aerosols

Clouds on the Horizon

jhalper — Sun, 08 Jun 2014 06:22:18 +0000

Clouds on the Horizon

Convective clouds forming over the Amazon in a blanket smoke. Image: Prof. Ilan Koren

Horse latitudes, doldrums, calms of Cancer and Capricorn: These are all synonymous names for the forsaken regions of the oceans that sailors of previous eras cursed because the winds that once pushed their sails die out there for weeks at a time. (One suggested explanation for the name “horse latitudes” is that some had to throw the horses overboard there when the supplies ran out.) On land, these subtropical belts – around 30-35° north and south of the equator – help form the world’s deserts.

These regions turn out to be nearly ideal “labs” for studying certain atmospheric physics. Fortunately, today’s researchers do not need to sit on a becalmed ship to study the processes occurring there. Satellite data can tell them exactly what they need to know. And what they want to know, in the case of Prof. Ilan Koren and his group, is whether the human action of polluting the atmosphere – which is usually treated as a local problem – could actually be affecting the climate in such remote locations.

Koren and his team zoomed in on three areas on the southern horse latitudes’ map, and looked at three months of satellite data analyzing clouds and aerosol data for each day.

The experimental question was: Does the aerosol count – whether from dust and sea spray or man-made soot – matter for cloud formation and rain? Some think that there is a saturation limit beyond which added aerosols don’t really affect cloud processes, but Koren and his team have been developing a model which suggests that added aerosols “invigorate” clouds – they create clouds that are larger, higher and rain more aggressively.

Image: Koren et al. Science 6 June 2014:
Vol. 344 no. 6188 pp. 1143-1146

The group chose to look at the horse latitudes data, in part, because the aerosol count there is generally low and the meteorological conditions there are such that so-called convective clouds could form. With no aerosols, clouds should not form at all, because these tiny air-born particles are what provide the nuclei for droplets. According to Koren, the relative humidity needed for a droplet to condense without that little seed would be an incredible 500%! So the model suggests that the clouds there are “aerosol limited,” meaning that the concentration of suspended particles serves as the main factor controlling cloud thickness and coverage. In the paper published by Koren and his group in Science, they demonstrate that convective clouds are aerosol-limited for a wide range of aerosol loading; therefore, any increase in aerosol concentration, whatsoever, will invigorate the clouds.

To really nail their case, they also checked their predictions against CERES data – a different satellite instrument that measures radiation emitted and reflected from Earth to space. That data suggests that back when those unfortunate sailors were waiting out the winds in the horse latitudes – before the advent of fuel-burning engines that let ships chug their way past – cloud formation was quite different from that of today. And in case you were wondering – the preindustrial clouds over their heads were sparser and smaller.

jhalper Sun, 06/08/2014 - 02:22

Tags

Chemistry

cloud-rain cycles

data analysis

environment

geophysics

aerosols

Cloud formation

cloud invigoration model

Volcanos may be countering greenhouse warming

illconsidered — Fri, 08 Mar 2013 10:22:43 +0000

Volcanos may be countering greenhouse warming

(image info and credits)

Fake skeptics of anthropogenic global warming love to set up the straw man that mainstream climate science believes that CO2 is the one and only driver of climate change. They can then use it in many different attacks, such as gee whiz isn't it stupid that they haven't even thought of the sun's influence. This is of course patently false as even the most cursory survey of actual scientific content will quickly reveal. This straw man is also an implicit part of the argument that the "16 year pause" in global warming proves that CO2 is not a climate driver. If CO2 has risen and temperature has not, then the theory of AGW has failed, they say. Well, this would only be true if CO2 were believed to be the only possible driver of the surface temperature record. (For this post I am ignoring the two facts that, one, 16 years is not enough to unambiguously show a trend and two, there actually is an upward trend).

Well, some recent research out of the University of Colorado, Boulder has found that despite the lack of any major eruptions, like that of Pinatubo in 1991, there has in fact been a significant increase in volcanic aerosols in the stratosphere over the last decade. This increase is large enough that its cooling effect could mask as much as 25% of the greenhouse warming we would expect to see if CO2 really were on its own as a climatic influence.

Between 2000 and 2010, the average atmospheric concentration of carbon dioxide — a planet-warming greenhouse gas — rose more than 5%, from about 370 parts per million to nearly 390 parts per million. If that uptick were the only factor driving climate change during the period, global average temperature would have risen about 0.2°C, says Ryan Neely III, an atmospheric scientist at the University of Colorado, Boulder. But a surge in the concentration of light-scattering particles in the stratosphere countered as much as 25% of that potential temperature increase, he notes.

Further modeling indicates that the Asian Brown Cloud, unpleasant and influential as it may be regionally, does not explain the global data being recorded by satellite observation.

Now, by using a computer model that includes processes due to global atmospheric circulation and atmospheric chemistry, Neely and his colleagues show that the human contribution of aerosols to the stratosphere was minimal between 2000 and 2010. In one set of simulations, the researchers estimated the effects of all known volcanic eruptions, including the quantity of aerosols produced and the heights to which they wafted, on the month-to-month variations in particulate concentrations.

The pattern of stratospheric particulate variations during the past decade “shows the fingerprint of volcanoes, with the right episodes showing up at the right time,” says William Randel, an atmospheric scientist at the National Center for Atmospheric Research in Boulder.

This is an excellent illustration of why what the IPCC publishes are not called predictions, nor can they fairly be treated as such. They are projections of what would happen given assumed trajectories of key climatic forcing agents. When those agents, be they insolation, CO2 concentrations, stratospheric aerosol concentrations, ozone or albedo changes, do not actually change the way it was assumed in a climate model run, this is not the fault of the model.

So in summary, we have now yet another reason to dismiss the suggestions that recent surface temperature trends require the scrapping of the last 150 years of research and we must abandon the idea that humans are changing the global climate. We are changing the global climate, and the temporary amelioration of our disastrous warming influence by other natural factors is not likely to last long.

illconsidered Fri, 03/08/2013 - 05:22

Tags

Coby

Of course, you know that deniers are also going to say that this research proves that volcanoes emit more CO2 than humans. In 3, 2, 1, ...............

mandas, can you cite articles which quantify CO2 emissions from submarine volcanoes in the pacific ocean?

Yes, so can you if you only google.

The US geological survey group look at that sort of thing for the USA.

All volcanoes add up to between less-than-1% and 3% of human production.

This last paragraph is a mess:

"So in summary, we have now yet another reason to dismiss the notion that recent surface temperature trends require the scraping of the last 150 years of research we must abandon the notion that humans are changing the global climate."

Scrapping, not scraping, I think, embedded in an accidental run-on sentence which is also missing a negation.

Feel free to delete my comment if you fix the sentence.

That was a mess, is hopefully better now...

Of course do volcanos counteract any atmospheric warming. The degree of the cooling effect is completely unknown since science has no sufficient values about submarine volcano eruptions. This deficiency in knowledge and GCMS parametrization is insufficiently known to the people outside the climate science circles, i.e. among politicians, media people, ordinary people like wow, jan, mandas, marco, etc. anf many other back seats in the audience without knowledge about what's going in science.

"Of course do volcanos counteract any atmospheric warming"

Really? So ANY amount of atmospheric warming is removed by volcanoes? But that would mean the world would drop to -33C after an eruption.

Please explain why this doesn't happen.

And how does freddykaitroll propose submarine volcanoes "counteract" atmospheric warming?

This "ordinary [person] not only knows about submarine volcanoes, he even knows that their effect on global climate, based on the assessment of volcanologists, is unlikely to be anything more than noise. Their effect on the trend is likely even less, as there is no evidence whatsoever of a trend in activity in the submarine volcanoes that are being monitored.

Freddykaitroll is once again showing off his ignorance.

coby, people ask me something and you preven me from answering. At least you could inform the blog participants that you censor me. Could you please com back to civility and abstain from German nazi police-like actions against me and civilized manners. Be a man and try to avoid the impression that you are one of the most primitive censors on the internet. I have already been banned several times from alarmist blogs, but every time the blog master had announced it. Not too long ago you proudly stated here that you would not censor any person. So what is your problem??
[coby: I have never said I would not censor anybody, and besides you have not been censored, I am just slowing you down. That makes your trolling a little less enjoyable for you, then that is probably the point. I do however really dislike sock puppets, take your handle either Kai or Freddy and stick with it.]

"And how does freddykaitroll propose submarine volcanoes “counteract” atmospheric warming?"

And without heating the oceans to be noticed, either.

"At least you could inform the blog participants that you censor me."

Censorship is government stopping you speaking, right?

And you can still type what you want elsewhere, can't you? So you're not being censored at all, you're just not being given a platform by someone else to speak.

Get your own.

coby, thank you, fair enough. I slow down, you are right.

What made people sick? Dust and aerosols at Ground Zero

egrossman — Wed, 28 Sep 2011 13:41:17 +0000

What made people sick? Dust and aerosols at Ground Zero

by Elizabeth Grossman

Why some people who inhaled the airborne contaminants unleashed by the destruction of the World Trade Center on September 11, 2001 became sick for only a short time, why some have become chronically ill, and others terminally ill, may never be known. What is known, however, is that the dust and aerosols released in that disaster contained a potentially treacherous mix of everything that was in those enormous buildings and in those aircraft. What is also known is that, as Paul J. Lioy, professor and vice chair of the Department of Environmental and Occupational Medicine at the Robert Wood Johnson Medical School at the University of Medicine and Dentistry of New Jersey, says succinctly in his book, Dust: The Inside Story of its Role in the September 11th Aftermath, "no research had ever been done on the toxicology of such a mixture as WTC dust." Ten years later, the impacts of that mixture are all too real in the form of lung and gastrointestinal diseases for many of those who worked at or near the site on 9/11 and in the days, weeks, and months that followed.

Vividly recounted by doctors involved in the ongoing medical studies of those impacted by WTC material exposures who spoke at the September 16 NYCOSH meeting on worker and community disaster health protection and, in emotional testimony from those who are now ill, is the seriousness of these conditions. For most who've been stricken by severe chronic illness and worse, also vividly described was their lack of expecting that what they had encountered by breathing 'Ground Zero' air would or could take such a toll.

Denise and Rhonda Villamia, sisters who volunteered first "spontaneously," as they described it, and then with the Red Cross several days a week or more for about six months beginning in September 2001, said their lives are "permanently changed" as a result of Ground Zero exposures. The sisters helped maintain workers' sleeping areas as well as boot and hand washing stations and brought provisions to those working on 'the pile.' Both are now suffering debilitating chronic respiratory and gastrointestinal illnesses. Daniel Arrigo, who worked with Local 79 of the Laborers International Union of North America and spent four months clearing wreckage from the World Trade Center site, spoke while being supported by supplied oxygen. He now suffers from chronic lung diseases that include bronchitis and severe gastric reflux.

Dr. Laura Crowley, specialist in pulmonary health and assistant professor of preventive medicine at Mount Sinai School of Medicine, reported on the treatment and monitoring of people exposed to hazards at Ground Zero. She reported that more than 30,000 people are enrolled for monitoring and more than 15,000 are receiving treatment for a list of conditions that includes upper and lower respiratory illnesses, and gastrointestinal, musculoskeletal, neurological, and psychological disorders. Until the passage of the James Zadroga 9/11 Health and Compensation Act of 2010, the World Trade Center Medical Monitoring and Treatment Program provided screening and treatment to responders and community members, but the program's Congressional appropriations were never certain for more than a year at a time. Since July 1, 2011, the newly established World Trade Center Health Program has taken over the monitoring and treatment functions, and it has the advantage of being funded by mandatory spending through the end of fiscal year 2015.

Results from monitoring
Among what the program is tracking are emerging and long-term latency diseases that include cancers. One of those that appears to be occurring in excess of what might be expected, is sarcoidosis, explained both Crowley and Dr. David Prezant, Chief Medical Officer for the New York City Fire Department Office of Medical Affairs. This is a disease in which tiny clumps of abnormal tissue called granulomas (clusters of immune cells) form in certain organs. When these granulomas form in the lungs, they that can cause inflammation that impairs breathing, and possibly lead to pulmonary hypertension, among other effects. Some of these symptoms are similar to those of certain stages of silicosis and asbestosis.

While much of the environmental monitoring of World Trade Center dust focused on asbestos, Dr. Joan Reibman, director of the Health and Hospitals Corporation World Trade Center Environmental Health Center associated with Bellevue and New York University hospital, reminding the NYCOSH conference that the dust contained other materials, including silica, talc, titanium, copper, chromium, aluminum silicate, as well as other substances associated with pulverized cement. In his book, Lioy notes that the dust also contained lead, glass shards and fibers, and what came to be called slag wool, in particles that ranged from the coarse to the very fine. Among what's been found in lung tissue of people who were exposed to WTC dust are carbon nanotubes, explained Bruce Lippy, who was formerly industrial hygienist for the International Union of Operating Engineers and is now an independent consultant. Research suggests that carbon nanotubes may affect lung tissue in ways similar to asbestos fibers.

The variety of particle size, the presence of so many large particles, and the high alkalinity of much of the dust, explains Lioy, are likely contributing factors to the health effects of exposure to World Trade Center dust.

The role of aerosols
For those at or near the World Trade Center on 9/11 or immediately following before the initial dust clouds had completely settled or were damped down by rain, exposure was not only to the components of what's come to be called WTC dust, but also to aerosols - a mixture of gasses and particulates. Lioy writes:

In retrospect, during the first twenty-four to forty-eight hours post-collapse, we should have been calling the WTC dust the WTC aerosol. ... That WTC aerosol contained both the dust and gases that were the net result of the emissions for the collapse of the WTC. Unfortunately we will never know completely what was in this WTC aerosol because we did not measure the gaseous phase of the combusted material released into the atmosphere.

As for the aerosols' likely effects on people, Lioy explains, "Those gases have been known for years as being very toxic in human lungs," and would likely have contained a mix of hydrocarbons associated with fuels as well as from burning of various other petroleum-based materials.

"We have no idea how toxic it was but you couldn't have dragged me off that pile. You couldn't have dragged any of us off that pile. We have an unwritten bond, if any of us go down, we have an obligation," said Patrick Bahnken, president of Uniformed EMS, Paramedics and Fire Inspectors with the New York City Fire Department, of the time he spent at 'Ground Zero.' But he said, "Until we start talking about cancer and hold people in power accountable, we'll continue to hear the bagpipes play, and personally, I'm tired of hearing them."

What was made clear from speaker after speaker at the NYCOSH conference was continued anger and frustration at the government assurances of safety in the days immediately following 9/11. "What we were told at that time was quite remarkable," said Micki Siegel De Hernandez, health and safety director of Communications Workers of America District 1. "This has informed every decision that followed. We are still living with those decisions."

Elizabeth Grossman is the author of Chasing Molecules: Poisonous Products, Human Health, and the Promise of Green Chemistry, High Tech Trash: Digital Devices, Hidden Toxics, and Human Health, and other books. Her work has appeared in a variety of publications including Scientific American, Salon, The Washington Post, The Nation, Mother Jones, Grist, and the Huffington Post. Chasing Molecules was chosen by Booklist as one of the Top 10 Science & Technology Books of 2009 and won a 2010 Gold Nautilus Award for investigative journalism.

egrossman Wed, 09/28/2011 - 09:41

Tags

Environmental health

Occupational Health & Safety

Another little-noted impact in the aftermath of the WTC collapse was the increase in dioxin/furan exposure, especially to those on-site. EPA (in 2002) estimated a 10% increase in body burden for these workers, but calculated that this would make little difference in their long-term health. Other analyses of dust levels on buildings nearby (S. Rayne, et al., ES&T, 2005) suggest that the exposure may have been higher, but in any case the full range of health effects would not be observed yet. Stay tuned.

As far as I know, no one measured alpha emitting particles in the dust (that would have come from the thousands of smoke detectors containing amercium 231 that burned) and cause lung cancer.

Emphasis on "complexity" of exposure or agents like dioxin (which have not previously been associated with respiratory and GRDS) distracts from generalizing the health effects observed among WTC responders and the community. It was the dust! Conventional measurements were made. The scientific questions are: whether the conventional measurements are appropriate for a fire and building collapse site (wherever it is); or, is the conventional interpretation of the conventional measurements appropriate. Specifically, what are the appropriate particulate criteria for protection at the site.

In the absence of such a consensus, the next time this happens we will be back to saying that even though measurements say there's no violation, we are asking all workers to all wear respirators all the time.

Much of this could have been mitigated had First Responders
been provided with proper FFPR (respirators).

Ash and Lightning Above an Icelandic Volcano

illconsidered — Wed, 21 Apr 2010 08:08:00 +0000

Ash and Lightning Above an Icelandic Volcano

Don't miss April 19th's APOD, a truly awsome sight!

And while on the subject of Eyjafjallajokull and my recent post about it, readers should be aware of a correction on the source site. The best estimate of CO2 is in fact 150,000 tons per day, not 7400, with a possible maximum of 300,000 tons per day. So the graphic is much less compelling, but the story of Joe vs the Volcano is not affected.

illconsidered Wed, 04/21/2010 - 04:08

Tags

Meh.

Where's Sauron? :-)

The website it comes from is a fantastic source of images.

Yeah, it doesn't LOOK like there's much carbon in that there cloud.
But what do you make of WUWT's article about it?

http://wattsupwiththat.com/2010/04/21/guardian-continues-to-spread-misi…

Is it true what he says, that the figures of 150,000 to 300,000 tons a day is comparible to a small industrial nation's emmissions?
This volcano could erupt for months! (years even)
That's an awful lot of Carbon!
(do I need to spell out my point?)

Hi all, I haven't posted for a while, but I've been lurking here and there.
I hope all is well where you are.

michael: http://initforthegold.blogspot.com/2010/04/climate-confusion-bugspotter…

According to the actual geologists report;

http://www2.norvol.hi.is/Apps/WebObjects/HI.woa/swdocument/1015769/Gas+…¶kull+2010.pdf

The 15,000 tonnes/day figure is correct. This was from sampling the fissure eruptions on 1st and 2nd April, before the sub-glacial phase that led to the ashpocalypse. Presumable adding the glacier would affect the amount of ash but not the gas composition?

It's the breitbart sums that are wrong. How surprising...

What About Mid-Century Cooling?

illconsidered — Sat, 25 Mar 2006 16:39:11 +0000

What About Mid-Century Cooling?

This is just one of dozens of responses to common climate change denial arguments, which can all be found at How to Talk to a Climate Sceptic.

Objection:

There was global cooling in the 40's, 50's and 60's even while human Greenhouse gas emissions were rising. Clearly, temperature is not being driven by CO₂.

Answer:

None of the advocates of the theory of Anthropogenic Global Warming claim that CO₂ is the only factor controlling temperature in the ocean-atmosphere climate system. It is a large and complex system, responsive on many different timescales, and subject to numerous forcings. AGW only makes the claim that CO₂ is the primary driver of the current warming trend, as in the rapid rising seen over the last 100 years. This rise has not been smooth and steady, nor would it be expected to be.

If you look at the temperature record for the 1990's you'll notice a sharp drop in '92, '93 and '94. This is the effect of massive amounts of SO2 ejected into the stratosphere by Mount Pinatubo's eruption. That doesn't mean that CO₂ took a holiday and stopped influencing global temperatures, it only means that this greenhouse gas forcing was temporarily overwhelmed by another opposite forcing.

The situation is similar to the cooling seen in the 40's and 50's. During this period the CO₂ warming (a smaller forcing at the time) was temporarily overwhelmed by by other factors, perhaps foremost among them, an increase in human particulates and aerosol pollution. Pollution regulations and improved technology saw a decrease in this different kind of emissions over the 60's and 70's and as the air cleared, the CO₂ signal again emerged and took over. Below, courtesy of Global Warming Art, is an image of the current understanding of the factors and their influence for the climate of the past century.

As the graph shows, as well as aerosol pollution (the sulphate line), volcanic influences were increasingly negative during the period of global cooling as also solar forcing slightly declined. All forcings taken together and run through the model are a very good match for the observations. (Please see the source page for details of what model and what study this image is derived from.)

So rather than confounding the climate consensus, mid-century cooling is actually a good test for the climate models, one they are passing quite convincingly.

Addendum: The opposing effect of cooling from airborne pollutants is often referred to as "Global Dimming" and Real Climate has a couple of articles on that effect:

One emerging concern is that as the pollution causing this effect is gradually cleaned up, we may see even greater greenhouse gas warming.

This is just one of dozens of responses to common climate change denial arguments, which can all be found at How to Talk to a Climate Sceptic.

"What About Mid-Century Cooling?" was first published here, where you can still find the original comment thread. This updated version is also posted on the Grist website, where additional comments can be found, though the author, Coby Beck, does not monitor or respond there.

illconsidered Sat, 03/25/2006 - 11:39

Tags

sceptic guide

aerosols

temperature

Why haven't you updated the graph to show current temperatures?

[ I will do that ASAP, these articles were written two years ago, my apologies.]

As a skeptic, I would postulate that it is because current temperature anomalies are around zero, and have gone negative.

[The short term trend has stalled, yes, but the anomoly is still .4oC as of 2007 (see CRU)]

It's such an easy spot on any alarmist site. Just look at the right hand side of graphs, and see when they truncate them.
Nick

[No, no conspiracy here, just a stale web page! Thanks for pointing it out. - coby]

Thanks, Nick, I've updated the graph as you rightly suggested. Other responses to you are inline, above.

" but the anomoly is still .4oC as of 2007 (see CRU)]"

Down to 0.2C or less as of 2008.

2008 was cooler than 8 of the previous 10 years and no warmer than 1980.

Hi Travis,

What source are you using? You are very incorrect in your statements. I have an idea what the misunderstanding relates to, but would appreciate it if you could point me to your information source.

(see http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/"

Hi Travis,

What source are you using? You are very incorrect in your statements. I have an idea what the misunderstanding relates to, but would appreciate it if you could point me to your information source.

(see http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/"

First to Travis, you need to supply a link so Coby can pick the crap out of it, whilst at the same time use words like "perhaps" when stating his case.

Coby i have another theory as to why the temps went down from 1940 to 1970 and then up from 1970 to 1998 and now why they are going back down again.

It is called the "Pacific Decadal Oscillations" you will find it listed under "science" so do yourself a favour and look it up.

Hi Crakar,

The problem with your PDO theory is that internal variability can not explain a net gain in thermal energy. Ups and downs maybe, but a century of steady climbing requires some kind of change in the radiative balance, i.e. a forcing of some kind that is external to the system.

Coby,

I thought i would mention the PDO bit because in the "answer" section of this topic you only mention man made pollutants as a cause for the cooling periods rather than the myriad of other non human factors that drive the planets climate. Therefore i found the "answer" section to be highly misleading. However i do understand for the need of simplicity and how hard it would be to cover all of the factors.

Having said that i believe you have come close to the heart of this issue, Lets assume that ONLY changing PDO and El Nino/La Nina cause a 30 year approx swing in planetary climate why has the temp been slowly rising?

As you state "but a century of steady climbing requires some kind of change in the radiative balance, i.e. a forcing of some kind that is external to the system."

What external forces could cause this? Well some beleive it is soley C02 others believe the Sun plays a large part as well, submerged volcanoes can also warm oceans and the list goes on...........

Travis is correct when he states the globe is cooling, yes it is above the anomoly but lets look at the big picture, and that shows the planet is cooling.

The question is will it continue to cool for another 20 years or so or will it get warmer in the short term as the IPCC etc state?

For me, history shows the planet warming and cooling the latest warming started 300 odd years ago and there is not a shred of evidence that points to C02 being a major driver of the warming, having said that all the evidence and theories that points to other sources as a major climate driver are still in their infancy.

I am more inclined to beleive that as you state the PDO plays a major role but their are other factors at work and to me the sun plays a much larger role than we understand. How big i am not sure but i beleive it to be much more than C02. Of course i might be wrong and if the temp starts to go up soon again then i suppose i am.

My question to you is if the planet continues to cool (lets assume it does) at what point would you abandon the AGW line of thought? What anomoly number (0, -.2 etc) would you consider as the level where C02 goes from being a major player to a bit part player in climate drivers?

For me it matters little what the temperature readings say from year to year, even the global temperatures. There are so many variables (forcings) that go into the averages that in the short run the temps are almost irrelevant. The danger is the steady increase each year of greenhouse gases, especially CO2. Now if we were to see those start to decline then we would have to rethink the entire theory of anthropomorphic climate change. But until that happens, the CO2 levels in the atmosphere are like a loaded gun at our head waiting for the other forcings to align. That is when we will see runaway temperatures as the greenhouse gases magnify the effects of other forcings such as sun activity and deforestation.

mikatollah,

"For me it matters little what the temperature readings say from year to year, even the global temperatures. There are so many variables (forcings) that go into the averages that in the short run the temps are almost irrelevant."

Agreed

"The danger is the steady increase each year of greenhouse gases, especially CO2."

Doubling CO2 will have half the impact of the previous doubling which was half the previous doubling. (I'll leave aside my contention that the CO2 absorption band is already saturated).

The levels of CO2 have been far higher than double the current levels - and in those times the oceans teemed with life including the current corals and other of the older groups of sea life that still exist today - lowered Ph or not. (Reports from the less politically correct experts state that the coral like the Barrier Reef is NOT suffering but that's another argument).

Given what we know about atmospheric CO2 concentration, that it has been higher in the past without the world turning into a desert and in fact when it was higher the Earth seemed to flourish more, I don't see any danger in higher CO2. I am becoming less and less convinced by the hypothesis of AGW which depends on apocalypse to get 'action' which always appears to be higher taxes.

Rant,

Strangely the more the histrionics from the proponents of AGW the more the doubt in what they are saying. So it was the Nobel and Oscar winning "An Inconvenient Truth" that convinced me that CO2 driven AGW was probably not real. If one has to tell untruths to support a hypothesis - then it cannot be correct.

So let us assume that the world was really going to come to an end in only 4 years (Hansen) with CO2 output as it is now. Is it responsible to reduce the number of temperature measuring stations and only keep those that are decrepit and known to be incorrect? Is it responsible to allow type approval to vehicles whose operation increases the CO2 in the atmosphere (locally or remotely)? Is it really responsible to allow the transoceanic and transcontinental transport of groceries? Is it responsible to allow China and India to carry on building coal fired power plants? etc etc

What we DO see is taxation taxation taxation just enough to get money but not enough to stop what is going on - and the AGW proponents crying crocodile tears as they fly off to the next tropical convention center where they cram 4 hours work into 2 weeks.

This is NOT a convincing case

The worst argument (and there are many) against human induced climate change is that greenhouse gases are not heating up the planet or they are not as bad as the scientists want us to believe. I don't know if doubling the CO2 levels in the atmosphere is going to have half the impact as in the past or twice as much. But neither do the GW deniers. And I'm not willing to bet everyone's future on the slim chance that they may be right.

Given the strength of the evidence that supports the global warming theory, the right thing to do is take action to reduce the amount of greenhouse gases we pump into the atmosphere each year. That is where the legitimate debate has shifted.

mikatollah,

Every scientist worth his salt knows the logarithmic relationship between C02 and temp, ie the doubling effect, both AGW proponents and the "deniers".

And just what is this "strength of the evidence that supports the global warming theory"

The IPCC projections for C02 levels to 2100 are already way too high after only 8 years!! Therefore their predicted temp for 2100 is already completely wrong.

C02 levels have been much higher in the past they were about 6000ppm (as opposed to 385ppm now), before the last ice age (the reasons for the ice age are debatable) but the fact still remains C02 did not stop the advance of said ice age, why is this so?

I do not know any "denier" that will state C02 has nothing to do with temp etc, however there is much debate on how much C02 causes the temps to rise. You need to do a bit of research yourself on these things to get a balanced view as i am sure i cannot and do not wish to convince you either way.

But remember if you have a computer model written based on assumptions, data inputted based on assumptions then what would you expect to get out? Like the old saying "GIGO" which translates into garbage in, gods truth out.

In summary, after 20 years the IPCC has not reduced C02 emmission by one molecule, after all the talkfests at some of the worlds most beautiful locations all they have come up with is an agreement that lets the worlds largest producers to keep on producing. In my country legislation will soon be debated that will allow the big producers to get carbon credits for free!!!! FOR FREE!!!!!!!!!!!!!!!!!

But dont worry none because i will be required to pay a TAX, and we like the rest of the world will continue to produce C02.

Since we haven't reached the year 2100 yet it is impossible to know accuracy of the IPCC temperature projections. What we do know for sure is that CO2 is increasing each year, man is causing this rapid increase, and the effect of the additional CO2 is to warm up the planet, possibly above levels that can sustain human life.

And remember, the concern here is the effect of rapid warming on human life. Were the CO2 levels to rise again to 6000 ppm it would be the end of human life as we know it. The fact that we had runaway CO2 levels 500,000,000 years ago is a poor argument for not paying attention to 21st century warming. Human development has occurred over a relatively narrow range of atmospheric CO2 levels.

Quote "Since we haven't reached the year 2100 yet it is impossible to know accuracy of the IPCC temperature projections."

There is a lot of irony in this statement as i thought the models were bullit proof?

Quote "What we do know for sure is that CO2 is increasing each year, man is causing this rapid increase, and the effect of the additional CO2 is to warm up the planet, possibly above levels that can sustain human life."

C02 comes from many sources, the oceans are the largest C02 deposit. C02 lags temp by at least 800 years so tell me how much C02 has man produced? And show me the proof it has caused all the warming from the past 60 to 70 years.

Co2 levels were well above 5000ppm or more when the dinosaurs were alive (could man survive these levels?)

The smoothed Co2 levels were about 307ppm in 1940 up to about 337ppm in 1980, then to a bit under 385 in 2007

How many thousands of years would it take to reach 6000? We need to keep this in perspective something the IPCC has failed to do, as i said after 8 years into a 100 year prediction they are already wrong, this effects the predicted temp as well dont forget.

Thanks for response

Cheers

I don't believe anyone has ever made the argument that climate models are "bulletproof". That is a straw man, and does not advance your argument... the models are tools used to make predictions based on the physical evidence.

We have a good idea what the CO2 levels have been in the atmosphere for the past several hundred thousand years, thanks to the ice core research. We also can see what has happened to them since the mid 19th century, which is roughly the beginning of the industrial age. The correlation is so clear to me and I don't know why some of my friends can't see it. Well, actually I do know, but I try to be nice anyway.

Sadly Crakar, there will never be enough proof for people like you. By that I mean folks who are too ideologically blinded to see the evidence. Fortunately, we don't need you to take action to reduce greenhouse gases. But it is important to respond to this nonsense so that people do not become complacent.

Don't hate the science...

Mikatollah,

Oh but it does advance my argument, the AGW theory is based primarily on model predictions and very little empirical data, therefore it is essential that the models are accurate or bullit proof. Models are not proof etc.

I suggest you take another look at the correlation you speak of, C02 levels have been up to 20 times higher in the past and yet temps have remained vertually steady at around 22C. In fact there seems to be very little correlation up until recently (as in thousands of years). Even then the correlation shown shows C02 LAGGING temp by about 800 years.

Co2 does not drive temp it is the other way around and C02 has very little effect on the green house.

There are many climate drivers out there that actually drive the climate for example, ocean currents that switch evey 30 years or so, ENSO and of course the sun.

Now if you want to look at correlation take a look at sunspot activity and the temps on Earth.

C02 is the gas of life below 250ppm plants stop growing, at 150ppm plants die so just how low do you want C02 to go?

All of these arguments you make have been made and debunked on this and other sites many times over, so there is no need to rehash them here. Just for the record, my favorite is the one where plants need CO2 or they will die. Interesting variation (and by interesting I mean bizarre) on the "CO2 is good for us" argument.

AGW theory does not exist because of computer modeling. The theory existed long before computer modeling and it's fate will rest on empirical evidence, not computer generated predictions. This is a red herring that I see every day to try and confuse the American public into inaction. The war against the truth of climate change is not about the science, it is about a disinformation campaign conducted as a PR battle.

Deniers have no scientists... they have bloggers.

Coby,

Your argument is very well reasoned but I do not think it is supportable. Hansen at Climate Change Congress in Copenhagen stated that:

Even if we accept the IPCC aerosol estimate, which was pretty much pulled out of a hat, it leaves the net forcing almost anywhere between zero and 3 watts.

We do not have measurements of aerosols going back to the 1800s â we donât even have global measurements today.

Any measurements that exist incorporate both forcing and feedback.

Aerosol effects on clouds are very uncertain.

As I under stand what Hansen is saying, there is no evidence to back up you position. Further, if what I read is correct, and I am not a statistian, on lucia's site, the acutal temperature falls outside the 95% confidence interval for the multi-model mean for GCM's that do incorporate volcanic forcings.

I think that you may be right, but there is no evidence to prove it. We just had a studies that show that aerosols are responsible for cooling the Atlantic and yet another study shows that aerosols are responsible for 1/3 to 2/3 of the warming in the Arctic.

This looks like this study explains the mid-century cooling better than aerosols.

http://www.uwm.edu/~kswanson/publications/2008GL037022_all.pdf

I have two critiques of the main article:

First, it appears to me that what has been done with the back-correction of the model for Volcanic and Aerosol effects is somewhat problematic. The key question is how do they know that they have the correct climate sensitivities for these effects? It appears that the authors of this study have assumed that the AGW models are correct and have used the offset between the AGW model results and the temperature record to calibrate the sensitivities of the Volcanic and Aerosol effects. That is fine, but it means they cannot then use those same sensitivities with the same data set to prove that the AGW models are correct!

The sensitivities they have gotten may be correct, but we will only be able to verify that is the case in the future when we have new data showing that the combined model including all effects correctly predicts the temperature trends.

My second critique is just a minor quibble about the last line:

"One emerging concern is that as the pollution causing this effect is gradually cleaned up, we may see even greater greenhouse gas warming."

If pollution-derived cooling is removed it may lead to additional global warming, but not to additional "greenhouse gas" warming, unless you are saying that the pollution somehow inhibits the ability of CO2 or other gases to behave as greenhouse gases.

Hi SemiChemE,

Point taken for your second quibble. I hope readers will understand what I meant.

For your first point, climate sensitivities to various forcing are not inputs to the models, they are derived outputs. There surely are many estimates of factors that are poorly constrained by observational data, this will always be the case. And a certain amount of back and forth between model adjustments and data improvements is going to be an ongoing process. But I don't think it is as simple as tweaking the expected effects of sulphates so that CO2 is seen to have a large role.

All of these factors combine and all have various observational data and physical derivations to constrain there possible importance, in the end the validation comes from hind casting, the time scales involved don't really allow for us to wait for predictions.

A while back it was suggested that a change in data collection methods could have resulted in an apparent spike in ocean temperatures (especially the North Atlantic) during and just after World War II. Have the data been corrected for this and does it make any noticeable difference?

Richard,

You are probably talking about this...?

I would assume that the current temperature records that incorporated that data have incorporated the corrections. I have not seen any before-after comparisons with the exception of the schematic guesstimate from the Guardian (you can see it at the link above.

Yes, Coby, that's the one (I looked for it but couldn't find it). I see that the graphic you used is based on 2004 data so it obviously won't include the 2008 correction. I haven't seen anything that explicitly included it but, if the Independent's graphic is any guide, the 1940s peak and dip might be a lot less conspicuous.

Temperatures seem to have been higher in the past, if the graphs created from the Vostok data are to be believed, with much lower levels of CO2. How do we know that what caused THOSE warmer climates isn't causing THIS warmer climate?

It also appears that the temperature increases PRECEDE the CO2 increases (which makes sense to me in that warmer climates are more conducive to life), so how do we know "how much" of this (or any other) warmer period is caused by CO2?

Anthony: it's called Milankovitch cycles. We know we're not in part of a cycle that should give warming. We're in part of the cycle that should give colder temperatures.

Moreover, we know that in the past(!) temperature increases *started* before CO2 increases, but for most of the time the two then increase in parallel. I don't see the "sense to me" in increasing CO2 levels at higher temperature related to life. Life doesn't just exist of CO2 emitting species. In fact, you need plants in larger amounts to be able to sustain the food chain. And plants *use* CO2.

Regarding your last question: physics.

Marco,

Re post 26

You delight yourself in ridiculing me at every opportunity but i will refrain from returning the favour this time as i know you can do better. The next time you type such rubbish i will not be so lenient.

The "source page" for the Climate Change Attribution graph does not come up.

Good catch Jerry. The correct link is http://www.globalwarmingart.com/wiki/File:Climate_Change_Attribution_png

It looks like the blog software was trying to treat that external link as an internal link. Coby will hopefully see these comments and fix that.

Fixed now, thanks guys.