Sustainability Science

Extreme La Niña events might be experienced about every 13 years, rather than every 23 years, as they are now, but not like clockwork, according to lead study author Wenju Cai, a climate scientist at the Commonwealth Scientific and Industrial Research Organization in Aspendale, Australia. "We're only saying that on average, we expect to get one every 13 years," said Cai. "We cannot predict exactly when they will happen, but we suggest that on average, we are going to get more."

The study finds that powerful La Niñas will immediately follow intense El Niños, causing weather patterns to alternate between wet and dry extremes.

see also:

http://www.nbcnews.com/science/environment/global-warming-may-lead-more-frequent-la-nina-events-study-n292451

We are now seeing a similar pattern; 1) following a significant natural disaster, folks are now primed to at least discuss a possible tie-in with  climate change, but they 2) take their cue from researchers who note that we can't definitively say if  event A is directly attributable to a changed climate, this leads some to then 3) get upset and say "how can you say that?  It is obvious..." and others to say "you can never tell: ask the scientists."

With the rising number of disasters (especially in the coastal zone) a separate way to investigate this is to look for a pattern in these extreme events themselves.  For example, NOAA now has a database of weather-related "billion dollar events."  This certainly seems an area worthy of spending some additional funds.  At the risk of a scientist asking for more money for science (a pox in some regions, I know), having a better understanding of the relationships to a changing climate is/would be a good thing.

This is increasingly a problem for our coastal zone worldwide.  And beyond the coastal zone as well.  Just this week we saw flooding outside the Arizona Cardinal's stadium in September and the greatest single day rain event in Nevada history.  While we are always cognizant of not wanting to confound "weather" with "climate," it should be clear to just about everyone that our infrastructure and hardened infrastructure is increasingly not up to the task of 21st century natural hazards.

Welcome to the new "normal."