Severe Weather = the New Normal is a Fraught Meme
This week NPR asks:
When can a big storm or drought be blamed on climate change?
If you have been nodding in approval to everything that Bill McKibben and his fellow climate concerned advocates say on this subject, then you already have your answer. And if you are familiar with the “new normal” meme, which I have written on previously, then you also know that nearly every severe weather event is now associated in some way with climate change. It’s been interesting to watch this play out in the media the past few years.
For example, plug into Google ‘s search engine “climate change” and “Typhoon Haiyan” (the tropical cyclone that devastated portions of the Philippines last year) and see all the stories that come up. A quick sampling of headlines:
“Is Climate Change to Blame for Typhoon Haiyan?”–Guardian
“Did Climate Change Cause Super Typhoon Haiyan?”–Time
“Super Typhoon Haiyan: A hint of What’s to Come?”–Climate Central
A definitive answer is impossible in the immediate aftermath of such an event, but many outlets still made a connection along these lines:
Hurricane researchers contacted by Climate Central said Haiyan is an example of the type of extreme storm that may become more frequent as the climate continues to warm.
This sets the stage for every major storm to be discussed in the context of climate change. And indeed, this is often what ends up happening with every heat wave, every drought, every big flood, and every unseasonable cold spell or blizzard. That is the whole point of the “new normal” meme, which by the way, may be counterproductive, Dawn Stover recently argued in the Bulletin of the Atomic Scientists.
In the last couple of years, scientists have tried to bring some clarity to these discussions. This has resulted in dozens of studies assessing whether or not severe weather events from around the world can be linked to global warming. The latest batch of research was published earlier this week in a special Bulletin of the American Meteorological Society report. The results were covered widely in the media–most with a particular slant. I found NPR’s summary of the findings to be among the most accurate:
Dozens of these researchers just published an analysis of 16 weather events from 2013 in the Bulletin of the American Meteorological Society, and what they found was a mixed bag.
As Justin Gillis explained in his New York Times write-up:
The findings relied on computer analyses of what the climate would have been like in the absence of human-caused greenhouse emissions, a type of research widely acknowledged to be imperfect, and which often produces conflicting findings from different groups.
That was the case with an assessment of California’s drought, with two groups of researchers not finding a a linkage to a warming climate (from rising concentrations of greenhouse gases) and a third group finding such a connection. Other studies in the report determined that catastrophic floods in Boulder, Colorado could not be attributed to human caused global warming but that a heat wave in Australia had such a connection. (Oddly, there was no assessment of typhoon Haiyan.)
In his NYT summary of the findings, Gillis included a helpful perspective from one UK scientist:
Myles R. Allen, a researcher at Oxford whose group conducted the study on the European rains, noted in an interview that the science of attributing specific events to human emissions was still contentious and difficult, so any answers given today must be regarded as provisional.
His group has found a measure of human influence on several weather events over the years. But with the science still emerging, he cautioned against the tendency to cite global warming as a cause of almost any kind of severe weather.
“If we don’t have evidence, I don’t think we should hint darkly all the time that human influence must be to blame somehow,” Dr. Allen said.
I doubt that Bill McKibben, whose twitter stream often resembles an extension of the weather channel, will be taking that advice to heart. It would be difficult for many others, as well, to stop hinting darkly about a relationship between global warming and severe weather. But McKibben and company might come to regret this if people start to shrug their shoulders and say, “oh well, I guess this is the new normal.”
UPDATE: See this related 2013 Dot Earth post by Andy Revkin, which makes some excellent points about how the emphasis on weather disasters can boomerang. An excerpt:
According to the latest science, in most cases (outside of extreme heat waves) the connections between today’s extreme weather events and human-driven climate change range from weak (hurricanes) to nil (tornadoes) — and the dominant driver of losses in such events is fast-paced development or settlement in places with fundamental climatic or coastal vulnerability.
So “here and now” arguments take the policy fight on global warming into the terrain favored by those who recoil at environmental regulation or profit from fossil fuels — an arena where there’s lots of real scientific uncertainty. All they have to do is sprinkle just a little of that uncertainty dust and the public disengages. Job done.
The joke is that while Bill McKibben and fellow travellers have been trying very hard to be the scourge of all the Koch and Exxon funded deniers the only impact they’ve had has been to swell the ranks of the confused. Journalism students included.
But he (and many others) have nailed their colours to the mast in such a public fashion that there’s no way they can go back on what they said. Their only option is full speed ahead with a prayer that a super El Nino might be just around the corner.
Klimate Kaos has four components, reducible to three:
1) That which supports Klimate Kaos supports Klimate Kaos.
2) That which ignores Klimate Kaos supports Klimate Kaos.
3) That which contradicts Klimate Kaos supports Klimate Kaos – test of faith!
4) Anybody who criticizes is thereby proven unqualified to comment – and must pay the Carbon Tax on Everything (along with believers, re Pascal’s wager).
A) The Earth will die for your sins.
B) If you do not sin, the Earth will die in vain.
C) Get on with it.
It is human nature to find something to blame for any natural event. It used to be the gods punishing us for our bad behavior (Thor, Zeus, Jove, etc.).
Today it is climate change (caused by humans of course).
There is always a need to blame humans at the bottom of it all. Why? Probably something psychological. Or maybe humans have always used natural weather events to try to gain influence and exercise power? The priests used to do it and now it is climate science advocates – using weather as propaganda to try to decrease carbon emissions.
The bottom line is all of these storms, their frequency, their severity, or any any other measure you care to name – all occurred in similar measures prior to the increase of CO2 above 280 ppm.
We simply have no evidence yet that any particular storm or series of storms are caused by humans – but we will continue to see every cold snap, warm snap, wet snap, dry snap, hurricane, typhoon, tornado etc. blamed on humans.
California had two centuries of drought about 1000 years ago, well before CO2 was increased by human emissions. But hey – 3 years of drought – it must be caused by humans (somehow)! The funny thing is that most of California is praying for el nino – which is a natural climate event – because they usually cause more rain. Get it! California is hoping for a natural event to offset what they blame on humans. I find that ironic. Of course, the drought probably is natural in origin (and that continues to be the null hypothesis).
I think you are on to something here.
This is a classic case of the Boy who Cried Wolf.
In a few years – no one will pay any attention to this meme.
Nice article.
Thanks.
“The bottom line is all of these storms, their frequency, their severity, or any any other measure you care to name – all occurred in similar measures prior to the increase of CO2 above 280 ppm.”
This isn’t clear, and only data are going to answer that question. There are definite trends that look suspicious, such as
Historic North Atlantic Hurricane Seasons:
http://policlimate.com/tropical/north_atlantic_hurricane.png
In the May 2012 issue of Physics Today, Lubchenco and Karl write (and give graphs for each):
“The US Climate Extremes Index shows that, collectively, the area percentage of the country experiencing extreme monthly temperature, drought severity, soil water surplus, days with
and without precipitation, land-falling hurricane activity, and one-day heavy precipitation events in any given year has grown steadily over the past several decades.”
http://www.leif.org/EOS/PTO000031.pdf
and Coumou and Rahmstorf have a few relevant graphs, mostly to heat, in their 2012 Nature paper (paywalled) DOI: 10.1038/NCLIMATE1452 , especially Figure 2 on monthly heat records since 1900.
“California had two centuries of drought about 1000 years ago, well before CO2 was increased by human emissions.”
I don’t see much use in comparing modern droughts to historical droughts. Far, far fewer people and animals were depending on the water then, so weaker droughts now are going to cause many more problems than stronger droughts then.
“But hey – 3 years of drought – it must be caused by humans (somehow)!”
AGW always makes droughts worse, because higher temperatures increase evaporation rates, and the amount of water vapor air can hold is an exponential function of temperature (the Clausius-Claperyon relation).
David:
The use in comparing historical droughts to modern droughts is that the mere existence of historical droughts means that just because California is having a modern drought does not mean it is per se caused by humans or AGW.
It is possible the 3 year modern drought is natural (and several studies conclude it is natural, while one concludes it is caused by AGW).
A 200 year drought is worse than a 3 year drought – no matter the cause. And we know the historical droughts were not caused by AGW.
So it is useful to pause and reflect when many many people start to blame every modern weather event on AGW that maybe some or even all of these weather events are natural in origin.
As you say – we need more data.
It would be nice to see this data over 60 years, or even better over 120. 40 years just seems incomplete. With a 30 year peak and a 30 year trough – it really makes sense to get 60 years of data and capture one entire ocean cycle.
But I agree we need more data.
I would fully support spending budget money on deploying climate data gathering instruments worldwide and gathering the data (as many parameters as possible) forever, going forward.
In a couple hundred years, we may actually know something.
“I don’t see much use in comparing modern droughts to historical droughts.”
Really? I many others disagree, including scientists. See, for example:
http://blogs.discovermagazine.com/collideascape/2014/01/27/california-must-reckon-longer-history-drought/#.VC_fPigwL18
http://blogs.discovermagazine.com/collideascape/2012/07/26/could-we-survive-a-30-year-drought/#.VC_f2CgwL18
The bottom line: It’s actually quite important for people–especially policymakers, planners and land managers to be mindful of the paleohistory of their state/region. And comparing a historical drought to those that occurred in the not so distant past (geologically, speaking) is one way to gain that perspective.
Accumulated Cyclone Energy is a good thing to look at, because it’s comprehensive. It reflects all kinds of windstorms, including hurricanes and tornadoes. It reflects both the number and the intensity of each event. There is no evidence of a systematic increasing or decreasing trend in ACE for the years 1970-2012. See http://www.wunderground.com/hurricane/accumulated_cyclone_energy.asp?basin=io
Kudos for deflating the hyperbole. There’s also the issue of baseline, and how much info was simply not recorded until the last few decades. For example, compare 19th Century hurricane landfalls with those of the 20th Century, or consider that, until widespread Doppler Radar, tornadoes were under reported unless they hit a well populated area, or caused fatalities.
Something that doesn’t seem to get much attention is that we already know what changing temperatures can do to weather, all without computer models. The planet’s temperature has been both colder and warmer in recorded history, and analysis of fossils, including pollen, can push this back further. We know that when temperatures begin to rise at the start of the Medieval Warm Period, there was a migration of North American Indians from the Southwest, including Mexico, toward the US Midwest and East. When temperatures fell at the start of the Little Ice Age, the Mound Builder culture collapsed due to failing crops.
A droughts a drought, whether there’s a large population or not. A rise in temperature is a rise in temperature, with the same effects whether it’s from AGW or some other cause.
This looks interesting:
http://www.ncdc.noaa.gov/ibtracs/index.php
Note that, like tornadoes, there is the problem of unreported storms. Until the advent of weather satellites, If a hurricane didn’t hit land or if a ship didn’t survive, it was not recorded. Our modern definitions of Tropical Depression, Tropical Storm, and Hurricane/Typhoon didn’t exist. Attempting to reconstruct storm tracks and intensity requires going through newspapers and diaries. Note that the database above only goes to 1850, a very short baseline in terms of climate.
Why? Consider that in the late 20th Century, hurricanes approaching the East Coast tended to avoid the huge bight of the Georgia Coast. But the 19th Century was much different, with several major hurricanes making landfall in Georgia. Which is the norm? The 19th Century tracks, the 20th Century tracks, or neither? No one knows.
“The use in comparing historical droughts to modern droughts is that the mere existence of historical droughts means that just because California is having a modern drought does not mean it is per se caused by humans or AGW.”
Droughts taking place now are in a different climate system than 500 or 1000 or more years ago. So knowing what a 500-year drought is (or, rather, was), while it might be interesting, isn’t especially useful to because drought frequencies and intentsities are changing in an AGW world.
In other words, you should plan for the history of droughts, but for the future of droughts.
And because droughts now will always be worse than an “equivalent” drought earlier, because warmer temperatures increase evaporation rates. And California as a whole has warmed by 2.2 F in 120 years.
“A rise in temperature is a rise in temperature, with the same effects whether it’s from AGW or some other cause.”
Droughts occuring now and in the future are and will likely occur in a warmer climate than droughts that occurred 500 years ago. That makes them worse for the same deficit of rainfall.
And the impact of a drought certainly depends on how many people & others want to use what water there is.
This page gives data back to 1900, but it can’t be very reliable simply because there weren’t systematic measurements made all along, and especially before the satellite era.
http://acd.ucar.edu/~drews/hurricane/SeparatingTheACE.html
I’ve talked with hurricane experts who’ve told me ACE is about the worst metric out there.
One reason is that it doesn’t take storm size into account. So, for example, it drastically underrepresented Sandy. But a metric like TIKE would:
http://davidappell.blogspot.com/2013/05/a-new-hurricane-metric.html
http://davidappell.blogspot.com/2013/11/2013-atlantic-hurricane-tike-near.html
The second reason is that hurricane damages don’t vary linearly with ACE, viz. with the second power of the maximum wind. A William Nordhaus paper found damages rise with the 8th power of maximum wind speed:
http://www.nber.org/papers/w12813
“If we don’t have evidence, I don’t think we should hint darkly all the time that human influence must be to blame somehow,” Dr. Allen said.”
My reaction on the AGW conversation in a nutshell.
I think it depends on what you’re using ACE for. Your points show why ACE is a poor metric for estimating the actual damage caused by a year’s worth of windstorms. However, ACE should be a good metric for determining whether windstorm frequency and severity are changing over time.
“it can’t be very reliable simply because there weren’t systematic measurements made all along”
That’s the case for every type of data used in climate science but you don’t hesitate to trumpet the data that supports your point of view.
As always, you’re disingenuous to the point of lying.
Five hundred years ago was during the Little Ice Age, when temperatures were cooler. you need to look further back to the Medieval Warm Period, or further still to the Holocene Climate Optimum. The idea is to look at local climate during periods of similar temperature.
No argument on the impact of drought.
So, simply put, ACE is the amount of energy available to fuel storms.
Storm severity (whatever that is) also depends on the size of the storm, which ACE doesn’t include.
ACE isn’t an energy, because it’s missing the mass term (~size), and it measures individual storms, not the available energy to them.
ACE doesn’t even have units of energy.
“That’s the case for every type of data used in climate science…”
Hurricanes used to go entirely uncounted. That’s a very different situation from having older data that DOES exist but has different uncertainties.
Well it is a relief to know I can discount all prior climate data.
Since the climate of today is a whole new ballgame – I guess all that paleo data and ice core data and cave data, and the rest, can just be dumped into the trash bin of history.
I guess we should just base our plan for future droughts on the guesses of the climate scientists (who are studying the brand new climate system of today).
What a pity that every guess (I mean model) they seem to make turns out to be erroneous.
I guess in a wetter world (more water content in the atmosphere in a warmer atmosphere), we can conclude that every drought will be worse than historical droughts.
Not me. I will continue to take past performance and incorporate it into what I think will likely happen.
I personally don’t think that every drought will be worse just because we are in a warmer world.
We don’t know that.
It may turn out to be more complicated that that (as it usually does).
We will have to gather data over centuries and see if droughts are worse or better or stay the same.
IPCC Reports – The Regional Impacts of
Climate Change
8.3.9.3. Extreme Weather Events
http://www.ipcc.ch/ipccreports/sres/regional/index.php?idp=232
“…there is no clear evidence that sustained or worldwide changes in
extreme events have occurred in the past few decades.”
—————–
Meanwhile, CO2 levels have steadily increased since the 19th century, especially in the past few decades. If there is a linkage between CO2 and climate why haven’t we seen “clear evidence” in terms of severe weather?
The long term pattern of extreme events has not changed, according to the IPCC. But those extreme events that fall into the normal pattern of climate are now assumed for some reason to be due to increased CO2, as opposed to what caused them before CO2 levels rose, as if those factors suddenly disappeared?
Exactly. Without evidence you might as well blame extreme events on goblins. It’s just superstition, not science.
“Since the climate of today is a whole new ballgame – I guess all that paleo data and ice core data and cave data, and the rest, can just be dumped into the trash bin of history.”
Not dumped, but closely scrutinized. That’s what the tree-ring divergence problem is about.
“I personally don’t think that every drought will be worse just because we are in a warmer world.”
Are you saying you don’t believe Clausius-Claperyon?
I do believe Clausius-Claperyon. It is my understanding that this equation for water vapor in typical atmospheric conditions means that the water-holding capacity of the atmosphere increases by about 7% for every 1°C rise in temperature.
Therefore, a warmer atmosphere holds more water.
What that means for worldwide drought is what I don’t personally believe we have a good understanding of.
To me – an atmosphere that holds more water means more rain – and where that rain falls could impact on drought.
I simply don’t know that a warmer world means every drought will be worse (compared to historical droughts) and I don’t think anybody else does either.
“Hurricane researchers contacted by Climate Central said Haiyan is an example of the type of extreme storm that may become more frequent as the climate continues to warm.”
The “consistent with” meme. If hurricanes were to get worse, than this would be what it would look like. Propaganda pure and simple.
Question: Did Climate Central contact hurricane researchers about the current record 8+ years since the US has had a Cat3+ landfall? Did they contact researchers about the last two extremely quiet hurricane seasons in the North Atlantic? Did they contact researchers about the documented lack of an increase in hurricanes over the past 40 years satellite record and 100 year US landfall records? Did they contact researchers about the recent statements from the IPCC AR5 and SREX on the flimsy to none evidence of this link?
Thought not.
Record 8+ years of no Cat3+ US landfalls = Not interesting or natural variability.
Record 8+ years of most Cat3+ US landfalls = Direct evidence of climate linkage.
It’s called confirmation bias.
Climate science has its political marching orders. Find and report linkage even if its not there. Those who claim to find the most linkage will be rewarded appropriately. Make it so.
ACE does take “size” into account:
http://en.wikipedia.org/wiki/Accumulated_cyclone_energy
“It uses an approximation of the wind energy used by a tropical system over its lifetime and is calculated every six-hour period. The ACE of a season is the sum of the ACEs for each storm and takes into account the number, strength, and duration of all the tropical storms in the season.”
Sandy was a weak storm. Not even a hurricane at landfall. The fact that it hit at high tide and worst case trajectory combined with a woefully under-prepared infrastructure isn’t the fault of ACE.
The cost of the disaster is very dependent on location, time of strike, and infrastructure present. Climate change didn’t cause the NY/NJ area to disregard infrastructure upkeep, build in vulnerable areas, or make the landfall occur at high tide or at an unfortunate trajectory.
The size of maximum winds is rather small compared to the size of a storm.
“I don’t see much use in comparing modern droughts to historical droughts.”
Unless there was trend evident, and then you would find it the most important metric available.
If you want to go out and champion infrastructure improvement then you will get a lot more support. If you want to pretend that progressive carbon policies will change the weather for the better you will get a lot less support. Which path one chooses shows a lot about what their true agenda is.
Vote Democrat, it will improve the weather. Good luck.
Here goes Appell again with his North Atlantic warming theory. He won’t show you the global trends. He won’t show you hundred year trends on US landfalls. Even though he is perfectly aware of this information, he chooses to engage in deliberate propaganda, as this trend certainly looks “suspicious”.
What is also suspicious is that this trend ends in 2011, but that must just be another incidental oversight by Appell. Strange that.
The rules of being a proper climate warrior are to never post contradictory information even when the alternate data sets are more comprehensive and more conclusive, and when presented with such information to pretend that you never have seen it.
IPCC AR5, not worthy of quoting. SREX? Nope.
“may become more frequent”
Even though there is no evidence that it has happened in the past few decades or is happening today, “may” happen in the future is reported as the news.
US hurricane landfalls
http://2.bp.blogspot.com/-YZOMk7BDP2A/Uo-mjzfxqFI/AAAAAAAADHs/QIuiGEAZnmU/s1600/uslandfalls1900to2013.jpg
Days between Major Hurricane Landfalls
http://www.washingtonpost.com/blogs/capital-weather-gang/files/2014/05/daysbtCat3plus2014-1024×662.jpg
US Hurricane Power Dissipation Index
http://4.bp.blogspot.com/-FvKw1wXEgVw/ULT79vG3FEI/AAAAAAAACO8/BHvsWZTqZqQ/s1600/PDI.1900-2012.jpg
Global Tropical Cyclone Landfalls
http://www.atmo.arizona.edu/students/courselinks/fall12/atmo336s2/lectures/sec2/global_landfall_hurricanes_1970_2010.jpg
Cat3+ Atlantic Basin
http://appinsys.com/globalwarming/GW_PART4_CLIMATICEVENTS_files/image001.gif
Global and Northern Hemisphere ACE
http://policlimate.com/tropical/global_running_ace.png
North Atlantic ACE
http://policlimate.com/tropical/north_atlantic_ace.png
North Atlantic ACE since 1950
http://www1.ncdc.noaa.gov/pub/data/cmb/images/hurricane/2011/annual/NAT_ace_2011.png
Eastern Pacific Basin
http://www1.ncdc.noaa.gov/pub/data/cmb/images/hurricane/2013/annual/EPAC_storms_2013.png
That why they use LANDFALLS for long term trend records. These are much harder to miss. It’s a proxy for power, but likely the best one available.
There is also a possible correlation between lack of landfalls and higher accumulated energy. Hurricanes that makes landfalls dissipate very quickly, where storms without landfall are longer lived and tend to have higher total energy scores.
Best to look at all the information cumulatively.
There is not much to see in hurricane trends. Whether that changes in the future is an open question.
A snowstorm on Sept 23rd dumped 6 inches of snow and I spent an hour just clearing trees fallen or bent by the snow out of the way before I could drive home with my kids from a country holiday. Never seen snow that early before. Real fun driving with summer tyres while the bottom of the car scrapes snow.
Wishing for a warmer new normal 😉
Appell has to discount ACE (as well as count of storms) now because it doesn’t fit the narrative that your Ford is causing big scary weather.
The fact is that “extreme weather” is goofiest and most transparently misleading part of the climate campaigners’ playbook (and that’s saying something!)
Even the IPCC (the so-called “gold standard” of climate science) admits now that the extreme weather attribution claim is bunk. When the advocates can’t even go along with what they allegedly advocate on behalf of, the whole thing gets silly.
People who don’t even follow the “climate wars” get a laugh out of the Appells and McKibbens- the weather is caused by humans if its rainy or dry, hot or cold, more ice or less ice, more hurricanes or fewer hurricanes. And to top it all off, if it’s rainy or dry, why that’s exactly what they predicted!
Le’ts propose a new metric. Perhaps storms should be rated according to the amount of media coverage instead.
We already have something like that… While the US media pays attention to the recent dearth of land-falling hurricanes in the North Atlantic, the Eastern Pacific is getting hammered by many storms that include the strongest ever recorded (Haiyan, Vongfong).
Eastern Pacific Basin
http://www1.ncdc.noaa.gov/pub/data/cmb/images/hurricane/2013/annual/EPAC_storms_2013.png
The Eastern Pacific ACE was lower than normal last year and is higher than normal this year. When the global data is looked at cumulatively, the last 3 years are low years.
Some hurricane researchers believe there are higher and lower periods of activity that last for two to three decades but they do not understand the mechanisms that drive this. They think we may be entering a low period but would need more low seasons to confirm this.
Picking and choosing a specific hurricane is similar to stating a particular winter snowstorm or cold snap disproves global warming. Picking a particular hurricane season or basin is like saying a bad winter disproves global warming. I assume you disapprove of these practices.
That’s the number of storms. What about their intensity?
“So “here and now” arguments take the policy fight on global warming into the terrain favored by those who recoil at environmental regulation or profit from fossil fuels…”
Or those who rationally examine the evidence.
Of course, we ALL profit from fossil fuels. Unless you happen to live in a cave.
East Pacific ACE Index
http://www1.ncdc.noaa.gov/pub/data/cmb/images/hurricane/2009/annual/2009EastPacACE.png
ACE is a poor representative of a hurricane, since it ignores the size of the storm. This would be especially important for the recent large storms.
Feel free to convince science that the “David Appell whatever formula we can come up with that supports my AGW agenda index” or “DAWFWCCUWTSMAAI” is superior. Until then we are stuck with hurricane counts, hurricane landfalls, and ACE. All 3 of these do not support AGW linkage.
Off topic: I agree with the point you made on NRO about satellite measurements. Could not respond there because it seems your post was blocked, but disqus sent it to me by email.
Ooo, I like the new avatar! It’s quark-tastic…
I am just trying to be scientific. If you disagree, then explain how ACE can be a good indicator of hurricane intensity when it doesn’t include the size of storms.
ACE is *called* an energy, but it’s not an energy and doesn’t have units of energy.
And if you do want to use ACE, let’s note that the ACE of North Atlantic hurricanes has been increasing at 22% per decade since 1970, a number that is very statistically significant (p<0.01).
Thanks. I didn’t realize they were blocking comments there. I’m seeing that more and more frequently from the anti-AGW sites.
ACE is designed to be proportional to damage capabilities.
Wee p numbers. Never seen any cases where that was misleading. Have you?
What happens if you extend that forecast backwards as a historical hindcast?
Ever wonder if the underlying physics of the NA ACE are controlled by a linear equation?
So….you are 99% absolutely positively sure that NA ACE will be 66% greater 30 years from now? Want to put money on that forecast?
Go ahead, at p<0.01 this should be easy money for you. It is scientific. Unless of course you think this statistical parameter has little forecast skill and are possibly cherry picking your statistics here.
What is the evidence that ACE is proportional to damages (or damage potential)?
Because I was recently told it was not. And that’s backupped by this study, which found damages proprtional to the 8th power of maximum wind speed. And you would expect the size of the storm to matter for total damages, too.
“The Economics of Hurricanes in the United States,” William D. Nordhaus, NBER Working Paper No. 12813, Issued in December 2006
http://www.nber.org/papers/w12813
“So….you are 99% absolutely positively sure that NA ACE will be 66% greater 30 years from now?”
Of course not. 22%/decade is the trend of the historical data, not a prediction. Surely you know the difference.
“Wee p numbers.”
By my p number, I meantthe trend has a statistical significance of over 99% (actually it’s 99.8%, if you assume no autocorrelation). That’s the confidence level. p < 0.002 is the probability it occurred by chance.
“Unless of course you think this statistical parameter has little forecast skill and are possibly cherry picking your statistics here.”
Here are the data. Download them and do the calculation for yourself:
http://models.weatherbell.com/global_ace_monthly.dat
You wouldn’t expect the trend to extend linearly (unless you had a good hysics reason to think so), because of…climate change. Future hurricanes won’t be taking place in the same climate as the historical hurricanes did.
As if you had any idea where future hurricanes were going to take place. Any change here is based on the flimsiest of evidence.
Do you want to bet or not? Don’t pretend you aren’t trying to infer that hurricanes are going to continue this trend. I’m asking you to put your money where your mouth is.
This is just another example of a blatantly misleading presentation that you rationalize to yourself somehow, and then laughably go on to lecture others about morals and ethics. Ironic isn’t it? Must be a pretty complex morals system in your head.
So.bet.me.
Surely you do not.
Trends don’t make predictions, especially in a changing environment.
It’s clear you don’t understand what a trend is. Its shows what’s happened, not what’s going to happen. Not only is the hurricane environment changing, they are subject to natural variability like everything else. North Atlantic hurricanes are even affected by ENSOs, which aren’t predictable.
Solving the physics gives an idea what hurricanes will do (with their associated uncertainties). The linear trend suggests something is going on in the North Atlantic.
Where is your proof that hurricane damages scale with ACE?