It is time to stop quivering in our boots in pointless fear of the future and just roll up our sleeves and build it.
- Ray Pierrehumbert

Friday, June 3, 2011

Climate, Weather, Severe Events

Is it getting weird yet?

This is a difficult question. Weird is not a quantifiable concept, at least not easily. And confirmation bias colors what we are seeing - those who expect weirdness see weirdness; those who don't simply experience nature's ordinary orneriness.

But let me try to explain what I mean when I say I expect weirdness. I do not mean that the atmosphere is slightly warmer and slightly wetter, so that warm extremes and wet extremes will slightly increase. That is easy to argue, and a lot of climate folk are falling back on that argument, but I think there is more to the case than that.

Let me go back to an analogy I have used to explain the difference between climate and weather. Imagine a large tropical fish tank on a table, say at a mid-range Chinese restaurant. The fish swim hither, the fish swim yon. As you watch the fish over many visits (perhaps you especially like to sit by the fish tank as you roll up your mu shu pancakes) you come to know their habits. The striped one likes to hang out near the surface but occasionally goes for a dive, the reddish one hangs out by the coral, and so on. As you learn the habits of the fish, you develop a sort of set of expectations for where they will be as you look up from your meal. Occasionally they will be a bit out of place; you'll think "that's a little weird" but not lose any sleep over it.

As an expert on the fish, you sometimes strike up a conversation with your companions. "Look, I bet that one's getting ready to dive to the bottom..." Congratulations, you are now an expert on fish prediction! This is like weather prediction, only with fish. Then someone asks you to predict where the clownfish will be in ten minutes. You chuckle and say you can only guess, based on its habits; it's current position gives you no information about that. Good. Now you have said something about fish climate.

Now imagine that your obnoxious Young Republican nephew us joining you for dinner, and leaning on the tank so hard as to make you worry that he will knock it over. You tell him so, and ask him to please stop messing with the fish tank, which after all is not his property, and which the restaurateur will surely come after you for rather than your ne'er-do-well nephew. And besides, you really do rather like the fishtank.

Of course, your nephew persists, invoking his freedoms. You see the corner of the tank lift off the table and become alarmed. You say you are pretty sure he will break the fishtank if he keeps pushing it harder and harder. Rather than complying, he asks you again where the clownfish will be in ten minutes.

"I have no idea!" you reply, exasperated. "What the heck does that have to do with it? That tank will be smashed before you know it; the fish will be flopping on the floor, I'll be out twelve hundred bucks, and I'll be persona non grata at my favorite Szechuan joint, thanks to you!"

"Aha", quoth he. "So you know nothing about tropical fish displays at all! You admit it! If you don't even know where a single fish will be in ten minutes, how can you make predictions about when it will hit the floor?"

I thought this analogy could make the difference between weather and climate clear. The weather is the unpredictable behavior of the fish, and the climate is the predictable behavior of the fish tank that influences the behavior of the fish.




I've come up with an extension to the analogy which I think may start to give the flavor of why I think extreme events ought to increase. This time, my nephew decides that as an exercise in his freedom, he will be pitching all his beverages into the fish tank. Clearly, the behavior of the fish will change. But the water level in the tank will also change. Some of the fish may end up spending some of the time at the top of the tank. That is above the level that they have ever been able to attain under normal conditions. The changed conditions make new fish configurations possible that had been impossible before.




I can make a somewhat less handwavy case using something like the Lorenz system, but there's no solid proof of this speculation. However, it is at least possible, through this analogy, to understand that we aren't just loading the dice. In another analogy we've referred to around here, we might roll a thirteen.

Are we doing so already? That's a harder question. I do not know that deferring to statistical arguments can tell us anything. An April tornado season without known precedent follows upon no detectable trend in tornadoes. So the idea that it's part of a trend in tornadoes is unsupported. But it's still a very weird event.

I think we have to expect the unexpected. And when it happens we are going to have to do the hard work of analyzing the underlying physics. Subdividing it by individual phenomenon will tell us nothing because we haven't got enough data to tell us about the distribution of extreme outliers.

14 comments:

Grypo said...

"I do not mean that the atmosphere is slightly warmer and slightly wetter, so that warm extremes and wet extremes will slightly increase. That is easy to argue, and a lot of climate folk are falling back on that argument, but I think there is more to the case than that."

I think the problem with the 'slightly' argument is that it doesn't put it into perspective of what it means to humanity. For instance, I find it difficult to put into words what it means, besides discussing the risk aspect and rephrasing in an ethical framework. Like, here I am trying to explain it, but my words are falling short. It's just difficult to demonstrate what "change" really means in a blog conversation.

Adam said...

I thought this analogy could make the difference between weather and climate clear.

My brother on the difference:

"I can't tell if it will rain or shine next Labor Day in Houston: that's weather. I can tell you it won't snow: that's climate."

(Yes, we have deniers in the family, too. He deals with them.)

Steve L said...

Not necessarily an apt analogy: disease outbreaks. There are certain things you can do that increase the likelihood of them. Some of those also make the outbreak worse. I'm primarily thinking of epizootics and, for example, keeping animals in tight quarters. Salmon farms might not have an obvious linear effect on wild salmon survival, but when conditions are right (wrong) an important event could result. How many such events would have to occur before people could confidently add 2 + 2? Well, it would be helped by experimentation and close monitoring. I think you're right that it comes back to mechanism (but this would be a posteriori unless the scientists were smart and properly funded).

dhogaza said...

"I can't tell if it will rain or shine next Labor Day in Houston: that's weather. I can tell you it won't snow: that's climate."

Judith Curry, of course, will point out that we can't state with absolute certainty that Congress won't abolish Labor Day in the next few months, therefore we shouldn't be speaking of Labor Day at all ...

Aaron said...

I submit that weird is very quantifiable. Look at Dr. Deming's books on industrial quality and control systems. Weather data can be expressed as statistical distance from past norms.

Weather from 1/1/2010 - 4/1/2011 is some 10 sigma off the 20th century mean, and we are only one decade into the new century. That is not just different, or unusual weather, that is weird.

Today we set records for June rainfall in both NYC and San Francisco Airport. And, we are only 4 days into the month.

Grypo said...

If Judith has already jumped the shark, I think her new post is now set her completely off the rails. Check out how she ends it.

"These are issues that need to be confronted. Even if Kevin Trenberth turns out to be correct in terms of his views regarding the role of AGW in worsening extreme weather events, even extreme mitigation measures would have no impact until the latter half of the century. Spending our efforts on discussing the links between AGW an extreme weather events is academic at best and misleading at worst."

I can't think of any discussion less academic than what to about risks from extreme weather in the future.

WORD VERIFICATION : sheek

dhogaza said...

Grypo - that statement by Curry's insane. We're supposed to intentionally bury our heads in the sand about what's happening while at the same time use "uncertainty" as justification for doing nothing ...

susan said...

We can certainly include extreme weather events as part of the data. Not doing so would be irresponsible.

What I'm beginning to understand is that we are being manipulated by people using scientific thoroughness and honesty as an excuse to exclude all extreme events from our understanding of trends. Now that, by definition, is off the wall.
--
In addition, not enough is said about the fact that science is not a religion, and therefore it only covers what it covers in a direct and practical way. Not being studied or understood is not the same as not existing in the real world. Reductionists who claim things don't exist unless they can describe and quantify them are missing the boat.
--
Curry et al. arguing that if we do something it won't work for a while, so we should do nothing ... sick and sicker.

Pangolin said...

Dear Texas,

Please come and take back your monsoon rains, humidity, and tornados.

Sincerely,

Northern California

What we are experiencing locally is rapid oscillation between extremes; heat, drought and fires one year, endless, unseasonal rains the next. While both of these conditions might be regarded as "weather" they are extreme variations from the mean "climate" that is required to grow agricultural crops with confidence of success.

Water rationing in the rice fields one year and too cold to grow rice the next is NOT how civilizations made the transition from herding goats to settled agriculture. It's how you get ruins buried under jungle, sands and grassland.

That's climate.

dhogaza said...

"Curry et al. arguing that if we do something it won't work for a while, so we should do nothing ... sick and sicker."

Oh, she's going further in saying that we shouldn't even *study* the subject since nothing we can do will do much good over the next few decades.

Imagine if AIDS researchers had taken that attitude ... situation hopeless in the face of insufficient knowledge, so, don't study AIDS/HIV!

Steve Bloom said...

This latest from Judy is just parroting RP Jr.

I'll repeat the point, even though Michael and others seem entirely bored with it, that the observed fundamental changes in the atmospheric circulation (expansion of the tropics and related effects) should lead one to expect massive changes in the weather, certainly including the highs misbehaving as was the case this spring in Britain and California.

Put briefly: It's a different atmosphere, and it's going to behave differently from the old one.

There's an implication there about what presumptions should apply, which is basically the point Trenberth is making.

Robert said...

Aaron - I see that SF has set a record for rainfall in June to date (just under 1"), but where did you get the idea a record has been set for NYC. There hasn't been any measurable rainfall here since before June 1.

Also where do you get that weather (what weather and where?) since Jan 1, 2010 is 10 sigma from the mean?

Michael - I was following your analogy up till the obnoxious young republican part. There it seemed to go more into climate change instead of climate versus weather. Personally, Adam's brother's analogy works for me.

Aaron said...

Robert,
My mistake on rain in NYC in June 2011, it was a recent article on old records, and I looked at the date of the article rather than the date of the actual rain.

The 10 sigma number was in a comment on a blog, and I cannot seem to put my finger on it right now.

Andy S said...

From the Houston - Galveston NWS office today.

THE HIGH TEMPERATURE AT HOUSTON REACHED 105 DEGREES ON SUNDAY. THIS
IS THE WARMEST TEMPERATURE EVER RECORDED IN THE MONTH OF JUNE. THE
PREVIOUS WARMEST JUNE TEMPERATURE WAS 104 DEGREES ESTABLISHED ON
JUNE 24TH AND JUNE 26TH 2009. THE EARLIEST HOUSTON EVER RECORDED A
TEMPERATURE OF 105 DEGREES PRIOR TO SUNDAY WAS JULY 26TH 1954.
RECORDS FOR THE CITY OF HOUSTON DATE BACK TO 1891 AND THERE HAVE
BEEN ONLY 15 DAYS IN WHICH THE TEMPERATURE HAS REACHED OR EXCEEDED
105 DEGREES.

4 - 1909
1 - 1954
2 - 1962
3 - 1980
5 - 2000

NEW MAXIMUM TEMPERATURE RECORDS (HOUSTON) HAVE BEEN ESTABLISHED
ON FOUR OUT OF THE FIRST FIVE DAYS OF JUNE. GALVESTON AND HOUSTON
BOTH CRUSHED THEIR PREVIOUS RECORD HIGH TEMPERATURE FOR THE DAY
(JUNE 5TH) BY SEVEN...YES SEVEN DEGREES.

OK, the trees have finally given up and are now dying here in Houston. Not a few isolated specimens in yards or the woods, but whole tracts of pine that survived the 1950's drought with no problems. Houston hasn't had a good soaker (an inch or more of rain at a time) since January. This is for a place that gets 52" a year on average and known for its bayous of cypress and palmettos.

It's too damn hot. Any hotter and we aren't going to be able work outside during the summer. It's already suicide to work past noon.

Note that 6 of the 16 times in the 120 years of records, the temps have reached 105 have happened since 2000. And it's supposed to hit that again today.

The suits and ties in Washington and Austin better figure this out soon. They go from their AC office to their AC cars with no knowledge of how work gets done in the rest of the world where us normal humans have to be exposed to the outdoors for long periods while working our butts off.

It's too damn hot!!!