Researchers Tie Increase in Atmospheric Moisture to Human Activities
18 September 2007
A new study by an international team of researchers has identified a human “fingerprint” on the climate in the increasing total moisture content of the atmosphere, despite the relatively short length (19 years) of the observed water vapor data. The study appears this week in the online edition of the Proceedings of the National Academy of Sciences.
Increased atmospheric water vapor—which is itself a greenhouse gas—amplifies the warming effect of increased atmospheric levels of carbon dioxide—a “positive feedback.”
When you heat the planet, you increase the ability of the atmosphere to hold moisture. The atmosphere’s water vapor content has increased by about 0.41 kilograms per square meter (kg/m²) per decade since 1988, and natural variability in climate just can’t explain this moisture change. The most plausible explanation is that it’s due to the human-caused increase in greenhouse gases.
—Benjamin Santer, lead author, Lawrence Livermore National Laboratory
There are three reasons to pay attention to water vapor in the atmosphere, Santer wrote in a summary of the paper:
Water vapor is itself a potent greenhouse gas, so it is important to have a good understanding of the cause or causes of its recent increase.
Atmospheric moisture content is one of the large-scale environmental conditions that influences the genesis and development of hurricanes. In the absence of countervailing changes in other factors, an increase in water vapor would favor the development of more intense hurricanes.
The observed increase in water vapor provides independent evidence of the reality of warming of the lower atmosphere. The observed water vapor increase since 1988 is consistent with pronounced warming of the surface and lower atmosphere, but fundamentally inconsistent with claims that the lower atmosphere has cooled over recent decades.
Using 22 different computer models of the climate system and measurements from the satellite-based Special Sensor Microwave Imager (SSM/I), atmospheric scientists from Lawrence Livermore National Laboratory and eight other international research centers showed that the recent increase in moisture content over the bulk of the world’s oceans is not due to solar forcing or gradual recovery from the 1991 eruption of Mount Pinatubo. The primary driver of this ‘atmospheric moistening’ is the increase in carbon dioxide caused by the burning of fossil fuels.
This is the first identification of a human fingerprint on the amount of water vapor in the atmosphere.
—Benjamin Santer
“Fingerprint” studies seek to identify the causes of recent climate change and involve rigorous comparisons of modeled and observed climate change patterns. To date, most fingerprint studies have focused on temperature changes at the Earth’s surface, in the free atmosphere, or in the oceans, or have considered variables whose behavior is directly related to changes in atmospheric temperature.
The water vapor feedback mechanism works in the following way: as the atmosphere warms due to human-caused increases in carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons, water vapor increases, trapping more heat in the atmosphere, which in turn causes a further increase in water vapor.
Basic theory, observations and climate model results all show that the increase in water vapor is roughly 6% to 7.5% per degree Celsius warming of the lower atmosphere.
The authors note that their findings, when taken together with similar studies of continental-scale river runoff, zonal-mean rainfall, and surface specific humidity, point toward an emerging human-caused signal in the cycling of moisture between the atmosphere, land and ocean.
This new work shows that the climate system is telling us a consistent story. The observed changes in temperature, moisture, and atmospheric circulation fit together in an internally- and physically-consistent way.
—Benjamin Santer
The Livermore authors included Karl Taylor, Peter Gleckler, Jim Boyle and Stephen Klein. Other scientists contributing to this research were Carl Mears and Frank Wentz at Remote Sensing Systems in Santa Rosa, Calif.; Tom Wigley, Jerry Meehl, and Warren Washington at the National Center for Atmospheric Research in Boulder; Tim Barnett and Dave Pierce at Scripps Institution of Oceanography in La Jolla; Wolfgang Brüggemann at the University of Hamburg in Germany; Nathan Gillett at the University of East Anglia and Peter Stott at the Hadley Centre for Climate Prediction and Research (both in the U.K.); Toru Nozawa at the National Institute for Environmental Studies in Japan; and Mike Wehner at Lawrence Berkeley National Laboratory.
Resources:
B.D. Santer et al. “Identification of Human-Induced Changes in Atmospheric Moisture Content” PNAS
This'll stir the pot. The anti-warming advocates have been hammering on the fact that water retains heat a lot more than carbon dioxide, so man-made pollutants can't be causing the warming.
Posted by: litesong | 19 September 2007 at 12:16 AM
Water vapor is also a product of hydrocarbon combustion.
Example:
CH4 + 2O2 → CO2 + 2H2O + heat
Posted by: AES | 19 September 2007 at 01:19 AM
"Researchers Tie Increase in Atmospheric Moisture To Human Activities"
So I take it fogging up the windows in your parked car will now be strictly verboten?
Seriously though, it should not come as a surprise that water vapor is an issue. The reason it was previously ignored is that any water produced by processing or burning fossil hydrocarbons is quickly absorbed into the much larger natural hydrological cycle. That meant it was difficult to trace any change in water vapor content back to anthropogenic sources. This is the first report I've seen that attempts to document such a link.
The warming that is undoubtedly going on is boosting the hydrological cycle. Most of the water evaporation occurs over the oceans, though forests and cultivated land also contribute. CO2 already dissolved in the oceans - in much greater concentrations than present in the atmosphere - is also outgassing at a higher rate, though any increase in plankton growth would offset that to some extent. The only reason we don't have a runaway greenhouse effect is that clouds increase the albedo.
The underlying notion is that anthropogenic GHG emissions are not directly responsible for the full extent of observed increases in global temperature and other effects (such as melting ice caps) that are consistent with a global warming scenario. Rather, they trigger and/or amplify natural climate dynamics.
Posted by: Rafael Seidl | 19 September 2007 at 04:13 AM
Finally, Someone exposes "Big Water". "Big Oil" "Big Business" and the "Big Three" are mere pawns. "Big Water" is really calling the shots. The question is why? and who is behind "Big Water"? My guess is Aliens seeking to make our planet more suitable for their invasion fleet, or it could be the skull and bones society, seeking to improve windsurfing conditions off Nantuckett.
Posted by: ESabre | 19 September 2007 at 04:32 AM
Just once in a while I want to see an announcement of a major new paper or breakthrough that's widely accepted and contains a surprise that's good news. It seems all we get on the enviro front are negative surprises--things are warming and melting much faster than thought, the Southern Ocean is saturated with CO2, this water thing, etc.
Oy.
Posted by: Lou Grinzo | 19 September 2007 at 05:25 AM
Water vapor is also a product of hydrocarbon combustion.
With the exception of water injected into the stratosphere by methane oxidation, direct production of water vapor from combustion has negligible effect. It is utterly dwarfed by water vapor produced by evaporation (including from plants).
Posted by: Paul Dietz | 19 September 2007 at 05:44 AM
On the positive side, won't this help decrease the rate of desertificaion of arid land around the world?
Posted by: gary | 19 September 2007 at 07:45 AM
While everyone's been quoting the LLNL news release, where's the actual paper? I can't find it at all on pnas.org.
Posted by: bluegreen | 19 September 2007 at 08:36 AM
Where does this leave the Hydrogen car. Isn't their only pollutant water vapor. I too am getting a headache.
Posted by: Joseph | 19 September 2007 at 09:11 AM
@Raphael,
You are catching on the real question. This solar caused warming results in a increased solar wind as well as an increase in the intensity of the light radiation emitted by the sun. That increased solar wind acts as a shield to ward off and slow down, the most energetic cosmic rays that penetrate deep into the atmosphere. So deep, that they reach into the troposphere, where they act as ionizing trails and additional formation points for the water vapor to condense into low level clouds. These clouds when present, do have an increased Albedo, cooling the Earth, the absence of the clouds by a marginal amount, reduces the Albedo, and certainly does amplify the warming. It results in slowing the formation of cloud cover is no the same as preventing cloud cover, it merely slow the effect.
Thus the water vapor is in the atmosphere, for a slightly longer time, before forming low level cloud cover, in any case. The result is a more humid atmosphere with less cloud cover, than at other times. Indeed, there was no way to record or to measure the variability in cloud cover when the original fear of warming were posed. That was true only until the satellite measurements became common in the mid 90s.
Even now, all the global weather climate models assume that cloud cover is a constant, that they diddle with a fudge factor. Even when modern Science measurements now shows that is is not constant at all. Cloud cover over the oceans does vary by a few percent, which allows the "green house gas" effect to work more efficiently, and this amplifies the warming.
You are quite correct about that; but the effect is small, and virtually all the warming so induced, HAS ALREADY occurred. The Earth didn't wait around for Science to measure it before it reacts. It does so even in our ignorance.
It raised the temperature of the planet by 6 tenths of a single degree over an entire century.
The effect you propose, is exactly the real, genuine and original basis for the "water explosion" that creates GHG caused but water-based runaway global warming. Hence the dreaded "Water Explosion".
Now that the MEASUREMENTS are in, the warming is restrained to be no more than a ridiculous few tenths of a single degree due to the primary effect of a several trace gases in the atmosphere,and their stimulative effect on H20. In any case, those several trace GHG gases have been reduced to but a single one; as all but CO2 are now no longer rising, but actually declining in the atmosphere.
What you have proposed is the actual basis for the original fear of Global Warming. Didn't you know that?
The problem is that "water explosions" just don't happen in the Earths historical record, as the effect is still a response characterized as an "over damped" response coefficient. The coefficient of water induced warming and what it actually is, was at the basis of the original global warming fears. This was true despite and even though the concerns seemed misplaced. The Science of the 70s and 80s did not know that answer.
If the unmeasured coefficient was positive, you have a system that will go into wild oscillation like any such feedback system.
But all history shows this is PROBABLY NOT the case. The weather and climate on the Earth has always been of a a moderate change (albeit of several degrees) but not wild swings into unrecoverable conditions such as has occurred on Venus. But such evidence while highly suggestive, is not proof. Hence the Global Warming hypothesis based on an assumption of a positive coefficient of feedback as the coefficient was UNKNOWN in the 70s and 80s.
That suggestive evidence didn't prove anything and that's why the Global Warming questions were asked in the 70s and 80s. The Science of the 90s and 2000s show BY MEASUREMENT, that the coefficient is highly negative and not even close to being near the the undamped region.
As a engineer, think of the NOW MEASURED response of the climate system like a feedback response curve; the Now Measured coefficient, is producing a heavily damped exponential function without even a single decaying sinusoid. It is measured NOW; we know that it isn't even in the region of a response curve (UNDER DAMPED) of a decaying exponential with a rate that produces a decaying sinusoid. And it certainly is NOT in the UNDAMPED region where you have a rising exponential with increasingly wilder sinusoids, as such response curve would show.
Early global warming Scientists were sincere, but they did not have the answers. So They posed valid questions and concerns. They asked the questions of the 70s posed as the basis for a sincere concern for a possible and hypothetical Global Warming.
That is why I have repeatedly said the issue is already resolved to those in the scientific know, in the peer reviewed Science papers published in the literature.
It just hasn't permeated into the general consciousness of the entire Scientific community yet. But that is certainly rising as many more are stepping forward to question the Global Warming hypothesis. It certainly hasn't penetrated into the general consciousness of the entire population yet,but it is starting. teh media is now starting to pickup the conflict issues, in the scientific community.
The Science of the 90s and 2000s have answered the questions, and allayed those concerns. That is why the IPCC is slowly and prudently, IMO, shrinking the "global warming" scientific concerns in each periodic update.
That is why I can really say that modern Science has answered the global warming questions and, the GHG fears will be allayed by 2012 to the general polulation. That is when the next IPCC Interim Update is due, (ARV? TARV?), if not before.
That does not mean that all is fine. That the Status Quo is fine.
There is a problem with the availability and security of fossil fuels. But those are other issues as to why we need to transition from fossil fuel as a primary energy source. I agree wholeheartedly, and look forward to the transition to non fossil energy sources. Electrified ground transport, is a necessary condition to this transition.
But that is not germane to the Global Warming discussion or the misplaced regulating of CO2 gas as if it were a pollutant which it is patently not. CO2 is a most necessary and useful gas to the half of the life on the Planet, that of the Plant Kingdom.
Meanwhile the politicians see an opportunity to raise taxes, and they have jumped into it, in ignorance but with both feet; and yelling at the top of their voices. How else could you get a Divinity school drop out produce documentaries that everyone breathlessly listens to? Especially as he proudly says he learned all this at the feet of his mentor, Dr Reveille. No one questions that he then proceeds to contradict and to reverse everything that the late Dr. Reveille taught him.
Posted by: Stan Peterson | 19 September 2007 at 09:47 AM
Lou Grinzo:
Ha! You switched to scary movie channel and complains why all movies are so scary?
MSM are having eternal environmental Halloween season. All news supposed to be scary. Take, for example, two all time records set in September this year: sea ice extend in Arctic is all time low, and sea ice extend in Antarctica is all time high (for about 30 years of satellite monitoring – before such data was non-existed). Currently, when scare of the day is Global Warming, news from Arctic is on the front pages. 30 years ago, when scare of the day was Global Cooling, that would be Antarctica.
Or, say, ocean uptake/outgassing of CO2. Some researches say that ocean dissolving more CO2 than outgassing, and we have panic articles in news papers about ocean acidification. Some researches suggest otherwise, and we have panic articles (apparently read by Rafael) that GW is accelerating. The real picture (annual ocean CO2 exchange with atmosphere is 20 times bigger than antropogenic CO2 emissions, and fluctuates both seasonally and geographically; averaged balance is such as oceans store yearly about half of CO2 emitted by combustion of fossil fuels) is not dramatic enough to make news papers at all.
Or take current article: Earth become wetter. What a beautiful news! More rain and snow, less droughts and famines, Antarctica is building-up continental ice (due to more precipitation, temperature now on South Pole is minus 80 C – if atmosphere would be total CO2, it would solidifies right now on South Pole, like on Mars). Take it from Global Warming perspective: water vapor over the oceans, which dominates South Hemisphere, is rising, yet South Hemisphere is not warming at all (according to all satellite, balloons, and weather stations measurements): climate models predicting run-away warming due to water vapor positive feedback are wrong again, there is no run-away effect.
Of course, if one manages to believe that more droughts and flooding globally could happen simultaneously, any weather event around the globe will be depressing news. As it was the joke in Scotland this summer:
“- It will be dry and hot. We are doomed.
- But it is, actually, wetter and cooler.
- Yep. As I said, we are doomed.”
Posted by: Andrey | 19 September 2007 at 09:49 AM
Flat Earth Johnny's still at it.
Posted by: jack | 19 September 2007 at 11:32 AM
On the positive side, won't this help decrease the rate of desertificaion of arid land around the world? -- gary
That doesn't follow. To get rain you need to have a saturated airmass, that is 100% relative humidity. Relative humidity is a measure of how much water vapor is in the air compared to how much that airmass could hold. It does NOT mean the same thing as absolute humidity. The amount of water vapor an airmass can hold depends very strongly on temperature, doubling every 10C or so. That's the whole point of the paper -- increasing the temperature increases water vapor content but not RH, and increases temperature even further.
Posted by: cidi | 19 September 2007 at 12:16 PM
@ Stan, Andrey -
I was merely trying to articulate why anthropogenic water vapor emissions have hitherto been considered irrelevant relative to other GHGs.
The global climate has been steadily warming since the end of the last ice age, as evidenced by the fact that Carthage was a major military power based on grain production in North Africa. Today, that entire area is not temperate to subtropical but semi-arid to desert. However, there has been an uptick in the rate of global warming ever since the industrial revolution. The aggregate difference to what would have been expected due the pre-industrial natural rate indeed appears to be just a few tenths of one percent at the moment.
One big unknown is, just how much extra cloud cover does that imply and what does that do the long-term trend. The models are indeed still far from perfect on this point. However, I am emphatically *not* suggesting the Earth will experience a runaway greenhouse effect, precisely because dry Venus has long had one and our wet planet does not. That does not mean that warming rates cannot rise substantially above today's levels for a number of decades or even centuries before they come back down again.
Humanity can easily adapt to slow climate change by migration over a period of centuries. The same absolute change in just a few decades would exacerbate an existing, economically motivated trend that is already leading to support for xenophobic politicians on both sides of the Atlantic.
For example, even modest changes in rainfall amounts and patterns over the course of a few decades could easily have a significant impact on agriculture at the regional level, because economies are a lot more volatile than the physical climate system. Additional migration, trade protectionism and/or armed conflicts may result. It is these potential economic and social consequences of climate changes that politicians are worried about, not the small change in temperature per se.
On top of that, there is concern about energy security. In the US, discussion on the topic is quite public, partly because there are still many who assume military might can keep oil-producing countries in line. The majority of Europeans and Japanese depend far more heavily on imported fossil fuels - especially for their transportation sectors. They are also unwilling to invest heavily in any military option, because history has taught them how dangerous it can become. IMHO, the entire present discussion of CO2 in Europe and Japan is therefore, at least to a significant extent, merely a diplomatic way to avoid offending the 800lb gorillas in the room: Russia and OPEC.
Besides, politicians' true motives for legislation are ultimately a moot point for e.g. the European auto industry: if a mandatory CO2 fleet average emissions scheme is put in place, the product mix will have to respect the letter and spirit of that law. Much the same applies for the tougher CAFE limits various Democratic contenders for the US presidency are proposing and, mandatory fuel economy measures in Japan and China.
Posted by: Rafael Seidl | 19 September 2007 at 12:43 PM
Cidi:
Right, but only at sea level in atmosphere without wind and convective circulation (aka in greenhouse, where these processes are arrested by glass roof and walls). In real world warm moist air near surface rises to upper troposphere, adiabatically cools to -50C, and form clouds. Winds carry these clouds elsewhere, and eventually they come down as rain. More moisture always means more rain, somewhere and at some time. It is written in books on meteorology, and it is confirmed historically over millennia: most severe drought happened when climate was cooler.
Rafael, so much misunderstanding… Global climate warmed after ice age, but it is not warming for couple of thousand years, rather fluctuates up and down; Medieval Warm Period and Roman Warm Period were at least same warm as today, and so-called Holocene Temperature Optimum was warmer. Regional multi-century climate changes as in Cartage, Mesopotamia, and Central Asia are happening all the time, without direct connection to global temperatures. Most severe droughts, which destroyed whole civilizations happened more often when climate was cooler. Hotter weather does not mean less rain. It is absence of rain which causes hot temperatures. Recent (1.5 centuries) “uptick in warming” is due to Earth recovering from Little Ice Age, industrialization began to pump CO2 in quantities only about 50 years ago. “Pre-industrial natural rate” existed only in the heads of AGW zealots, who claim that climate was stable and optimal, and hence are real Climate Change deniers.
As for what effect changing regional and global climate would have on countries and regions, you forget that we live in 21 century. Just remember that there is such things as chronic agricultural overproduction (France? Corn ethanol? Vegetable oil biodiesel?), and there is international trade.
As for energy security, it is a big concern. I hate to think that global economy is a hostage of ME, which could explode any moment like keg with gunpowder. But I do not believe that meaningless CO2 emission reduction to address non-existed problem of AGW will do any good to solve our real problems – global poverty, energy insecurity, air pollution, waste of recourses, etc.
Posted by: Andrey | 19 September 2007 at 02:54 PM
Fascinating to watch this cat and mouse game between the alarmists and others less prone to alarm. As has been pointed out, this "paper" is nowhere to be found yet. But it does take the bold step of acknowledging finally, water vapor as the most predominant GHG in our atmosphere (approx 70-80%). Water or Big Water, is now on the carpet as a primary culprit in global warming climate change for behavior modification - lesson 101.55!
On technical merits the data presented here all come from computer models which are at the center of dispute by the scientists called "skeptics." As in the case of Arctic ice, the models appear to be far off the actual field obtained data. A full resolution to the icecap debate is not expected until new satellite data become available in a couple of years.
http://www.climatechangefacts.info/?searchFor=satellite&goButton=go#
Meanwhile we have this paper based on models and satellite data from SSM/I. According to NOAA these SSM/I sensors are designed to effectively "see through cloud cover" to measure surface meteorology, as ocean, land, frozen, snow or mixed. That would mean "see through"
water vapor of course.
http://www.nohrsc.nws.gov/html/opps/ssmihelp.htm
On closer examination it seems questionable that this technology is capable of imaging resolutions required to measure water vapor gas with any accuracy. Indeed the NOAA documents suggest the sensors failing to distinguish far coarser weather events such as heavy rain and snowfall.
Finally, does Dr. Santer, a self-described human "fingerprint"
investigator have an agenda to meet? Hmmm. At the very least we can now discuss the existence of plain old clouds as major climate effectors. Maybe next year we can begrudgingly discuss the effect of solar radiation. Progress!
Posted by: Rich | 19 September 2007 at 02:57 PM
Do I own a house. Yes
Do I know that the house will burn down? No.
Do I even think it likely that the house will burn down? No.
Do I have fire insurance on the house? Yes.
Does man produce prodigious quantities of CO2. Yes
Do I know absolutely that this CO2 is causing climate change. No
Do I think it's possible that we could be damaging our world with CO2. Yes.
Should we reduce our GHG emissions as insurance against global warming? Absolutely!
Posted by: Neil | 19 September 2007 at 04:01 PM
If humidity increases,air polution is eliminated, and hydrogen is the alternate fuel of choice-how will it rain?
Posted by: Devarity | 19 September 2007 at 04:20 PM
Of course we want to prevent against damaging climate change and the adverse effects of fossil fuel combustion. Should it be accomplished by exaggeration or by good science, global vision and awareness of others? The danger is that we discover the insurance salesman has tampered with his actuarial tables in order to get us to buy in. When the tampering is brought to light, the customer forever doubts the word of insurance salesmen - resulting in an expanding microcosm of uninsured doubtful.
Posted by: gr | 19 September 2007 at 07:29 PM
Thanks, Neil, for sharing my sentiment on the issue.
There is no doubt that water vapor is a potent GHG. But, water is in equilibrium with an ocean of water 3/4 the surface of the earth. Increasing the oceanic and atmospheric temperature will drive this equilibrium toward higher atmospheric water vapor concentration, whereas lowering the temperature will do the opposite.
"Anthropogenic cause" of increase of water vapor concentration in the atmosphere is an absurd idea given the existence of the dynamic equilibrium of the water cycle. One can drive the equilibrum either way by manipulating the temperature, but not by putting more water vapor into the air, as it will condense and come down as precipitation.
Stan's idea of cosmic radiation as way of seeding clouds may, however, "hold water" (pardon the pun), as higher rate of cloud formation can drive the water equilibrium a little bit toward lower water vapor concentration since cloud takes away atmospheric water vapor. Clouds' greater cooling effect by altering the albedo has even much more potent effect in driving the equilibrum of vapor-water state.
However, these were natural phenomenons that change slowly in geologic time frame. What we are alarmed about is the very good correlation between anthropogenic exponential CO2 level rise and drastic jump in global temperatures for since the beginning of the industral age, during which time, coal, gas and oil were burned at unprecedented rates, and dumping all the carbon sequestered for billions of years into the atmosphere in a short 150 years!
Remember that CO2 is not in equilibrium state in the atmosphere. But, an escalating exponential rise in CO2 level will cause small rise in global warming, which will then drive the water-vapor equilibrium forward, bringing higher water vapor concentration in a positive feedback vicious cycle since water vapor is an even more potent GHG gas at much higher concentration in the atmosphere, and higher atmospheric temperature will reduce the rate of cloud formation, causing effectively an amplification of the effect of anthropogenic exponential CO2 rise!
Now, Stan, if you can help us derive a way of seeding clouds to reverse this global warming thing...How about jet engines tuned to deliver a lot of particulate matters in the upper atmosphere, eh? Also, jet cargo planes can also be fitted with mechanism to pump out a lot of fine volcanic dusts that hopefully, seed more cloud formation? We just can't wait for cosmic rays to do their part, you know.
Oh, pardon, I forget, you don't believe in global warming.
IMHO, this article is misleading, and may be a subtle kind of proganda from the GW denialists.
Posted by: Roger Pham | 19 September 2007 at 11:09 PM
Clarification to the above:
There is no doubt that water vapor is a potent GHG. But, atmospheric water vapor concentration is in dynamic equilibrium with an ocean of water 3/4 the surface of the earth. There is nothing human can do to influence this, except by increasing the oceanic and atmospheric temperature, which will drive this equilibrium toward higher atmospheric water vapor concentration, whereas lowering the temperature will do the opposite.
Posted by: Roger Pham | 19 September 2007 at 11:18 PM
I'd like to retract this from my previous posting:
"IMHO, this article is misleading, and may be a subtle kind of proganda from the GW denialists."
Sorry, I've slightly misread the article, which attributes the rise in atmospheric water vapor content entirely to rise in global temperature as the result of man-made rise in CO2 concentration in a positive feedback loop, or vicious cycle.
The article does not attribute any other human activities beside causing elevation of CO2 as the cause of the elevation in water vapor concentration. Human contributions such as irrigation, or water vapor released in combustion, are much much less than a drop in the bucket of the huge oceans covering 3/4th of earth surface.
Again, my apology to all the distinguished scientists authors cited in the article from the fine Lawrence Livermore National Laboratory.
Posted by: Roger Pham | 19 September 2007 at 11:59 PM
Andrey
We had a lengthy discussion about whether the planet was warming or not at the report about melting polar sea ice.
http://www.greencarcongress.com/2007/09/arctic-sea-ice-.html#more
Question: Did you see my comment to you at the end of that thread?
I urge you to read it and take a look at the mentioned reference.
Posted by: Henrik | 20 September 2007 at 12:19 AM
@ Andrey -
climate change has always happened naturally, at multiple time scales. If you decompose the reconstructed temperature signal by Fourier analysis and apply a suitable low-pass filter, you get the pre-industrial signal at a time scale of many centuries. That is the one I was referring to.
More rapid natural changes, such as the Little Ice Age, are occurring as well. Indeed, we may currently be in the middle of a rising flank of one of these higher frequency components. If so, anthropogenic activity may be exacerbating something that would otherwise be normal and quite manageable.
That's not being alarmist, it's just that the science is hard enough yet to properly quantify this risk. Decision-makers have to do their job based on imperfect information. Some deny the existence of any risk at all, while others prefer to do nothing disruptive until the risk is better understood. This may prove sensible or an under-reaction - we just don't know yet.
Others are more averse to risk and want to take corrective action now lest the risk proves to be significant and growing, making it more difficult (read expensive) to deal with if they wait. That could yet prove to be an over-reaction to a false alarm, but to the extent that it happens to also deal with energy security issues, it is perhaps the lesser of the two evils.
Posted by: Rafael Seidl | 20 September 2007 at 04:45 AM
Henrik:
I knew what are you talking about and gave you answer in the first post on the subject, long before you ask the question. I wrote:
“Temperatures of the rest of the world (and there is not many weather stations in the rest of the world with record spanning to 1930s: Antarctica has zero, whole Africa has 8, India has about 30, China and Russia has almost nothing because of Cultural and Communist revolutions, Europe also has few because of two World Wars, versus US 2500 stations) is re-evaluated right now.”
And fresh from the press, from World Conference on Recearch Integrity, 16-19 Sept 2007, Portugal, press release by European Science Foundation:
“Addressing the urgent need for fighting fraud, forgery and plagiarism in science world-wide…
The controversies surrounding the recent assessment report of the United Nations' Intergovernmental Panel on Climate Change demonstrates how research integrity is a critical issue not only for the science community, but for politicians and the society as a whole as well. In August 2007 the US National Aeronautics and Space Administration (NASA) had to withdraw previous published historical climate data. The incident came after a Canadian mathematician discovered that the sources used by the Intergovernmental Panel for Climate Change (IPCC) have disregarded the positions of weather stations, plus intentionally using outdated data on China from 1991 and ignoring revised data on the country from 1997.”
Read again: “…plus intentionally using outdated data on China…”
http://www.esf.org/ext-ceo-news-singleview/article/world-conference-on-research-integrity-to-foster-responsible-research-318.html
Rafael:
The irony: Fourier analysis does not have predictive power.
And the question you are raising was addressed a long time ago. RISK MANAGEMENT is much better way to deal with uncertainties of the future then PRECAUTIONARY PRINCIPLE.
Posted by: Andrey | 20 September 2007 at 08:16 AM