Monthly Archives: August 2008

DECR: The message starts to slide 11

In a recent interview, Kevin Hennessy backpedals on a key claim in the Drought Exceptional Circumstances report (DECR) explaining: (1:20m) … there has not been a clear indication of changes in exceptional low rainfall years. (1:40m) … but in terms of a long term trend its not very clear in terms of exceptional low rainfall […]

Comparison of Models and Observations in CSIRO/BoM DECR 62

There must have been some way that the models of exceptionally low rainfall (drought) were validated in the CSIRO/BoM Drought Exceptional Circumstances Report. Usually, models are checked against observations to make sure they have ‘skill’ at the purpose for which they are intended. In this case, the global climate models used in the Drought Exceptional […]

Rybski Model Proof 10

This post is the first cut at R statistics for the Rybski approach to detecting change in global temperature. It follows Global Warming Statics giving the literature context to the analysis, and the introductory post July 2008 Global Temperatures that caused all the fuss at ClimateAudit. The R script is here. You should uncomment the […]

Global Warming Statics 42

It is often stated that global temperature has increased over some specific time frame. Few realize there are different ways to answer this question, and the increase may not actually be significant, particularly in view of persistent correlation between temperature over long time scales (LTP). In Statistical analysis of hydroclimatic time series: Uncertainty and insights […]

July 2008 Global Temperatures 75

Much ado has been made about global warming stopping since 2001, since 1998 or not increasing in the last decade. Here’s more grist to the skeptic mill. The analysis below shows the global temperature has not increased significantly since July 1979! Data are from the TLT Satellite measurements of the Earth’s lower troposphere at RSS […]

William M. Briggs, Blogger 7

William M. Briggs, Statistician, is one of the outstanding technical blogs on the internet today. As indicated by the sub-title, “All manner of statistical analyses cheerfully undertaken”, it occupies a similar niche to Niche Modeling, recognizing and filling a felt need for basic statistical analysis of everyday events. The posts are often illustrated by programming […]

Kevin Rudd on Scientists 12

The Prime Minister of Australia, Kevin Rudd, made more indecorous remarks about scientists on 60 minutes last night. He obviously felt the need to retell his joke about scientists, first made on the 18th July, as nobody laughed the first time. There’s a group of scientists called the International (sic) Panel on Climate Change – […]

Scientific Fraud and HIV/AIDS 20

Author and scientist Dr Henry Bauer invites reviews of his book “The Origin, Persistence and Failings of HIV/AIDS Theory” (McFarland 2007) at WikiChecks. I was led through a by-the-way remark in a “dissident” HIV/AIDS book, and subsequent astonishment as I looked at the original source, to collect essentially all the published data on HIV tests […]

Avoid Bias in Climate Research 44

The author Paul Spite invites reviews at WikiChecks of his book “A Climate Crisis a la Gore.” It is organized as follows: • Introduction – What motivated the assembly of this research for public use. • Part 1 – excerpted ideas from Mr. Gore’s book, The Assault on Reason, regarding what he claims to be […]

Temperature Index Drought 4

Following up on the post from yesterday, I test the assumption underpinning the regional climate change work in Australia. The most common approach has been to assess how well each of the available models simulates the present climate of the region (e.g. Dessai et al. 2005), on the assumption that the more accurately a model […]

Western Australia Future Rainfall 10

I have started looking into the way GCMs are used to produce regional climate predictions. The method seems to consist of weighting GCMs according to their regional concordance. I wonder if they are aware of the pitfalls of ‘chasing higher correlations’. The most common approach has been to assess how well each of the available […]

Feedback on Review of CSIRO Drought EC Report 11

Its time to address comments on my review of the CSIRO Drought Exceptional Circumstances Report. Thanks to Lazar for taking the time to provide the following feedback at Open Mind, placed at WikiChecks here. I have not yet received any comments from the authors, or Kevin Hennessy of CSIRO. I think its clear that the […]

Linear Regression Example 54

Here is an example of doing statistics in R, illustrating a pitfall of simple linear regression, using the global temperatures by satellite from 1979 to 2008. I have never seen the problem of ‘spurious compensation’ mentioned, but it is a common problem when trying to develop a model from a set of additive factors. The […]

Cherry-picking in Australia 20

One of the very first questions that a person who is promoting a model encounters from scientists and engineers is “has your model been validated?”. By validation we mean, has it been shown to adequately perform its intended use. According to Charles M. Macal, Argonne National Laboratory, if the answer to this critical question is […]

Five Steps to Statistical Prediction 17

These are the generally accepted steps to prediction using statistics. When you obey these rules, you have taken out insurance by demonstrating good practice. The chances of reliable prediction are maximized. When steps are missed out or done badly, poor predictions result. Either people don’t know them, or they just forget a step, like validation […]

Selling Carbon Credits 24

For those interested in how to make money from carbon credits, here is an interesting example of a successful scheme from the Northern Territory of Australia. The WALFA project (West Arhnem Land Fire Abatement) certifies it will create a minimum annual carbon offsetting of 100,000 tonnes of cabon dioxide equivalent by controlling late-season wildfires. In […]

IPCC Predictions 53

I don’t recommend blogs or blog posts often; that’s for lazy bloggers. But here is an exception. William M. Briggs, Statistician is a man who beats his own path through the underbrush of uncertainty. His article, “Don’t be too sure” is worth reading. His polygenous blog is worth adding to your feed. “I think the […]

Effects of Global Warming 25

My evaluation of the validity of the modelling in the CSIRO Drought Exceptional Circumstances Report, and the R code used to produce it, is available below. A pdf and invitation for review is posted on WikiChecks. Tests of Regional Climate Model Validity in the Drought Exceptional Circumstances Report Abstract In a statistical re-analysis of the […]

What is Niche Modeling Up To? 7

WikiChecks started out so I didn’t have to search for my reviews, then grew when I realized it might be of use to the whole community. I am still writing the software, but it is usable. I need help populating it with reviews, documents and web design. If you are slick with a digital camera, […]