It is an ill-posed question whether the 2003 heatwave was caused, in a simple deterministic sense, by a modification of the external influences on climate—for example, increasing concentrations of greenhouse gases in the atmosphere—because almost any such weather event might have occurred by chance in an unmodified climate. However, it is possible to estimate by how much human activities may have increased the risk of the occurrence of such a heatwave.
This is from a 2004 article in Nature about the European heatwave of 2003. The same can probably be said about the Russian heatwave of 2010. Arguing about whether this was ‘caused’ by AGW doesn’t make sense, unless you clarify carefully what you really mean.
A single weather event can not be attributed one-to-one to an external forcing of the climate. But the chance of occurrence can. Therefore it is in principle possible to say something about the relative likelihood of a certain extreme event in an unperturbed climate versus that in a human-perturbed climate. Or, to put it differently, to assign a certain portion of the blame/causality to the external forcing.
The return period for European heatwaves: Human influence has increased the chance of occurrence 9 fold. Figure from a 2008 presentation by Myles Allen (slide nr 24).
Weather is not climate. But of course they are related. In fact, climate change is a consequence of the weather changing over time. Due to changes in the planetary energy balance the chance of certain weather conditions changes. Over time this becomes apparent as a change in the mean weather: The climate has then observably changed. You cannot have climate change without changes in the weather.
Nielsen-Gammon has a good article about how to deal with these attribution issues related to single weather events. (h/t Judith Curry over at Kloor’s)
In between these two extremes, where AGW in a sense causes everything and AGW changes the probabilities but doesn’t in a sense cause anything in particular, there are, I think, two possibilities for ways in which we can assign a portion of the blame to AGW if appropriate.
The first way is to consider the direct effect of AGW on the mean state of the atmosphere, and consider that change to the mean state as AGW’s contribution to individual weather events. I’ll call this the “additive effect” approach. (…)
So, for example, temperatures in large parts of Russia are averaging 6 C or more above normal. At this point, climate change (from all anthropogenic causes), according to best estimates, has produced about 1 C of warming in the area. So it would be fair to say that man has turned what would have been a 5 C heat wave into a 6 C heat wave. Climate change has added one degree to the heat wave.
This sounds like a small impact, but it’s not appropriate to attribute 1/6 of the impacts to anthropogenic climate effects. Deaths, fires, and the like increase nonlinearly with the severity of a heat wave, so anthropogenic effects have made this heat wave lots more than 20% more severe than it would have been otherwise.
(This is meant to be an illustration, not a rigorously quantitative attribution.)
The second way is to consider the estimated effect of AGW on the probability of extreme events. I’ll call this the “probabilistic approach”. (…)
For extreme events, we want to know how often a certain threshold is crossed. (…)
So, to correctly say that an individual event was likely caused by AGW, its probability of occurrence would need to have increased, because of AGW alone, by a factor of 3 or more over pre-AGW conditions.
(bold in original; “likely” in the IPCC sense refers to 67% to 90% chance, hence the factor of 3)
Michael Tobis puts the question as follows:
“Is the average time between persistent anomalies on this scale anywhere on earth in the undisturbed holocene climate much greater than a human lifetime?” In other words, is this so weird we would NEVER expect to see it at all?
There are two approaches to answering this question. One is statistical (mathematical), and the other is integrative (based on experience and expertise rather than number-crunching).
He also summarized his position nicely in a comment at Kloor’s:
Stopping at “attribution of causality of individual events is impossible” is not strong enough for the recent astonishing situation in Asia. “We are absolutely certain this couldn’t have happened in an undisrupted atmosphere” is too strong (…)
Why claim it is so unusual? Three reasons 1) this is an uncommonly stable and long-lived pattern (those are not good) 2) this is an uncommonly intense pattern, dipping all the way to the monsoon zone and fraternizing with the monsoon, to Pakistan’s great detriment and 3) the really big events tend not be in summer and not to be centered on hot spots but on cold spots. In other words, this blocking event has features dramatically different form other ones we have seen.
From ClimateCentral:
While there’s overwhelming observational evidence showing that humans are affecting climate, this evidence comes from long-term trends, rather than individual events.
Extreme events are related to climate change, however: the odds of them happening are much greater with climate change. (…)
We can estimate probabilities, but rarely can it be asserted with 100 percent confidence that there is a causal relationship between variables.
Tom Yulsman has an interesting article based on an interview with Peter Stott. What struck me though was Steve Bloom’s comment, comparing the manner in which doctors talk about the health risks of smoking versus how climate scientists talk about the climatological risks of greenhouse gas emissions. See also this pointy comment by SecularAnimist. Doctors tend to be much more upfront about the risks than climate scientists are (see also my previous post).
Tags: 2003, 2010, climate change, extreme weather, flood, heatwave, Pakistan, Russia
My view on climate change 
August 18, 2010 at 23:03
@Bart,
You directed me to this new Blog entry. I do not endorse the comparison with disease, for the follwing simple reason:
A disease is life threatening for the patient. Cancer is synomous with death.
When the patient succumbs, the story ends.
Global temperature is not. It can kill, but it can also enhance life. The bandwith of life is astonishingly large. We have organisms that can withstand being frozen at minus 200 C, or that are thriving at 120 C at 200 atmospheres in a toxic, sulfuric acid rich environment.
And then we start paniking about a rise in CO2 content of the atmosphere of 100 ppm, possibly resulting in an artificially calculated global temperature rise of 0.8 C per century?
A fatally sick patient can not even measure this temperature increase, even using the most sophisticated devices, because his/her body shows daily fluctuations of 10 times as high.
August 19, 2010 at 00:44
” Normal core temperature at rest varies between 36.5 and 37.5 °Celsius (°C)…
During exercise, heat is produced mainly from working muscle contractions and core temperature can go above 40 °C (104 °F). ”
Daily fluctuations of 8C are not … normal.
“Global temperature is not. It can kill, but it can also enhance life. The bandwith of life is astonishingly large. We have organisms that can withstand being frozen at minus 200 C, or that are thriving at 120 C at 200 atmospheres in a toxic, sulfuric acid rich environment.”
Some of us aren’t interested in ceding the planet to rats and cockroaches. We’re concerned about the well-being of humans.
August 19, 2010 at 00:56
@Dhogaza,
Then you need to be the Master of the Universe. Flash Gordon?
The well being of humans is your wetting stone? You will have to have mastered a lot of physics and statistics. Both of which you have not, so far as I can see.
August 19, 2010 at 01:04
@Dhogaza,
But it must be physics.
August 19, 2010 at 01:10
@Dhogaza,
And yes, we have measured these differences in a cancer patient.
August 19, 2010 at 02:48
Well, and after the patient is dead, it will fluctuate according to the environment.
Sorry, I didn’t interpret “fatally ill” as being, literally, “dying”.
You’re talking about outliers compared to the normal natural variation of body temps.
Sorta like the month long outlier of heat in Russia that’s never been seen in the last 1,000 years.
Maybe Steve Bloom’s analogy isn’t so bad, after all. After all, that month long outlier is killing a lot of Russians, as does cancer.
August 19, 2010 at 08:54
Harry,
Clean up your language, please. I removed an offensive post of yours. Detailed expositions of human body temperature regulation is off topic.
August 19, 2010 at 13:19
harry’s first post does raise the winners/losers question yet again, as in measuring extra deaths from increased warmth needs to be set against deaths saved from less cold.
In the context of extreme weather, which I guess by definition is dangerous, it’s somewhat less symmetrical. The winners from 1c of global warming win very slightly. The losers from a hurricane lose heavily. BUT, the above example indicates that one way of looking at extreme weather might be that it is not necessarily more frequent, but more extreme. So the Russian heat wave would have happened, but was a bit hotter. Ditto a hurricane, would have happened, just stronger. So the extra deaths and damage are marginal to some extent?
So, if the combination of increased CO2 and warmth happened to lead to greater world food production in the next two decades, set against extreme weather being more extreme, would those deaths saved from more food offset those lost by more extreme extremes??
So how would we measure whether the human race is better or worse off.
Just musing.
August 19, 2010 at 13:23
Btw, that thought re Russian heat wave was spurred on by Putin’s comment to Schellnhuber:
‘At a conference in Moscow, Russian Prime Minister Vladimir Putin told me quite openly: We are looking forward to global warming. We won’t need to heat as much, our fleet will be able to operate in an ice-free sea, and we’ll have more fertile land to farm.’
So, in a purely Russian context, do they win or lose?
August 19, 2010 at 17:41
Roddy, if you’ve been following the news you would know that they lost big time. Around 7,000 excess deaths in the Moscow area, failure of this year’s wheat crop to such an extent that they have gone from exporting to importing wheat, etc, etc. Big lose.
August 19, 2010 at 18:15
Ratty, I was looking across a decade or two for cost-benefit. I would expect a hurricane to be accompanied, say, by flooding, and the Russian heatwave by drought. Extreme weather is likely to catch agriculture unprepared.
The 7,000 excess deaths – do we know how many of those 7,000 would have survived 1c lower, as per the example in the post? If very few, then …
August 19, 2010 at 19:02
I don’t think you have enough data points to even consider whether recent weather is a result of or heavily affected by the 0.8C warming of the past century.
There are many summers in our recent past with extreme weather events. In 1887, flooding along the Yellow River killed 2 million people. The Dustbowl era in the 1930s is famous. Anyone with an Almanac could increase the list ad infinitum. Many of these weather events were closely connected geographically, decades before anyone thought up the term ‘teleconnection.’
I understand when I see hysteria from Tobis and Rabett–that’s their schtick, it’s what they do, it’s what they bring to the table.
But Bart? At the very least, instead of asking the question, you should say here are the components of a successful answer.
August 19, 2010 at 22:03
Tom,
Asking good questions is an art. In this post I was musing over how to frame a useful question, and how one could go about answering it. I don’t have any answers myself though.
How is that hysterial?
August 19, 2010 at 22:08
It is common sense and basic physics that a warming planet will experience greater heat waves, more drought in some locations, greater flooding events, stronger storms of all kinds, etc. Energy drives the weather and there is more energy available.
People need to remember that society has settled in to a particular climate and that climate is now behind us and getting further behind every decade. To think that society will not be very strongly impacted by a “new climate” is nonsensical.
None of these extreme events is a surprise because models predict these weather events will occur with greater frequency and stronger intensity. We see the hammer dropping so why do we have to wait for the pain to say “ouch”?
“What’s the use of having developed a science well enough to make predictions if, in the end, all we’re willing to do is stand around and wait for them to come true?”
— Nobel Laureate Sherwood Rowland (referring then to ozone depletion)
My blog if interested.
August 19, 2010 at 22:15
@Bart,
OK, you are the boss. But I still find the use of the patient metaphor inappropriate. The patient will die, this planet not by 0.8 C per century global average temperature increase. And any niche that fails will be inhabited by opportunist species in the blink of an eye.
August 19, 2010 at 22:25
@Scott Mandia,
As a professor of physics you ought to know the rules for energy. If we have 1% more solar energy absorbed by increasing CO2 from 380 to 760, I think you can calculate its effects in the sense of weather and storms using the models you cite? What can we do? Stop emitting CO2? It will not have any effect until after 50 years, according to the models. What could be done, with very fast effects on climate and human health is supplying electrical energy from coal fired plants to cook for the areas of this planet that still fire stoves to cook with animal dung, eliminating black soot.
August 20, 2010 at 00:05
Bart, I don’t think you’re hysterical at all. I think MT and Eli Rabett can often be.
I confess that I still do not see any sign that the weather we have experienced recently is in any way categorically different from weather extremes we have seen in the past.
Again, I want to introduce a concept that people have a tendency to resolutely ignore–that much of what concerns us is in fact a series of artefacts introduced by improved measuring techniques. What would we really be saying about Arctic ice if we didn’t now have satellite measurements? What would we be saying about ocean temperatures without Argos?
For that matter, what would we be saying about paleoclimatic temperature reconstructions without statistical software packages?
August 20, 2010 at 02:52
“Anyone with an Almanac could increase the list ad infinitum.”
Sounds like something for you to contribute, Tom. It would certainly be a good balance if you can show from the historical records that this “1000 year event” was just another one of many equivalent events over the last hundred years.
Or not.
August 20, 2010 at 04:35
Well, this is U.S. only, but here you go…
HURRICANE CAMILLE OF 1969
This hurricane made landfall on the Mississippi coast on August 17th, and was later declared, “the severest storm . . . the most concentrated destructive power. . . of any hurricane ever to make a landfall on a built-up portion of the United States mainland.”
THE GREAT GALVESTON HURRICANE OF 1900
This hurricane is on the weather record books as the most lethal American hurricane. In the years before this storm’s arrival on the Texas Gulf Coast, the residents of Galveston, had, for “aesthetic” purposes, gradually removed a 16-foot-high sand dune that might have protected them from what followed. When the hurricane arrived on the fateful day of September 8th, its floodwater was able to rush unimpeded into the city. A severe hurricane tide inundated this island city with up to 15 feet of water; over 6,000 people lost their lives
THE BLIZZARDS OF 1888
There were actually two severe snow and windstorms that occurred during the winter of 1888. The first occurred from January 12th through the 14th, and was caused by a sharp cold front (a “blue norther”) that dropped rapidly south through the Dakotas to Wisconsin before finally sweeping across Texas, all within less than 36 hours. Temperatures dropped to -52°F.
THE GREAT TRl-STATE TORNADO OF 1925
This intense tornado adversely affected Missouri, Illinois, and Indiana on March 18th, creating what still remains today as the worst U.S. tornado disaster. It traveled along a path nearly 220 miles in length; one of the longest known paths for any tornado. It carved a path of total destruction that was almost a mile wide in some places. This one twister passed directly through nine towns, and killed 695 people, including 234 at Murphysboro, Illinois, and 126 at West Frankfort, Illinois
1816: THE YEAR WITHOUT A SUMMER
1816 has gone down in Almanac fame as the “poverty year,” and “eighteen hundred and froze-to-death.” It was comprised of a backward spring with record late snows (heavy snows fell in New England between June 6th and 11th), and an exceptionally cold summer featuring frosts in July and August. On July 4th, the high temperature at Savannah, Georgia, was only 46°F.
THE SAXBY GALE OF 1869
A powerful, tropical hurricane, moving northwest over the western Atlantic waters became a deep extra tropical depression–a sort of winter-type gale–as it passed over the colder waters of the North Atlantic. The eye of the storm made landfall on October 4th and 5th, in the area of the Maine and New Brunswick, Canada, border. The combination of this storm’s strong winds and excessive rainfall created one of the worst natural disasters for this part of the world. It was responsible for the death of as many as 100 people in New Brunswick and the surrounding areas. Rainfall records were set for much of New England, records that still stand today.
THE GREAT SNOW OF 1717
Four successive snowstorms-two of them minor, two of them of major proportions-fell within a ten-day interval (February 27th through March 7th), and left a snowfall estimated to be somewhere between three and four feet across much of New England.
The Dust Bowl Drought
The Dust Bowl drought was a natural disaster that severely affected much of the United States during the 1930s. The drought came in three waves, 1934, 1936, and 1939-40, but some regions of the High Plains experienced drought conditions for as many as eight years.
August 20, 2010 at 14:05
A list of events like this (Tom Fuller 04:35) tells us nothing without context. I haven’t looked into any of the others but 1816 at least is a well known date , “The Year Without a Summer”, following the eruption of Tambora.
Given that almost everyone expressing the view that the recent extreme events might be connected to global warming are being relentlessly careful in their phrasing it would be good to see this being reciprocated.
Personally I feel that the emphasis should be on those doubting there is any validity in the attribution to show that these events are not statistically unusual.
August 20, 2010 at 14:12
When combined with rising sea levels, storm surge inundation (which causes more than 90% of the casualties in hurricanes, typhoons, and cyclones) will be more common and more extensive. As the population grows and building accelerates near coastal locations, the economic damage from storms will increase. Hurricane Katrina, which struck the Gulf Coast on August 29, 2005, was the single largest natural disaster loss in the history of the U.S. insurance industry. Insurance companies paid $41 billion arising from 1.7 million claims for damage to homes, businesses and vehicles to policyholders in six states. “While 2005 was by far the worst year ever for insured catastrophe losses in the U.S., future storms could prove even costlier, reaching upwards of $100 billion,” said Dr. Robert Hartwig, an economist and president of the Insurance Information Institute. In the United States alone, the value of coastal property exposed to hurricanes increased by 24 percent, or $1.7 trillion, from $7.2 trillion in 2004 to $8.9 trillion by year-end 2007, according to AIR Worldwide (Insurance Information Institute, 2008).
Rising sea levels will flood the word’s largest ports. According to The Tipping Points Report (2009) commissioned jointly by Allianz, a leading global financial service provider, and WWF, a leading global environmental NGO, a rise in sea level by 0.5 meters by 2050 could put at risk more than $28 trillion worth of assets in the world’s largest coastal cities. The value of infrastructure exposed in port mega-cities, is just $3 trillion at present. A hurricane in New York, which could cost $1 trillion now, would mean a $5 trillion insurance bill by the middle of the century. Insurance rates will rise and taxes will increase to pay for the recovery and to move ports inland.
August 20, 2010 at 14:15
On the question of the Cancer analogy some seem to be misunderstanding the concept of an analogy, which, almost by definition, can never be perfect.
No, climate disruption will not lead to the end of all life, runaway-Venus-scenarios aside, and is very unlikely to lead to the end of human life, certainly without additional help from us humans, but it is likely to lead to a ‘bad’ outcome.
August 20, 2010 at 14:24
Having just started reading the next post down and the first few comments on it I withdraw my previous comment to avoid endless circularity.
August 20, 2010 at 14:50
I think the problem with Tom Fuller’s list is that none of those can necessarily be classified as 1 in a 1000 events. Take hurricane Camille: its only apparent uniqueness is that it is the only recorded hurricane that was still at category 5 upon landfall. But in all other (weather-relevant) aspects, Katrina was bigger: lower pressure, larger radius of maximum wind, larger area of hurricane-force wind. In fact, we can point to several others that beat Camille.
Then there’s the dust bowl drought: paleoclimatology has shown there have been worse droughts in the last 500 years than that of the 1930s. The dust bowl is remembered because so many confounding factors played a role.
And as Heraclitus already noted, the 1816 “year without a summer” has a well known attribution…
August 20, 2010 at 15:14
Marco,
There have been three Category 5 landfalling hurricanes in the US that we know of:
1935 Labor Day (Florida Keys)
1969 Camille (Mississippi)
1992 Andrew (Florida)
August 20, 2010 at 15:18
By 2100, the climate is expected to warm 4 oC to 6 oC or more above pre-IR values. During the Pliocene, about 2.5 to 5 million years ago, CO2 levels were comparable to today’s levels (near 400 ppm) and the climate was about 3 oC to 5 oC warmer than pre-IR. Geographically, the Earth was also very similar to today so the Pliocene offers a glimpse of what the world may look like by the year 2100. Federov, Brierley, & Emanuel (2010) modeled the expected TC activity in the early Pliocene world. Fig. 7.21c (linked below) is a comparison of modern TC activity (a) and that of the Pliocene (b). This image is a sobering look at what may lie ahead in our world by 2100.
http://bit.ly/cLFl7y
August 20, 2010 at 16:03
Tom Fuller:
I just want to clarify something about your Dust Bowl citation. You refer to it as a natural disaster, when in fact, it’s the kind of naturally occurring drought to a region that was made into a social/economic disaster by bad agricultural practices in decades leading up to that particular drought.
Additionally, for those interested in droughts that hit North American over the past 1,000 years, this is one of the definitive papers:
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V62-4MR86MY-1&_user=10&_coverDate=03%2F31%2F2007&_rdoc=3&_fmt=high&_orig=browse&_srch=doc-info(%23toc%235802%232007%23999189998%23645152%23FLA%23display%23Volume)&_cdi=5802&_sort=d&_docanchor=&view=c&_ct=3&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=3935c043b58fd19c3f1edc44c9617cdf
August 20, 2010 at 17:21
Keith, NOAA has a site that discusses historical perspectives (no need for paying):
http://www.ncdc.noaa.gov/paleo/drought/drght_home.html
Scott: noted.
August 20, 2010 at 18:06
Hi all,
First, my list was just pasted from an online almanac at the request of the previous commenter–I didn’t analyze the events nor do I suggest that they are ‘one in a thousand’ events.
However, nor do I think the flood in Pakistan/China or the heatwave in Moscow are ‘one in a thousand events.’ I think they have been happening for a thousand years with regularity in different parts of the globe. Now we can monitor and measure them more effectively, so they look both new and unusual.
I do not accept Mr. Mandia’s categorical statement about the temperatures in 2100, and think that he does us all a disservice by presenting them as fact.
His description of Katrina is not relevant to this conversation, as it was not an unusual weather event. The consequences would have been much lighter had we adopted the adaptation strategies I favor–they would serve as a prime example to me of where the possibilities for constructive work lie.
We have new ways of measuring things. We have millions more people reporting these things. Everybody with a mobile phone is happy to snap a picture of a small tornado and send it to the Weather Channel.
The population of Pakistan was 33 million in 1950. It is 173 million today. Most of the ‘new’ population settled in river valleys. The effects of flooding are more drastic–and tragic–than similar events 100 years ago.
Flooding on the Yellow River killed 2 million people in 1887.
The heatwave in Moscow was 1.4 C over the July median.
Recent weather events may well serve as a ‘preview of coming attractions’ and point us to areas where we can shore up infrastructure. But that’s about all.
To claim they are caused by global warming is disingenuous at best. To hint that they may be partially influenced by the temperature rise we have experienced to date is an interesting question, and one to explore.
But a realistic look at these events would push us more towards greater efforts in adaptation, not mitigation, and I doubt if that’s what the bulk of commenters here really want. So I would suggest they examine their premises and records of weather events more carefully.
August 20, 2010 at 19:10
Tom,
You were challenged as follows:
“Sounds like something for you to contribute, Tom. It would certainly be a good balance if you can show from the historical records that this “1000 year event” was just another one of many equivalent events over the last hundred years.”
You respond by something that you now admit “I didn’t analyze the events nor do I suggest that they are ‘one in a thousand’ events”. In short, you did not respond to the challenge.
Regarding the heatwave in Moscow: care to provide a source?
Weather Underground puts your suggestion to shame:
http://voices.washingtonpost.com/capitalweathergang/2010/08/relentless_heat_wave_roasts_ru.html
7.8 degrees above the mean, Tom. A factor 5+ higher than you suggested, and 2.5 degrees higher than the previous record.
Regarding your final statement: I don’t think anyone here so desperately wants mitigation more than adaptation. Like Michael Tobis, many of us realise you cannot adapt to what you don’t know will come. Should Moscow adapt to permanently higher than normal temperatures? Or is this a one-off event, and should another region of Russia adapt to much higher temperatures? And what about rainfall? So many unknowns. To know what we’d had to adapt to, we would have to wait until we can ascertain that a new pattern has emerged, and hope it doesn’t change again as we continue throwing more CO2e in the air, and thus can expect more climate change.
August 20, 2010 at 19:20
Marco, as I may have mentioned before, I don’t have any desire to engage with you, given what you have written about me before. Feel free to go all crazy over me or whatever I’ve written, but don’t expect me to answer any of your trash talk.
August 20, 2010 at 21:28
@All,
Back to topic, guys. Are the most recent events weather or climate? As Dhogaza suggested, only record-breaking events qualify for climate, the rest is weather. As Marco noted, the succession in a row of record breaking events makes it climate, not weather.
I think it was Zorita who has been playing with this type of reasoning to prove the absence or presence of AGW. (Correct me if I am wrong). It was as far as I know on this blog.
August 20, 2010 at 22:12
Michael Tobis cross posted a chart Patrick Michaels put up from 1936 that show a very similar global anomaly range to what we are seeing now. Does that answer your question, Harry? No, nor mine. I do not think your question can be answered at the present moment. It’s either unusual weather or a harbinger of the future. Stay tuned…
August 20, 2010 at 23:40
Tom
Regarding the heatwave in Moscow: care to provide a source?
Should Moscow adapt to permanently higher than normal temperatures? Or is this a one-off event, and should another region of Russia adapt to much higher temperatures?
(I don’t believe I have written anything about you before.)
August 20, 2010 at 23:47
@Heraclitus,
I would advise the Russians to store sufficient amounts of Wodka. Both for heath or cold.
August 21, 2010 at 00:14
Harry, I think vodka is actually at least as big of a problem as the heat, as many Muscovites took a bottle with them into the river to cool down for an extended period and drowned.
Heraclitus, in all honesty, it’s something I read on a blog… not the most robust of sources and I’ve seen other, higher figures since. I think the article by Pat Michaels that Tobis sites has the best information and background I’ve seen so far.
August 21, 2010 at 00:35
Just an idea FWIW. What kicked off the weird weather this year was El Nino. With the increase in temp differences the amplitude of the longwaves increase. Gw looks like it enhances the amplitude also. With the height of the ridge enhanced this opens the door for the heat to move north and cause the heatwave. This is also the time we should be seeing cold records being set for areas in the longwave trofs. With the enhanced waves, the amount caused by GW, more subtropic and tropic air is driven north. This is why the records for high temps are being smashed and not just 1 deg higher. If it were not for GW outbreaks would not last as long and record lows would be more in line with with record highs. This is a bad year and not every year will be bad. But exteme events will continue to be worse than without GW.
August 21, 2010 at 01:01
Tom: Marco’s post seemed reasonable enough to me. Tossing around statistics like “The heatwave in Moscow was 1.4 C over the July median” without attribution is dangerous, as you have been shown.
The claim isn’t that recent weather events were caused by global warming but, as I see it, that recent weather events have exceeded the realm of natural variability. The first figure given by Bart demonstrates this – heatwaves that previously had a 1:10000 chance of occurring will have a 1:10 chance of occurring. This is a colossal shift.
Like it or not, these probability of occurrence statistics are actually pretty reliable. Its how engineers design bridges, roads, dams, etc., and you don’t need to sample the past 1000 years of data to come up with the magnitude of a 1000 year event. Thats the beauty of statistics.
August 21, 2010 at 02:13
Hi Joe,
Well, one of the things that concerns me is that we have these 1000 year stress scenarios and now we’re talking about changing them based on a summer’s worth of bad weather. I’m not sure yet that that’s wise. Obviously if it happens every year for 10 years, I’ll change my mind.
My comment to Marco is based on prior history, not his comment of today. Sorry for letting personal stuff intrude on the topic.
August 21, 2010 at 07:27
Joe, let me add a bit more background, don’t want Tom to have the sole narrative here:
I’ve corrected many supposed ‘facts’ of Tom Fuller in the past, and as a result have not been very positive about his abilities on various blogs. Call it human nature: if someone is caught in talking out of his behind, he gets spoken of in less than positive terms.
Of course, the person caught in making stuff up/not knowing his facts won’t be too happy about being caught…
August 21, 2010 at 08:16
Fuller: “Michael Tobis cross posted a chart Patrick Michaels put up from 1936 that show a very similar global anomaly range to what we are seeing now.”
The most casual examination of Knappenberger’s (not Michaels’, it turns out) post would note that one of those anomaly graphs didn’t indicate a base period. I checked, and indeed it was a standard WCR trick. Holding the baselines equal shows a pretty radical difference in appearance between the anomalies (although there is a blocking pattern present over Russia in both). July 1936 Russian temps weren’t all that exceptional.
As you say, Marco.
August 22, 2010 at 01:02
As I wrote: By 2100, the climate is expected to warm 4 oC to 6 oC or more above pre-IR values. Personally, I view this as conservative but it is the scientific consensus. Have you seen the Climate Scoreboard which shows just under 3.8C IF countries actually adopt their carbon reduction proposals?
Mitigation is the priority, adaptation is a distant second.
Analogy: Scientists tell us that they are measuring increasing levels of poison in our water supply, it will get much worse in the deacdes ahead and it is primarily coming from industry. We can choose to mitigate the poison or as one person here has suggested, we can just learn to adapt.
D-K is alive and well.
August 22, 2010 at 02:57
Mr. Mandia, it may be expected by you, but the IPCC does not agree:
“For the next two decades, a warming of about 0.2°C per decade is projected for a range of SRES emission scenarios. Even if the concentrations ofall greenhouse gases and aerosols had been kept constant at year 2000 levels, a further warming of about 0.1°C per decade would be expected.”
“Best estimates and likely ranges for global average surface air warming for six SRES emissions marker scenarios are given in this assessment and are shown in Table SPM.3. For example, the best estimate for the low scenario (B1) is 1.8°C (likely range is 1.1°Cto 2.9°C) A1FI is 4.0°C (likely range is 2.4°C to 6.4°C).Although these projections are broadly consistent with the span quoted in the TAR (1.4°C to 5.8°C), they are not directly comparable.”
August 22, 2010 at 04:41
And we are tracking very closely to A1F1 with the very conservative IPCC projections.
August 22, 2010 at 05:04
I’m not sure how you can say that with trends below 0.2C / decade since 1980. Concentrations are indeed up, but temperatures are not responding in lockstep.
Kind of the point of the whole argument, isn’t it…
August 22, 2010 at 13:20
The rate of warming since the 1970s has been .15C – .20C per decade. The IPCC projects 0.2 per decade for 2010-2030 and 2010 is already blowing away most years before so I am unsure what your point is. (This, despite the insistence of the naysayers who keep harping about “cooling will begin soon”.)
4C is a society-buster so that fact that it is the likely value it is deeply unethical for world governments not to immediately take action.
August 22, 2010 at 18:54
And your endless repetition of 4C does not make it any more likely. And you must explain to me why developing countries with starving populations should act to mitigate Western profligacy at the expense of their people.
That isn’t ethics.
August 22, 2010 at 23:32
Tom,
You have a bad habit of putting words into people’s mouths. Read what I actually write.
September 21, 2010 at 16:56
Tom Fuller, you left out a very important extreme event:
Chicago “Black Sox Scandal” of 1919
From Wikipedia:
The Black Sox Scandal refers to an incident that took place around and during the play of the 1919 World Series. The name “Black Sox” also refers to the Chicago White Sox team from that era. Eight members of the major league franchise were banned for life from baseball for throwing (i.e., intentionally losing) games, and essentially giving the series to the Cincinnati Reds. The conspiracy was the brainchild of White Sox first baseman Arnold “Chick” Gandil, who had longstanding ties to petty underworld figures. He persuaded Joseph “Sport” Sullivan, a friend and professional gambler, that the fix could be pulled off. New York gangster Arnold Rothstein supplied the money through his lieutenant Abe Attell, a former featherweight boxing champion.
John L. McCormick