Climate Journalists now out of line with scientists

Judith Curry has reviewed the major climate stories of 2012. She notes

The theme of these seems to be dangerous impacts of climate change, bypassing of course the issue of attribution of these events.  Maybe the big story is that a critical mass of bad weather events happened in the U.S., so we are experiencing in the U.S. another round of what we experienced post Katrina in terms of elevating concern about global warming.

The leaked draft AR5 SPM Page 3 Lines 46-47

Changes in many extreme weather and climate events have been observed, but the level of confidence in these changes varies widely depending on type of extreme and regions considered.

The leaked draft AR5 SPM Page 4 Lines 10-11

There is low confidence in observed large-scale trends in drought, due to lack of direct observations, dependencies of inferred trends on the index choice, and geographical inconsistencies in the trends

The leaked draft AR5 SPM Page 4 Lines 14-16

Tropical cyclone data provides low confidence that any reported long-term changes are robust, after accounting for past changes in observing capabilities. This is a revision from previous IPCC Assessments Reports…

Are the commentators going to come into line with the consensus of scientific opinion, or will it be the other way round? Maybe, like in the disaster movies, they will continue to insist to believe that the world only consists of USA.

For those who still think that extreme weather is still increasing, check out the Wattupwiththat “Extreme Weather” page. In particular take a look at Ryan Maue’s accumulated cyclone energy graph.

Adelaide – a decline in extreme heatwaves?

Joanne Nova has posted data from Ian Hill on extreme heatwaves in Adelaide, Australia. To quote

It’s another mindless record used to remind the public to “keep the faith” and recite the litancy:

“Adelaide had it’s hottest start to the year since 1900 Sky news

Picking three particular days out of 365 and comparing them over a century is about as cherry-pickingly meaningless as it gets. But Ian Hill went back through the records to find that not only have there been 79 heatwaves in Adelaide since 1887, but there have been 51 heat-waves that were hotter since 1887.

I have done a bit of number crunching of my own, that is quite revealing. Higher temperatures are meant to lead to more extreme heatwaves. Using Ian Hill’s figures Adelaide is providing an exception. Hill’s definition of a heatwave is 3 or more consecutive days where the maximum temperature exceeds 38oC. I have downloaded the figures and categorised by decade. There are two ways I have analysed this data. First is by the number of heatwaves per decade. Second is the number of days per decade.

There are a number of points.

  1. The temperature data only starts in 1887, so the 1880s are probably more significant.
  2. The current decade might be more significant.
  3. Last decade, beginning 2000 was no more significant than the decades 1890s, 1900s, or 1930s.
  4. The 1990s was no more significant than the decades 1910s and 1920s

Is there, however, a revival of extreme heatwaves in the last twenty years?

Nope. Just a couple of extreme years in 2008 and 2009.


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