EXTREME WEATHER: Greenhouse gas emissions from human activity may be predisposing the climate to produce more extreme weather events, such as Hurricane Katrina.
Image: Jeff Schmaltz, MODIS Rapid Response Team, NASA/GSFC
In the United States, 2011 was a year when weather seemed to ping-pong between extremes.
A historic drought struck Texas while floods devastated communities along the Missouri and Mississippi rivers and Hurricane Irene swamped the East Coast. Swarms of tornadoes rolled through the center of the country, and record-setting wildfires blazed in the Southwest.
But while 2011's litany of extreme weather was notable, it was "not unique" -- at least not in recent experience, according to a new analysis published yesterday in the journal Nature Climate Change.
The world has experienced an "exceptional number of unprecedented extreme weather events" for the past decade, say co-authors Dim Coumou and Stefan Rahmstorf, researchers at the Potsdam Institute for Climate Impact Research in Germany, who surveyed recent research linking climate change to shifts in the frequency and intensity of extreme weather.
"The evidence is strong that anthropogenic, unprecedented heat and rainfall extremes are here -- and are causing intense human suffering," the two write.
Recent studies suggest that the number of warm nights increased significantly between 1951 and 2003, and twice as many record hot days than record cold days are occurring in the United States and Australia.
More footprints appear in weather patterns
The number of record hot months observed at different points around the globe is three times as high as it would be in a climate that was not changing, the scientists note.
Notable heat waves of the past decade include those that struck Europe in summer 2003 (the warmest summer recorded there in at least 500 years), Greece in summer 2007 and central Russia in 2010 (when July temperatures broke the previous record by 2.5 degrees Celsius).
"Several recent studies indicate that many, possibly most of these heat waves would not have occurred without global warming," the new analysis concludes.
But it's not just heat waves that appear to be altered by climate change. Previous research has linked some recent extreme rainfall events to climate change -- including the precipitation that doused England and Wales in autumn 2000, during the wettest fall season there since recordkeeping began in 1766. The floods damaged more than 10,000 properties and caused losses estimated at £1.3 billion.
When extreme weather hits, journalists and the public often ask whether climate change has caused a particular event -- and are told that scientists cannot say a single weather event was caused by climate change.
"This is often misunderstood by the public to mean that the event is not linked to global warming, even though that may be the case -- we just can't be certain," Coumou and Rahmstorf write. "If a loaded dice rolls a six, we cannot say that this particular outcome was due to the manipulation -- the question is ill-posed."
The more correct analogy is that loaded dice will roll more sixes than if they weren't loaded, thus man appears to be raising the odds for certain types of extreme weather to turn up as the climate warms.
March continues a roll call of extreme U.S. weather
"Attribution is not a 'yes or no' issue as the media might prefer," Coumou and Rahmstorf say. "It is an issue of probability. It is very likely that several of the unprecedented extremes of the past decade would not have occurred without [human-caused] global warming."
The study echoes findings of the Intergovernmental Panel on Climate Change, which released its own report last year examining the effect of climate change on weather extremes.
That report found evidence that climate change is increasing the frequency of drought and heat waves and the intensity of rainstorms, warning that such shifts will require the world's governments to change how they cope with natural disasters (Greenwire, Nov. 18, 2011).
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24 Comments
Add CommentHere is the link to the study:
Reply | Report Abuse | Link to thisA Decade of Weather Extremes
http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1452.html
And here is a link to an earlier study on the same subject by the authors:
Increase of Extreme Events in a Warming World:
http://www.pnas.org/content/early/2011/10/18/1101766108.abstract
http://www.dailymail.co.uk/sciencetech/article-2120512/Global-warming-Earth-heated-medieval-times-human-CO2-emissions.html
Reply | Report Abuse | Link to this@Morebhp,
Reply | Report Abuse | Link to thisThe Daily Mail article you linked to is flawed in multiple ways. The article claims, "At present the Intergovernmental Panel on Climate Change (IPCC) argues that the Medieval Warm Period was confined to Europe – therefore that the warming we’re experiencing now is a man-made phenomenon."
This is wrong in two different ways:
1.The IPCC makes no such claim that the the Medieval Warm Period was only confided to Europe. Here is a link to the appropriate section of the IPCC report:
The Last 2,000 Years
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch6s6-6.html
2. The basis for Anthropogenic Climate Change is not based upon whether the Medieval Warm Period was warm or not. The basis for that claim is the physics and predictions and observations of those predictions in Nature. Disagree? Then please go to the IPCC site and show me where it gives the line of reasoning that is made in the Daily Mail article.
The Physical Science Basis
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/contents.html
So what I want to know is why did you swallow so willingly these lies as told by a notorious scandal rag as the Daily Fail?
Trent says: "The Daily Mail article you linked to is flawed in multiple ways."
Reply | Report Abuse | Link to thisWhy of course it is. --It draws the wrong conclusion. You've chosen your position. I'm sure you'll stay busy defending it.
@Pokerplayer,
Reply | Report Abuse | Link to thisI see that you have not broken that nasty habit of making bald faced assertions with out a hint of substantiating science. I think you may want to check your assumptions about what nationality I am or what party affiliation I have.
Will everyone please note that the fake skeptics are not addressing the article beyond expressing incredulity and are engaging in blatant attempts at sidetracking the thread topic.
@Morebhp,
Reply | Report Abuse | Link to thisSo you are not going to address the blatant misrepresentations that I pointed out? I provided resources for everyone to see that the IPCC makes no such claim as found in the Daily Fail article.
You are not entitled to your own set of facts.
Trent says: "Will everyone please note that the fake skeptics are not addressing the article beyond expressing incredulity and are engaging in blatant attempts at sidetracking the thread topic."
Reply | Report Abuse | Link to thisI wouldn't worry too much. Actually, I don't think many people read these articles. Not sure why I do frankly.
Morebhp says: Not sure why I do frankly.
Reply | Report Abuse | Link to thisTrent Says: Come on now. It is apparent that you do not read it. Why else would you post totally unrelated agitprop for... Oh, wait. Yes, I forgot the other possibility is that you are a propagandist. My bad.
Trent Says: "Come on now. It is apparent that you do not read it. Why else would you post totally unrelated agitprop for... Oh, wait. Yes, I forgot the other possibility is that you are a propagandist. My bad."
Reply | Report Abuse | Link to thisDarn. You broke my cover. Yes, I'm a paid propagandist slinking around the SA site posting links. Now I'm going to have to get a real job. (Wow...)
And here we have it folks. Distraction to original story attempt #3. Every effort is being engaged to talk about anything but the topic of the paper.
Reply | Report Abuse | Link to thisdon't reply to the denier rubbish - it's a waste of space and energy (that SciAm is letting the denier garbage stand and delete this comment is not proof of the deniers' validity)
Reply | Report Abuse | Link to thisGee, Pokerplayer, it is like you did not bother to read the article or the links to the peer reviewed literature. It is almost like you have no concern for the science. I wonder why?
Reply | Report Abuse | Link to thisI see that the one actual science cite that you approvingly linked to is a draft to the summary of the science for the IPCC on climate extremes. So I say let us take a look at what it says:
"There is evidence that some extremes have changed as a result of anthropogenic influences, including
increases in atmospheric concentrations of greenhouse gases."
Page 5
"It is very likely that there has been an overall decrease in the number of cold days and nights,3 and an overall increase in the number of warm days and nights,3 at the global scale, that is, for most land areas with sufficient data. It is likely that these changes have also occurred at the continental scale in North America, Europe, and Australia. There is medium confidence in a warming trend in daily temperature extremes in much of Asia. Confidence in observed trends in daily
temperature extremes in Africa and South America generally varies from low to medium depending on the region."
page 6
"There is evidence that some extremes have changed as a result of anthropogenic influences, including
increases in atmospheric concentrations of greenhouse gases. It is likely that anthropogenic influences have led to warming of extreme daily minimum and maximum temperatures at the global scale. There is medium confidence that anthropogenic influences have contributed to intensification of extreme precipitation at the global scale. It is likely that there has been an anthropogenic influence on increasing extreme coastal high water due to an increase in mean sea level.
many (but not all) regions over the globe with sufficient data, there is medium confidence that the length or number of warm spells or heat waves has increased. [3.3.1, Table 3-2]"
Page 7
And what do they say about what the future holds?
"Models project substantial warming in temperature extremes by the end of the 21st century. It is virtually
certain that increases in the frequency and magnitude of warm daily temperature extremes and decreases in cold
extremes will occur in the 21st century at the global scale. It is very likely that the length, frequency, and/or intensity of warm spells or heat waves will increase over most land areas."
Page 11
Funny how a draft summary of the science does not at all agree with what you claim it says.
"Funny how a draft summary of the science does not at all agree with what you claim it says."
Reply | Report Abuse | Link to thisDude - I think they just pretty much count on nobody READING it. It isn't aimed at anyone who has command of the facts, it is just a tactic to reinforce and shore up the doubt of those who don't know better. "Wow, a link that this guy says proves his point, I can feel good about believing him!" It might as well point to some lorum ipsum, but of course a good URL pointing at something scholarly probably works better, just in case someone happens to click on it.
Ah well. They can keep hiding under rocks, at least until they get flooded out from underneath...
@Tharter,
Reply | Report Abuse | Link to thisFake skeptics going to fake it :)
Personally, I think that the climate is, in general, warming as a result of human activities. Here in the U.S., for example, the population has now more than doubled, from ~152k to ~314k, since I was born in 1950. In addition that population has increasingly migrated to urban environments, with the majority of the U.S. population now living in large urban areas rather than being dispersed throughout the country in smaller towns.
Reply | Report Abuse | Link to thisThe net effect of these changes (that seem readily apparent to me) is that there are now many urban areas acting as enormous localized heat engines, sucking up potable water from surrounding areas and pumping heat extracted from building interiors by air conditioning into the environment.
That all not to mention the increased and more concentrated combustion of fossil fuels and other locally dense environmental changes. As I understand, these general changes have been even more pronounced in China and India, and even in Europe. So, I generally expect that there are serious environmental consequences occurring as a result of these significant changes.
That being said, I'm also generally skeptical of statistical studies based on the quality of historical data that is available about local environments around the world during that period. IMHO, while much better information has been collected in the past 20 years or so, establishing meaningful correlations to preceding environment conditions is likely very difficult. However, I am not an expert and have no intention of becoming one.
I have worked in specific areas in which enormous amounts of unreliable data could be used to produce 'evidence' supporting many conflicting conclusions. When we look at the clouds in the sky, we often imagine many different images from the same complex patterns of visual information. Arguing about what we see in the sky is futile...
I must wonder whether the extreme conditions of the Great Drought in Western North America during the 12th & 13th centuries, for example, have been approached by any recent conditions. I don't think sufficiently detailed data exists to determine how short term erratic changes within that period might have compared with those we are experiencing today.
For these reasons, it's difficult for me to get excited about any specific detailed studies of recent conditions even though I really do think that erratic climatic changes will contribute to conditions making the continuation of recent urban population growth trends and depletion of critical global resources untenable.
To suggest that extreme weather events are not becoming more frequent is as ignorant as saying Scientific American magazine is not publishing real science. The kind of people that make these kinds of claims will never be taken seriously by educated readers. Why bother? You are wasting the time of readers that really do have something of value to contribute.
Reply | Report Abuse | Link to this@Pokerplayer,
Reply | Report Abuse | Link to thisWhy lie and try to derail the thread so blatantly? Can you not just admit that you have been had? It is perfectly obvious that the one scientific source you cited says the exact opposite of what you claimed it said. It is also obvious that you can not bring yourself to read this article or the peer reviewed articles that show a relationship between warming and weather extremes?
Who do you think you are fooling?
You have to wonder at the cognitive processes of someone who claims "-nothing but peer reviewed articles that prove the point that there is no evidence to support the claim or your fear." on an article about weather extremes showing an increase and those results being published in the peer reviewed literature.
Reply | Report Abuse | Link to this@Pokerplayer,
Reply | Report Abuse | Link to thisDo you suffer from reading comprehension problems? I asked because you seem to not have read (again) the only other peer reviewed paper you cited. The paper you just cited dealt only with with hurricanes and frequency. Here is what it what did not address:
1. Temperature extremes.
2. Hurricane strength:
http://www.nature.com/nature/journal/v455/n7209/abs/nature07234.html
3. Droughts
4. Severity of thunderstorms.
And yet here you are claiming that this one paper on Atlantic basin hurricane frequency debunks multiple papers on extremes.
@PokerPlayer,
Reply | Report Abuse | Link to thisYour first link reveals that you are mindlessly copying and pasting from CO2 science. A site notorious known for misrepresenting the science. And if I take the trouble to find the real article here is what the abstract reveals:
http://www.agu.org/pubs/crossref/2003/2003GL018052.shtml
"The frequencies at the beginning of the 20th Century were nearly as high as during the late 20th Century for some combinations of duration and return period, suggesting that natural variability cannot be discounted as an important contributor to the recent high values."
So no, that article from 2003 that examines extreme precipitation events from 1895 to 200 does not say what you claim it says. But hold it. Has the same researcher done more work in this area since 2003? Why yes, he has:
"Meteorological Causes of the Secular Variations in Observed Extreme Precipitation Events for the Conterminous United States"
http://journals.ametsoc.org/doi/abs/10.1175/JHM-D-11-0108.1?journalCode=hydr
Abstract:
"On a national scale, there are upward trends in events associated with fronts and tropical cyclones, but no trends for other meteorological causes. On a regional scale, statistically significant upward trends in the frontal category are found in five of the nine regions."
Funny how you and CO2 science did not cite that later work, eh?
But hold it. That researcher did not stop there either:
http://www.mendeley.com/research/how-spatially-coherent-and-statistically-robust-are-temporal-changes-in-extreme-precipitation-in-the-contiguous-usa/
"How spatially coherent and statistically robust are temporal changes in extreme precipitation in the contiguous USA?"
From the abstract:
"The majority of stations that exhibit significant linear trends show evidence of increases in the intensity of events above the 95th percentile."
I am going to guess CO2 science that you copy and pasted from did not cite that work either.
Weather and Climate Extremes in a Changing Climate
2.2.2.2.2 United States
http://downloads.climatescience.gov/sap/sap3-3/sap3-3-final-all.pdf
"One of the clearest trends in the United States
observational record is an increasing frequency
and intensity of heavy precipitation events. ... The area of the United States affected
by a much above normal contribution from
these heavy precipitation days increased by
a statistically significant amount, from about
9% in the 1910s to about 11% in the 1980s and
1990s."
Can you explain these omissions?
@Poker Player,
Reply | Report Abuse | Link to thisIt is painfully obvious that you are copying and pasting links given out by WUWT and CO2 science. You are regurgitating propaganda. All it takes is for some one to copy and paste your cites into Google and the first sites that pop up are CO2 Science with exactly the same cites. Notice how I went to the original articles and saw what they actually said.
This is why I keep on hammering you. I always go to the original article and take a look at the authors/s subsequent work. This is why citing Kunkel is such a disaster for you. It is painfully clear that you are swallowing propaganda and have no concern for the science.
Disagree? Then you got to explain how Kunkel's work as found in "Weather and Climate Extremes in a Changing Climate". From the Executive Summary of the report of which Kunkel is an author.
"Many extremes and their associated impacts are now changing. For example, in recent decades most of North America has been experiencing more unusually hot days and nights, fewer unusually cold days and nights, and fewer frost days. Heavy downpours have become
more frequent and intense."
Page I
How can it become any more clearer for you? That is not an abstract but a summary of the science with Kunkel among other experts reporting the state of the science for weather extremes as it was in 2008.
http://downloads.climatescience.gov/sap/sap3-3/sap3-3-final-all.pdf
Why do you ignore this? Do you think that if you scream loud and long enough that it alter the summary of the report?
from swiggipedia:
Reply | Report Abuse | Link to thispokerplyer = An idiot, dolt, carlyle or dullard, either way a mentally deficient person, or someone who acts in a self-defeating or significantly counterproductive way. Archaically the word mome has also been used. The similar terms moron, imbecile, and cretin have all gained specialized meanings in modern times; the term "pokerplyer" is the only one known to mean all of them.
The one thing I think is clear is that we must find a way to stifle human population growth. Our wars aren't killing as many as they used to and globalization has caused those who would have otherwise starved or died disease to be treated by organizations such as the Red Cross and continue to populate. No one wants to discuss population control because they find it dehumanizing to discuss human population the same we we do with animals. Well, guess what? We are animals. We have advanced to the point though were natural selection is no longer taking place and we are passing on weak genes. This is not a good thing for the world.
Reply | Report Abuse | Link to thisI am sure there will be a nice reduction in population though when resources get truly scarce and massive wars break out destroying most of mankind. I don't know about you, but I'd rather nip the problem in the bud before it gets to that.
@morebhp,
Reply | Report Abuse | Link to thisRemember that piece of propaganda you linked to at post #2?Well, guess who is not happy with the blatant misrepresentation of their research? The researcher himself:
"Syracuse University scientist seeks to set the record straight on climate research"
From the article:
"Several of these media articles assert that our study claims the entire Earth heated up during medieval times without human CO2 emissions. We clearly state in our paper that we studied one site at the Antarctic Peninsula. The results should not be extrapolated to make assumptions about climate conditions across the entire globe. Other statements, such as the study “throws doubt on orthodoxies around global warming,” completely misrepresent our conclusions. Our study does not question the well-established anthropogenic warming trend."
Now I asked you before and you dodged and I am going to ask you again. Why were you so credulous to swallow this story?