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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As it got hotter in Spain, less people died. Thank air conditioning and electricity.

Cheap energy might save more lives than expensive “climate-changey” energy?

Researchers looked at 47 major cities in Spain, from 1980 to 2015 and checked 554,491 deaths. Even though temperatures have risen, less people are dying of heat in Spain. Apparently human ingenuity, energy and air conditioners were more than able to keep up with climate change. The population is older but less vulnerable to heat now than it was forty years ago.

Air conditioners rose from 5% of the population to 35% during the study period.

Oh the dilemma — to save lives, should we build more windmills to try to change the global climate or aim to get 100% of households access to an air conditioner?

Welcome to the dire threat of climate change:

The relative risk of death fell as temperatures rose (According to the model used). See the caption below.

From the Discussion in the paper:

The temporal evolution of heat-related mortality risks here found is, in general, consistent with those reported by previous studies in some other countries [12–15], which provide evidence for a decrease in vulnerability to climate warming despite the ageing of societies. For example, in Spain, the proportion of people [...]

Eucalyptus trees cope fine with extreme heatwaves, defy climate models, survive 50C temps

What happens to a poor tree when you withhold rain for a whole month, then hit it with four days in a row of 43C temperatures? It was so hot, some of the leaves on these trees got close to 49-50 °C.

In at least one gum species in Australia, the answer is “not much”. They suck up lots of water from their deep roots and sweat it out til the heatwave passes. The trees become evaporative coolers “siphoning up” water. They cope so well, that not only did the trees not die, but their trunk and height growth were unaffected. Indeed, only about 1% of the leaf area even exhibited browning.

Whole tree chambers in Richmond, New South Wales, Australia. Twelve 9-m-tall chambers in a field setting (a) enclose the canopies of individual Eucalyptus parramattensis trees rooted in soil (b). Two heatwave chambers can be seen on the left of the infrared image, along with several control chambers (c; temperature in °C).

But with global warming running at a heady 0.13C per decade, you might wonder how many years will it take for the trees to adapt?

From the paper — “one day”:

The gums rapidly [...]

This extreme cold is just weather but all heat waves are climate change

There is a deep asymmetry in science. Don’t take it from me, take it from the former President of American Meteorological Society (AMS) and a current Director of the University of Georgia’s (UGA) Atmospheric Sciences Program. Marshall Sheppard would know, he has written over “80 peer reviewed papers” which gives him secret weather knowledge. It’s a kind of smarts that people who analyze MRI scans, design aerofoils or find minerals 3,000m underground can only aspire to.

He’s worried that people are mocking climate change, just because snap-frozen sharks are washing up on the beach, and it’s hitting minus 50C in Canada.  In the last twenty years mankind has put out more than a third of all the CO2 homo sapiens has ever made since Homo Erectus lit their last fire. Despite that whole extra blanket on the planet, the last time it was this cold was, like 1917.

So to help train believers Marshall Sheppard has written a handy retort to skeptical cynics:

Step One: It’s only cold where you are:

Girls and boys, global weather is hills and valleys. You are in a valley, but the crest of the wave is coming (or something like that).

Near surface [...]

Health Warnings issued for Tasmanians facing six days over 25 degrees (77F +) !

Hobartians face a record heatwave for November

Things are so serious they may find Echidnas in their dog’s water bowl.

Wildlife struggling to find water during the hot weather are likely to seek relief in your backyard. Photo: Emma C

Spend billions. Stop climate change. We simply can’t allow this kind of disaster:

Heatwave health alert issued for southern Tasmania as 130yo record set to fall

The weather bureau’s Tim Bolden said it was shaping up to be the first time Hobart has recorded six consecutive days on or above 25 degrees Celsius in November in nearly 130 years.

“[We'll break the record] if we make it to the six days that we’re currently forecasting over 25 degrees — since last Saturday up until Thursday — and it’s certainly looking very likely,” Mr Bolden said.

“[We are] currently forecasting 28 for Tuesday, 29 for Wednesday and 29 for Thursday, having reached 30 last Saturday, 27 on Sunday and 27 on Monday.

“If we make it to that stretch of six days above 25 degrees, that would be a record heat spell for November, and equal to the maximum heat spell for [...]

Climate numerology! Man-made CO2 caused heatwaves in 1930s,’40s, ’80s and ’90s

How convenient?! A new study shows that human influence on the climate started just before the major (and unerasable) heatwaves of the late 1930s, thus wrapping those awkward years under the banner of Man Made Climate. This study provides the handy peer reviewed link-bomb “answer” to that.

The inexplicable heat of the 1930s and 40s has been a constant source of pain  for Global Worriers. Skeptics can point out that the decadal rate of warming was pretty much the same back then, even though CO2 was at the ideal, clima-perfecto level, of 310ppm. How could it be that massive 400ppm of CO2 was barely able to break the heat records set when CO2 was almost 25% lower?

Well, finally, mystery solved. A new Australian study compares models that don’t-explain-the-climate with CO2, to ones that-don’t-explain-the-climate without CO2. These models assume CO2 causes warming, so when they take out the CO2 factor that was added in to produce “the climate”, the models prove, ipso gloriousi, that CO2 causes warming. Indeed their method is so good, it can’t fail. As Anthony Watts says “it seems clear to me that the conclusion existed before the paper was written.”  Quite.

Say hello to Climate Numerology [...]

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, [...]

BOM method finds more heatwaves in Antarctica than Marble Bar

The danger is in the definition

Ken Stewart has been diligent at trying to understand the Bureau of Meteorology (BOM) method for finding heatwaves. He’d heard BOM head, Rob Vertessy speak on ABC radio, declaring that heatwaves were the “number one cause of death” from natural disaster in Australia. Ken wrote to Vertessy repeatedly  but for some reason, despite the deadly risk to Australians, Vertessy was unable to answer the question of how to define and estimate heatwaves. (Perhaps if the BOM had The Internet, he could have sent Ken Stewart this link, which Stewart has now found himself four months later.)

The Excess Heat Factor: A Metric for Heatwave Intensity and Its Use in Classifying Heatwave Severity, John R. Nairn and Robert J. B. Fawcett (2015) [1]

With these instructions Ken has now replicated the BOM results for the 2014 heatwave in Melbourne. He has also used the same technique on Marble Bar, Western Australia, and Mawson, Antarctica and found that potentially heatwaves are a killer danger to our Antarctic researchers, and if heatwaves kill, they’d be much safer in Marble Bar. For the record, Marble Bar is the place that had 160 days in a row [...]

Fewer heatwaves for 9 million Australians in Sydney, Darwin, Hobart, Melbourne –”thank CO2″!

Let’s play the Heatwaves PR game. If CO2 had an effect we’d see a significant increase in the rate of global warming over the decades since WWII, the models would work, and climate scientists would be able to predict our climate. Since none of that is true, those with a political agenda have to clutch at noisy but marketable extremes instead. Apparently even a half-true, noisy, non-causal link is good enough for post-modern scientists.

Heatwaves are perfect for generating scientific sounding fear, but not so useful for generating actual scientific knowledge. There are an infinity of ways to measure them. They can last 3 days – 160 days, and be cut off at any number from 35  – 40C, or at some percentile outlier. They can be measured one town at a time, or on a regional or state-wide level. The permutations are rich with headline scoring possibilities. And in the end, on a long warming trend that started 300 years ago, it is obvious, inevitable, and predictable that we should score more now. What’s surprising is how often we don’t.

On ABC radio before Easter, Dr Vertessy, Director and CEO of the Bureau of Meteorology, claimed that we are seeing [...]

Heatwaves in Australia: in many ways they are not hotter, longer or more common. Why won’t BOM and ABC say that too?

Heatwaves are a wonderful headline generator. That’s because the term sounds scary, yet the “wave” itself is undefined. A hundred different types of heatwave are theoretically possible, but they all sound the same in a headline. It means an activist team could pick and choose the particular one that scores a “record”. Heatwaves can be 3, 4, 5, 7 or 10 days. They can be measured by town, city, state or national data and they are can be above 35, 37, 40 degrees or… pick a number. A heatwave can be measured as days above some percentile of average. That means a few warm days in a cold town can be defined as a heatwave.

Geoff Sherrington, drawing no dollars from the taxpayer, takes a simple and obvious approach, and looks at 5 capital cities with the BOM raw and adjusted ACORN data. He considered 4, 5, and 6 day heatwaves to see if there was a trend. With 5 cites, 2 data types, 3 lengths of heatwave, Sherrington created 30 graphs. After testing all those different combinations of heatwaves, there were only three graphs out of 30 that showed an increasing trend. Over half of the heatwave graphs showed [...]

Be afraid! Trapped atmospheric waves on the rise. Extreme heatwaves to come.

There are waves piling on waves in the weather.

A new press release tells us that there have been an “exceptional” number of weather extremes in summer.

Weather extremes in the summer — such as the record heat wave in the United States that hit corn farmers and worsened wildfires in 2012 — have reached an exceptional number in the last ten years. Human-made global warming can explain a gradual increase in periods of severe heat, but the observed change in the magnitude and duration of some events is not so easily explained.

Heatwaves lend themselves to headlines. Not only are they scary, but for climate researchers at a loose end, there are 1,000 flavors of wave to comb through. Is that a 3 day, 4 day or 7 day wave you are interested in? Is the cut-off 40C, 38C, 35C or a flexible percentile anomaly above the monthly average? Is it a statewide average, a national record, or a hot week in Houston? Shall we analyze that in seasons, by months, years, or part thereof? The combinations and permutations can keep a supercomputer up late at night. There’s a whole field of cherry trees ripe for the plucking.

It [...]