A science presenter, writer, speaker & former TV host; author of The Skeptic's Handbook (over 200,000 copies distributed & available in 15 languages).


The Skeptics Handbook

Think it has been debunked? See here.

The Skeptics Handbook II

Climate Money Paper




The nerds have the numbers on precious metals investments on the ASX



John McLean – ENSO drives sea surface temperatures on the Great Barrier Reef

Ove Hoegh-Guldberg wants us to consider putting sun shades over the Great Barrier Reef, but it begs the question — how much is the reef heating up, and how sure are we that it’s man-made and not natural?

John McLean digs into the data and finds that temperature variations on the reef appear to be closely tied to the ENSO cycle, and that there is little reason to think our SUVs and coal fired plants have anything to do with the rises and falls.

We wonder, as usual, why those paid by taxpayers can’t do the same basic calculations and graphs that the volunteers do online.


Great Barrier Reef sea temperatures – What the data says

John McLean


Inspired by the absurdity of putting shades on the Great Barrier Reef (GBR),  I studied the observational data.

We can extract data  for the grid cells that cover the reef from NOAA’s “Optimal Interpolation” sea surface temperature data (see here).  When that data is averaged across the entire reef we find that the average sea surface temperature along the Great Barrier Reef has an annual cycle very similar to that of Willis Island, a Bureau of Meteorology observation [...]

Messages from the global raw rural data. Warnings, gotcha’s and tree ring divergence explained!

Have you wondered what the global raw rural data tells us?

What did those thermometers say before the adjustments, smoothing, selection, and averaging?

This just might be the first time anyone has publicly compared the global raw data to published adjusted data sets in this way.

Frank Lansner has been dedicated in the extreme, and has developed a comprehensive Rural Unadjusted Temperature Index, or RUTI. One of the most interesting points to come out of this extensive work is the striking difference between coastal stations and inland stations. Frank kept noticing that the trend of the inland stations was markedly different from coastal stations and island stations.

Fig1. Red-Blue lines mark regions where there was a different coastal to inland trend. In green areas the two trends were similar.

What he finds is perhaps not so unusual: The coastal areas are heavily influenced by the sea surface temperature. Inland stations record larger rises and falls in temperature, which is hardly surprising. But, the implications are potentially large. When records from some stations are smoothed over vast distances (as in 1200 km smoothing), results can be heavily skewed by allowing coastal trends to be smoothed across inland areas. What Lansner [...]