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## We can't say Hurricane Harvey caused climate science deniers but it certainly worsened them

Sou | 3:29 PM
 Harvey. Credit: NASA
Science deniers were so put out by the deadly rains from Hurricane Harvey that they lost their sense of sight. Now we can't say that Hurricane Harvey caused climate science deniers, they've existed since we changed climate in a big way. We can say that Hurricane Harvey hasn't improved them.

Joe Bastardi, a science denying weather forecaster, got all excited and wrote a dumb article that was copied and pasted in the deniosphere. Danny Hayes first alerted us here at HotWhopper. It took some time before it was copied and pasted at WUWT (archived here). It was in response to an article in the Guardian, by Professor Michael Mann. The Guardian article had the following:

In case you're a science denier, let me repeat that headline and sub-head:

We can’t say that Hurricane Harvey was caused by climate change. But it was certainly worsened by it
In the article, Professor Mann explains why the flooding from Harvey was worsened:
• Sea level rise - partly from climate change and partly from subsidence
• Higher sea surface temperatures meant more moisture in the atmosphere
• Higher sub-surface sea temperatures gave even more fuel to Harvey
In addition to the above factors, Professor Mann put forward two other factors why the storm stalled and hung about for days. One that has been predicted in models, and the other, which he said was more tenuous, but appears to be a factor in this case, and has been described previously in the scientific literature.

The first pattern:
The stalling is due to very weak prevailing winds, which are failing to steer the storm off to sea, allowing it to spin around and wobble back and forth. This pattern, in turn, is associated with a greatly expanded subtropical high pressure system over much of the US at the moment, with the jet stream pushed well to the north. This pattern of subtropical expansion is predicted in model simulations of human-caused climate change.

The second, if more tenuous pattern, that resulted in Harvey stalling and dumping so much water over Texas, was described in a recent paper in Scientific Reports:
More tenuous, but possibly relevant still, is the fact that very persistent, nearly “stationary” summer weather patterns of this sort, where weather anomalies (both high-pressure dry hot regions and low-pressure stormy/rainy regions) stay locked in place for many days at a time, appears to be favoured by human-caused climate change. We recently published a paper in the academic journal Scientific Reports on this phenomenon.
The last paragraph emphasises that it's not possible to say that Harvey was "caused" by climate change (who knows if that particular hurricane would have appeared at this particular time without climate change). What can be said is that the impact of Harvey was made worse by climate change. He wrote:
In conclusion, while we cannot say climate change “caused” Hurricane Harvey (that is an ill-posed question), we can say is that it exacerbated several characteristics of the storm in a way that greatly increased the risk of damage and loss of life. Climate change worsened the impact of Hurricane Harvey.

#### A strawman from Joe Bastardi and Anthony Watts

Joe Bastardi and Anthony Watts decided to build a strawman. The ludicrous nature of their attempt was immediately apparent. You'll recall how the Guardian article had in the sub-headline and the article, that "We can’t say that Hurricane Harvey was caused by climate change."  So what was Anthony and Joe's headline? Look and see.
Michael Mann’s claims that Harvey was caused by global warming are destroyed by an operational meteorologist
Michael Mann specifically wrote that we can't say that (it's an ill-posed question).  Not only did Anthony and Joe base their article on a lie of a strawman, they even had evidence their article was a lie, right up top. The article even had a picture of the Guardian headline that showed that Anthony and Joe had built a strawman:

The really strange thing is that Joe Bastardi put up a quote from Michael Mann, then proceeded to say that what he wrote was wrong, while simultaneously showing that what Professor Mann wrote was right.

This is what Joe quoted from Mann's Guardian article:
The stalling is due to very weak prevailing winds, which are failing to steer the storm off to sea, allowing it to spin around and wobble back and forth. This pattern, in turn, is associated with a greatly expanded subtropical high pressure system over much of the US at the moment, with the jet stream pushed well to the north. This pattern of subtropical expansion is predicted in model simulations of human-caused climate change.
Joe then put up this image of the weather pattern, which I've annotated showing the patterns that Dr Mann referred to:

Here's a video explaining how Harvey was blocked to the west and the east by high pressure systems, and how the jet stream, which would otherwise have pulled it north east, was too far north to do so. This is almost identical to what Michael Mann wrote.

#### How Joe Bastardi claims he'd have done what Michael Mann did

The other oddity is that Joe Bastardi wrote what he would have pointed to, which is exactly what Michael Mann did say. Joe wrote:
Now if it’s me, I would be talking about the warmth of the oceans.

Compare that to what Dr Mann wrote at The Guardian:
Sea surface temperatures in the area where Harvey intensified were 0.5-1C warmer than current-day average temperatures, which translates to 1-1.5C warmer than “average” temperatures a few decades ago. That means 3-5% more moisture in the atmosphere.

#### About that accurate forecast from Michael Mann

What about Joe chastising Dr Mann for not making a forecast? Well, Joe mustn't follow Michael Mann on Twitter because Joe wrote:
But what is despicable is what I see coming out. If Dr. Mann was out on a limb before the season showing what he thought, or even earlier this week, that is one thing, But this is an example of what will be a relentless tirade of statements Say nothing, make no forecast you can actually be held accountable for, then come out after and grab headlines with stuff like this.
Here is what Michael Mann tweeted before Harvey made landfall, while it was still "only" a Category 2 hurricane, forecast for maybe Category 3:
Now that was tweeted at 8:04 am 25 August Australian time, which was about 6:04 pm 24 August US east coast time. Here's an NOAA animation of the path of Harvey. There was also this:

By contrast, this is what Joe tweeted not long before Harvey struck:

In my view, Joe Bastardi's view is not that different to Michael Mann's description. He just wanted to pick a fight, because he doesn't want to "believe" that we have influenced weather. Just the same, he doesn't and can't deny that warmer waters fueled the hurricane, affected the amount of rain dropped onto Texas and Lousiana, or that the jet stream wasn't far enough south to pull Harvey further north east.

For the record, at the time when I saw this next tweet I thought maybe Eric Holthaus' prediction was too ominous. It turns out to have been conservative:
Harvey dangers go beyond death by drowning or wind, losing your home and business to floods, and not being able to get about. It affects drinking water, and causes chemical plants to explode, and a whole lot more, as described in this article at the Washington Post.

Philip Clarke pointed out the fact that the Guardian headline said the opposite of what Joe and Anthony claimed. He wrote:
August 31, 2017 at 9:33 am
WUWT Headline: “Michael Mann’s claims that Harvey was caused by global warming are destroyed by an operational meteorologist”
Guardian Headline: “We can’t say that Hurricane Harvey was caused by climate change.”
Tosh of the day.
As for Bastardi, tl;dr as usual.
garyh845 thinks it doesn't matter what was written, it's what he thinks they wanted to write that matters. That's conspiracy nuttery at work.
August 31, 2017 at 10:20 am
“Guardian Headline: “We can’t say that Hurricane Harvey was caused by climate change.””
But, they really do want to say that.

Richard couldn't be bothered reading the Guardian article for the answer to his question, let alone a scientific paper:
August 31, 2017 at 9:35 am
Soooo……global warming forced Harvey to stall out and flood Texas, not because of intensity but because of lack of movement?
How does that work?

Jim Steele seems to think that Harvey was so horrible because of cooler gulf waters. He knows as much about hurricanes as he does about coral - that is, nothing. He posted an image of temperatures, not of the gulf itself, just the coastline and a link to a paper from 2015, which was a study of global coastal SST from 1982 to 2013. Yep, the data stopped four years ago!
August 31, 2017 at 9:38 am
Not to mention Gulf Coast waters have cooled since 1998

This animation is for Jim, so that he knows that warmer sea surface temperatures fuel hurricanes. It's from NOAA and shows the temperature anomaly in Celsius, from 17 August through to 31 August. Temperatures were up to 1.5 or 2 C higher. You can also see in the last two frames how Harvey cooled the sea surface after it churned things up.

There was a lot of nastiness toward Professor Mann, as intended by Joe Bastardi and Anthony Watts. Maybe he was unaware that Michael Mann did express alarm before Harvey hit, because Tom Judd wrote:
August 31, 2017 at 3:15 pm
Perhaps, with his acute awareness of the AGW modified characteristics of hurricanes, Michael Mann should’ve shared this expertise with the Houston mayor and convinced him to evacuate the city after all. But, then again it’s always less risky to prognosticate after the fact. And, of course, it’s not inconceivable that the only evacuations Michael Mann really should be involved with are those from his lower intestines. Unfortunately, however, those evacuations always seem to be more common leaving his body from his mouth

Mary Brown wants what she'll never get. As if Michael Mann would lower himself to debate someone like Joe Bastardi. It would be like an astronaut debating a flat earther whether the world was round or flat.
August 31, 2017 at 10:15 am
Joe Bastardi and I go way back to Penn State days. He is crazy as hell… in a good way. And he calls it like he sees it. We have often disagreed over forecasting greatly but I’ve seen the utmost integrity from him in a moment when no one was watching. I’ll always remember that.
We are both now appalled that Michael Mann slithers through the halls of our formerly beloved University.
I would pay good pay-per-view money to watch the two in a MMA cage… or maybe more appropriately, a televised debate on climate change.

garyh845 doesn't understand what he's read. This comment is upside down and back to front. garyh845 was referring to this article in the LA Times.
August 31, 2017 at 9:10 am
Get a load of this. The LAT’s yesterday, in an article headlined, “Catastrophic storms, once rare, are almost routine. Is climate change to blame(?),” quoted Mann saying:
“There is a good chance it would have happened anyway,” Mann wrote of Harvey in an email.
So, Mann is suggesting that absent AGW, there was a chance that Harvey would not have formed into a tropical system .. a hurricane . . a cat 4 hurricane?
No, gary. Don't put words into his mouth that mean the opposite. Professor Mann is saying what he said, that "“There is a good chance it would have happened anyway,” Mann wrote of Harvey in an email. However, he added, “the impacts were likely greatly amplified by climate change.”

John Enns was appropriately disgusted with what goes on in the deniosphere, and said:
August 31, 2017 at 5:26 pm
Watt a bunch of bullshit. You reference Michael Mann saying that Harvey was caused by global warming warming and than quote what he actually said, that Harvey was influenced by it. Not the same thing at all.
Once in a while I’m curious enough about the broken logic behind adamant deniers to actually read one of your articles but the falsehoods are consistently right their in the first few paragraphs. In this case the title and subheading.

1. Harvey was worsened by Rex, a freak of nature which loomed over Texas for years.

2. I post a comment at WUWT only, it sinks without trace. I cross-post it here, it gets posted at WUWT.

Funny, that.

1. Prosecute Watts - or expect extrajudicial reckonings in the near future (like I do).

2. Careful your jackboot is showing...

3. Oh look: now Eric is pretending he can't tell the difference between Nazis and ordinary decent people. Where Trump leads the sheep must follow.

4. Ahhh good ol' WUWT. Claims people are not blocked, then leaves every comment you make in moderation. Meanwhile posts that contain nothing but insults of other posters are published.

3. Perhaps, with his acute awareness of the AGW modified characteristics of hurricanes, Michael Mann should’ve shared this expertise with the Houston mayor and convinced him to evacuate the city after all.

Finally, we're making progress! The evidence is so strong now that they either have to lie outright or move on to the next stage, "Why didn't you warn us???"

1. No, some more US cities need this before any progress has a chance. Aslo, the window for confrontational education is closing fast, and what happens then: see Syria.

4. "For the record, at the time when I saw this next tweet I thought maybe Eric Holthaus' prediction was too ominous." - Heh, Sou, isn't it addictive, all that climate revisionism! This straight as math, no kidding.

Prosecute Bastardi - or expect extrajudicial reckonings in the near future (like I do).

5. An average hurricane that IS slow-moving due to local weather conditions and ends up absorbing more moisture from the coastal waters. Goes on to dump the extra water on Houston and the surrounding areas.
What part of average hurricane do alarmists not understand?

1. The bit where Harvey was not an average hurricane. The bit where it dropped record amounts of water. The bit the fossil fuel industry tells you to lie about.

2. What part of high ocean temperature which caused Harvey to strengthen so quickly do you not understand? Ocen warming due to climate change...

3. Hmmm,
The Gulf SST at the time when Harvey was intensifying were around 1 degree Celsius above normal. OK. But the SST anomaly has been around that figure for years. It isn't rising much at all.
It is a fact that when Harvey came ashore in Texas ,prevailing weather conditions, by chance, caused it to virtually stop moving with half of the hurricane still over the Gulf waters.So it sucked up shedloads of extra water due to this.

https://www.esrl.noaa.gov/psd/map/images/sst/sst.anom.gif

4. ZebM, it's called "warming" and it's happening at many localities as well as for the world as a whole (global warming). (What do you think "normal" means in the context of "above normal"?)

SUMMARY: CRW's SST Anomaly is produced by subtracting the long-term mean SST (for that location in that time of year) from the current value. A positive anomaly means that the current sea surface temperature is warmer than average, and a negative anomaly means it is cooler than average. The spatial resolution is 0.5-degree (50-km), and the data and images are updated twice-weekly.

https://coralreefwatch.noaa.gov/satellite/methodology/methodology.php#ssta

5. "Sea surface temperatures in the area where Harvey intensified were 0.5-1C warmer than current-day average temperatures, which translates to 1-1.5C warmer than “average” temperatures a few decades ago. That means 3-5% more moisture in the atmosphere."

6. Yes i know what the terminology means. Just because i question your article, it doesn't mean i don't grasp anomaly data.
On that NOAA SST map i linked, most of the Gulf of Mexico is within the baseline 0.5 degrees Celsius. As is the Caribbean Sea ,where tropical storms usually intensify into hurricanes.
So i feel linking the extreme rainfall of a very slow-moving hurricane to elevated sea surface temperatures seems a bit of a stretch.
If the hurricane was moving overland at an average speed would it still break rainfall records?

7. So i feel linking the extreme rainfall of a very slow-moving hurricane to elevated sea surface temperatures seems a bit of a stretch.

You might want to rethink that, ZebM.

8. @Jammy Dodger.
So 5% more moisture for hurricane Harvey to absorb translates into extreme flooding never before experienced? Only because the hurricane hung around sucking up extra moisture .Yes?

9. What i'm trying to say is :it's all about speed. A hurricane milling around on the coast is obviously a major disaster. Irrespective of SSTs . That's it.
Thanks for letting me comment.

10. If the hurricane was moving overland at an average speed would it still break rainfall records?

That's a hypothetical. The article explains why that didn't happen, and attributes it in part to climate change.

To compare it with other recent events (which are also affected by climate change), here are two articles.

The first illustrates the amount of water from Harvey (to the date of the article):
https://www.vox.com/science-and-health/2017/8/28/16217626/harvey-houston-flood-water-visualized

The second is about the Louisiana floods cf Katrina:
https://www.washingtonpost.com/news/capital-weather-gang/wp/2016/08/19/no-name-storm-dumped-three-times-as-much-rain-in-louisiana-as-hurricane-katrina/?utm_term=.949ce9e48dc5

11. No, not only because.

You are looking at this far too simplistically and not looking at the system as a whole. Yes, Harvey hung about sucking up extra moisture. It also hung about dumping that extra moisture. Moreover it dumped it at a rate 5% greater because, you know, that extra 5% holding capacity.

Or perhaps even more. Who knows what the exact dynamics are of extra holding capacity? Perhaps it also sucked it up even faster like super dry blotting paper.

12. Jammy Dodger.
Thanks for that.

13. ZebM.

I think you need to understand when you are making an argument from ignorance.

I am sure good studies looking at the dynamics of Hurricane Harvey will be done in the future and will not be based on opinions from blogs.

What is know at this point is projections suggest the rainfall from large hurricanes will become more intense because of global warming, and the intense rainfall from Hurricane Harvey is consistent with those projections. The projection is in the IPCC AR5 report.

14. So i take it you haven't read the recent NOAA report?
https://www.gfdl.noaa.gov/global-warming-and-hurricanes/

6. It's appalling to see the "you can't prove it's climate change" argument still happening, years after there was a discernible impact of human-caused global warming on the planet.

I think the first time I commented on the human influence on climate was after the Queensland floods in 2011, when I remarked on the contribution of additional warmth to extra moisture moving through the hydrolgical cycle. Twelve months later I was again caught in the denialist tar baby, again discussing the issue of extra heat affecting the climate, and it's just rolled on with the same regularity ever since.

Many in the hard-core crowd amongst us has been making the same observations repeatedly for as long as I have, and longer, and yet here we are today, still throwing punches at that bituminous neonate, and with little more impact than has been realised in the past. And if the Greek tragedy continues we'll still be in the same place in the mid-2020s, when it's far too late to hope to avoid anything but the worst scenarios.

Somehow it's fitting that today it was announced that Australia's winter just past was a record hot one, at 1.9C degrees above the 1961-1990 average. And still we have a government hell-bent not only on denying the damage that we're doing to our climate, but actively working to ensure that they stymie as much as they can any effort to mitigate carbon emissions. These money-grubbing sociopaths should stop and consider that climate change will happen despite any and all efforts on their part to pretend otherwise, and that our civilisation simply cannot afford to keep reactively reconstructing every time another extreme climate event wreaks destruction. They really should talk to the actuaries in insurance and re-insurance companies - I'm sure that they have thousands of pages of projections on the economic consequences of the insane climate experiment that we've inflicted on the only lump of rock we'll ever have on which to live.

7. For what they're worth, early cost estimates of Harvey's damages range from $100 billion to$200 billion. But I suspect that won't cause Pielke Jr or Lomborg to shut up.

1. Roger Pielke Jr hints that he's one of those warmunist/communist/socialist types. He keeps putting up charts to say that GDP is rising faster than the cost of disasters, implying the rich who benefit will pay for it all.

(There are flaws in his implied argument, and not just that some rich people object to paying for weather disasters that don't affect them personally.)

2. Its not just rich people who object to paying for weather disasters. The good people of Houston do, or did. They recently reelected to Congress people who voted against relief for the victims of Hurricane Sandy.

8. Great take down. I noticed that Michael Mann linked to it on his Facebook page.

Just read a denial-sphere article using paucity of hurricanes hitting the US mainland to claim Harvey was just weather. Having witnessed the aftermath of non-hurricanes Melissa and Sandy, mind boggling that this is used as an argument. And the US centric nature of the article is all to common in the denial-sphere. Obviously the uptick in killer typhoons, cyclones, and monsoons is irrelevant in the US centric denial=sphere since they are not terms used to describe extreme weather hitting the US mainland.

9. If the climate is changing then ALL weather events from an insignificant rain shower to the most powerful storm are a part of that change. The only way anyone can argue that a particular event isn't influenced by climate change is to show that the event is occurring in total isolation from the rest of our climate system or prove that no part of the climate is changing.

10. OT but this is hilarious.

Anthony is trotting out a variation on the corals have been around for a bejillion years so will survive a little warming' myth.

What happened to his hiatus? Anyhow he clearly needs a break to collect his marbles.

The trigger for the post was an ARC Press release about a recent paper, headed 'Can corals survive climate change?'

To which the stressed and exhausted Watts replies

'Yes  In fact, they’ve already survived millions of years of climate change.'

And he's googled up a document from the Global Reef Project from which he picks out this quote Corals are 500 million years old, and date back to the late Cambrian period, during the Paleozoic era

Panic over? Sadly no, all the calcite coral species from the Cambrian are now long dead. In fact corals have suffered several extinction events since the Cambrian, not least during the Paleocene/Eocene Thermal Maximum (PETM). The clue is in the name, Tony. Modern Aragonite corals (Scleractinia) date from the Triassic or later.

The funniest, funniest part of this is that the extinctions are detailed in the very GRP document that he cited. If he had taken the trouble to read to the end he would have found this:

The climate of the globe is currently undergoing a rapid PETM-like event (a warming period), driven by greenhouse gases as in the PETM. Evidence now suggests that coral reefs will pass a point of no-return around 2040, and go into terminal decline, eventually disappearing at the end of this century. If so, based on past evidence, it is likely that many millions of years will pass before they return.

Some, not me you understand, might think that to describe Anthony Watts as a dumbass is manifestly unfair to dumbasses.

11. They can't help it, the deniers. It's catching, like yawning.

12. Both Dr Curry and Dr Spencer put out blog posts attempting to downplay the influence of global warming on the hurricane. Same ol' same ol'.

13. jazz,so I'm not the crazy one after all. : |

"Judith Curry, ask a stupid question, expect a stupid answer! Harvey's global warming connection." (August 29, 2017)

The hallmark of a great scientist is the ability to ask great questions. Questions who's pursuit leads to meaningful progress towards understanding. When it comes to our country's contentious manmade global warming discussion, it also comes down to how serious one is about asking meaningful questions that allow for meaningful constructive answers.

Judith Curry writes, “Anyone blaming Harvey on global warming doesn’t have a leg to stand on.” (I thought she knew about climatology. Please consider.)

* Global warming is definitely directly related to that hot Gulf of Mexico waters that fed an explosive intensification of a tropical storm.

* Global warming is definitely directly related to the fact that the atmosphere is holding more moisture and making it available for storm systems such as Harvey to collect and dump.

* Global warming is definitely directly related to the fact that our Jet Stream has gotten weirder and is currently causing the stalling and reversal of Harvey’s northward movement.

* Global warming is definitely directly related to the fact that sea level is rising and thus adding substantially to damaging storm surges.
~~~~~

** Global warming definitely directly related the Brown Ocean effect that continued feeding moisture into the storm after it made land fall.

h/t to Paul Beckwith

14. I'm curious why the question itself is not called out for being stupid and misdirecting. Hurricanes are a "natural" part of our planet's heat distribution engine. They WILL form.

The point that should be made over and over and over - is that we and our climate system exist within a warming system - PHYSICALLY THERE CAN BE NO WEATHER PATTERN INDEPENDENT OF THAT WARMED UP SYSTEM. ~~~

For me its been demoralizing watching reporters and scientists continuing to soft peddle the clearly understood connections by posing stupid questions that receive inevitably stupid answers.

Tonight listening to another round I got a vision of people desperately clinging to dreams of yesterday’s normal, like a child desperately clinging to her mother as they're being inexorably torn apart. Unfortunately, what we refuse to comprehend will harm, nay destroy all we’ve come to love about this world.

Incidentally, about that terminology game. Can we please start being clear: Manmade global warming is what’s driving increasing climate change.

15. @citizenschallenge

I agree. It is a non-question. Using the contrarian words:

1. Climate change has and always will occur.
2. Does climate change affect the weather? Yes.

End of discussion!

16. Maybe the end of your interest, but sadly not the end of the discussion.

Time to get real, this ladies and gentlemen is our new normal, and given the new conditions you can be sure that this is just the beginning of the infrastructure and life destroying extreme storms that will be battering our coastal cities in this next decade and beyond.

Incidentally, are you aware of compounding interest and such?
It happens within our climate system and biosphere also.

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