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Showing posts from December, 2022

On the Nature and Value of Consensus

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About 20 years ago, I remember participating in a meeting where participants were actively debating a proposition. The moderator was enforcing parliamentary procedure, and speeches for and against the proposition were heard in turn - one speech for, then one speech against. This being the first meeting I had been in following this kind of procedure, I began to think that the room was evenly divided between the two positions. I was strongly in favor of it, and I was disheartened to see so much opposition to it. But when the vote was finally taken, I was more surprised by the results. The proposition passed by an extraordinarily large margin. In fact, it appeared that those speaking against the proposition made up almost all the people that voted against it, and the vast majority of the people in the room were like me. Most of us had essentially made up our minds, and we had no intention of making any speeches; we were just waiting for the debate to be over so we could vote.  My impressi

Comparing CO2 Forcings and Temperature in the Geologic Past

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For over 20 years, geologists have attempted to model CO2 concentrations across the geologic past. Geologists currently have sufficient proxy evidence to reconstruct CO2 concentrations for significant parts of the last 420 million years, but models can be useful to infer concentrations when proxy evidence is weaker or lacks sufficient resolution. While "box" models like COSPE or GEOCARBSULF  confirm broad correlations between CO2 and global temperatures , the correlation may be improved if the models take better account of tectonic processes affecting CO2 concentrations. Evaluation of Proxies for CO2 and Temperatures In a study published three years ago, Mills et al 2019 evaluated the performance of CO2 proxies as well as COPSE and GEOCARBSULF "box" models for CO2. The latter model is the most recent update to the GEOCARB model that is frequently misused in contrarian graphs of CO2 and temperature - GEOCARBIII was published in Berner 2001 and is often plotted wit

Bulverism & Debate Dysfunction

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Recently I came across a new word, "bulverism." The term was coined by C.S. Lewis to describe what is broadly similar to what Antony Flew called the "subject/motive" shift. Strictly speaking, it's a form of the logical fallacy, ad hominem - attacking the author instead of the argument. Bulverism takes the the following form:      A. Assume your opponent is wrong      B. Explain why your opponent is wrong in terms of your opponent's identity rather than the argument or evidence Bulverism often springs up in debates that are highly contentious - that is, when people have strongly held beliefs that are also strongly opposed by others. In highly contentious debates, we tend to react in terms of our contempt for the other side of the debate (and even the person that holds the view being opposed). Lewis describes bulverism with an example from math, where Ezekiel Bulver's father claims that the sum of any two sides of a triangle must be longer than the third,

Tropical Cyclone Trends

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In a previous post , I covered the distinction between detection and attribution. These are normally considered sequentially. First you detect a signal above natural variability, then you examine if some portion of that signal can be attributed to human activity. The previous post shows that the two are statistically independent from each other, so there is no need to limit attribution studies to signals that are detectable above natural variability. This distinction and clarification I think is important in discussions of tropical cyclone trends. While trends are clear since 1980, the longer term record (since ~1850-1900) is less clear due to selection biases arising from our increasing ability to detect tropical cyclones. This makes detection difficult long term, but that doesn't necessarily mean that scientists can't also examine ways in which human activity is affecting tropical cyclone trends. Detection in the Satellite Record (Since 1980) The satellite record provides us