News24

Extreme events narrow climate doubts

2012-08-22 08:35

Paris - Heatwaves, drought and floods that have struck the northern hemisphere for the third summer running are narrowing doubts that man-made warming is disrupting Earth's climate system, say some scientists.

Climate experts as a group are reluctant to ascribe a single extreme event or season to global warming.

Weather, they argue, has to be assessed over far longer periods to confirm a shift in the climate and whether natural factors or fossil-fuel emissions are the cause.

But for some, such caution is easing.

A lengthening string of brutal weather events is going hand in hand with record-breaking rises in temperatures and greenhouse-gas levels, an association so stark that it can no longer be dismissed as statistical coincidence, they argue.

Extraordinary weather

"We prefer to look at average annual temperatures on a global scale, rather than extreme temperatures," said Jean Jouzel, vice chair of the UN's Nobel-winning scientists, the Intergovernmental Panel on Climate Change (IPCC).

Even so, according to computer models, "over the medium and long term, one of the clearest signs of climate change is a rise in the frequency of heatwaves", he said.

"Over the last 50 years, we have seen that as warming progresses, heatwaves are becoming more and more frequent," Jouzel said.

"If we don't do anything, the risk of a heatwave occurring will be 10 times higher by 2100 compared with the start of the century."

The past three months have seen some extraordinary weather in the US, Europe and East and Southeast Asia.

The worst drought in more than 50 years hit the US Midwest breadbasket while forest fires stoked by fierce heat and dry undergrowth erupted in California, France, Greece, Italy, Croatia and Spain.

Heavy rains flooded Manila and Beijing and China's eastern coast was hit by an unprecedented three typhoons in a week.

Irrefutable link

July was the warmest ever recorded for land in the northern hemisphere and a record high for the contiguous US, according to the US National Oceanic and Atmospheric Administration (NOAA).

Globally, the temperature in July was the fourth highest since records began in 1880, it said.

James Hansen, arguably the world's most famous climate scientist (and a bogeyman to climate sceptics), contends the link between extreme heat events and global warming is now all but irrefutable.

The evidence, he said, comes not from computer simulations but from weather observations themselves.

In a study published this month in the peer-reviewed US journal Proceedings of the National Academy of Sciences (PNAS), Hansen and colleagues compared temperatures over the past three decades to a baseline of 1951 - 1980, a period of relative stability.

Over the last 30 years, there was 0.5°C - 0.6°C of warming, a rise that seems small but "is already having important effects", said Hansen, director of Nasa's Goddard Institute for Space Studies.

During the baseline period, cold summers occurred about a third of the time, but this fell to about 10% in the 30-year period that followed.

Hot summers which during the baseline period occurred 33% of the time, rose to about 75% in the three decades that followed.

Even more remarkable, though, was the geographical expansion of heatwaves.

During the baseline period, an unusually hot summer would yield a heatwave that would cover just a few tenths of 1% of the world's land area.

Today, though, an above-the-norm summer causes heatwaves that in total affect about 10 percent of the land surface.

"The extreme summer climate anomalies in Texas in 2011, in Moscow in 2010 and in France in 2003 almost certainly would not have occurred in the absence of global warming with its resulting shift of the anomaly situation," says the paper.

In March, an IPCC special report said there was mounting evidence of a shift in patterns of extreme events in some regions, including more intense and longer droughts and rainfall. But it saw no increases in the frequency, length or severity of tropical storms.

Comments
  • Tony Lapson - 2012-08-22 09:22

    5000 years too early to call it a "natural cycle"

  • aaron.radebe.1 - 2012-08-22 09:24

    What misleading nonsense. There has been extreme weather at varying frequencies since the planet was born. James Hansen is better known as one of the worlds more controversial and extreme global warming advocates than "the world's most famous climate scientist" (due to several completely incorrect past predictions). There has been a lot of response to his latest paper by the scientific community, many very sceptical that recent heat waves can be attributed to man made global warming, and not just natural variations in climate. Beware of a certain sector of society that just want an excuse to impose a ridiculous global carbon tax, restrictive social controls on everyone and return the world to a non-existent idealistic technology bereft "Garden of Eden". Their Marxist agenda is terrifying and I would urge anyone to do as much of their own research as possible - if you genuinely do so you will discover that global warming is nowhere near "settled".

      aaron.radebe.1 - 2012-08-22 09:28

      http://www.skepticalscience.com/hansens-new-climate-dice-loaded-misunderstood.html

      denis.dendrinos - 2012-08-22 09:46

      oh and as an aside - you ever wonder who sponsors those who "oppose" the climate change data as mere "natural variations"? That's right sunshine - the oil and coal companies! Those with the most to lose! and look at your last paragraph - and you want to call them marxist?

      Tony Lapson - 2012-08-22 09:58

      Denis, what he is saying is, "I am 100% sure that global warming is a myth, therefore I am right and everyone can pollute and consume as much as they want, even if there is a small chance that I am wrong, I am right, and you are wrong, I am right, and you are wrong."

      stirrer.stirrer - 2012-08-22 10:11

      Denis, here in the Cape we have the coldest and wettest winter ever. Please don't tell me it's global "warming". Climate change, maybe. Global warming? Hell no! For your information, there have been periods in Earth's history where it was a lot warmer than the current global average. Was that man made, too?

      ernst.j.joubert - 2012-08-22 10:14

      @aaron.radebe: "What misleading nonsense. There has been extreme weather at varying frequencies since the planet was born." 1) Once again, the same old argument that is used over and over and over.....and over........and over agian. Arguing that the climate changed before, therefore human activity has no effect is like arguing that in the past bush fires were caused naturally therefore man cannot start bushfires. To conclude: The climate reacts to whatever the dominant force is at the time; humans are currently the dominant force. 2) 98% of climate scientists actively publishing in peer reviewed scientific journals agree that there is substantial evidence that human activity is damaging the STABILITY of the climate. (See below) A 2010 paper in the Proceedings of the National Academy of Sciences of the United States (PNAS) reviewed publication and citation data for 1,372 climate researchers and drew the following two conclusions: (i) 97–98% of the climate researchers most actively publishing in the field support the tenets of ACC (Anthropogenic Climate Change) outlined by the Intergovernmental Panel on Climate Change, and (ii) the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers.

      denis.dendrinos - 2012-08-22 10:22

      @stirrer - Cape Town has a mediterranean climate - very different - and yes - it's because of global warming. Just because it's getting hotter, does not mean that in winter it HAS to be warmer. Climate isn't exactly a simple system - there are so many factors and systems at play. One gets disturbed by heating, influences another, and sometimes in a indirectly proportionate way. Here we've had the warmest winter I ever experienced. as for you very condescending last paragraph - well heck y'a don saaay...... Sure - the dino's had it waaaay hotter. Funny enough no humans were around to verify why etc. Could be massive dino methan farts, volcanic activity etc etc. The world has also been alot colder than you little winter you had now......was called the ice age - maybe you heard of it - and funny enough, that followed the hottest time ever too!

      stirrer.stirrer - 2012-08-22 10:30

      Thank you, Denis. It takes a very brave proponent of AGW to admit that climate change is natural and cyclical, as you just did very eloquently.

      alan.gernet - 2012-08-22 10:49

      er Stirrer - if you read up on the effects of Global Warming and understand the reasons, then you will understand that Global Warming is driving climate change. The biggest cause of global warming is deforestation, human consumer greed/wastage (which fuels the industry that produces consumer goods and services), and of course the planet's overpopulation where every person leaves a carbon footprint in a world that already cannot sustainably meet the demands of it's population.

      denis.dendrinos - 2012-08-22 10:50

      and only a proponant would see that as me saying it's natural. First - yes we know it was hotter or colder - but we don't know why. We can theorise - like dino farts - kinda natural - but still a dominant force's effect on the climate - as ernst said..... ans as the rest of us know - methan being a far more potent greenhouse gas than carbon dioxide...... and a massive meteor smashing into earth - well - miiiight kinda be "natural" but most certainly unforeseen and definitely a dominant force. At the end of the day you cannot quote past models - there were not 7 billions humans on earth, eating tons of beef (cows fart methan) and demanding space (destruction of forests) and consuming (high output from various industries and their carbon related manufacturing processes)...... but live in your cute little world bud - mine is getting hotter....

      Thermophage - 2012-08-22 12:44

      lol...all you haters... You are wrong and right at the same time. Climate change is NOT cause by humans and our BS. It IS most definitely a natural phenomenon. Currently we are in a relatively cool period in earth history speaking from a geological standpoint. However, the effect which human activity is having is to accelerate NATURAL climate change. The earth was always going to get hotter at some point, we might just have caused it to happen a little sooner than it would have happened naturally.

      ernst.j.joubert - 2012-08-22 12:58

      @Stirrer: So stirrer, what you are implying is that the top climate scientists in the world were so stupid that they didnt consider natural variability as a possible cause for global warming? This claim that its natural and only natural is absurd. Natural variability was one of the first things that was taken into account.

      aaron.radebe.1 - 2012-08-22 15:43

      Come on people, now seriously, you need to get over it. You've been spun a yarn by fat cat globalists who want to make trillions by charging YOU a tax for the same gas you breathe out and at the same time fulfil their sordid Malthusian/Luddite fantasies. The so-called "consensus" has been thoroughly debunked by the research of (among others) Donna Laframboise in her book "The Delinquent Teenager". Do yourself a favour and read it - she does an excellent mathematically objective study of the contributors to the IPCC "consensus" and how it is achieved that will open your eyes. Furthermore, the dark secret of the global warming industry is that we are actually in a cooling period. Notice that "Global Warming" became "Climate Change" at about the same time that this highly inconvenient fact started to sink in. Not to mention the various leaks from the primary contributors to the UN IPCC reports that show data completely manipulated to fit the ideology. Anyone who does not exhibit a healthy scepticism about the AGW industry is either in some way directly benefiting from the continued scaremongering or out of touch with reality. Please, there are many far more pressing, directly threatening environmental concerns such as acid mine drainage and the high sulphur load being deposited in our atmosphere. These should be addressed in a sensible fashion instead of wasting all our time and energy on a bunch of billionaires' scheme to make money selling carbon credits.

      aaron.radebe.1 - 2012-08-22 15:58

      @Denis "but live in your cute little world bud - mine is getting hotter...." Actually, no it's not... bud: http://thetruthpeddler.files.wordpress.com/2011/01/hadcrut-global-mean.jpg

      ernst.j.joubert - 2012-08-22 16:44

      @Aaron.radebe: "Notice that "Global Warming" became "Climate Change" at about the same time that this highly inconvenient fact.." It was the G.W Bush administration (one of the most pro-fossil feul administrations ever) that mandated that reports that mentioned "global warming" should be toned down by using "climate change" instead, because "climate change" sounds less severe. "Furthermore, the dark secret of the global warming industry is that we are actually in a cooling per..." For global records, 2010 is the hottest year on record, tied with 2005. "The so-called "consensus" has been thoroughly debunked by the research of (among others) Donna Laframboise in...." Is this a joke? Perhaps you should see the below link on the credentials (or lack thereof) of Donna Laframboise: http://www.desmogblog.com/donna-laframboise Lastly, A 2010 paper in the Proceedings of the National Academy of Sciences of the United States (PNAS) reviewed publication and citation data for 1,372 climate researchers and drew the following two conclusions: (i) 97–98% of the climate researchers most actively publishing in the field support the tenets of ACC (Anthropogenic Climate Change) outlined by the Intergovernmental Panel on Climate Change, and (ii) the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers.

      stirrer.stirrer - 2012-08-22 17:10

      Ernst, its been said that statistics is like a drunken man hanging on to a lamp post - it's there for support, not illumination. You fell squarely into the spin trap. "97–98% of the climate researchers most actively publishing in the field support the tenets of ACC" - note, nowhere does it say 97-98% of ALL climate scientists. What was the size of the "most actively publishing" sample? There's money to be made if you support ACC i.t.o. government grants and consultant fees, so proponents will be more actively publishing, it's good advertising. "the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers." - Yeah right. They would say that, wouldn't they? How do they define expertise? If you are a proponent of ACC, you are an expert, else not? Or what? The same with "scientific prominence". Read the "Open Letter to the IPCC", have a look at its signatories, it reads like a Who's Who in climatology. Not prominent? Bah.

      aaron.radebe.1 - 2012-08-22 17:30

      No @Ernst, 2010 was only the hottest year on the satellite record if you use the incorrect moving average calculation. Mathematically, the central moving average is more representative of the annual sample. This firmly places 1998 as the hottest year instead. Here's some info to back this up: http://wattsupwiththat.com/2011/01/03/rss-data-2010-not-the-warmest-year-in-satellite-record-but-a-close-second/ . The reports about 2010 being the hottest year were all media hype.

      aaron.radebe.1 - 2012-08-22 17:34

      @Ernst And your ad hominem attack on Donna Laframboise does nothing to refute the facts of her research which shows quite eloquently that the IPCC is nowhere near as representative of the world's top climate scientists as it claims to be.

      ernst.j.joubert - 2012-08-22 17:42

      @Stirrer: "There's money to be made if you support ACC i.t.o. government grants and consultant fees, so proponents will be more ...." Sweeping, unsubstatiated statement. There is much more money behind denying manmade global warming. Think oil coal and gas. These industries are TRILLION dollar industries that have made record profits. These profits are in the direct firing line as a result of AGW. ".note, nowhere does it say 97-98% of ALL climate scientists." Did you read my comment? The study doesnt refer to individuals per se, but to citations i.e. they looked at the latest PUBLISHED PEER REVIEWED (i.e. scientific work that was scrutinized by experts) scientific papers and reached their conclusions based on this research. Could you please provide me with citations to the latest peer reviewed literature that refutes manmade global warming. "Read the "Open Letter to the IPCC", have a look at its signatories, it reads like a Who's Who in..." Did the signatories refute manmade global warming? I dont think so. Read the piece below taken from the letter: Continue.

      ernst.j.joubert - 2012-08-22 17:43

      Continue: "Many in the popular press and other media, as well as some in the halls of Congress, are seizing on a few errors that have been found in the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) in an attempt to discredit the entire report. None of the handful of mis-statements (out of hundreds and hundreds of unchallenged statements) remotely undermines the conclusion that “warming of the climate system is unequivocal” and that most of the observed increase in global average temperatures since the mid-twentieth century is very likely due to observed increase in anthropogenic greenhouse gas concentrations." DUH!!!

      ernst.j.joubert - 2012-08-22 18:00

      Aaron.Radebe: Your source "whatsuppwiththat" is hardly credible. The people that run this site have cyberbullied numerous climate scientists with death threats and hate mail. http://thinkprogress.org/climate/2012/01/15/404673/mit-climate-scientist-wifecyberbullying-pushed-by-deniers/ Donna Laframboise credentials: Degree in Women's Studies, University of Toronto (1989). What a joke. Not even a PHD in climate science. So this women knows more than the worlds top climate scientists. Pathetic.

      aaron.radebe.1 - 2012-08-23 08:40

      @Ernst - Again, your responses are entirely ad hominem. Do you refute the mathematics behind the claim that 2010 was the hottest year was based on an invalid moving average calculation? Do you refute the facts in Donna Laframboise's book, which are objective facts regardless of her training? Do you need to be a climate scientist to index the papers used by the IPCC and check which were actually peer reviewed? No, you just need to be a journalist. The fact that you resort to attacking reputations and not actually addressing the facts speaks volumes, my friend.

      aaron.radebe.1 - 2012-08-23 08:50

      @MemeMan "Please try to understand the mega-political, economics and mass psychology at play here" I'm afraid that you've swallowed the psychology of the anti-carbon ideological movement hook, line and sinker, and your comments make it abundantly clear that you, in fact, have a very poor understanding of "the mega-political, economics and mass psychology at play here".

      stirrer.stirrer - 2012-08-23 10:40

      @Ernst: Sorry dude, it's glaringly obvious you have no clue what the letter entails. The excerpt you quoted is from "Open Letter from U.S. Scientists on the IPCC", a totally different letter, written in response to the original one. It contains nothing to actually refute what the original letter said. So, when you Google to quickly read up on something you have no clue of, please Google the CORRECT info. DUH!!! @MemeMan (August 23, 2012 at 07:47): Strange but true, I actually agree with you. I totally believe climate change is with us, with all of its challenges and looming disasters, I just don't believe it's global WARMING (no believable data that supports it, much of it is fabricated and/or manipulated), or that it's man made, I am a firm believer that it's cyclical. What is a fact, is that we are seeing more and more extreme weather conditions, and we must adapt to the changing climate. We are in the fortunate position that we are socially and technologically more advanced than previous civilizations faced with the same problems, so I trust we will be OK.

      ernst.j.joubert - 2012-08-23 10:56

      @Stirrer: "Sorry dude, it's glaringly obvious you have no clue what the letter entails. The excerpt ..." Could you please then refer me to the link of the letter that you are talking about. And also, could you provide me with citations to the latest peer reviewed research that refutes manmade global warming. Thank you.

      ernst.j.joubert - 2012-08-23 10:59

      @Stirrer: Could you also provide me with the list of signatories that you claim to be the "whose who" in climate science.

      stirrer.stirrer - 2012-08-23 11:28

      @ernst: http://scienceandpublicpolicy.org/reprint/open_letter_to_un.html The signatories are at the bottom of the letter. Enjoy.

      stirrer.stirrer - 2012-08-23 13:16

      @MemeMan - Problem is, the data is hogwash. Did you ever read the Climategate emails? You actually need to be in IT to fully understand what went on - I am. The facts are REALLY SCARY - by that I mean the manipulation, omission, fabrication and general screwing-up of data - some intentional, some not - that happened. And that is the data that the whole GW premise is built on! Apart from that, there is more and more data and evidence coming in that conflicts the GW theory. I know you read the article on the 600 year old Antarctic warming. That article alone contains two documented, undisputed cases of what I'm talking about. That is the main reason why I'm an AGW sceptic - note, not climate change, just AGW.

      ernst.j.joubert - 2012-08-23 13:38

      @Stirrer: 1) The majority of signatories provided on your pitiful list arent even climate scientists. Most of them dont even have publications in climate science. As an example: a) Arthur Rorsch, PhD, Emeritus Professor, Molecular Genetics, Leiden University, The Netherlands b) Len Walker, PhD, Power Engineering, Australia c) Stephan Wilksch, PhD, Professor for Innovation and Technology Management, Production Management and Logistics, University of Technolgy and Economics Berlin, Germany d) Owen McShane, PhD, economist, head of the International Climate Science Coalition; Director, Centre for Resource Management Studies, New Zealand e) Ross McKitrick, PhD, Associate Professor, Dept. of Economics, University of Guelph What the hell does a molecular geneticist, an economist and engineer know about climate science!!!? and c)? What a joke (What does this guy know about climate science!??). You gotta be kidding me. 2) This list also contains climate scientists that have been debunked numerous times. As an example: Dr S. Fred Singer: http://www.skepticalscience.com/fred-singer-debunks-and-denies.html Roy W. Spencer:http://www.skepticalscience.com/Dessler-2011-Debunks-Roy-Spencer-And-Richard-Lindzen.html

      stirrer.stirrer - 2012-08-23 14:44

      Ernst, AGAIN it's obvious you did not read the letter. Let me help you (again). The general gist of the letter is (a) to refute the data that AGW is based on, and (b) to ask the UN not to waste their energies on the doubtful notion of AGW, and rather focus on the real issues that will ensue due to climate change (which, by the way, they do not deny - only a fool would do that). Those issues are social, economic, scientific, everything - THAT's what those guys are doing there. So, in a nutshell (pun intended? Maybe...): Stop screaming "AGW! We are doomed!" and trying to prove it with useless empty rhetoric. Rather just admit that climate change is with us (wow, if it's natural - so be it!!!) and let's find out how to deal with it.

      ernst.j.joubert - 2012-08-23 14:57

      @stirrer: "The general gist of the letter is (a) to refute the data that AGW is based on, and (b) to ask the UN not to waste their energies on the doubt......" Stirrer, did you actually read my comments (or can you read?)? I am pointing out that the majority of signatories to the letter have no climate science expertise and/ or have been debunked countless times. So what credibility do they have in terms of the validity of AGW? Hence, the fact that they endorse what is said in the letter (i.e. as you put it: to refute the data that AGW is based on.....) means absolutely F-all because they are NOT REAL experts. Following your logic, I might as well consult a plumber in the future if I have heart disease, because a plumbers opinion is much more valuable than the opinion of a heart surgeon.

  • denis.dendrinos - 2012-08-22 09:37

    and here we want to build - oh sorry - are building "cheap" coal powered stations...... The stupid sun didn't want to enter into a tenderpreneur agreement with the government to supply it's rays to solar panels - so screw it!

      Tony Lapson - 2012-08-22 09:59

      One can't help but ask why we are paying a carbon tax when South Africa has no intention of becoming 'greener'.

      denis.dendrinos - 2012-08-22 10:28

      Tony - ypu the same green tax that government gladly collects - but allocates 0% of it to any green initiatives. Not solar panels for the poor, not mass tree planting, not scrubbong technology for eskom....... zip, niks, nadda, bubkis......... well - unless you count Jonny green as an initiative.

      alan.gernet - 2012-08-22 10:53

      Tony - it's ust a way of extorting more Tax. Ideally, that money would be used to going 'greener', but we all know that our Govt. "Lives for today" and screw the future. Like our President attending the summit in Durban, waxing on lyrical about the SA Govt's 'Green commitment', and they showing how serious he was by jetting off to a USA shopping spree with friends and family in 3 jets.

      robert.cerff - 2012-08-22 12:32

      @MemeMan: Actually... Coal can actually be cheaper... in all sensese of the word here. I've yet to have someone define what exactly green is? Solar? Wind? Wave? But where do the materials... plants... storage facilities come from... how do you transport it... what is the life span... what is the cost? Cheap and green are both concepts that can honestly be argued from both sides equally. While I agree with many of your posts, this is one that I have to disagree on.

      robert.cerff - 2012-08-22 12:53

      @MemeMan: "Population Growth" is easily the biggest contributing factor to strain on all resources. As for your solutions... education - well we can hope. The others have been around since life began, and no doubt have been the cause to many a lifeform being wiped out. I'd argue that's not "Climate Change" (or at least what is being termed as much today) but simply nature taking it's course.

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