Category Archives: Uncertainty

Uncertainty and the IPCC

Posted on June 17, 2011 by curryja | 25 comments

by Judith Curry

Two previous threads (here and here) have presented sections of my draft paper on Climate Science and the Uncertainty Monster. Here is an additional section on Uncertainty and the IPCC.

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25 Comments

Posted in IPCC, Uncertainty

Taming the Uncertainty Monster

Posted on June 16, 2011 by curryja | 54 comments

by Judith Curry

The concluding section in my draft paper on “Climate Science and the Uncertainty Monster” (discussed previously on this thread) is entitled “Taming the uncertainty monster.”

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54 Comments

Posted in Uncertainty

Doubt, uncertainty and ignorance

Posted on June 2, 2011 by curryja | 316 comments

by Judith Curry

The word “doubt” has a bad connotation in the climate debate owing to the merchants of doubt meme. Richard Feynman puts the word “doubt” into the appropriate perspective in the context of science:

When a scientist doesn’t know the answer to a problem, he is ignorant. When he has a hunch as to what the result is, he is uncertain. And when he is pretty damn sure of what the result is going to be, he is still in some doubt. We have found it of paramount importance that in order to progress, we must recognize our ignorance and leave room for doubt. Scientific knowledge is a body of statements of varying degrees of certainty — some most unsure, some nearly sure, but none absolutely certain.

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316 Comments

Posted in Uncertainty

Uncertainty, risk, and (in)action

Posted on May 28, 2011 by curryja | 321 comments

by Judith Curry

“So when you take uncertainty into account, it actually leads to the decision that we should take action more quickly.”

I first spotted the statement in the Discover Magazine interview with myself and Michael Mann . I thought it had to be a typo or misquote (note, Mann said this, not me :))

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321 Comments

Posted in Policy, Uncertainty

Uncertainty in Catastrophe Modeling

Posted on April 28, 2011 by curryja | 66 comments

by Judith Curry

Roger Pielke Jr. has a very interesting post on uncertainty in catastrophe modeling. The basis for the post is an interview with Karen Clark. Karen Clark developed the first catastrophe model, and is worried that these models are being given more credit and influence than they deserve.

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66 Comments

Posted in Uncertainty

Dempster on climate prediction

Posted on April 11, 2011 by curryja | 113 comments

by Judith Curry

I spotted this presentation by Arthur Dempster, Harvard statistician, in the Series on Mathematical and Statistical Approaches to Climate Modeling hosted by the Isaac Newton Institute for Mathematical Sciences.

Dempster is widely known as the co-originator of Dempster-Shafer Evidence Theory (see the Wikipedia for an overview). Elements of evidence theory have been discussed on several previous threads (see Italian Flag, reasoning about floods).

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113 Comments

Posted in Prediction, Scientific method, Uncertainty

Reasoning About Climate Uncertainty – Draft

Posted on March 24, 2011 by curryja | 217 comments

by Judith Curry

Here is a complete (albeit rough) draft of my paper for the special issue in the journal Climatic Change (founding editor Steve Schneider) entitled Framing and Communicating Uncertainty and Confidence Judgments by the IPCC.

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217 Comments

Posted in Uncertainty

Reasoning about floods and climate change

Posted on March 15, 2011 by curryja | 151 comments

by Judith Curry

I just came across a paper that I view to be remarkably important, entitled “Influence diagrams for representing uncertainty in climate-related propositions,” by Hall, Twyman and Kay. This paper integrates a number of themes that we have been discussing here: reasoning about uncertainty, consilience of evidence, attribution of extreme events, floods, and even the Italian flag(!). And it does the best job I’ve seen of assessing uncertainty and confidence in a climate-related proposition.

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151 Comments

Posted in Attribution, Uncertainty

Neverending Reflections on Climategate

Posted on March 3, 2011 by curryja | 624 comments

by Judith Curry

Motivated by a post by David Roberts at Grist, there has been some interesting reflection on Climategate this past week. Roberts’ post entitled “What we have and haven’t learned from Climategate” says:

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624 Comments

Posted in Communication, Ethics, Uncertainty

Uncertainty and the IPCC AR5: Part II

Posted on February 13, 2011 by curryja | 190 comments

by Judith Curry

I am currently digging into the treatment of uncertainty in the IPCC AR5, pursuant to Part I and the paper that I am writing for Climate Change.

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190 Comments

Posted in Uncertainty

Probabilistic(?) estimates of climate sensitivity

Posted on January 24, 2011 by curryja | 144 comments

by Judith Curry

James Annan (with Hargreaves) has a new paper out, entitled “On the generation and interpretation of probabilistic estimates of climate sensitivity.” Here is the abstract:

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144 Comments

Posted in Sensitivity & feedbacks, Uncertainty

Learning to love uncertainty

Posted on January 15, 2011 by curryja | 92 comments

by Judith Curry

I am returning to the topic of uncertainty (my article for Climate Change on this topic is overdue). I just spotted this article (h/t Bishop Hill):

We must learn to love uncertainty and failure, say leading thinkers Planet’s biggest brains answer this year’s Edge question: ‘What scientific concept would improve everybody’s cognitive toolkit?’

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92 Comments

Posted in Uncertainty

Scenarios: 2010-2030: Part II

Posted on December 27, 2010 by curryja | 380 comments

Part I introduced the challenges of climate prediction on decadal scales, specifically in the context of global climate model simulations. On the Part I thread, Paul_K writes:

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380 Comments

Posted in Uncertainty

Scenarios: 2010-2030. Part I

Posted on December 23, 2010 by curryja | 437 comments

by Judith Curry

On the time scale of a few decades ahead, regional variations in weather patterns and climate will be strongly influenced by natural internal variability. The potential applications of high resolution decadal climate change predictions are described in this CLIVAR doc. Based upon my own interaction with decision makers, I see a need on these time scales that is primarily associated with infrastructure decisions. Sectors that seem particularly interested in predictions on this time timescale are city and regional planners, the military, and the financial sector.

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437 Comments

Posted in Attribution, climate models, Uncertainty

Waving the Italian flag. Part I: uncertainty and pedigree

Posted on November 28, 2010 by curryja | 95 comments

by Judith Curry

The Italian flag (IF) is a representation of three-valued logic in which evidence for a proposition is represented as green, evidence against is represented as red, and residual uncertainty is represented as white. The white area reflects uncommitted belief, which can be associated with uncertainty in evidence or unknowns.

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95 Comments

Posted in Scientific method, Uncertainty

Uncertainty gets a seat at the “big table:” Part IV

Posted on November 17, 2010 by curryja | 222 comments

STATEMENT TO THE SUBCOMMITTEE ON ENERGY AND ENVIRONMENT OF THE UNITED STATES HOUSE OF REPRESENTATIVES

Hearing on “Rational Discussion of Climate Change: the Science, the Evidence, the Response”

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222 Comments

Posted in Policy, Uncertainty

What we know with confidence

Posted on November 14, 2010 by curryja | 390 comments

by Judith Curry

Of the four IPCC assessment reports, I think the first assessment report (FAR) presents the case with the greatest clarity.

Since the FAR was published 20 years ago, it is worth taking a look to see how their conclusions and levels of confidence and uncertainty have stood up to the test of time.

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390 Comments

Posted in Uncertainty

Decision making under climate uncertainty: Part I

Posted on October 31, 2010 by curryja | 203 comments

by Judith Curry

Based upon the precautionary principle, the United Nations Convention on Climate Change (UNFCCC) established a qualitative climate goal for the long term: stabilization of the concentrations of greenhouse gasses in the atmosphere. The view of climate change held by the UNFCCC regards both the problem and solution as irreducibly global. This view of the problem has framed the IPCC’s assessment and national funding priorities on the subject of climate science.

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203 Comments

Posted in Policy, Uncertainty

Uncertainty and the IPCC AR5

Posted on October 29, 2010 by curryja | 138 comments

by Judith Curry

I am starting to see some encouraging signs that people (including the IPCC) are paying more attention to the uncertainty issue as it relates to climate change. Nature has an editorial on this issue that summarizes the situation as:

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138 Comments

Posted in IPCC, Uncertainty

Disagreement

Posted on October 27, 2010 by curryja | 474 comments

by Judith Curry

While my goal is to build bridges, I realize that there is no hope of eliminating disagreement on the climate change issue. Does this mean that we are we forever are doomed (Anthony Watts once referred to it as the world’s longest monopoly game), or do we have some chance of dealing with this issue and the risks it presents in a sensible way?

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474 Comments

Posted in Uncertainty

Do IPCC’s emission scenarios fail to comply with the precautionary principle?

Posted on October 12, 2010 by curryja | 63 comments

by Judith Curry

On the uncertainty monster thread, a scenario was defined as a plausible but unverifiable description of how the system and/or its driving forces may develop in the future. Scenarios may be regarded as a range of discrete possibilities, often with no a priori allocation of likelihood. An example is the future greenhouse gas emission scenarios used to force global climate models.

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63 Comments

Posted in IPCC, Uncertainty

The culture of building confidence in climate models

Posted on October 10, 2010 by curryja | 260 comments

by Judith Curry

As climate models become increasingly relevant to policy makers, they are being criticized for not undergoing a formal verification and validation (V&V) process analogous to that used in engineering and regulatory applications. Further, claims are being made that climate models have been falsified by failing to predict specific future events.

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260 Comments

Posted in climate models, Uncertainty

What can we learn from climate models?

Posted on October 3, 2010 by curryja | 205 comments

by Judith Curry

Short answer: I’m not sure.

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205 Comments

Posted in climate models, Uncertainty

No consensus on consensus

Posted on September 27, 2010 by curryja | 465 comments

by Judith Curry

Towards providing a robust scientific basis for climate policy, the United Nations initiated a scientific consensus building process under the Intergovernmental Panel for Climate Change (IPCC), which consisted of an intergovernmental multidisciplinary panel of experts.

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465 Comments

Posted in IPCC, Uncertainty