Climate Shift impact Risk Assessment revisited
Recently a reader pointed me to a draft paper from David Wasdell, which concludes that climate sensitivity “Charney Sensitivity”, is to low, by the factor of 2.5.
I will add hear the keypoints of this draft, for now a must read for everybody..
Shaheer writes: A new report by David Wasdell show that climate sensitivity may be far higher than expected. Both Charney and Hansen sensitivity may be grossly underestimated. I haven’t read over the report fully since it’s late, but it seems interesting.
“A multi-disciplinary approach, independent of any climate model, and supported by a specially designed Graphic Simulator, identifies a (minimum) value for the Earth System Sensitivity of 7.8ºC for the equilibrium outcome of doubling the concentration of atmospheric CO2. That is an Amplification Factor of 6.5 times the effect of the CO2 on its own. The new value has a much higher degree of certainty than the Charney Sensitivity and indicates that the current conservative estimate of climate sensitivity falls far short of reality and must be increased by a factor of just over 2½ times. This new value of the Earth System Sensitivity (ESS) should now replace the Charney Sensitivity.”
I asked Ken Caldeira about the Wasdell paper and he replied that a team in 2006 set climate sensitivity at 6.8 to 7.8 C per CO2 doubling, to account for the PETM methane spikes.
In the attached paper, we provide evidence for a long-term climate
sensitivity of 6.8 to 7.8 C per CO2 doubling, but this probably depends on
having strong functioning methane feedbacks in the Eocene.
My point below was that there is not a right and wrong way to define climate
sensitivity, radiative forcing, and so on, but there are different ways.
Depending on what you count as a feedback and what you count as a forcing,
and what timescales and processes you consider, you come up with different
I haven’t gone through the Wasdell writing in great detail but it seems to
be a mostly reasonable, if somewhat imprecise, review of the literature.
An important question is how fast and how powerfully will various feedbacks
come into play and how fast will anthropogenic forcing on the climate system
be removed by natural processes. If the timescale of concern is short or
feedbacks end up being weak, then Charney sensitivity is probably
appropriate for current policy. If timescales of concern are longer or
feedbacks end up being more rapid or more powerful than generally
anticipated or atmospheric CO2 adjustment time ends up longer than
anticipated, then the climate sensitivities estimated from paleo climates
become more relevant.
In any case, it is important to separate issues that have to do with
differences in definitions from issues that have to do with uncertainty
about the facts.
David Wasdell has been working with top climate scientists around the world to draw together the findings from a 6 year study of how the earth’s climate system responds to increases of CO2 and other Greenhouse gases in the atmosphere so that we can better assess the risk of more dangerous rises in the average global temperature from CO2. This study is based on paleology, systems analysis and mathematical calculations rather than computer models that cannot yet represent the complexities of feedback dynamics in our climate system. The first formal presentation of results has been at the 3rd Global Conference on Global Warming in Lisbon in July 2011.
He recorded a 8 part video interview with David Wasdell, this July:
1. David introduces himself and his work. He has a highly relevant mix of an understanding of climate science helped by his knowledge of physics, and a background of research and consulting in complex, large scale social systems and how they are maintained and changed, and in the psychology of resistance to change and how it can be overcome. Top climate scientists were involved in the study conducted over the last 6 years (the Apollo-Gaia or Sun-Earth system project) 5 mins 25 secs
2. The greenhouse effect explained in relation to the deviation from the balance between light wave energy from the sun and the long wave, infra-red energy from heat coming from the earth system (the sun-earth system). Recent excessive CO2 increases linked to the use of fossil fuels by mankind since the industrialisation of the economy and especially the availability of cheap energy from oil over the last century which in turn enabled the economic growth and consumerism that occurred alongside population growth – a whole system change. 5 mins 34 secs
3. Amplifying feedback explained. How global heating, kept within the earth’s atmosphere by CO2, is amplified by feedback processes within the climate and earth systems, speeding up the rate of increase in average global temperature. Some examples of the family of amplifying feedback processes or loops within these systems. 6 mins 30 secs
4. Estimating climate sensitivity – the sensitivity of the earth system to increases in CO2, or in other words, by how much the average global temperature will rise as CO2 in the atmosphere increases (measured in parts per million or ppm) as it is amplified by feedback processes. Working within the limits of computer modelling or, as done in this study, making estimates based on historical records of effects of change in CO2 levels in the past. The findings are alarming and were first published in July 2011. 8 mins 3 secs
5. Consequences of increases in global temperature. Delay in experiencing the consequences – some of which are already “in the pipeline” as a result of what has already happened in the climate system. The risks are so great now that we need not only to stop putting any more CO2 into the air by the way we generate and use energy, and grow or make what we need, but also take CO2 out of the atmosphere. Using George Bush’s analogy, we need to stop the addiction to fossil fuels and (no longer) cheap energy and detox the system (take CO2 out). 6 mins 29 secs
6. Anxiety and denial arising from highly disturbing estimates. The need to build confidence in our ability to solve the problem to overcome denial and mobilise action based on a realistic sense of urgency. Tipping points in systems explained. The risk of “runaway” feedback processes where equilibrium cannot be maintained within the boundaries of a condition of a system. Examples given in the earth climate system. Uncertainties about where these boundaries or thresholds are between equilibrium and runaway until a new equilibrium is found (less hospitable to life on the planet for thousands of years); such fast change in global temperature and energy balance has not been known before in the earth’s history. 8 mins 44secs
7. Distinction between uncertainty and risk. Intensity of risks now clearer than in the recent past. But conservative assessments of temperature increases need to be updated and revised. Risks are now so great that they cannot be taken even if uncertainties remain. There now needs to be a consensus on the facts arising from the current study, after others have validated it after trying to falsify it, as is best practice in modern science. Resistance to making the real findings more widely known as long as solutions seem impossible. 8 mins 10 secs
8. Next steps: reaching consensus and showing viable solutions, making it totally unacceptable to block or misrepresent valid scientific findings and hold the life support system on earth to ransom, and reducing the dependency on keeping the current system as it is, particularly the collusive interdependencies between the different parts of the power elite and the key institutions in societies that reinforce vested interests in the status quo. 7 mins 21secs
Then, one day, to your horror, you open a journal of Uighur studies and find a lead article proving that everybody has been interpreting Uighur wheat production records wrong, and that all previous estimates of what the Uighur numbers mean were off by a factor of two. Natural Variability and Climate Sensitivity