get the same credence as the claims of peers (as in "peer-reviewed literature," not House of Lords). I should note that this also undercuts *my* credence in this area: I don't have the PhD, and I haven't worked on global ESMs. (I *have* worked on regional atmospheric models.)

3. You (plural) spent much time bashing the IPCC for underestimating ultimate forcings (particularly temperature and sea level) without mentioning one *crucial* fact, of which you should be aware. (And I should be able to find a cite, but my brief websearch failed.) Since it's so important, I'll bold it: the IPCC does not forecast beyond 100 years from present. (You (Alex) could have done, and hopefully will do in future, a tremendous service to environmental journalism by pointing out this simple but important fact. When any environmental journalist say that "the IPCC forecasts [whatever]," they should always follow that by saying "by [terminal forecast date], with [whatever] likely to increase after that.") You (plural) spent a *lot* of time bashing the IPCC (et al) for excluding the slower feedbacks, and implying that this was ideologically driven. Ideology may contribute, but one must give credence (at least, attention!) to the fact that the folks with the formal credentials in this domain generally agree that only the fast feedbacks apply over the IPCC's *defined* temporal scale.

FWIW, I completely agree with you--following Kevin Anderson and other folks with formal credentials in this domain--that 2 °C increase in global mean temperature by 2100 CE is already "baked in," and continuing to discuss it as an achievable policy goal for 2100 CE is probably fradulent (though probably well-intentioned). "Silly and dangerous" (to quote you) STM reasonable predicates for such discourse. That being said, when Wasdell claims that one can forecast the full effects of *all* paleoclimate-attributable feedbacks to occur not by (e.g.) 3000 CE but by 2100 CE, you really should note that this is an extreme minority opinion with not much backing it: see points 2 (above) and 4 (next comment).

(Continued from previous comment, due to your 4096-character limit on comments.)

4. Wasdell repeatedly valorizes claims from paleoclimate over claims for modeling. I'm a modeler, but humble: I accept (mostly :-) your (plural) claims regarding the inadequacies of our current efforts. That being said, it was *totally irresponsible* of him (primarily--you (Alex) secondarily) to *not* point out the *huge* uncertainties attached to paleoclimate evidence, esp WRT temperature and timescale. We don't have paleo-thermometers or -calendars! we have only *proxies*. And guess what: we infer from the proxies to the quantities of interest using ... wait for it ... models!

Hence I *strongly* encourage you to do a show on paleoclimatic evidence in the near future: host a guest with formal credentials in the domain to discuss what we can legitimately forecast from it, and how the uncertainties regarding paleoclimate compare to those of widely-used (e.g., CMIP5-included) models.

Net: this show was not a high point for Ecoshock, but (based on past performance) I hope for better in the very near future.

FWIW, Tom Roche <>

Tom Roche Reply Part 1
Point 1. Alex using the term "scientific proof". At the beginning of the podcast Alex mentions: "...So I try to stick to rational voices and back those up with the best scientific proof we can find". Here is a quote from Douglas Theobald, Ph.D. at http://www.talkorigins.org/faqs/comdesc/sciproof.html illustrating Roche's point:

"All scientific statements and concepts are open to re-evaluation as new data is acquired and novel technologies emerge. Proof, then, is solely the realm of logic and mathematics (and whiskey). That said, we often hear 'proof' mentioned in a scientific context, and there is a sense in which it denotes "strongly supported by scientific means". Even though one may hear 'proof' used like this, it is a careless and inaccurate handling of the term."

While I disagree with Roche - from the scientific context of Alex's statement I read "strongly supported by scientific means" - perhaps Alex could've used the phrase "scientific evidence" instead.

Point 2. Wasdell's lack of credentials. It is true Wasdell is not a climate scientist and Alex did not mention this explicitly at the beginning or at the end of the podcast. But he readdresses this at the beginning of the next Eco Shock episode. See point three under https://ecoshock.info/2015/11/true-voices.html. This was posted last week.

Tom Roche Reply Part 2
Point 3 - 4. The summary of your argument appears to be some feedbacks are not relevant for determining the average temperature rise at the end of the century:

"You (plural) spent a *lot* of time bashing the IPCC (et al) for excluding the slower feedbacks, and implying that this was ideologically driven. Ideology may contribute, but one must give credence (at least, attention!) to the fact that the folks with the formal credentials in this domain generally agree that only the fast feedbacks apply over the IPCC's *defined* temporal scale."

The feedbacks discussed in Wasdell's presentation when looking a the main graphic from the IPCC summary report for policy makers are: fast feedbacks, carbon cycle (Hadley Centre), ice sheet feedbacks (Hansen) and Full Earth Sensitivity (Wasdell). Hansen et al and folks over at the Hadley Centre are climate scientists. The question is whether the feedbacks aside from the fast feedbacks would affect the climate sensitivity for the timescale of now to 2100 CE. Here's a portion of a citation available at http://www.nature.com/nature/journal/v408/n6809/abs/408184a0.html regarding the work of the Hadley Centre:

 "Here we present results from a fully coupled, three-dimensional carbon–climate model, indicating that carbon-cycle feedbacks could significantly accelerate climate change over the twenty-first century."

Including the carbon cycle feedback in the sensitivity value puts the proposed IPCC carbon budget in the red as shown by Wasdell's presentation.
Furthermore, there are known feedbacks not considered by Hansen and Hadley. For example, the acceleration of methane emissions from thawing permafrost. See the Natalia Shakhova et al paper at http://m.rsta.royalsocietypublishing.org//content/373/2052/20140451
The paper concludes that 10% of the East Siberian Arctic Shelf is in open water during winter consequently producing methane all year round. Given the temperature in the Arctic region is set to rise to at least twice the rate as the rest of the planet, the climate forcing of this feedback will only increase the melt of the sea ice further exposing the methane hydrates to additional warming. The significance of this feedback, slow feedbacks and unknown feedbacks are uncertain. To quote Hansen from http://www.columbia.edu/~jeh1/mailings/2012/20120508_ClimateSensitivity.pdf:

"It is difficult to assess the speed at which slow feedbacks will become important in the future, because of the absence in paleoclimate history of any positive (warming) forcing rivaling the speed at which the human-caused forcing is growing."

Tom Roche Reply Part 3
But just how uncertain? Stephan Lewandowsky is a cognitive scientist at the University of Bristol who studies uncertainty in climate-human interactions. He wrote an article for the Guardian about how uncertainty can be used as an excuse to cast doubt on the science, which has been used by Exxon, available at
http://www.theguardian.com/environment/climate-consensus-97-per-cent/2015/dec/01/uncertainty-is-exxons-friend-but-its-not-ours.
To quote the final paragraph:

"Uncertainty may be Exxon’s friend, but it is not ours. And we therefore know, from uncertainty, with considerable certainty that we need to act on climate change."

His work is laid out in detail at:

http://www.theguardian.com/environment/climate-consensus-97-per-cent/2014/apr/04/climate-change-uncertainty-stronger-tackling-case

I would like to draw particular attention to this particular section of the article:

"Lewandowsky's team combined the shape of the curve showing the probable values of the Earth's climate sensitivity with the shape of climate economic costs curve, and came to an inescapable conclusion: more climate uncertainty means the expected damages from climate change are higher."

The graph is found at http://www.skepticalscience.com/pics/RoeBaker.jpg. Notice the shape of the probability distribution. In summary, more calamitous events are more likely than benign events in the future. The probability of warming between 1-1.5°C is extremely close to zero. However, the probability of warming of say 6°C, depending on curve, is somewhere between 5-10%. For the sake of comparison the probability for 3°C warming is in the range of about 35-45%. 5-10% is a lot more uncertain than 35-45%. But would you ride a plane with a 5-10% chance of crashing? By the same token, would you do the same for the Earth's future?
This lack of risk management is what Wasdell is drawing our attention to. Wasdell has taken a sensible approach to try and quantify the more unlikely known and unknown events to help derive more sensible policy change. Can this be done? Yes, to quote Stephan:

"Even deep systemic uncertainties, often described as “unknown unknowns”, can—ironically—be a source of knowledge. Wendy Parker and James Risbey have recently shown that although unknown unknowns, by definition, cannot be anticipated in the particular, the likelihood that one or the other surprise may arise can be anticipated. We cannot specify what the unknown unknowns are but it doesn’t follow that it is impossible to recognize the risk that such features exist in climatic-ecological-social systems."