Yes, global warming can boost the most severe tornados
I am not saying the “unusually ferocious winter tornado system” that hit five southern states yesterday was caused by global warming. I am saying — or rather NASA is saying — we’re probably going to have to get used to it:
So did John Kerry go too far on MSNBC when he said:
That sounds about right to me, though it wasn’t the “weather service” really, it was NASA. The conservative Business & Media Institute said Kerry was using the tragedy, which killed over 50 people, “to advance global warming alarmism.” But BMI embarrasingly undercuts its credibility by quoting one meteorologist from last year who obviously isn’t very good at forecasting:
Kerry’s assertion tornado activity is related to any type of climate change is questionable based on the writings of at least one meteorologist. Roger Edwards, a meteorologist at the Storm Prediction Center of the National Weather Center in Norman, Okla., has doubts about any global warming and tornado relationship.
“As of this writing, no scientific studies solidly relate climatic global temperature trends to tornadoes,” Edwards wrote on the Earth & Sky Web site in April 2007. “I don’t expect any such results in the near future either, because tornadoes are too small, short–lived, hard to measure and count, and too dependent on day to day, even minute to minute weather conditions.”
Doh! NASA’s paper, “Will moist convection be stronger in a warmer climate?” was actually submitted to Geophysical Research Letters in April 2007, and published in August!
Significantly, yesterday the country saw an unusually powerful tornado system:
Tennessee Gov. Phil Bredesen, who flew over the disaster area Wednesday, said he was stunned by the storm’s power. Watch Bredesen describe a ‘nightmare’ [you’ll have to watch a commercial first]:
“I don’t think that I have seen, since I’ve been governor, a tornado where the combination of the intensity of it and the length of the track was as large as this one,” Bredesen said.
We have known for a while that global warming is making our weather more extreme, especially extreme heat, drought, heavy rainfall, and flooding. Now NASA says the “most violent severe storms and tornadoes,” should be added to the list. Perhaps that is why we have been setting records for tornados lately. This is especially bad news for this country because, as the study notes: “The central/east U.S. experiences the most severe thunderstorms and tornadoes on Earth.”
So, again, I wouldn’t say any specific tornado was caused by global warming, but we have been warned that we should expect to see more severe tornado systems on our current path of uncontrolled greenhouse gas emissions.
February 7th, 2008 at 12:32 pm
I never really understood what the BMI and other skeptics believe is the motivation behind “global warming alarmism”? Is it more access to funding for research?
Is it the same rationale behind the motivations of the military industrial complex (except, that one actually exists and has a much greater budget than anything dealing with climate change)- i.e. more money?
February 7th, 2008 at 12:38 pm
Yes, greedy scientists! I’ll blog on this soon.
February 7th, 2008 at 1:21 pm
I look forward to your blogging on the greedy scientist meme, Joe. And thanks, Nick, for making that comparison with the defense budget, which gobbles up such a huge chunk of the national budget, is largely wasted, and is justified by questionable fear mongering.
February 7th, 2008 at 2:18 pm
Of course John, jump on that “Global Warming” bandwagon. Didn’t get the “Climate Change” memo is see.
By the way, what “Climate Change” was responsible for this little out break in 1884? What was going on back then?
“February 19, 1884: The Great Southern Tornado Outbreak
Over 60 tornadoes swept the entire Southeast. At least 170 were killed, possibly more. Considered the largest outbreak until the Super Outbreak of April 3-4, 1974. ”
http://www.ezl.com/~fireball/Disaster15.htm
February 7th, 2008 at 4:13 pm
Beefy,
1) Little science behind tornadoes- they are natural, much like Hurricanes, etc. What this post is saying is that we should witness more intense tornadoes due to increase moisture and heat convection. While frequency may not increase, larger storms will. It’s quite unfair and unscientific to say that just because a tornado occurred in the past, that it negates the role of climate change in tornado creation today. It’s the same argument that people use to compare the amount of anthropogenic greenhouse gas emissions today with what the Earth naturally emits. You can’t compare one event to the baseline.
2) What we don’t know behind the 1884 Tornado is how strong it was, as we did not have a categorization system back then. So… having 170 people killed doesn’t say how intense the storm is.
February 7th, 2008 at 4:17 pm
One more thing:
What kind of source is Joe’s Fireball Express page???? Seriously, need something more credible than http://www.ezl.com/~fireball/
Or at least, less animated .gifs
February 7th, 2008 at 4:57 pm
Okay, how about this, I just went with one of them.
http://www.weather.com/ encyclopedia/ tornado/ 1800.html
And I know that tornadoes and other forms of weather “extremes” are natural and even normal, always have been and always will be.
My original response was to that noted climate expert Kerry jumping on the bandwagon.
February 7th, 2008 at 5:01 pm
Which still leaves the question unanswered, what was going on in the 1800 to cause these massive storms?
February 7th, 2008 at 5:15 pm
Interesting, if largely irrelevant question. Lots of things can, temporarily, boost extreme weather (like a big El Nino). Global warming, however, has begun to dwarf them all, now.
February 7th, 2008 at 5:24 pm
“Global warming, however, has begun to dwarf them all, now.”
According to what animated.gifs free website? One without an agenda would be nice. Or is this based on noted non-scientists Gore and Kerry’s opinions?
February 7th, 2008 at 6:48 pm
Beefeater — At the beginning of the Holcene, the atmospheric carbon dioxide concentration was 260 ppm. By about 1880, it had risen to 280 ppm, almost as high as during the peak of the Eemian interglacial, when temperatues and sea stands were higher than even today’s. Suggest anything to you?
February 7th, 2008 at 7:11 pm
Try this one:
http://www.giss.nasa.gov/ meetings/ pollution2002/ background.html
“It is clear that human-made forcings have begun to exceed the magnitude of natural climate forcing agents during the past few decades.”
This is 6 years old of course. He quantifies this in many of his recent papers, most of which I have linked to on this site.
Now Hansen does have an agenda, though, as I do. He is desperately trying to stop humanity from destroying the climate and hence the livability of the planet for centuries if not millennia….
February 7th, 2008 at 7:38 pm
The cited Geophysical Research Letters paper does not come to the conclusions suggested here.
February 7th, 2008 at 9:29 pm
The cited Geophysical Research Letters paper does not come to the conclusions suggested here.
I no longer have a sub so I can only read the abstract, but I think it does. Certainly I have had issues in the past with Joe’s interpretations, but not this time. Essentially, the paper claims frequency of storms may decrease, but the frequency of the most intense will increase.
Best,
D
February 7th, 2008 at 9:42 pm
“David B. Benson Says:
February 7th, 2008 at 6:48 pm
Suggest anything to you?”
Sure does. It suggests that “climate change” is the norm. Always happened, always will.
Unless you are referring to the completion of the Transcontinental Railroad in 1869 as a cause of extreme weather.
February 8th, 2008 at 1:26 am
The death numbers were greater in the 1800s (despite lower pop. density) for several reasons:
1) little advanced warning and no forecasts for severe storms
2) lack of knowledge to predict possible tornado activity.
3) no civil defense to warn neighbors after funnels were spotted.
4) no education on best way to survive storm
5) no way to warn neighboring communities after tornados touched down.
Dano - the GRL submission is linked above.
Joe’s summary is a good one and in no way overreachs the paper’s conclusions.
February 8th, 2008 at 9:20 am
Got it. Thank you Jay.
The denialist in this thread is using the long-ago refuted argument that has passed beyond tedium into a condition where it doesn’t even register any more - kinda like pictures on a wall in the hallway: yes you see them, but they barely register in the consciousness. “There’s a picture of your mother, honey, in the hall?!? Um…oh, yeah, yeah - in that nice dress, right?”
Here’s a highly recommended Oreskes talk that should be viewed and passed around. Good enough that you can walk around with the sound on and not miss anything, as she’s not a Tuftean.
Best,
D
February 8th, 2008 at 12:13 pm
I no longer have a sub so I can only read the abstract, but I think it does. Certainly I have had issues in the past with Joe’s interpretations, but not this time. Essentially, the paper claims frequency of storms may decrease, but the frequency of the most intense will increase.
But tornadic storms are not necessarily more intense than non-tornadic storms. The measure of intensity they use in the paper is parameterized updraft strength and updraft strength is tied much more closely to hail than to tornadoes. The decrease in environmental wind shear the paper reports is detrimental for tornadoes.
The press release and the paper seem somewhat disconnected. The only mention of tornadoes in the text is in a background sentence, “The central/east U.S. experiences the most severe thunderstorms and tornadoes on Earth.” The paper makes no attempt to link changes in tornado frequency and intensity to the modelled environmental changes. When I read it, without seeing the press release, I assumed the results applied to the hail problem, mostly, and that the results were consistent with a couple of other papers that were published last year.
There’s also some in-press historical work on hail and environmental changes in the last quarter of the 20th century that suggests a relationship between US mean temperatures and large hail occurrence, but the record isn’t long enough to reach statistical significance, given the problems in the reporting database.
February 8th, 2008 at 2:36 pm
I agree Harold, and it is a rather confusing paper, but they are saying that increased updraft speed increases shear [15] due to the increased generation of potential energy.
This is perhaps made more confusing than it should be because they don’t like CAPE (maybe they had a word limit or suggestion to take it out). Wrt your intensity statement, if I think of PE of the storms rather than whether simply hail or tornadic activity occurs as a result, it becomes clearer for me to understand what they are trying to say.
I’d also like to see a bit more work on convective activity wrt more intense precip episodes, as this has a lot of effect on soil moisture flux & crop health and also lessened evapotranspiration, which is less moisture for cloud formation overall.
Best,
D
February 8th, 2008 at 3:22 pm
Harold Brooks,
Thanks for explaining the contents of the GRL paper much better than I could have. Joe cited the paper to mockingly refute Roger Edwards’ statement that “no scientific studies solidly relate climatic global temperature trends to tornadoes.” Clearly, it does not.
February 8th, 2008 at 3:25 pm
I think the aversion to CAPE has to do with the parameterization of convection in the model. Depending on the scheme, CAPE may be difficult to interpret as a proxy for convection. I agree that the paper is looking at an increase in PE (although I’m not sure I buy the increased generation of PE by the convection-it could be a synoptic association of regions of PE with high shear), but one of the critical points is that stronger storms, as defined by any direct or proxy estimate of updraft, don’t necessarily mean more or stronger tornadoes. Energetically, tornadoes aren’t very important in the context of the overall storm.
As far as precip is concerned, that’s a nasty problem on the scales of the models. The work on thunderstorms essentially is looking at relatively large scale environmental conditions, in a manner akin to a forecaster looking for the large area of potential threat for storms, not as a forecaster warning on a particular storm. Converting those large-scale conditions to precip is really challenging.
February 8th, 2008 at 6:02 pm
I think one of the common chances for severe tornadic activity anyway, Harold, is out of MCCs with favorable jet positions (or frontal), so I agree that having shear at the scale described in the paper may be a bit much wrt tornadoes (altho hail is another story, back to your point, I’m close to being convinced).
I think you can get at the precip bit with PDI and many of the ag networks with pan evaporation that are out there now. I can’t go out and Google the papers right now, but IIRC there are a couple papers out there attempting to look at soil moisture and rainfall records to gauge the effects of what appears to be more episodic precip, esp in upper midwest (totals about the same, but more episodic hence more drought stress). I come at this from the plant side now, but I was a weatherman in the service ~25 years ago…long enuf to be dangerous, surely.
Best,
D
February 8th, 2008 at 6:53 pm
Beefeater — A trite and meaningless reply. How about thinking it through?
The industrial revolution began in, say, 1750. By 1880 already humans had burned enough fossil carbon to raise the concentration of carbon dioxide in the atmosphere by 20 ppm or so. This during an extended period when the natural forcings should lead to slightly less carbon dioxide in the atmosphere.
Now that I have spelled it out for you, does this suggest anything regarding your question?
February 9th, 2008 at 12:29 am
It’ the same old question. How many meteorological events does it take to screw up a climate? There was an Australian drought study last year that found different precipitation patterns on either side of the rabbit fence dividing cultivated and uncultivated land. This was possibly due, it was thought, to differences in reflective properties. The IPCC report cites land use and CO2 as the two causes of AGW. For some reason land use hasn’t gotten much attention in the discussion.
February 9th, 2008 at 11:30 pm
Sorry, Dano, I thought you were referring to model work on the precip problem. I can’t recall the exact references off the top of my head, but there are several papers talking about the observed changes in precip distributions.
February 11th, 2008 at 12:02 am
Yet again the actual data doesn’t support the articles statement: If AGW is true, the atmosphere warms because of increased ‘green house’ warming there will be of course less delta T due to the lowered effects of solar radiation acting through the ‘blanket’. As one piles more blankets on the bed the the standard deviations of the interior (sheets) temps will decrease.(check out Mars and Venus for test cases) Tornadoes are the product of shears between masses of air. Deaths from Tornadoes don’t correlate to the alleged AGW. Higher numbers of REPORTED tornadoes are an artifact of radar and improved communications.
It appear Senator Kerry wishes to emulate the father of the Internet, Mr. Gore with unfounded assertations.
As one records a natural phenomenon more and more extremes will be recorded as time increses. In other words, DUH!
Question for the group: What have average wind speeds done during the alleged AGW period?
The final paragraph equals any phrase a gypsy fortune would utter to a junior high girl,” I see a tall dark handsome young man in your future…..”
February 15th, 2008 at 2:49 pm
I think that global warming is connected to the nastier tornadoes and other weather issues.