by Andrew Freedman, via Climate Central
As the people of Duluth, Minn. — a community of about 86,000 tucked away at the southwest corner of Lake Superior — try to recover from the record flooding of the past week, it’s reasonable for them to ask whether global warming may have played a role in the floodwaters that so heavily damaged their city.
A car partially swallowed by floodwaters in Duluth. Credit: NWS
Given the unusual nature of the rainfall, and the prevalence of extreme weather in Minnesota and other states so far this year and during recent decades, the answer, according to the scientific evidence, is “maybe.” (That the jury is still out is reason enough for concern.).
Here are some of the facts regarding the unprecedented and devastating flooding event that took place this week in Duluth. A cold front sparked slow-moving thunderstorms that repeatedly moved over the Duluth area between June 17-19, dumping between 8 and 10 inches of rain in a 24-to 36-hour period on Duluth and neighboring communities in Minnesota and Wisconsin.
An all-time record 24-hour rainfall was set in Duluth, with 7.24 inches of rain falling during that period. The rainfall came during an already wet month in Minnesota, as the state rapidly lurched from drought conditions during the spring to suddenly having a precipitation surplus.
The rainfall washed out numerous roads in the Duluth metro area and nearby counties, and a state of emergency was declared in the city. The heavy rains caused rapid increases in the levels of local rivers and creeks. The St. Louis River at Scanlon, Minn., crested at an all-time record high of 16.62 feet on June 21, up from 5.5 feet just two days prior.
In other words, this was not your ordinary heavy downpour, and the flooding the rains caused were not your typical floods, either. It’s likely that the flooding will go down as among the most destructive in Duluth’s history.
The U.S. Climate Extremes Index, showing an increase in 1-day precipitation extremes in recent years across the Lower-48 states. Credit: NCDC.
It’s been well documented that global warming is already contributing to an increase in the amount of water vapor in the atmosphere, and an increase in the number of heavy precipitation events across large parts of the globe. A 2008 report from the U.S. Climate Change Science Program found that there has been a 31 percent increase in very heavy precipitation events from 1958 through 2007 in the Upper Midwest.
As Paul Huttner of Minnesota Public Radio wrote: “What we can credibly say and support with facts is that events like the Great Duluth Flood of 2012 ‘fit’ within the overall pattern of climate changes we’re observing in Minnesota.”
Some recent studies that have assessed global warming’s relative contribution to specific extreme precipitation events have shown that by putting more moisture into the air, global warming made them more likely to occur.
Given the studies showing changes already occurring in the planet’s water cycle as a result of global warming, it’s quite possible that global warming aided and abetted the extreme rainfall event such as the one that occurred in Duluth by making more moisture available for the thunderstorms to wring out of the air as heavy rainfall.
Chart showing the rapid rise and record crest of the St. Louis River at Scanlon, Minn. Credit: USGS.
Global warming did not cause the thunderstorms, of course, and they would likely have occurred regardless, but it may have made the rainfall heavier than it would otherwise have been.
As I’ve previously written, one can think of global warming’s role in extreme weather events as a suspected accomplice to a crime, not necessarily pulling the trigger, but still playing a role for which it could be held accountable.
As in a courtroom, in meteorology and climate science, it’s important to examine all of the possible factors that led to a certain outcome, be it a crime or an extreme weather event, and the scientific evidence to date suggests that global warming may have left some fingerprints at the scene of this particular crime.
– Andrew Freedman. This piece is reprinted with permission from Climate Central.
Related Climate Progress Post:
- NCAR’s Trenberth on the link between global warming and extreme deluges: “There is a systematic influence on all of these weather events now-a-days because of the fact that there is this extra water vapor lurking around in the atmosphere than there used to be say 30 years ago. It’s about a 4% extra amount, it invigorates the storms, it provides plenty of moisture for these storms.”
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The chart on extreme precip events sure looks like climate change is shifting the probability curve for these extreme events.
If so then my understanding of statistics is that it is correct to say that the more extreme the event the more likely it is “caused” by climate change.
This is the very point that Hansen has been making about the dramatic increase in extreme summer heat events worldwide. Because the global temperature probability curve has shifted towards warmer temps then the math says the most extreme heat events are going to see the greatest increases in relative occurrence. Sure enough, extreme heat events in summer now occur nearly 100 times more frequently than they did before. The math says that the vast majority of extreme heat events in summer would not have occurred without the small shift in global temperatures. And the more extreme the heat event the more likely it would not have occurred in the past.
Small shifts in distribution curves make the leading extremes much more likely to occur, while not changing the likelihood of typical events very much at all.
I think the public doesn’t have a good understanding of how small shifts bring big increases in extremes.
The public doesn’t have a good understanding of any of this. Especially in Minnesota, where we are used to extreme temperatures swings, and extreme weather events, and extremes of all kinds in weather, this will be explained away as just another freakishly extreme weather event. As others have said here, there will be no talk of adaptation to climate change until it’s well past too late. People can’t even grasp that weather and climate are not the same thing. No one in media or government is doing anything about explaining this to anyone. Our leaders seem to be lacking all common sense and conscience in this matter.
Our “leaders” are by their nature the least qualified people on the planet to lead anything. They’re politicians, for crying out loud… they have none of the skills or knowledge that a competent leader requires in order to make sound decisions about energy, economy, foreign policy, science, education, health care, or anything else that matters to real people.
Our leaders are basically chosen for their hair, not for their qualifications.
Need proof? One word: filibuster.
They might as well be chosen on the basis of their hair.
Hansen’s maths was on heatwaves, where he showed as far as I remember that 3 standard deviation events affected 10% or thereabouts of global land area in one recent year compared to the expected 0.15%. It would be interesting to see a similar evaluation of drought and extreme precipitation.
$100,000,000 of damage to a town w/a population of 96,000. ~$1,000 for every person; how many have an extra $1,000 they don’t mind parting with.
Watch the “adaptation” unfold.
Another ‘hockey-stick’, yet the numbskull Homo allegedly sapiens slumber on. Well, snore on, in need of CPAP. It would be interesting to interview the Dunning-Krugerite denialists in Duluth (they will exist)to see how they ‘irrationalise’ the disaster. We know how the denialist industry genocidists will, ‘It’s all just natural variability’, which it ain’t, and ‘It has all happened, even worse, in the past’, by which they mean thousands or millions of years ago, when Duluth was not what it is today.
Pah to adaption. What gets rebuilt in Duluth will be rebuilt to the same standard at best.
We don’t do adaption until it has happened again and again.
When it happens again, they will be as unprepared as they were last week.
We don’t do adaption until it has happened again and again.
That’s the hell of it; adaptation requires a lot of iterative destruction in order to happen. All the blithe “adaptation” chatter assumes perfect foresight and the wisdom to follow it.
Large-scale adaptation will occur when some intrepid businesses learn how to make a profit selling those goods and services; or via forceful government action; or anarchy and chaos.
Plan A is inherently flawed.
Plan C is too horrible to contemplate.
To borrow from Gandalf, is it folly to pick the only remaining answer when all other choices have been considered and found wanting? Where is our forceful government action?
And that constant “maybe” answer instead of speaking plainly is what is keeping people from wanting to even understand this. How many more years of these events and trends are we going to to have to go through with “maybe” being the answer? How many more crops ruined? Lives taken?
More. Research. Is. Needed.
Not any more. Delay, yet further delay, will be suicidal. And no amount of research will ever convince the Dunning-Krugerites or stop the genocidists of the denialist industry.
Gail’s comment was 100% sarcasm.
Oops! You’re right-I am becoming a humourless bastard.
Fema has a chart of disaster declarations going back to 1953. The trend is up, and it’s startling.
http://www.fema.gov/news/disaster_totals_annual.fema
The flash floods (around the world) , the massive fires, and the terrible droughts, the record high temperatures are all a result of climate change.
And I don’t think there’s much “maybe” involved.
‘Maybe’ at this late stage, simply smacks, in my opinion, of moral cowardice.
I think the debat about hurricane frequency is just about over…
Another Atlantic Tropical Record Falls
News – Jun 23, 2012; 4:15 PM ET
The formation of the fourth tropical storm of any Atlantic Hurricane season has never occurred in June — that was until Tropical Storm Debby took shape.
These events can’t be predicted. Watch for one in your nieghborhood some day, probably sooner than later.
Already happened for us.
Nothing like having your first phone call of the day come from the guys doing your house remodel w/news that fountains of dilute sewage are spewing in the bottom floor. Part of adaptation. :-)
This month, two record-setting rainfall events so far. Seattle used be more “drizzle,” now it seems a bit more “dump.”
The thing is these events are happening not only more frequently but also over a wide rwange of regions, often in parrellel. A similar Xtreme evnt to duluth is happening right now in England. And we r starting to see them happen on a more frequent cycle for a given region. This is trending to under five yr!
We are effectively in a climate bomb.
And in terms of adaptation its already too late for modern society. Too bad. We have to fight for survival now.
The USA already suffers from a tremendous infrastructure deficit, amidst gigantic debt. Debt so huge that interest rates must be kept at zero, probably for decades. Every multi-billion climate and weather catastrophe will destroy more infrastructure, whether through flood, storm, mega-fire or landslide, and a broke country, wasting over a trillion a year trying to militarily terrorise the planet into submission to its insatiable elite’s diktat, isn’t going to fix it. It’s ‘crumble-time’.
In the UK we had severe flooding 5 years ago, with similar events unfolding in some areas now. Yet amongst our right wing government’s first actions in office was to cut flood defence spending.
Spike, for the Rightwing misanthropes, so long as it is not them drowning, well, not only don’t they give a stuff, their tremendous reserves of sadistic relish at the suffering of others delight in the misfortune of others. These are wicked creatures, by every definition of the term.
the problem has already been solved in NC by making it illegal to say that rising waters are linked to climate change.
I can’t see what the fuss is all about, why can’t Minnesota do the same thing? surely NC can’t be smarter, can they?
Sorry for going off topic, but I thought this deserved a mention. Joe Bastardi, the famous (or infamous) climate science denying Fox News weather and climate expert, just compared the failure of PSU officials to report suspected child sex abuse with PSU’s exoneration of Michael Mann in the climate denier inquisition over on his Twitter account. Stay classy, Joe. Just unbelievable that people still listen to this clown.
In response to this Tweet by Kimberly Jones:
@KimJonesSports: PSU prez Erickson says he & “Board of Trustees maintain a steadfast commitment to pursuing the truth.” This continuing lie offends, sickens.
He responded with this:
@BigJoeBastardi: @KimJonesSports Heh Kim, we have the same thing in the meteo dept with the global warming scam. That was white washed
http://twitter.com/BigJoeBastardi
Wow, sounds like Bastardi’s been spending time with Judith Curry’s house jester Tucci78.
The name says it all, really. Surely, even in the USA, Mann can sue over such garbage. I’d chip in a few bob to help pay. As I have observed, when the Right is proven wrong, stupid, ignorant and fifth-rate they never learn, change their ways or try to make amends. They simply dive deeper into the black pit of their perverted psyches and emerge more toxic than ever.
You can contribute to the Climate Science Legal Defense Fund:
http://climatesciencedefensefund.org/
I know it’s just a coincidence that Penn State stands up for Mann and suddenly this sex scandal thats been under the rug for years pops out. Just coincidence I’m sure. Like Giffords was the biggest proponent of Solar Power in congress and she gets a bullet in the head while Barton and Imhoff are still up there quacking like ducks. I’m sure it’s just coincidence but does “maybe” fit in here some where? Dinosaur backed in to a corner indeed. Those boys play rough.