Image: Flickr/steven_schroeder
BOSTON—If droughts, floods and wildfires are the criminal, climate change is the accomplice.
This is how the population must begin regarding global warming, experts said at a session at the annual American Academy for the Advancement of Science meeting here. Although extreme weather events, from the creeping drought that scorched last year's corn crop to Superstorm Sandy, are worrisome, automatically and simplistically tying them to the scientific phenomenon of climate change could be misleading.
Last year's drought in Texas, for example, could not be specifically tied to climate change, said John Nielsen-Gammon, the Lone Star State's climatologist. Over the past century there has been an increase in rainfall -- not a tendency toward dryness -- over most of Texas by about 10 percent.
"Changing climate has not contributed to the lack of rainfall over the long term, as of yet," he said. Last year's drought, much like the famed Dust Bowl drought of the 1930s and another significant drought in the 1950s, is tied to rising sea surface temperatures in the Pacific Ocean -- the weather event known as la Niña.
"Until we see a long-term decrease in rainfall in Texas, it will be hard to say that climate change has caused a decrease," Nielsen-Gammon said.
Temperatures have risen in Texas, meaning the increased rainfall is being evaporated at a more rapid rate, he added. But for the drought, which continues to seize more than half of the lower 48 states, heat was a drought accelerant but not the main cause.
All weather seems suspicious
The strong link to past events divorces the drought from climate. As climate scientists strive to educate the public, not tying a weather event to climate change is proving to be just as difficult as showcasing droughts and hurricanes as examples.
"All weather seems suspicious now," said Andrew Freedman, a senior science writer with Climate Central. The Thailand floods of 2011 are another example of a weather event with a tangential tie to climate. The devastation was more of a cause of poor management than anything else. The blizzard that hit the Northeast earlier this month was, despite dropping a tremendous amount of precipitation in 24 hours, nothing more than a strong nor'easter, according to Freedman.
"We see that, it looked like a nor'easter on satellite, it talked like a nor'easter," he said. "A lot of the climate discussion I thought was off-base."
La Niña and its weather brother, El Niño, are atmospheric events triggered by changes in surface sea level temperatures. The current drought was characterized by cold sea surface temperatures in the tropical Pacific Ocean, said Richard Seager, a research professor at the Lamont-Doherty Earth Observatory at Columbia University.
Sea surface temperature has a strong control on precipitation and soil moisture, said Seager, who compared the 2011 and 2012 droughts to the 20th century's other major droughts across the central United States.
Extending normal drought patterns
By using tree ring records to study ancient climates, David Stahle, a professor of geosciences at the University of Arkansas, found patterns between the recent droughts and the Great Pueblo Drought of the 13th century in the region across Colorado, New Mexico, Utah and Arizona.
"What's worrisome is that the escalation of temperature may cause these kinds of normal-occurring drought patterns to be more intense and prolonged," he said.
Poor soil management during the Dust Bowl is another factor to consider. The overtilling and poor nurturing of soils led to massive dust clouds and exacerbated the drought in the 1930s. Dust creates an energy sink by absorbing solar radiation, Seager said. Today, advances in agriculture have greatly controlled that problem.
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27 Comments
Add CommentThe question is not "should" recent extreme weather events be tied to climate change, but is there reliable evidence to conclude that any recent weather event is due to additional CO2 in the atmosphere.
Reply | Report Abuse | Link to thisHow can any reasonable person not be skeptical of claims that a particular bad weather event is due to AGW? The people who make these claims are the same people who say we should implement policies that are expensive and do virtually nothing to impact the climate.
You're building a strawman. The vast majority of warming since the Industrial Revolution and more than 100% of the warming since 1970 have been caused by humans. Since aerosol emissions have cancelled out some of our own warming, that is how we can cause more than 100%, btw.
Reply | Report Abuse | Link to thisSolar activity has been flat or declining since the middle of the 20th Century and cloud formation has shown little if any correlation with the solar / galactic radiation cycle. The pattern of warming is EXACTLY what we would expect due to greenhouse warming: the poles are warming faster than the tropics, nights are warming faster than days, and the troposphere is warming while the stratosphere is cooling. So yes, most of the 1C warming since preindustrial times is due to human GHG emissions.
Now as far as attribution is concerned, climate change can't primarily CAUSE any given event. However, it can make events much more likely, like the massive heatwave in Russia in 2010 or flooding in England in 2003. Given the generally warmer average air and water temperatures, combined with generally higher humidity levels, climate change makes ALL extreme weather more likely and more intense when it does happen.
You would know all of this if you bothered to ACTUALLY KEEP UP WITH THE LATEST SCIENCE instead of gulping down fossil fuel company propaganda without question.
You sir, are in error. Your statement......
Reply | Report Abuse | Link to this""You're building a strawman. The vast majority of warming since the Industrial Revolution and more than 100% of the warming since 1970 have been caused by humans. Since aerosol emissions have cancelled out some of our own warming, that is how we can cause more than 100%, btw"".
................Is ridiculous right on the face of it. Are you saying that there is no such thing as "natural global warming"? Y'know the warming that has warmed the planet after each of the last six ice-ages and has been doing so for about 17,000 years before mankind had its "Industrial Revolution"?
Where is the research to support your claims? Please?
.
Here you go:
Reply | Report Abuse | Link to this"Modern climate change is dominated by human influences, which are now large enough to exceed the bounds of natural variability. The main source of global climate change is human-induced changes in atmospheric composition."
http://www.sciencemag.org/content/302/5651/1719.short
"The Intergovernmental Panel on Climate Change fourth assessment report, published in 2007 came to a more confident assessment of the causes of global temperature change than previous reports and concluded that ‘it is likely that there has been significant anthropogenic warming over the past 50 years averaged over each continent except Antarctica.’ Since then, warming over Antarctica has also been attributed to human influence, and further evidence has accumulated attributing a much wider range of climate changes to human activities."
(Stott et al., 2010)
"The attribution of global temperature variations over the past century to a combination of anthropogenic and natural influences is now well established, with the anthropogenic factors dominating."
http://www.annualreviews.org/doi/abs/10.1146/annurev.environ.040308.101032?journalCode=energy
I could do this all day if SciAm's website wouldn't block me from posting more than 3 links per comment. you know, there's this thing called Google Scholar. It helped me find all these papers in less than a second. Remember, unless it's SCIENTIFIC and peer-reviewed, it doesn't have a place in a SCIENTIFIC discussion.
Tell us who peer reviewed this recent post of yours, or does your peer review requirement only apply to others?
Reply | Report Abuse | Link to thisSault you persist in giving misleading information. Recently you posted: “As a result, power exports from Germany to France reached 4 to 5 gigawatts – the equivalent of around four nuclear power plants – last Friday morning according to German journalist Bernward Janzing. It was not exactly a time of low consumption in Germany either at 70 gigawatts around noon on Friday, but Janzing nonetheless reports that the grid operators said everything was under control, and the country’s emergency reserves were not being tapped. On the contrary, he reports that a spokesperson for transit grid operator Amprion told him that ‘photovoltaics in southern Germany is currently helping us a lot.’”
http://cleantechnica.com/2012/02/09/clean-energy-loving-germany-increasingly-exporting-electricity-to-nuclear-heavy-france/#aopCK64gWaiB8tZP.99
This was false. Germany has NOT exported solar power to France.
In the early seventies a cyclone hit what is now Bangladesh and killed four hundred thousand people. A few years later another one killed forty thousand.
Reply | Report Abuse | Link to thisNow that was some extreme weather!
Sandy was minor except that it hit a major city that was also a media center. For obvious reasons the media ignore the fact that similar storms hit that region every few decades. Some areas get storms like that every few weeks.
If you are personally affected by it, then it's a tragedy. But climate wise, it's a nothingburger.
Now you're just being silly. First of all, your post is a glaring non sequitur unrelated to the current discussion. Secondly, that article presented a STATEMENT by a French grid operator. If you want to peer-review my claim that I had a sandwich yesterday, feel free...
Reply | Report Abuse | Link to thisBut just so you'll drop this nonsense, I can provide other sources as well:
"The rapid increase in power generation in Germany from wind, solar and hydro, however, has been accompanied by an equally rapid decrease in the price of electricity - and not just for German consumers, but also for large customers outside Germany.
This has resulted in a rise in demand for cheap power from Germany; in particular, from the Netherlands, where - due to the cheap imports - several domestic gas-driven power plants have been taken off the grid. Switzerland and Austria are also among Germany's best customers."
http://www.dw.de/power-exports-peak-despite-nuclear-phase-out/a-16370444
"Germany exported the equivalent of the output of two large power stations - 12.3 terawatt hours - during the first three quarters of the year, according to a preliminary report from the German Association of Energy and Water Industries (BDEW), seen by the business weekly Manager Magazin.
Experts say the surplus is thanks to the massive development of renewable energies in Germany. Huge quantities of wind and solar energy have reduced prices. "The low prices mean that more energy is being exported from Germany to the neighbouring countries," Bloomberg market analyst Brian Potskowski told the magazine.
This now includes France, the Netherlands, Belgium, and Germany. "The power stations of participating countries compete with each other, and electricity is produced in the stations that make the cheapest offer," the spokesman said."
So yes, Germany is exporting renewable energy to France.
But what's really revealing is that you are merely trying to distract everyone from the scientific PROOF that I posted concerning humanity's culpability in climate change. Why is that?
The Quilotoa volcano was a catastrophic VEI-6 eruption about 800 years ago, which produced pyroclastic flows and lahars that reached the Pacific Ocean, and spread an airborne deposit of volcanic ash throughout the northern Andes. A VEI-6 is enormous on the scale of 0-8
Reply | Report Abuse | Link to thisIn another, Ice cores from both the Arctic and Antarctic record a massive volcanic eruption in around AD 1258. The inter-hemispheric transport of ash and sulphate aerosol suggests a low-latitude explosive eruption, but the volcano responsible is not known. This is remarkable given estimates of the magnitude of the event, which range up to 5 × 1014-2 × 1015 kg (200-800 km3 of dense magma), which would make this the largest eruption of the historic period, and one of the very largest of the Holocene. The associated collapse caldera could have had a diameter up to 10-30 km. Palaeoclimate reconstructions indicate very cold austral and boreal summers in AD 1257-59, consistent with known patterns of continental summer cooling following tropical, sulphur-rich explosive eruptions. This suggests an eruption in AD 1257, producing a stronger climate forcing than hitherto recognized.
So the earth would continue to cool and warm due to these natural events such as Orbital forcing due to cycles in the earth's orbit around the sun has, for the past 2,000 years, caused a long-term northern hemisphere cooling trend that continued through the Medieval period and the Little Ice Age. The rate of Arctic cooling is roughly 0.02 degrees Celsius per century. This trend could be extrapolated to continue into the future, possibly leading to a full ice age, but the 20th-century instrumental temperature record shows a sudden reversal of this trend, with a rise in global temperatures attributed to greenhouse gas emissions.
Neat thing about the earth and our climate is it does not lie.
I'm compelled to point out that referring to peer reviewed journal articles provides substantiation of claims but does not provide proof of your viewpoint. In most cases, even superb research reports do not provide definitive evidence, and conflicting opinions are often published in peer reviewed journals - many times even within the same journal.
Reply | Report Abuse | Link to thisI agree that unsubstantiated declarations should be questioned, but merely providing published references does not conclusively prove your point.
I shared Carlyle's reaction to your imposition:
"Remember, unless it's SCIENTIFIC and peer-reviewed, it doesn't have a place in a SCIENTIFIC discussion."
There is no such restriction placed on reader comments, even in scientific journals - although supported assertions are generally more favorably received.
By the way, your earlier statement is hardly 'scientific':
"The vast majority of warming since the Industrial Revolution and more than 100% of the warming since 1970 have been caused by humans. Since aerosol emissions have cancelled out some of our own warming, that is how we can cause more than 100%, btw."
Can you provide any peer reviewed 'scientific' support for this strange assertion? Do not demand of others what you can't produce.
BTW, I agree with you that the climate is changing, generally warming, mostly as a result of the increasing activities of a human population that has increased six-fold, consuming natural resources at an continuously increasing rate since the industrial revolution.
Reply | Report Abuse | Link to thisI don't think there's any need to formally substantiate these assertions, but I can provide references if necessary.
UA geoscientists Cody Routson, Connie Woodhouse and Jonathan Overpeck recently published that the second century saw an extended dry period of more than 100 years characterized by a multi-decade drought lasting nearly 50 years in the Southwest USA. There were many such multi-decadal droughts in the 2200 year reconstruction.
Reply | Report Abuse | Link to thisSo we will we need 49 more years of drought to consider current drought to be unprecedented in Texas?
We are putting more carbon in the atmosphere, and more energy is being kept from leaving the atmosphere. Simple physics. Keeping this up until there we are beyond all doubt that this is a bad idea is just crazy. But crazy is not beyond the range of behaviours for homo sapien.
Reply | Report Abuse | Link to thisYet another article that has wiped all comments.
Reply | Report Abuse | Link to thishttp://www.scientificamerican.com/article.cfm?id=arctic-needs-protection-from-resource&posted=1#comments
You say <Neat thing about the earth and our climate is it does not lie.> So, you attribute a series of past climate change to forcing events. And to what event(s) exactly do you attribute current warming? You are correct, the earth and our climate do not lie. There have been no plausible alternative sources to forcing by co2 that explain the current warming. Care to offer up any?
Reply | Report Abuse | Link to thisWhy would this event be any different to the numerous previous events before humans could have been a factor. What caused them. Some periods with much higher CO2 levels have been cooler. Why has the rate of warming levelled off for at least the past decade yet CO2 emissions continue to climb.
Reply | Report Abuse | Link to thisThe CO2 theory is one of many. Recently soot has been proposed as a major contributor for example.
still largely man caused of course but the science is NOT settled & many believe CO2 is a minor player.
I notice my first comment posted here is now gone, which is very curious to me - I can't really remember what it was, but I do recall thinking that it was quite innocuous!
Reply | Report Abuse | Link to thisI've had another comment deleted recently - it was very critical of the article. Afterwards, I posted a dissertation explaining and justifying my brief, deleted comment: it never was deleted.
In both cases, the article was sourced from one of SA's business partners. I can only guess that perhaps they are also weighing in on whether a comment should be deleted, using some unknown criteria. I can think of no other reason why my initial comment here should have been deleted. I guess we are left to simply wonder why...
I certainly agree with your sentiments. I do try to keep a log of the comments in which I invest a lot of energy, but I do get caught by some more casual remarks that get deleted, such as the one here. I never would have guessed that anyone would want to delete it...
Reply | Report Abuse | Link to thisIt does seem that ignoring unexplained censorship constitutes complicit endorsement. On the other hand, I suspect that sciam.com readership would not suffer much if no one commented, but there's no way of knowing.
It would certainly be appropriate for SA to publish a set of terms and conditions that commentators should comply with or risk deletion. SA's sister publication, "Nature" includes a reminder posted with its comment entry box and links to its terms
http://www.nature.com/info/tandc.html
and more welcoming community guidlines
http://www.nature.com/info/community-guidelines.html
It would be extremely helpful if SA would follow suit, and comply with it own formal guidelines when censoring comments. In the meantime, I reckon I'll play it by ear...
Slightly warmer does not necessarily mean bad.
Reply | Report Abuse | Link to thisWhy do people BELIEVE that a slighly warmer world is worse overall over the long term for either the US or the world???
Google scholar returns 243,000 results for "negative climate change effects", just for published works since 2009!!!
Reply | Report Abuse | Link to thisThe fact that you think this has anything to do with BELIEF means you're just too lazy to look into the ACTUAL SCIENCE being conducted on the subject.
Here's some quotes:
"Here we show that changes in vegetation over the last 21 years, due to climate effects on plant–herbivore interactions, have consequences for songbird nest site overlap and breeding success. Browsing-induced reductions in the availability of preferred nesting sites for two of three ground nesting songbirds led to increasing overlap in nest site characteristics among all three bird species with increasingly negative consequences for reproductive success over the long term."
(Auer & Martin, 2012)
"Here we show that by combining historical crop production and weather data into a panel analysis, a robust model of yield response to climate change emerges for several key African crops. By mid-century, the mean estimates of aggregate production changes in SSA under our preferred model specification are − 22, − 17, − 17, − 18, and − 8% for maize, sorghum, millet, groundnut, and cassava, respectively. In all cases except cassava, there is a 95% probability that damages exceed 7%, and a 5% probability that they exceed 27%. Moreover, countries with the highest average yields have the largest projected yield losses, suggesting that well-fertilized modern seed varieties are more susceptible to heat related losses."
http://iopscience.iop.org/1748-9326/5/1/014010
"These estimates show that climate change initially improves economic welfare. However, these benefits are sunk. Impacts would be predominantly negative later in the century. Global average impacts would be comparable to the welfare loss of a few percent of income, but substantially higher in poor countries. Still, the impact of climate change over a century is comparable to economic growth over a few years. There are over 200 estimates of the marginal damage cost of carbon dioxide emissions. The uncertainty about the social cost of carbon is large and right-skewed. For a standard discount rate, the expected value is $50/tC...Most important among the missing impacts are the indirect effects of climate change on economic development; large-scale biodiversity loss; low-probability, high-impact scenarios; the impact of climate change on violent conflict; and the impacts of climate change beyond 2100."
http://www.ingentaconnect.com/content/aea/jep/2009/00000023/00000002/art00003
The $50/tC might be $183/tCO2, but it doesn't really matter. Even at $40 / tCO2, we can refund 80% or more of the fees back to U.S. taxpayers and STILL finance a steady transition to clean energy over the next few decades. The carbon tax would eliminate itself by funding emissions reduction approaches.
Reply | Report Abuse | Link to this21. sault
Reply | Report Abuse | Link to thisin reply to Sisko
01:00 PM 2/21/13 posts some quotes from Google..
..quote.."Here we show that changes in vegetation over the last 21 years, due to climate effects on plant–herbivore interactions, have consequences for songbird nest site overlap and breeding success. Browsing-induced reductions in the availability of preferred nesting sites for two of three ground nesting songbirds led to increasing overlap in nest site characteristics among all three bird species with increasingly negative consequences for reproductive success over the long term." (Auer & Martin, 2012).. end quote
One thing we know for sure, I guess, that there has been no habitat destruction over the long term by humans. Must be the case, right.
..quote.."Here we show that by combining historical crop production and weather data into a panel analysis, a robust model of yield response to climate change emerges for several key African crops. By mid-century, the mean estimates of aggregate production changes in SSA under our preferred model specification are − 22, − 17, − 17, − 18, and − 8% for maize, sorghum, millet, groundnut, and cassava, respectively. In all cases except cassava, there is a 95% probability that damages exceed 7%, and a 5% probability that they exceed 27%. Moreover, countries with the highest average yields have the largest projected yield losses, suggesting that well-fertilized modern seed varieties are more susceptible to heat related losses."...end quote.
At last!! The mystery of reduced crop yields in Zimbabwe, Democratic Republic of Congo, Mali, et al has been solved. It's climate change (whatever that means).
..quote...
estimates....could..would...expected...uncertainty...indirect...low probability, high impact...impact beyond 2100...end quote.
I left out the meaningless stuff in between the important words. You can check out the original at http://www.ingentaconnect.com/content/aea/jep/2009/00000023/00000002/art00003
Yep. All those quotes just loaded with real science and not belief.
You have no idea how science works. Please save your ignorant comments for a website that doesn't have SCIENTIFIC in its title.
Reply | Report Abuse | Link to this'Nothing off-limits' in climate debate
Reply | Report Abuse | Link to thisTHE UN's climate change chief, Rajendra Pachauri, has acknowledged a 17-year pause in global temperature rises, confirmed recently by Britain's Met Office, but said it would need to last "30 to 40 years at least" to break the long-term global warming trend. http://www.theaustralian.com.au/news/nothing-off-limits-in-climate-debate/story-e6frg6n6-1226583112134
I note that previously climate scientists were claiming that it needed a 15 year trend. Nothing like having portable goal posts. Still he is also calling for open debate & is not claiming that the science is proven. I hope SIAM takes note of the open debate part & causes their authors to cease & desist from deleting posts simply because they disagree.
7. sault in reply to Carlyle 09:52 AM 2/20/13
Reply | Report Abuse | Link to thisAnyone who checks your claims quickly finds that you simply do not provide truthful information. For instance I have repeatedly challenged you about your claim that Germany made a large sale of solar electricity to France. Your latest response is also full of falsehoods. For example you claim: that article presented a STATEMENT by a French grid operator.
It was NOT a French operator, Amprion is German. Also the author deliberately mislead his readers by implying that the Amprion spokesperson was talking solar power. He was not. The statement is entirely taken out of context to mislead. The author Zachary Shahan, is not a reliable source.
He was talking solar power but not in connection with the sale of power to France is what I meant to say.
Reply | Report Abuse | Link to thisIn reply to Northern Guy......you are the Occams Razor of this discussion.
Reply | Report Abuse | Link to this@scribblerlarry
Reply | Report Abuse | Link to thisYes, there is such a thing as natural global warming! But natural global warming has a cause. What is the cause of the current, ongoing global warming if not from atmospheric CO2? Do you think no one has looked for other causes? Pleeease!