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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500% more rain over a million square kilometers – Wettest September across Eastern Australia in 116 years

It is not surprising there are floods all over the East coast at the moment

September brought 500% of normal rain to 2 million square kilometers of Eastern and Northern Australia. There are floods across the South East.  There are flood alerts in South Australia, floods have been washing through NSW (and some of those floods were caused by a dam release). There are floods in Tasmania. Flood watches are active in Victoria. Spare a thought for farmers who are taking big losses from both frost and flood in Australia. (So much for endless droughts, and early springs. Hello, Tim Flannery.) Heavy snow  has also fallen — 25cm in Threadbo (it so late in the season, some ski lifts have stopped operating). Right now, thousands of people still don’t have power in South Australia, while others are being rescued from floods across SA and NSW. Floods have stranded 181 families for month on islands in the middle of NSW.

h/t to Warwick Hughes, and Lance Pidgeon

Source: Australian Bureau of Meteorology

A large part of the scary purple area got only 100-200mm of rain in a month (4-8 inches). It’s just very unusual in these dry areas.

To give [...]

Australian – Asian rainfall linked to solar activity for last 6000 years

A new study by Steinke shows that the sun could have been a driver (somehow) of some of the monsoonal rain changes over the last 6,000 years over Indonesia and Northern Australia. h/t to The Hockey Schtick

In the spirit of the Perfect ClimateTM that existed prior to Henry Ford, we also find that Indonesia had a dry spell that lasted for a while, like say, 3,000 years. It ended about 800BC whereupon things got wetter, and mostly stayed wetter. The authors (Steinke et al) think this might have something to do with solar minima which was very low 2800 years ago. (Though I note the Greek Dark Ages also finished then, and “city states” arose, right, so it could have been that too. Ahem?)

To get straight to the action in Figure 6 the top squiggly line is AISM Rainfall (that’s the Australian-Indonesian summer monsoon). It shows how things were wetter in the last 2800 years ago and drier before that (annoyingly, the present time is on the left). The second part of the graph in red shows sunspot numbers. That gets flipped upside down and superimposed on the rainfall graph in the third part, and we can see [...]

Bushfire predictions in 2070 are nonsense on stilts. Models can’t predict rainfall

Showing that academics can cost the country more than they return, ANU’s Geoff Cary posits that there is an 80% consensus (an unmeasured, meaningless statistic) that there will be more fires in Australia 60 years from now.

This is an opinion about opinions of experts who use models that we know can’t predict temperatures. Not only is this “fact” already piled three layers of nonsense deep, the most abjectly stupid point is the fourth layer, the pretense that these models might, in their wildest dreams, be able to predict rainfall — which is an order of magnitude harder than just predicting global temperature. Predicting bushfires is dependent on knowing not just total rainfall in one region, but how that rainfall is spread throughout the year. Not to mention that bushfires depend on wind speed, wind direction, land-use (fuel load), and humidity.

Everyone knows that different climate models predict both higher and lower rainfall in the same areas at the same time, and the type of phrases used to describe the ability of climate models are: “low confidence”  (National Centre for Atmospheric Research),  “irrelevant with reality” (Koutsoyiannis ), or an “absence” of skill (Kiktev). Compare the different projections of climate models [...]

Land clearing caused drop in rainfall in South West of Australia

Rain rain go away, let’s chop a forest down today?

Mark Andrich and Jorg Imberger compare the rainfall patterns in different regions of southwest Western Australia. The areas where the most land was cleared show the greatest decline. They estimate that as much as 50 – 80% of the observed decline in rainfall is the result of land clearing, which doesn’t leave much to blame on CO2.  The paper came out in 2012.

This fits with other researchers working on the Amazon who estimated chopping down the forests could reduce rain by as much as 90%. Once again: it’s not so much that trees grow where the rain falls, but that the rain falls where the trees grow, and the taller the trees, the better.

So the good news for Greenies is that we ought to plant more trees (and I’m all for that). But driving a Prius, building windmills, and using solar panels won’t do much for our rainfall. (It’s so strange anyone thought it would. The witchdoctors have them completely bamboozled.) The Abbott government’s plan to plant trees to sequester carbon may work, but by accident, not because of anything to do with CO2.

Oh the [...]

Do forests drive wind and bring rain? Is there a major man-made climate driver the models miss?

Clouds over Amazon forest (Rio Negro). Image NASA Earth Observatory.

What if winds were mainly driven by changes in water vapor, and those changes occurred commonly in air over forests? Forests would be the pumps that draw in moist air from over the oceans. Rather than assuming that forests grow where the rain falls, it would be more a case of rain falling where forests grow. When water vapor condenses it reduces the air pressure, which pulls in more dense air from over the ocean.

A new paper is causing a major stir. The paper is so controversial that many reviewers and editors said it should not be published.  After two years of deliberations,  Atmospheric Chemistry and Physics decided it was too important not to discuss.

The physics is apparently quite convincing, the question is not whether it happens, but how strong the effect is. Climate models assume it is a small or non-existent factor. Graham Lloyd has done a good job describing both the paper and the reaction to it in The Australian.

Sheil says the key finding is that atmospheric pressure changes from moisture condensation are orders of magnitude greater than previously recognised. The paper concludes “condensation [...]

Climate Models: 100% right except for rain, drought, storms, humidity and everything else

Yet more observations from the planet show that modelers misunderstand the water based part of the climate – on our water based planet.

Modelers thought that dry ground would decrease afternoon storms and rainfall over those frazzled parched lands (though I don’t remember many headlines predicting “More Drought means Fewer Storms” ). But observations show that storms are more likely to rain over dry soil. Why? Probably the dry soil heats up faster than moist areas thanks to the cooling effect of evaporation, and that in turn creates stronger thermals over dry land. Modelers assumed that wetter soils means more evaporation and thus more rain, but the moisture laden air is evidently coming from further away.

It’s another example of a point where climate modelers assume a positive feedback, yet the evidence suggests the feedback is negative. Once again water appears to be the dominant force with feedbacks (it does cover 70% of the surface). In a natural stable system the net feedbacks are likely to be negative. Positive feedbacks make the system less stable (and more scary and harder to predict.)

Climate change models misjudge drought: “A four-nation team led by Chris Taylor from Britain’s Centre for Ecology and [...]

Clouds dominate everything

Al Gore describes how carbon dioxide beats up Mr Sunbeam and stops him leaving the atmosphere. But he “forgot” to mention that clouds reflect around a quarter of all the sunlight that hits the earth. Those beams of light travel all the way from the sun to get bounced off into space when they are just a few kilometers from the ground.

Any change in cloud cover makes a major difference. The IPCC assumes clouds respond to warming, but clouds could easily drive the warming.

[...]