Monthly Archives: October 2009

Possible Error in OHC? 20

An objective analysis of the evidence for global warming suggests little if any anthropogenic effect, consistent with a direct radiative effect from increased CO2. It is also obvious that global temperature and ocean heat content should be related, so it’s somewhat surprising to see OHC rising so fast around 2002-3 when ocean temperature is relatively […]

Robustness of Natural Variation 20

Here, out-of-sample tests are used to test the robustness of the linear regression models of natural variation in global temperature. Previous models were developed on the whole data set. Here we develop them on partial data sets and examine how well they predict temperatures on the other part. These are also called independent tests. The […]

Natural Variation vs Human Influence 51

One simple way to separate the influence of humans from natural variation is to fit a simple linear regression containing sinusoidal terms, as shown in previous posts. The figure below shows the result: linear (dotted red), periodic (dashed red) and their sum (solid red) applied to global temperature data sets (A) GISS and (B) HadCRUT […]

Natural Variation – 60 year cycle 24

Below is quick review of some of the evidence and consequences of a 60 year climate cycle. According to Roy Spencer, the argument that increasing carbon dioxide concentrations alone are sufficient to explain global warming is reasoning in a circle. By ignoring natural variability, they end up claiming that natural variability is insufficient. However, the […]

Is OHC Accelerating (II)? 58

In tests of the rigor of the Steffen/Wong statement that “not only is the OHC increasing, it is increasing faster“, we previously used a linear regression model including natural cycles. The question was raised about the confounding of an upward trend with part of the quadratic terms representing ‘acceleration’. This risk is increased by the […]

Is OHC Accelerating? 87

Code and figures to quantify the answer to the question “Is ocean heat content is accelerating?” are below. The idea is that ‘acceleration’ is synonymous with the significance of a quadratic term in a regression: 1. Annual OHC data from NODC. 2. Fit a regression model (M1) incorporating linear and periodic terms of period 60 […]

Ocean Heat Content Stumbles 44

We’ll be watching the drop in ocean heat content (OHC) raised by the brilliant Bob Tisdale for a potential follow-up to the Recent Climate Observations: Disagreement With Projections paper, where observations disproved speculations. To some, the OHC represents a change in alarmist direction that became evident at as a result of due diligence activities of […]

Briffa McIntyre tree-rings etc 10

My comments on the topical ‘Yamal’ issue: My AIG article demonstrating reconstruction of a hockey stick with red noise, neatly illustrated the possibility of circular reasoning in screening trees by their response to temperature. Around 20% of random series (or 40% if you count the inverted ones) correlate significantly with the temperature instrument record of […]

Magnetism Science Exercise 7

This numeracy exercise for schools can be adapted to grades pre-up. You need: 1. A number of strong magnets, at least two per group 2. Iron filings 3. Selection of nuts of various metals: iron, copper, brass, some lead sinkers. The hour long exercise is presented as an introduction to scientific thinking in the higher […]