Rainfall intensity increases are not in your (or my) imagination

I've been posting for years about my impression that an increase in rainfall intensity is one of the first obvious, and underrated, disastrous effects of climate change.   [Go on, use my blog search bar at the side for the topic "rainfall intensity".]   I noted in 2015:

My strong, strong hunch is, however, that at least South East Queensland (if not other parts of the country) is now clearly undergoing the type of intensification of rainfall that was always expected under global warming and is suffering badly for it.  

Last Friday's rainfall was deadly, remarkable, and unseasonal across most of the South East, but particularly just to the north of Brisbane.   It reminded me of the intensity of rainfall that led to the Lockyer Valley disasters in the 2011 floods - where all forms of normal drainage (and Brisbane's drainage is built to sub-tropical standards) is so overwhelmed  that the flood is disastrously out of the norm in terms of suddenness of onset.    

But I'm not sure whether we are getting a good analysis of this in a timely fashion.

Well, it took them a while, but we now seem to have a paper which confirms the hunch, and it is getting plenty of publicity.

The SMH writes:

"Unique and alarming": Engineers to be tested as rain events intensify

which ties in neatly with my recent complaint here:  

...sure, in theory, you can argue that flood prone cities can prepare themselves by spending more on higher capacity drainage systems.  But replacing pipes and drains of one diameter that used to be adequate 100 years ago with significantly larger drains to cope with the increased frequency of intense, overwhelming rainfall, is  surely going to be very expensive; and for a regional government it is not going to be clear which particular location is going to face an unexpected downpour first.

Why on earth should I think that the economic modelling of climate change effects could be accurately making estimates of that when tallying up the figures for their estimates of when the benefits of climate change crosses the line of being clearly outweighed by the harm?    I would think they can put a rough estimate of of the cost of increased damage from flooding - they've got some historical guidelines for that - but as flooding increases, governments will be under pressure to pre-empt them by the expensive sorts of capital works that I would think is very, very hard to estimate.

Even the Courier Mail appears to be covering the story with the some headline about "freak superstorms" and making reference to infrastructure too.  Good.

As for a science site that explains a bit about the study, try Science Daily:

Published today in Nature Climate Change, the study shows that in Australia:

• Extreme daily rainfall events are increasing as would be expected from the levels of regional or global warming that we are experiencing
• the amount of water falling in hourly rain storms (for example thunderstorms) is increasing at a rate 2 to 3 times higher than expected, with the most extreme events showing the largest increases.
• this large increase has implications for the frequency and severity of flash floods, particularly if the rate stays the same into the future.

Dr Selma Guerreiro, lead author, explains:
"It was thought there was a limit on how much more rain could fall during these extreme events as a result of rising temperatures.
"Now that upper limit has been broken, and instead we are seeing increases in rainfall, two to three times higher than expected during these short, intense rainstorms.