JoNova

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


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Bourke: How 1km of land clearing can warm a million square miles

Yet again, we have to ask: does the Bureau of Meteorology care about Australia’s long term climate trend? Are they even trying?

Bourke could be one of the top ten most influential temperature sites in the world, mostly by virtue of being miles from anywhere, and used to homogenize a large slab of the land mass of Australia. Bill Johnston documents how changes to the site create most of the temperature trend.

The Bureau of Meteorology’s fancy magical and secret homogenization protocol does not detect changes that obviously affect the temperature (like the clearing in the photo below). But sometimes the BoM make “corrections” because of site changes that don’t appear to have mattered. Is it conveniently selective or just inept?

The BoM don’t even document major site changes a lot of the time. Even iconic sites that affect huge areas are badly managed. Someone got the tractor and plough and cleared the vegetation. As usual, a citizen scientist, a volunteer, documents it (along with a suite of other site changes).

In the last ten years land was cleared around the thermometer. This denuded area has a lower humidity, and higher volatility of temperatures.  The data from this thermometer [...]

Scandal: BoM ignores major site changes at iconic, historic, Sydney Observatory. Sloppy or deliberate?

Australia’s oldest and most iconic site has changed dramatically, but major site changes are not even being recorded.

The way the Bureau of Meteorology (BoM) treat this site says a lot about the unscientific, shoddy, biased standards it uses at sites everywhere. This was their headquarters. Experts walked past new walls, construction and highways, yet they didn’t record them? Beggars belief.

Just as Peter Ridd warns us that we can’t trust some marine and reef institutes,  Bill Johnston is the whistle-blower warning us about the Bureau of Met. There is no law  of science that says human institutes are infallible. When they run off the rails, how do we find out? Ridd issued a warning from the inside and ended up in the Federal Court. When people, like Bill write from the outside, the BoM waves the peer-review gatekeeper, and anonymous reviewers can easily shut that gate, and without any penalty.

The louvered thermometer house in front of the Observatory in 1864. (Courtesy of the State Library of NSW.)

Sydney Observatory is one of the longest running stations in the Southern Hemisphere, starting in 1859. It was Australia’s premier meteorology site and in the 1800′s it was known [...]

Canberra’s “hottest ever” September record due to thermometer changes and a wind profiler

With only a million dollars a day it’s hard for the BoM to keep up with their own stations. Luckily Bill Johnston has arrived to help out for free. The BoM announced that it was Canberra’s hottest ever day last week, but forgot to check whether the heat was due to the site moving three times,  changes in thermometers and a wind profiler they installed themselves in 2010.

Normally the BoM would detect and correct for these sorts of things by using Homogenisation Magic (HM). That’s where they spot these effects by comparing a station with surrounding stations. However in this case HM missed all three site moves and the wind profiler.  It looks like those might add up to 2.2°C of artificial warming. Nothing to worry about, but the hottest ever record will have to be shredded, and naturally, the BoM will need to issue a correction with at least as much fuss and coverage as the mistaken headlines. It’s only fair…

After the effect of rainfall is removed there are at least three site moves, a screen change, equipment change, and alterations to the surrounding area that may influence the site. These step changes align with documented [...]

Another BOM scandal: Australian climate data is being destroyed as routine practice

Historic climate data is being destroyed

The Bureau have a budget of a million dollars a day, but seemingly can’t afford an extra memory stick to save historic scientific data.

In the mid 1990s thermometers changed right across Australia — new electronic sensors were installed nearly everywhere. Known as automatic weather sensors (AWS) these are quite different to the old “liquid in glass” type. The electronic ones can pick up very short bursts of heat –  so they can measure extremes of temperatures that the old mercury or liquid thermometers would not pick up, unless the spike of heat lasted for a few minutes. It is difficult (impossible) to believe that across the whole temperature range that these two different instruments would always behave in the exact same way. There could easily be an artificial warming trend generated by this change (see the step change in the graphs). The only way to compare the old and new types of thermometer is to run side by side comparisons in the field and at many sites. Which is exactly what the bureau were doing, but the data has never been put in an archive, or has been destroyed. It’s not easily available [...]

The Conversation — cleansing skeptical thoughts — Read the banned comments here

The Fake Conversation where Bill’s informative, polite comments are removed, but the replies are left there.

Last week Bill Johnston posted a detailed, comprehensive analysis of Sydney Observatory thermometer record here that shows that most of the warming recorded there is due to buildings and freeways. But photo’s and graphs are “denier” stuff, and The Conversation is so afraid some its readers might see those historic photos they ban links to Bill’s work and joannenova.com.au. Apparently when the Bureau of Meteorology discusses “Australia’s hottest decade” it is off topic to discuss the condition of their thermometers.

Bill Johnston was happy to defend his work in comments at The Conversation, but Blair Trewin, who wrote the post itself, was entirely absent. Cory Zanoni had to close the dangerous thread. He removed scores of comments, but left replies to Bill Johnston intact. Some “conversation”.

At least 46 of Bill Johnston’s comments were deleted from Australia’s climate in 2016 – a year of two halves as El Niño unwound   and 19 deleted from Australian climate politics in 2017: a guide for the perplexed. As Bill says: They obviously want to stay perplexed; uninformed; scary-cats, without a paddle for their leaky canoe.

Some skeptics [...]

Sydney Observatory where warming is created by site moves, buildings, freeways

The iconic Sydney Observatory is Australia’s longest running weather station. But everything around the site has changed. Bill Johnston has spent months researching, photographing, and hunting through historic files to document those changes. He wasn’t paid for this work, but what he found was that the BOM has missed that the area around the thermometers has changed dramatically over the last century, so much so, that he claims it’s scientifically meaningless to try to construct climate trends from this data. Aerial photographs show exposure of the instruments changed in 1950, when Stevenson screens were moved, and after a brick wall was built metres from the screen in about 1972. It is suspicious that the changes are undocumented in Bureau reports, especially given they are responsible for much of the “unprecedented warming” in Sydney’s temperature data.  The BOM may counter that this site is not used to calculate warming trends across Australia, but as Bill points out, Sydney Observatory is used to homogenize other sites that are. So site changes and the urban heat island effect infects many country sites, and the traffic in Sydney “warms the nation”.  — Jo

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Its fake news week! Guest post by Dr. Bill Johnston[1]. [...]

Let’s play BOM Bingo, and turn every heatwave into a media scare-fest

Despite the headlines, there was no paranormal extreme in Perth last week — just a game called heatwave bingo

Perth set a sort of record last week for four days in February above 40C. The BOM and media paraparazzi glorified the latest heatwave, chasing it like it was a celebrity Kendall-Jenner-type-event when it was not that different to the heatwaves we’ve had before. Before it came, there were headlines about how it was coming, there were minute-by-minute graphs of degrees C, stories of people cooking cupcakes in hot cars, and there were projections  about hypothetical bigger, longer heatwaves that might come, maybe one day, someday: look out for “Temperatures into the fifties”!

Chris Gillham points out that this record was made at the Perth Metro station. Few seemed to mention that 9km away, at Perth Airport similar kinds of heatwaves were pretty common and things had been hotter and lasted longer in years gone by. This year the four day average at the airport was 42C but in 1956 there were 5 days at an average scorching 43.7. In 1933 there was a six day heatwave of 42C average in Perth city. And there were other heatwaves a lot like this a couple of weeks earlier, [...]

Blockbuster: Are hot days in Australia mostly due to low rainfall, and electronic thermometers — not CO2?

Blame dry weather and electronic sensors for a lot of Australia’s warming trend…

In this provocative report, retired research scientist Bill Johnston analyzes Australian weather records in a fairly sophisticated and very detailed way, and finds they are “wholly unsuitable” for calculating long term trends. He uses a multi-pronged approach looking at temperatures, historical documents, statistical step changes, and in a novel process studies the way temperature varies with rainfall as well.

His two major findings are that local rainfall (or lack of) has a major impact on temperatures in a town, and that the introduction of the electronic sensors in the mid 1990s caused an abrupt step increase in maximum temperatures across Australia. There will be a lot more to say about these findings in coming months — the questions they raise are very pointed. Reading, between the lines, if Johnston is right, a lot of the advertised record heat across Australia has more to do with equipment changes, homogenisation, and rainfall patterns than a long term trend.

Bill Johnston: On Data Quality [PDF]

“Trends are not steps; and temperature changes due to station changes, instruments and processing is not climate change”, he [...]

The BOM: Homogenizing the heck out of Australian temperature records

There are adjustments on top of adjustments. Homogenised records are being used to correct raw records. Some man-made adjustments can infect data for miles around…

Rutherglen is a long running station in central Victoria. There are no documented site moves, but the long raw trend of slow cooling was adjusted up to a warming trend. What was cooling of 0.35C per century became a 1.7C warming trend.

Jennifer Marohasy, and others, have spent months trying to get answers from the BOM explaining why these massive adjustments were made. Excuses flowed. In the latest round, the BOM claim the changes are necessary to make the Rutherglen record match the trends in the neighboring stations. What the BOM doesn’t say is that there was no warming in the neighbours either,  not until after they were homogenized. The order in which stations are homogenized matters, which rather says something important about the arbitrary nature of the adjustments. Anomalous trends from far distant and poor locations can spread through waves of homogenization until better, longer stations succumb to political correctness and show the “correct” result. Small choices about which stations to to use first in the process can make a huge difference to the [...]

The Rutherglen Stoush on homogenisation — Bill Johnston bravely ventured onto “the Conversation”

Rutherglen is one of the seemingly best stations in Australia, apart from a break from 1955-1965. Bill Johnston looks closely at the raw data, finding that there is probably no trend — flat temperatures — rather than either cooling or warming. And that it’s difficult to fill in data from surrounding stations. He speculates that something fishy goes on in 1924. He also finds that rainfall probably drives a fifth of the temperature swings. He discusses his disappointment at the intellectual level of debate on The Conversation.

Because he knows the area, he also talks about the effect of wet years and dry years, and how that affects winter and summer temperatures. He has a dry wit, and lovely casual style.

I think that if we have to rely on statistical analysis to “know” whether data was shifted or moved when there is no documentation suggesting it was, all certainty is shot, and any definitive statement about temperature trends in Australia is a joke.  — Jo

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The Rutherglen stoush

Guest post by Bill Johnston

The raw trend is very different from the HQ adjustments which are very different from the ACORN [...]