Water evaporated from trees cools global climate

From the Carnegie Institution – maybe we should build more cooling towers.

Evapotranspiration - Image: Wikipedia

Washington, DC. — Scientists have long debated about the impact on global climate of water evaporated from vegetation. New research from Carnegie’s Global Ecology department concludes that evaporated water helps cool the earth as a whole, not just the local area of evaporation, demonstrating that evaporation of water from trees and lakes could have a cooling effect on the entire atmosphere. These findings, published September 14 in Environmental Research Letters, have major implications for land-use decision making.

Evaporative cooling is the process by which a local area is cooled by the energy used in the evaporation process, energy that would have otherwise heated the area’s surface. It is well known that the paving over of urban areas and the clearing of forests can contribute to local warming by decreasing local evaporative cooling, but it was not understood whether this decreased evaporation would also contribute to global warming.

The Earth has been getting warmer over at least the past several decades, primarily as a result of the emissions of carbon dioxide from the burning of coal, oil, and gas, as well as the clearing of forests. But because water vapor plays so many roles in the climate system, the global climate effects of changes in evaporation were not well understood.

The researchers even thought it was possible that evaporation could have a warming effect on global climate, because water vapor acts as a greenhouse gas in the atmosphere. Also, the energy taken up in evaporating water is released back into the environment when the water vapor condenses and returns to earth, mostly as rain. Globally, this cycle of evaporation and condensation moves energy around, but cannot create or destroy energy. So, evaporation cannot directly affect the global balance of energy on our planet.

The team led by George Ban-Weiss, formerly of Carnegie and currently at Lawrence Berkeley National Laboratory, included Carnegie’s Long Cao, Julia Pongratz and Ken Caldeira, as well as Govindasamy Bala of the Indian Institute of Science in Bangalore. Using a climate model, they found that increased evaporation actually had an overall cooling effect on the global climate.

Increased evaporation tends to cause clouds to form low in the atmosphere, which act to reflect the sun’s warming rays back out into space. This has a cooling influence.

“This shows us that the evaporation of water from trees and lakes in urban parks, like New York’s Central Park, not only help keep our cities cool, but also helps keep the whole planet cool,” Caldeira said. “Our research also shows that we need to improve our understanding of how our daily activities can drive changes in both local and global climate. That steam coming out of your tea-kettle may be helping to cool the Earth, but that cooling influence will be overwhelmed if that water was boiled by burning gas or coal.”

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John Marshall
September 16, 2011 3:13 am

These people must know about latent heat of evaporation and condensation and the heat lost/gained in this process. This is hardly ‘new’ research. I was doing experiments on this 55 years ago in physics class.
The mind boggles.

September 16, 2011 3:43 am

We just spent 24 hours listening to intelligent rebutals of the false theory of agw and now we are to believe the earth is getting warmer because of CO2? And of course evaperation causes cooling. Looking forward to apple harvest here in Oregon. Thank you all for the last 24 hours, it was interesting and informative.

wayne Job
September 16, 2011 3:45 am

So increased CO2 makes flora grow bigger and better and stronger and respires more, thus we have a negative feed back, negating any warming from CO2. Perfect natural balance, what is the problem, I see none.

Dave Springer
September 16, 2011 3:56 am

“Increased evaporation tends to cause clouds to form low in the atmosphere, which act to reflect the sun’s warming rays back out into space. This has a cooling influence.”

Oliver OFlynn
September 16, 2011 3:57 am

In all the discussion of global warming (cooling) I have never read of the contribution of the heat generated by using electrical energy. An easy sum shows that it is not negligible. Have I missed something . Oliver OFlynn

R. de Haan
September 16, 2011 4:07 am

How much tax money has this Carnegie Institution report cost us?

September 16, 2011 4:15 am

Inreased CO2, increased plant growth, more evaporation, more clouds, more reflection, cooler planet.

September 16, 2011 4:16 am

“The Earth has been getting warmer over at least the past several decades, primarily as a result of the emissions of carbon dioxide from the burning of coal, oil, and gas, as well as the clearing of forests.”
That’s a given, then?
Dang! Just when I’d been convinced the science was not settled.

Patrick Davis
September 16, 2011 4:24 am

Interesting read however, its a well established fact trees have an “air conditioning” effect, not just their shade. So no surprise here for me.

September 16, 2011 4:28 am

Except that burning gas or coal adds water to the atmosphere. And since they don’t actually have a clue as to how much warming each molecule of CO2 causes, nor how much cooling each molecule of H2O causes, they haven’t the slightest hint of the beginning of a notion of the barest clue of an idea of what the overall effect* is.
*Haha, sorry, that funny lookin’ word there is a synonym for the common Illiterate English term “impact”

Scottish Sceptic
September 16, 2011 4:32 am

How did this paper get past the climate sensors Do I see another rebuttal paper in 18 days?
According to environmentalists … we’ve been cutting down forests. We’ve certainly been putting more land to farmland which doesn’t have vegetation when ploughed. We now have a plausable explanation for the dramatic change in “urban heating” even when population density in the US changed by a few 10s of people per km.
Like a blow from a hidden assailant out of the dark:
1. Bang goes the claims that urban heating is not affecting most temperature sensors — even in rural areas.
2. We now have another plausible explanation for any temperature rise which is not CO2 (I now count, solar activity, reduced global dimming, CO2 as other prime contenders)
3. The science is settled … is it really?
4. We now have a paper which in effects supports sunspots as it is the same basic mechanism of cloud cover.
5.And to top it all, there is now good reason to believe increasing bio-fuel output by changing farmland to crops will increase warming.
I am reminded of the scene in Jurassic Park, when the hunter is hunting the Velociraptor and with all his attention on the one before him, he fails to see the other about to hit him from the side.

Bruce Cobb
September 16, 2011 4:32 am

More post-normal CAGW-inspired gobbledygook. It is absurd to think that land-use decision making, which is entirely a local decision should even consider whether or not vegetation, particularly trees might have a cooling effect on the Earth. The gist of their argument seems to be to discourage development of any sort, particularly in (what else) developing countries, with the possibility of developed countries like the U.S. of paying them not to develop, “for the good of The Planet”.
Nice that they give a nod to the cooling effect of clouds, though.

roger samson
September 16, 2011 4:34 am

This has always been one of my pet theories. In fact folks, anthropogenic warming may slowly be occurring due to deforestation. Its possible both cosmic ray fluxuation and forest cover changes are the primary variables affecting cloud cover changes. Unfortunately there has been not enough science done on cloud formation and its impact on global climate change. Pity we rushed to cut primary forests to put up oil palm plantations when we knew so little about the science of climate change.

Frosty
September 16, 2011 4:35 am

There are so many land use effects on local climate, that these climate scientists seems unaware of, that it makes me wonder if there’s not an issue with basic education, or at least cross discipline basics.
Most pre 1950 land management/agricultural books will tell you to plant a copse of trees if you want to increase local rainfall, most old farmers will say the same thing in my experience.
The Holistic Management grazing techniques (increased herd numbers on smaller rotated ranges, mimicking natural herd movements) reversed desertification in Zimbabwe, during a drought!
Another example I heard about was about how prairie dogs effect local rainfall. They were seen as pests, so were eradicated in a certain area (I can’t remember where), it was found that this caused a reduction in downwind rainfall. How so? Prairie dogs build lots of tunnels, each entrance has a raised edge, like a small volcano. As the wind blows across these entrances, the higher opening creates low pressure, which exchanges air inside the tunnels, the air which is removed is loaded with +ive ions, which are attracted to the -ive ions at the cloud base, seeding clouds. Removing the prairie dogs edged the local downwind environment towards desertification. Keyline ploughing (P.A. Yeoman) mimics this tunnel system, so besides being effective in influencing run-off water to stay in the landscape (by ploughing along contour lines at the keyline), it actually increases downwind rainfall too.
Land use issues are key to local climate IMO, much more so than any possible effects of a trace gas, but then there’s not much money in it for climate scientists, or governments, so we’re stuck with the current paradigm.

MarkW
September 16, 2011 4:42 am

When this evaporated water condenses, it is many thousands of feet in the air, so that the heat released escapes to space much more easily. So even if that were the only affect, increased evaporation from plants would result in a net cooling. Not the balanced out that is assumed by the authors.
BTW, increased CO2 results in more plants. So CO2 results in cooling. Very interesting.

September 16, 2011 4:42 am

So the burning down of the rain forests in S America and SE Asia over the last 30 years or so could well have been responsible for the recent warming and now that there’s none left the rise has levelled off?
NB I was in Singapore during the great Indonesian burn off in ’96

old construction worker
September 16, 2011 4:43 am

Who would have “thunk” evaporation of water would have a cooling effect? Do we live in a big “swamp cooler” or what?

Stephen Wilde
September 16, 2011 5:03 am

Hmmm.
More CO2 soon leads to more and bigger plants in more locations. Perhaps the additional evaporative cooling amounts to more than the projected CO2 warming?
At the very least it would reduce sensitivity to more CO2 in the air.
So that is another negative system response to add to the negative system response from clouds and a faster water cycle.
“Also, the energy taken up in evaporating water is released back into the environment when the water vapor condenses and returns to earth, mostly as rain. ”
Crikey, that is just daft. Rain is colder than the air around it because the energy released by condensation higher up gets radiated out to space faster than it would have been if the energy had been retained at the surface.
Evaporation DOES affect the global energy balance by transporting energy upwards for a quicker loss to space thereby offsetting the slower loss to space that would otherwise arise from the thermal characteristics of GHG.
This article concedes more evaporation but then denies the well known thermal effects of more evaporation in order to preserve the faulty CO2 paradigm.

Bloke down the pub
September 16, 2011 5:05 am

The evapotranspiration cycle may be energy neutral, but if it helps to transport energy to higher altitudes it is likely to increase the heat lost to space.

Mike Davis
September 16, 2011 5:09 am

Some folks have been saying this for years! Although the last sentence is still based on pathological science!

September 16, 2011 5:09 am

“The Earth has been getting warmer over at least the past several decades, primarily as a result of the emissions of carbon dioxide from the burning of coal, oil, and gas, as well as the clearing of forests.”
And ~96% of total global CO2 emissions come from other sources other than anthropological sources, i.e. natural sources. In a few years time, we may be more concerned with global cooling than global warming. Oh, and we haven’t seen any global warming since about 1998 (unless you use James Hansen’s tainted surface temperature products).

September 16, 2011 5:13 am

Also related is Anna Makarieva’s hypothesis about the generation of winds covered here a while back.
http://wattsupwiththat.com/2011/01/21/an-appeal-to-the-climate-science-blogosphere/#more-32135

Ralph
September 16, 2011 5:24 am

>>>But because water vapor plays so many roles in the climate
>>>system, the global climate effects of changes in evaporation
>>>were not well understood.
But the science was, nevertheless, settled.
.

Gary
September 16, 2011 5:30 am

Globally, this cycle of evaporation and condensation moves energy around, but cannot create or destroy energy. So, evaporation cannot directly affect the global balance of energy on our planet.

Willis is not going to like this statement. Dr. Spenser, neither.

Scottish Sceptic
September 16, 2011 5:43 am

I’m amazed people don’t see the importance of this paper. Think it from the point of view of the “treehugger”. We need a way to explain to them that there are other things that effect climate. They want to believe that chopping down trees is bad, they also want to believe warming is bad.
So, now we can encourage them to say: chopping down trees causes global warming
Which is the same as saying:
Chopping down trees caused global warming
This is the equivalent of throwing a bitch in heat into the foxhounds. How can they resist making the connection? They can’t … it ticks all boxes. But as soon as they start saying: “chopping down the amazon causes global warming”, they are also saying that: “CO2 isn’t causing that global warming”, and more importantly: “we also don’t think the science is settled … not when it suits us”.

Viv Evans
September 16, 2011 5:46 am

I hope I got this right: increased evaporation has a cooling effect, but evaporation cannot affect the global energy balance? IAW, there must be warming somewhere to offset this cooling, right?
Hm.
One thing’s for sure: this is again our fault, for chopping down trees. I bet the CO2 police will now enforce a massive tree planting policy, aimed at us.

John B (UK)
September 16, 2011 5:47 am

“Using a climate model”…………………..
?????
sigh……

Alan D McIntire
September 16, 2011 5:50 am

John Christy put out a paper on this effect years ago.
http://ams.confex.com/ams/84Annual/techprogram/paper_68739.htm
Due to irrigation of the central valley in California, daytime temperatures went down and
nighttime temperatures went up. By introducing water and irrigation to a desert region, the net effect overall was a slight warming. I suspect that much of the measured slight warming worldwide is due to this irrigation effect.

GaryP
September 16, 2011 5:51 am

Will there also be increased organics released into the air from all this water evaporating from trees? These will tend to increase nucleation sites for water droplets and increase cloud cover.

Cementafriend
September 16, 2011 5:56 am

I am amazed that this paper was accepted by the reviewers. Does no one search the internet or look at Russian literature. Look at this web site http://www.bioticregulation.ru/pubs/pubs2.php

Ron Cram
September 16, 2011 5:57 am

Wait. Are you saying sophisticated IPCC climate models don’t take this into account? Really?

patrioticduo
September 16, 2011 5:58 am

They obviously needed a few hundred thousand in grants to conclude on something that bleeding obvious, previously known, and well established.

Nuke Nemesis
September 16, 2011 5:58 am

Roger Carr says:
September 16, 2011 at 4:16 am
“The Earth has been getting warmer over at least the past several decades, primarily as a result of the emissions of carbon dioxide from the burning of coal, oil, and gas, as well as the clearing of forests.”
That’s a given, then?
Dang! Just when I’d been convinced the science was not settled.

There is not one shred of evidence given to support that statement, is there? Yet this will be added to a catalog listing it as a scientific paper supporting the “consensus.”

Robertvdl
September 16, 2011 5:59 am

“evaporation of water from trees and lakes could have a cooling effect on the entire atmosphere.”
And evaporation of Ocean water ?

arthur clapham
September 16, 2011 5:59 am

It is very presumtious to state the world has been getting warmer over several decades,
I have lived through several decades and can see no difference since my boyhood.
Iwould like the truth and some proof of this statement please!!

Ron Cram
September 16, 2011 6:01 am

I am having a hard time reconciling these two statements:
New research from Carnegie’s Global Ecology department concludes that evaporated water helps cool the earth as a whole, not just the local area of evaporation, demonstrating that evaporation of water from trees and lakes could have a cooling effect on the entire atmosphere.
and
Globally, this cycle of evaporation and condensation moves energy around, but cannot create or destroy energy. So, evaporation cannot directly affect the global balance of energy on our planet.
These statement appear to contradict each other. If the first is true, the AOGCMs need to account of evapotranspiration. If the second is true, they do not. Which is it?

chris y
September 16, 2011 6:02 am

As the Daily Bayonet says- “Wait, What?”
It appears that this climate model study has stomped on CACC.
The authors state- “The researchers even thought it was possible that evaporation could have a warming effect on global climate, because water vapor acts as a greenhouse gas in the atmosphere.”
“was” possible?!?
The settled science says that surface warming from any forcing causes increased humidity due to evaporation of water. The increased water vapor concentrations then cause a greater greenhouse effect, further warming the surface. This positive feedback is claimed to double or triple the temperature increase from CO2 alone.
“But because water vapor plays so many roles in the climate system, the global climate effects of changes in evaporation were not well understood.”
This is a direct challenge to the water vapor positive feedback being settled science. This is heresy, a direct challenge nailed to the front door of the CACC cathedral.
But now we have this paper’s stunning claim.
“Using a climate model, they found that increased evaporation actually had an overall cooling effect on the global climate.”
This is another Trenberth travesty. Say goodbye to the water vapor based positive feedback multiplying factor for CO2 warming. The AR5 lead authors will have to find a way to exclude this paper from the next report, even if they have to redefine what peer reviewed literature is…

Pamela Gray
September 16, 2011 6:11 am

Just one more reason treehuggers will use to stop timber sales. Before loggers came along, our forests burned naturally, cleaning up the floor and continually replacing fully mature adult trees with meadows and thinned younger trees. We replaced that with something similar: timber sale harvest/slash burning. For some reason, tree huggers want to replace all of that with some kind of no touch no burn forest system that will only lead to one thing: catastrophic burns from fuel heavy forests. And this is good how?

September 16, 2011 6:16 am

“The Earth has been getting warmer over at least the past several decades, primarily as a result of the EMISSIONS OF CARBON DIOXIDE from the burning of coal, oil, and gas” (caps added)
Immediate deduction of 30 IQ points and a major downgrade of the value of the presentation and content.
Is this now simply another attack on human activities and an argument for de-industrializing and planting more trees?
Forget mowing the lawn ever again—I have a great excuse! There oughta be a law.

Ex-Wx Forecaster
September 16, 2011 6:18 am

Wait a minute…I thought evaporation resulted in cloud formation, which reflected heat back to Earth and warmed the planet. At least, that’s what the IPCC has been saying for the past couple decades. I mean, it’s in their models, it can’t be wrong.

September 16, 2011 6:24 am

Re: the Amazon
The rainforest is resilient and grows back very quickly. Recent estimates have it growing back much faster than it is being cleared. As farmland the soil is poor and only produces a few crops and then the people move on. The forest takes the land back. There is more rainforest now than there was 40 years ago. City expansion is really not a big factor.
The Greenies always talk about the damage without ever talking about the healing. Bleached coral reefs recolor back to health rather quickly. Greenies NEVER go back later to check on bleached corals as they really do not want to know that they have recovered quite nicely, thank you. They want the crisis to be human and resolution not be natural.

trbixler
September 16, 2011 6:26 am

So the lake in Central Park helps cool and the Atlantic ocean is not mentioned. Of course the Atlantic is but one of the oceans and maybe they might evaporate a little as well.

TomL
September 16, 2011 6:33 am

Isn’t this a rather involved way of saying that water vapor acts as a negative feedback on temperature?
When does the editor resign?

Greg Holmes
September 16, 2011 6:33 am

The big engine is in the sky, its big and hot, sometimes very hot sometimes not so hot, but how can we tax it folks?

September 16, 2011 6:34 am

“Water evaporated from trees cools global climate”
[church lady]Well, isn’t that inconveeenient?[/church lady]

September 16, 2011 6:36 am

So when I sweat and it evaporates taking heat from me into the surrounding air, that heat radiates back and makes me hotter?

September 16, 2011 6:42 am

Shouldn’t apologies and resignations be forthcoming? Clouds sure seem to be doing a lot of things while not playing a significant role in our climate.

Crispin in Waterloo
September 16, 2011 6:46 am

roger samson says:
September 16, 2011 at 4:34 am
…In fact folks, anthropogenic warming may slowly be occurring due to deforestation.
++++++++
Good to hear from you, Roger. For folks who don’t know, Roger is probably the single greatest motivator for switchgrass as a native, local biofuel. Practically created the concept. I have several products to test courtesy of him.
Yeah, but Roger, what do you have as info on the (natural) reforrestation of the NE USA as people left the farms? Is total forest cover in, say, the USA increasing? Virginia, NY (etc) are getting massive regrowth. Then, is there an increase in Arctic vegetation with increasing temps? I read once it’s about 6 C in the past 150 years. That should bring a very large increase in mass, a draw-down of CO2 and an increase in transpiration.
I am not arguing against your point, I want to look at the global forest cover. One of Harold Annegarn’s remote sensing students is trying to use satellite radar to estimate the total biomass using average tree height. Resolution is tricky but it is already working for very tall and short trees.
We see reports now and then about total tree cover but they are always alarmist and never talk about areas with increasing vegetation, as if that is ‘off message’. That means it is not a ‘report’ but a ‘message’. What can you report? Is there any correlation (even anti-) with tree cover or total biomass and temps?
I would not be at all surprised to find a long-lasting influence. It is abnormal for watered soil to have nothing growing on it.

Robertvdl
September 16, 2011 6:48 am

The cooling effect of trees is that the energy coming from our star does not heat the surface of the earth but the leaves of the tree.
These leaves evaporate water to cool themself.
Both the ground under the trees and the leaves don’t accumulate heat so the moment the sun is gone there is no heat radiation. Our buildings and roads do accumulate heat. That’s why a big city is a bad place to sleep when it’s warm and moisty.

Warren in Minnesota
September 16, 2011 6:54 am

The Carnegie Institution says:
“The Earth has been getting warmer over at least the past several decades, primarily as a result of the emissions of carbon dioxide from the burning of coal, oil, and gas, as well as the clearing of forests.”
The Earth has not been warmer this last decade and the emission of carbon dioxide has continued. The premise and the conclusion, primarily as a result, is illogical and unfounded.

September 16, 2011 7:06 am

.
Doh!
.
.
Can’t think of any other reply as a) several others have already amply responded and b) I think the one-word ‘Doh” exclaimed puts the icing on it ..
.

alex
September 16, 2011 7:10 am

Eureka! Vapor cools. More CO2 -> more vapor -> more cooling.
Or did I miss anything?
Stupidity of these propaganists is infinite.

September 16, 2011 7:14 am

If increased evaporation from tress cools the planet increased evaporation from the warming of c02 must also cool the planet. There you go we have our negative feed back.end of discussion the argument cannot be broken we all agree!

Kevin Kilty
September 16, 2011 7:37 am

So, that’s why I feel cool air as I ride my bike past the grove! Evaporation cools. Who knew?

Ian W
September 16, 2011 7:45 am

“Globally, this cycle of evaporation and condensation moves energy around, but cannot create or destroy energy. So, evaporation cannot directly affect the global balance of energy on our planet.”
Not quite true – the energy taken from the surface – or from the leaf – as the latent heat of evaporation is released as the water changes state as it condenses and/or freezes higher in the atmosphere where the air is less dense. This is _heat energy_ and it is easier for it to escape to space without being ‘absorbed’ by green house gases. This heat release will have no effect on atmospheric temperature unless it is absorbed.

Ray
September 16, 2011 7:51 am

Good thing there is less evaporation in winter or it would really get cold. /sarc

JFD
September 16, 2011 7:53 am

“Globally, this cycle of evaporation and condensation moves energy around, but cannot create or destroy energy. So, evaporation cannot directly affect the global balance of energy on our planet.”
——-
This statement in the paper is essentially true for water that is in equilibrium with the hydrological cycle, but is not true for water that is not in equilibrium. Water that is not in equilibrium with the hydrological cycle comes from two sources, 1) ground water produced from aquifers that are no or slow to recharge – so called fossil water and 2) water produced when hydrocarbons are burned using oxygen in the air. This new water releases heat into the troposphere for one cycle of the hydrological cycle then is in equilibrium and acts the same as the water in the oceans and other impoundments.
Produced fossil water is about 93% of the total new water added to the atmosphere each day. The large majority of the produced fossil water is used for irrigation of food & fodder and for makeup water for evaporative cooling towers. The production of fossil water is currently about 1000 cubic kilometers per year. The production of fossil water got started in earnest around 1950.
There seems to be a misunderstanding of how liquid water is evaporated into water vapor and the condensed back into liquid water. Liquid water is in a state of potential energy in its normal setting. Evaporation takes place at constant temperature and the contained potential energy is changed to kinetic energy as the liquid gives up 1000 btu/lb of latent heat. If we look at the effluent from evaporative cooling towers, it contains aerosols and essentially 100% saturated water vapor at about 120F. This mixture is lighter than air so rises until it cools enough to start condensing whereby the kinetic energy is changed back to potential energy and the absorbed latent heat is released as specific heat of 1 btu/lb/F. The specific heat raises the temperature of the atmosphere.
This evaporation/condensing process undoubtedly has some influence on cloud formation which could offset some of the temperature rise.
JFD

September 16, 2011 8:01 am

@Scottish Sceptic

So, now we can encourage them to say: chopping down trees causes global warming
Which is the same as saying:
Chopping down trees caused global warming

BRILLIANT!

Stephen Wilde
September 16, 2011 8:10 am

I think it is reasonable for them to confirm that more evapotranspiration from plants cools the climate GLOBALLY rather then just locally or regionally.
That point would previously have been denied by the AGW fraternity.
THey just need to think it through a bit 🙂

Ed Caryl
September 16, 2011 8:12 am

Will somebody PLEASE study climate!

September 16, 2011 8:17 am

That photosynthesis in plants has a cooling effect has been known for ages, can’t see anything new in this paper. The more CO2, the more photosynthesis, the more surface cooling. That is why CO2 is an overall coolant.

Jon E. Kassaw MA LPC
September 16, 2011 8:22 am

I lived in the desert for over 12 years and used evaporation cooling and the hotter it got, the more it cooled the house. I am no scientist, but it seems to me that the ‘system’ has been working long enough to understand at least part of the reason why our earth can ‘modulate’ and keep life going.

AnonyMoose
September 16, 2011 8:24 am

“It is well known that the paving over of urban areas and the clearing of forests can contribute to local warming by decreasing local evaporative cooling,…”
The urban forests in the middle of the prairies wooood like a word with you.

September 16, 2011 8:28 am

Bloke down the pub says:
September 16, 2011 at 5:05 am
The evapotranspiration cycle may be energy neutral, but if it helps to transport energy to higher altitudes it is likely to increase the heat lost to space.

It would seem to me that the way this would work is that even though the same heat is released by condensation high in the atmosphere that was removed by evaporation at the surface, that heat now has fewer GHGs to work its way through to reach space. The net effect is cooling, via a reduced net GHG effect. Although the lower atmosphere has more H2O in it, the latent heat in the water vapor is in effect “taking the elevator” past the lower atmosphere via convection currents, so that the lower atmosphere GHG content becomes less relevant.

Bruce
September 16, 2011 8:30 am

So, deforestion causes possible global warming, increased solar activity posiibly causes global warming, black soot, black roof-tops, land use changes all cause warming…. With 0.8 degrees C warming over the last 150 years, where is CO2’s slice of the pie?

Robertvdl
September 16, 2011 8:45 am

“Increased evaporation tends to cause clouds to form low in the atmosphere, which act to reflect the sun’s warming rays back out into space. This has a cooling influence.”
So if the atmosphere is only clouds and no bleu sky we could start a new Ice-age. or would the heat generated by our planet be enough to keep us warm thanks to the greenhouse gas H2O ?

Richard111
September 16, 2011 8:49 am

70% of the surface of this planet is water! Of the remaining 30% a lot of it is ice and snow. Then count rivers and lakes and FINALLY trees and grass. If that lot isn’t in the models then what is the point?

Pete H
September 16, 2011 8:51 am

Having worked with air conditioning on marine vessels for over 30 years my first thought was….No Sh/ye Sherlock! Hells teeth! This was junior school stuff!
Ray sums it up with…..
September 16, 2011 at 7:51 am
“Good thing there is less evaporation in winter or it would really get cold. /sarc”
Now I am off to find the aspirin due to the headache caused by banging my head on the keyboard!

September 16, 2011 9:09 am

Two things about the statements in the article that I am amazed about.
One is the unsustained claim that CO2 has been making it warmer the last decades, in spite of the article mentioning water evaporated from trees as a coolant. The other is the lack of the natural connection that urban areas where many measurements now come from is in fact measuring a higher temperature than if the vegetation had remained, independent of any climate change.
— Mats —

Laurie
September 16, 2011 9:11 am

In fiscal year 2010, Carnegie benefitted from continuing increases in federal support. Carnegie’s federal
support has grown from $24.5 million in 2006 to more than $36 million in new grants in 2010. This is a
testament to the high quality of Carnegie scientists and their ability to compete successfully for federal funds.

Laurie
September 16, 2011 9:14 am
Stephen Wilde
September 16, 2011 9:26 am

Here you go:
http://climaterealists.com/index.php?id=3735
“Our Saviour – The Hydrological Cycle”
which says amongst other things:
“Thus extra energy in the air from extra GHGs increases the evaporation rate which increases the speed of the hydrological cycle which prevents the extra energy in the air from warming the oceans whether via the ocean skin theory or otherwise.
AGW is thus falsified because the air cannot warm the oceans and the air circulation systems always adjust to bring surface air temperatures back towards sea surface temperatures.
Climate models do not reflect this obvious truth and the ideas of Tyndall et al whilst correct if taking the air in isolation cannot affect the global equilibrium temperature set by the constantly varying interplay of sun air and oceans.”
It is time the climate establishment caught up. They have been stuck in the CO2 merry-go-round for over 20 years whilst the real world went its own way.
Time for a re-evaluation and a fresh start.

Catcracking
September 16, 2011 9:39 am

I guess this also indicates that cutting down trees to grow biofuels is also counterproductive for “global warming” assuming that trees are better at evaporation than corn or other vegitation.

SteveSadlov
September 16, 2011 10:19 am

Mother Nature’s swamp coolers.

Josh Grella
September 16, 2011 10:33 am

I actually cringed when I read this quote, as others seem to have as well: “Globally, this cycle of evaporation and condensation moves energy around, but cannot create or destroy energy. So, evaporation cannot directly affect the global balance of energy on our planet.”
This is part of the problem I found years ago when I decided to investigate the “science” behind global warming. How can any actual scientist be comfortable making that kind of statement? Energy cannot be created nor destroyed. Got it. It’s the Law of Conservation of Energy. Most people (in the U.S.) are taught that somewhere along the line before they graduate from high school. But how do you then make the gigantic leap of logic (or is it a leap of faith, since AGW is really a religion?) that there is no way for evaporation to affect the global energy balance? After all, we know that new energy comes in via sunlight. If the energy balance cannot be affected by evaporation due to the Law of Conservation of Energy, then, using that logic, it cannot be affected by incoming sunlight.
The problem with this pseudoscientific statement is that the law doesn’t actually apply to our atmosphere/climate system. Simply put, our planet is not an isolated system. There are external exchanges between the sun, top of the atmosphere, and space. Pretending it is isolated is great for creating models that might possibly help to undestand parts of how things may or may not work, but that falls apart when dealing with the reality of our atmosphere and energy balance. I won’t even get into the whole “energy does not equal temperature” discussion…
I will now sit back and wait for my check from Exxon…
/sarc

September 16, 2011 11:01 am

Freeman Dyson’s comments in this 2008 NY Tiimes book review are still worth reading on the economics and science of tree-planting, especially his apparent support of the the Nordhaus plan to genetically-engineer “carbon-eating trees”.
http://www.nybooks.com/articles/archives/2008/jun/12/the-question-of-global-warming/?page=1

Carbon-eating trees could convert most of the carbon that they absorb from the atmosphere into some chemically stable form and bury it underground. Or they could convert the carbon into liquid fuels and other useful chemicals. Biotechnology is enormously powerful, capable of burying or transforming any molecule of carbon dioxide that comes into its grasp. Keeling’s wiggles prove that a big fraction of the carbon dioxide in the atmosphere comes within the grasp of biotechnology every decade. If one quarter of the world’s forests were replanted with carbon-eating varieties of the same species, the forests would be preserved as ecological resources and as habitats for wildlife, and the carbon dioxide in the atmosphere would be reduced by half in about fifty years.

September 16, 2011 11:03 am

Bruce says:
September 16, 2011 at 8:30 am
So, deforestion causes possible global warming, increased solar activity posiibly causes global warming, black soot, black roof-tops, land use changes all cause warming…. With 0.8 degrees C warming over the last 150 years, where is CO2′s slice of the pie?

Josh’s Theo ate it.
Burp.

Doug Proctor
September 16, 2011 11:03 am

So more water vapour in the air leads not to a positive temperature feedback, because water is such a powerful GHG, but to a cooling, because water vapour and clouds are such weak climatic forcing agents.
Warmcool, strongweak, it all works.

September 16, 2011 11:20 am

The tiaga in Russia spans thousands of mile. The forests of Canada the same. The forests in the temperate zones are immense. The idea that the cooling is not global is well silly.

phlogiston
September 16, 2011 11:28 am

GB Dorset says:
September 16, 2011 at 4:15 am
Increased CO2, increased plant growth, more evaporation, more clouds, more reflection, cooler planet.
There can be no doubt that plants cool the earth. This paper by Frank et al. (causes and timing of future biosphere extinctions):
http://www.biogeosciences.net/3/85/2006/bg-3-85-2006.pdf
Shows that the appearance of multicellular life, including the colonisation of land by plants and formation of soils, was accompanied by a sharp drop in global temperature in the early phanerozoic that has been favourable to life – the Gaia paradigm.
Further, this paper by Beerling and Berner (feedbacks and the coevolution of plants and atmospheric CO2):
http://www.pnas.org/content/102/5/1302.full.pdf
show that any relationship between CO2 and global temperatures (leaving aside the issue of time lags) does not necessarily imply any direct physical effect of CO2 on temperatures via radiative balance – this notion having been torpedoed in any case by Roy Spencer. Beerling and Berner show that falling CO2 in the Devonian / Carboniferous was directly caused by evolution and spread of trees with ever wider leaves and more leaf stomata, and greater tree height. A positive feedback prevailed in which plants sucked CO2 out of the air and in response became more efficient at using diminishing atmospheric CO2. We now have confirmed by the paper reported in this post the obvious fact that plant and tree transpiration causes cloud formation and cooling (since – thanks to Bill Illis – we also have confirmation of the dominant effect of cloud cover on global radiative balance.) Thus cooling that accompanied falling CO2 was due to plant transpiration and cloud formation, not any physical effect of CO2. In any case changes in global temperature and CO2 over earth’s history are grossly mismatched and noncorrelated:
http://img801.imageshack.us/img801/289/logwarmingpaleoclimate.png
http://www.biocab.org/Geological_Timescale.jpg
In short – the relation between CO2 and global climate is entirely biological, not physical – it is mediated by plant metabolism and transpiration.
The conservation of trees and vegetation covered land area is a much more important issue than atmospheric CO2 which is secondary and more or less irrelevant to any consideration of environment and temperature.

Stephen Wilde
September 16, 2011 11:44 am

Doug, you said:
“So more water vapour in the air leads not to a positive temperature feedback, because water is such a powerful GHG, but to a cooling, because water vapour and clouds are such weak climatic forcing agents.”
Water vapour and clouds are STRONG forcing agents. Water vapour may be a strong GHG but note that water vapour in the atmosphere varies hardly at all because the water cycle speeds up to keep it stable. That is why there is an overall negative feedback.
Instead of global humidity increasing we see a faster water cycle so that the effect of GHGs in slowing energy transmission to space is negated by a faster energy transmission to space by the faster water cycle.
Non radiative processes cancel out the radiative effect of GHGs.

September 16, 2011 11:48 am

Evaportation also moves the heat aways from the surface, circumventing the GH effect and releasing heat higher up, where it is less likely to be make its way back down to the surface.

September 16, 2011 11:50 am

There are a few misconceptions, or wrong assumptions in this thread that make some of the posts contradict or refute each other…
1)- Increased CO2 causes increased plant activity which increases evaporation from plants.
But increased CO2 means plant can reduce the time they open the stomata that let in CO2 and let out the water vapor. Studies show plants are more resilient to drought when CO2 is high because they can reduce the transpiration/evaporation from stomata.
2)- Increased evaporation = increased low cloud = cooling.
This is the Carnegie studys’ justification for claiming that the net global effect of local increases in evaporation is cooling.
But while low thick cloud cools during the day by reflecting more sunlight, it warms during the night by back radiation. As another poster noted, introducing a water feature or park to an urban environment reduces peak daytime temperatures and increases minimum nighttime temperatures. The characteristic of a ‘greenhouse’ effect.
3)- Evaporation removes energy from the surface without raising the temperature and carries that energy as latent heat into higher altitudes where on condensing, it escapes more easily to space.
But the rate at which energy is lost from an object depend much more strongly on its temperature than its altitude. E==T^4
The low cloud from extra evaporation is at a lower temperature than the surface it came from, it will emit energy at a significantly lower rate than the evaporating surface. It will certainly emti energy at a much lower rate than the much higher surface temperature if evaporation had not stabilized the surface temperature.
This is why dry deserts get hot – but freeze at night while the oceans at the same latitude have a stable temperature.
The hydrological cycle transports energy around but cannot create or destroy it. It has a profound effect on the spread, the variability of temperatures on a local and global scale, but little effect on the total energy content of the environment. It alters the distribution rather than the mean, the area under the curve stays the same.

Stephen Wilde
September 16, 2011 12:43 pm

izen:
1) If there is adequate water the plant increases growth rather than shutting down stomata. Over most of the Earth there is plenty of water.
2) The energy value of the shortwave reflected is always greater than that of the longwave which is slowed down in its exit from the system. Shortwave reflected is lost to the system altogether but downward longwave cannot develop unless the shortwave enters the system first so less shortwave getting in also reduces downward longwave.
3) The cloud itself might emit at a lower temperature than the surface but that is irrelevant. The cloud only forms AFTER condensation and it is the process of condensation that dumps energy at the higher level for faster exit to space.
So all three points are utter rot and reek of desperation.
The water cycle speeds up energy transfer from surface to space by non radiative means and thereby offsets the slowing down of energy transfer from surface to space from the radiative characteristics of GHGs.
AGW is not plausible.

Joe
September 16, 2011 12:59 pm

Anybody have a copy of this paper, doesn’t even appear under accepted papers. Interested in the methods.

Mike H.
September 16, 2011 2:49 pm
Brian H
September 16, 2011 3:00 pm

Trees do the metabolism thing, too. Building and consuming sugars, etc. Especially at night, they thus contribute heat to the mix.
Evaporation changes due to tree cover is a factor to the extent the evaporation would not have occurred otherwise. I.e., change in total evaporation is what needs quantifying. That would also imply increase in RH and/or speedup of the hydrological cycle.
Does anyone have a link to a recent study/paper I seem to recall, that found that forested/vegetated areas of the planet are on the whole warmer than less bioactive ones? I can’t locate it.

September 16, 2011 3:25 pm

Oliver OFlynn says:
September 16, 2011 at 3:57 am
Oliver, Last time I did the calculation total energy useage by the human race was 1/10,000 of incoming solar. Temperature increase less than .01 deg C

Berényi Péter
September 16, 2011 3:36 pm

OK. So benign green water vapor, evaporated by sweet breezes from stomata of silky leaves cools the planet, while evil black water vapor, evaporated from wind driven angry sea spray by nasty downwelling thermal radiation warms it. Understood, it’s simple as a wood wedge.

Philip Bradley
September 16, 2011 4:45 pm

The significance of this is that it calls further into doubt the validity of the surface temperature measurements as a measure of ‘global warming’.
This is because surface temperatures are predominantly measured in cities and agricultural areas.
And as the study points out the 2 competing effects of more/less trees (and of course more/less irrigation) occur in different places.
There is an increased water vapour GH effect where the the WV is introduced into the atmosphere (ie warming) and increased cloud reflectivity downwind (ie cooling).
Thus the 2 competing effects occur at different places and times.
One example is here in Perth, Western Australia where there is extensive urban irrigation – people like green gardens and lawns, even in a hot arid climate like ours. The hotter it gets the more they irrigate and as I have remarked before the resultant near ground humidity is noticeable on hot days.
However, this near ground humidity doesn’t result in cloud formation locally, because the layer of humid air is too shallow.
Eventually this water vapour will form into clouds but that will be either far out over the Indian Ocean or far into the interior, where there are almost no temperature measuring surface stations.

September 16, 2011 5:54 pm

Fail
“The researchers even thought it was possible that evaporation could have a warming effect on global climate, because water vapor acts as a greenhouse gas in the atmosphere. Also, the energy taken up in evaporating water is released back into the environment when the water vapor condenses and returns to earth, mostly as rain. Globally, this cycle of evaporation and condensation moves energy around, but cannot create or destroy energy. So, evaporation cannot directly affect the global balance of energy on our planet”.
They should pay greater attention to the changes that pressure differentials have on enthalpy and sensible heat of a mass of water being transported by convection from the surface of the earth to any height of cloud formation. If they did they would determine, the nett effect of evaporation from the surface to the height of cloud formation, bypasses the greenhouse effect by transporting “hot” water vapour to heigher levels of the atmosphere and lower pressures. Such that, at the point of condensation to “cold” water the radiation captured by the surface water is miraculously released back into space, i.e. a nett negatiive feedback of the climate system.

David S
September 16, 2011 7:36 pm

I don’t want to rock the boat here but clouds can also produce a warming effect. Clouds radiate heat back to the earth. That produces a warming effect. There is a simple experiment to demonstrate it. You need an infra-red thermometer. These usually cost less than $100.
On a summer day when the ambient temp was about 75F I aimed my infra-red thermometer at a patch of clear blue sky. The reading was -18F. Then I aimed it at the underside of a low cloud. The reading was 45F. That’s a huge difference. The energy radiated from a warm body is proportional to the fourth power of the absolute temperature. So something at 45F will radiate 70% more energy back to the earth than something at -18F.
Of course clouds reflect sunlight and that produces a cooling effect. But which dominates the cooling effect or the warming effect? There is another factor that would have to be considered too. That is the emissivity of the cloud and of the clear blue sky.

phlogiston
September 16, 2011 10:20 pm

izen says:
September 16, 2011 at 11:50 am
But while low thick cloud cools during the day by reflecting more sunlight, it warms during the night by back radiation.
So here’s the dilemma – clouds reflect sunlight during the day back out to space (albedo), a cooling process, while at night they reflect radiated electromagnetic thermal energy from the earth’s surface back down – a warming process.
So here’s the really tough question – which process predominates, the day albedo or the night “insulation”? Is the net effect warming or cooling?
Another way to phrase this (really difficult) question is, which is warmer, day or night? Or – which radiation is more intense and energetic – that from the sun, or that from the earth during the night.
Any takers?

September 16, 2011 10:24 pm

@- enthalpy says:
September 16, 2011 at 5:54 pm
“Fail…
They should pay greater attention to the changes that pressure differentials have on enthalpy and sensible heat of a mass of water being transported by convection from the surface of the earth to any height of cloud formation. If they did they would determine, the nett effect of evaporation from the surface to the height of cloud formation, bypasses the greenhouse effect by transporting “hot” water vapour to heigher levels of the atmosphere and lower pressures. Such that, at the point of condensation to “cold” water the radiation captured by the surface water is miraculously released back into space, i.e. a nett negatiive feedback of the climate system.”
I would be interested in seeing calculations that supported this claim.
If it is a natural physical process that governs the release of energy back into space, rather than a miraculous one, then the claim seems to be that a mass of air and cloud a mile high will release more energy to space than the surface which is 10 degK warmer.
How much easier is it for energy released at cloud height to reach space compared to ground level? I think you may need to use the radiative transfer equations to determine this, and I suspect the claim of a net negative effect may be difficult to justify.

Stephen Wilde
September 17, 2011 12:03 am

phlogiston and izen.
I dealt with both your points upthread as follows:
“The energy value of the shortwave reflected is always greater than that of the longwave which is slowed down in its exit from the system. Shortwave reflected is lost to the system altogether but downward longwave cannot develop unless the shortwave enters the system first so less shortwave getting in also ultimately reduces downward longwave..”
By definition shortwave has greater energy content than longwave which is why it can penetrate the oceans up 200 metres.
and:
“The cloud itself might emit at a lower temperature than the surface but that is irrelevant. The cloud only forms AFTER condensation and it is the process of condensation that dumps energy at the higher level for faster exit to space.”
After all the air at the higher level never gets as warm as the surface when the energy is dumped by condensation. Instead it goes straight out to space for virtually no effect on the cold temperature at the higher level.

LarryOldtimer
September 17, 2011 12:20 am

400 ppm of CO2 is the same as 40 molecules of CO2 amid 99,954 molecules of nitrogen and oxygen, and about 6 molecules of other trace gasses. Of that 40, about 2.5% is caused by human activity, which equals a single molecule of CO2, amid 99,999 other “natural” molecules.
To think that a change in the temperature of a single molecule could have any measurable temperature change effect on 99,999 other molecules is absurd, however warm the single molecule became.

Laurence M. Sheehan, PE
September 17, 2011 12:53 am

Of course additional CO2 would cause the temperature of the planet to become cooler. Transpiration of water from the greater abundance of green plants would result in more cloud cover, which would increase the albedo of the planet, and more, in the tropical and temperate latitudes, where the intensity of sunlight is the greatest.
CO2 also is the sole source of the oxygen in the air we and other animals have to breath to live, and provides to green plants one of the three fundamental components, carbon, along with water and light, that green plants must have to even exist.

September 17, 2011 2:08 am

@- LarryOldtimer says:
September 17, 2011 at 12:20 am
“400 ppm of CO2 is the same as 40 molecules of CO2 amid 99,954 molecules of nitrogen and oxygen, and about 6 molecules of other trace gasses. Of that 40, about 2.5% is caused by human activity, which equals a single molecule of CO2, amid 99,999 other “natural” molecules.”
You have made the mistake of counting all the NON ‘greenhouse’ gas molecules, to get a sense of how significant the change in CO2 might be try just counting the GHGs.
-“To think that a change in the temperature of a single molecule could have any measurable temperature change effect on 99,999 other molecules is absurd, however warm the single molecule became.”
A single molecule does not really have a ‘temperature’. That is a collective property of matter which expresses the averaged kinetic energy of the molecules. As such the addition of just one molecule to millions will still have an impact on the bulk average. This is because the molecules of a volume of air rapidly share their kinetic energy by collision.
@- Stephen Wilde says:
September 17, 2011 at 12:03 am
“The cloud itself might emit at a lower temperature than the surface but that is irrelevant. The cloud only forms AFTER condensation and it is the process of condensation that dumps energy at the higher level for faster exit to space.”
HOW much faster?
I am still interested in some calculations that would justify the claim that a body of air and water droplets at cloud height and near to freezing releases energy to space faster than a warmer surface at a lower altitude. Given the depth of the atmosphere cloud height is only a small fraction of the way out to space for emitted LW radiation so the advantage would seem to be small. But emission of energy is massively changed by temperature, proportionate to its 4th power.
-“After all the air at the higher level never gets as warm as the surface when the energy is dumped by condensation. Instead it goes straight out to space for virtually no effect on the cold temperature at the higher level.”
There IS an effect, it is the source of the difference between the dry and wet adiabatic lapse rates. Science of Doom (the link is in the right hand list) has a good exposition of the way energy is moved by evaporation and water vapor by convection. He at least puts some numbers on the size of the effect…

Stephen Wilde
September 17, 2011 4:19 am

“the claim that a body of air and water droplets at cloud height and near to freezing releases energy to space faster than a warmer surface at a lower altitude.”
No one is making that claim.
Instead the claim is that when vapour condenses out there is a release of latent heat at the higher level which is instantly lost to space by radiation upwards.
Since that latent heat does not affect temperature (hence the term latent) it plays no part in the greenhouse effect and so the transfer of latent heat by non radiative means is an ADDITION to the transfer of sensible heat by radiative means.
So more evaporation which always involves latent heat always results in faster energy transmission than radiation alone.
Asking for figures to prove that simple well established fact is just daft. It’s like saying you don’t accept Newton’s laws of physics without figures in support or you don’t accept E=mc2 from anyone who doesn’t go through the proof with you.
I’ve been very surprised to find ,here and elsewhere, how those who believe in AGW seem never to have picked up the long established physics of the phase changes of water.

roger samson
September 17, 2011 5:54 am

Crispin in Waterloo
The best correlation for long temperature trends is with the solar wind with a lag of 4-8 years. However it tends to track less well since 1970 when temperatures moved ahead of the geomagnetic activity index. See for example this link which discusses the breakdown after 1970.
http://www.academicjournals.org/ijps/pdf/Pdf2006/Oct/El-Borie%20and%20Al-Thoyaib.pdf
It’s possible that accelerated deforestation since 1970 may have added the extra warming through loss of forest cover (and yes folks its an anthropogenic global warming effect).
I have linked here a pretty basic summary of global deforestation trends which discusses how some areas are recovering (Asia and North america) and some areas continue to lose forests (africa and south america).
http://www.environmentaltrends.org/fileadmin/pri/documents/2011/Forests.pdf
Overall we have lost 3% of the worlds forest cover over the last 20 years (likely its about 6% since 1970). I think that cloud cover variability is primarily influenced by deforestation and cosmic ray fluxes and its an additive effect and these factors are the primary drivers of long term tempertaure trends. I think the primary driver is celestial ( cloud cover changes from changes in galactic comic rays) and the secondary factor of deforestation is anthropogenic.

September 17, 2011 7:03 am

@- Stephen Wilde says:
September 17, 2011 at 4:19 am
“Instead the claim is that when vapour condenses out there is a release of latent heat at the higher level which is instantly lost to space by radiation upwards.”
Then the claim is nonsense.
The condensation of the water vapor does not change the temperature of the atmosphere at that altitude, just reduces the rate of cooling with altitude – the difference between the dry and wet adiabatic lapse rates.
WHY is the latent heat of a body of air and cloud at a higher level going to be ” instantly lost to space by radiation upwards.” ??
Half that radiation from a mass colder than the surface will be towards the surface. But more significantly the lower temperature of the air/cloud mass at altitude will emit LESS energy than a warmer mass at the surface. By taking energy from the surface and transporting it into the boundary layer which is at a lower temperature than the surface it REDUCES the rate at which energy is lost from the surface and lower atmosphere.
That is why the sea surface at the equator never cools as much as a dry desert area at the equator at night, the loss of energy from the cooler sea surface and clouds above is less than from a hotter land surface with dry air above.
If an increase in the hydrological cycle because higher temperatures increase evaporation causes a negative feedback that reduces warming then at what level does this feedback stabilise the temperature? And why did it not stabilize it during past warming episodes (Eemian, Minoan, Roman, MWP) ?

Stephen Wilde
September 17, 2011 7:21 am

“WHY is the latent heat of a body of air and cloud at a higher level going to be ” instantly lost to space by radiation upwards.” ??”
Simply because it is surrounded by very cold air molecules which absorb it and radiate it upwards. The higher a molecule is situated the more emitted radiation will go upward because the air above is much less dense and presents less of an obstacle to upward radiation than does the much denser air below the radiating molecule.
The fact is that the net flow is always upward and the higher the emitting molecule the more of the emitted energy goes upward.
The evaporation/condensation process gives a parcel of energy a head start in its exit from the system without it registering in terms of temperature at the surface. It is EXTRA energy ejected from the system over and above the energy radiated upward as a result of the sensible heat which does register in terms of temperature at the surface.
If you still don’t get it then you have a mental block that I cannot break.
As regards the Eemian etc the situation there would have been driven by a change in solar energy into the oceans which DOES alter surface temperatures but that is nothing to do with downward IR and indeed a change in the water cycle DID stabilise the warming by shifting the surfacve air pressure distribution poleward for a faster exit of energy from the system.
AGW theory would say that at such times there should have been runaway heating leading to catastrophe but it didn’t happen.

Dave Worley
September 17, 2011 7:26 am

izen says:
September 17, 2011 at 7:03 am
“Half that radiation from a mass colder than the surface will be towards the surface.”
At that altitude the radiation emitted upward will not likely be absorbed by anything. Downwelling IR will be most likely absorbed on the way down due to the thickening atmosphere. Subsequent emissions, use same formula and you have the reverse of greenhouse effect and a flow of energy into space. Convection carries energy upward and by-passes the majority of greenouse gases. You are correct that it is not instant but it is a huge volume of energy carried aloft all day every day by all forms of convection. The entire atmosphere continually circulates upward and downward.
You appear to have it stuck in your head that heat is somehow attracted to the surface.

phlogiston
September 17, 2011 7:31 am

Stephen Wilde says:
September 17, 2011 at 12:03 am
phlogiston and izen.
I dealt with both your points upthread as follows:
“The energy value of the shortwave reflected is always greater than that of the longwave which is slowed down in its exit from the system. Shortwave reflected is lost to the system altogether but downward longwave cannot develop unless the shortwave enters the system first so less shortwave getting in also ultimately reduces downward longwave..”

This is of course a more complete analysis, to look at short and long wave components.
To simplify this discussion and avoid obfustication and distractions, one should focus on the radiation balance with respect to clouds without involving temperature. Dragging in temperature just mires the discussion intractably – this is perhaps the goal. Scientists do this a lot – particularly when the outcome of research has political interest implications – bring in impressive technical sounding arguments that complicate and bog down the discussion, but which are in fact irrelevant.
Someone made a very persuasive post recently (possibly david hoffer) that in studying satellite radiative balance data it would be much more precise to deal only with measured fluxes of radiation, rather than the current practice of trying to interpret temperatures from satellite measured radiation. However this makes the paucity of support for AGW much more clear cut. But bringing in attempts to model temperatures from satellite measurements brings i huge additional error and complexity, and mires the debate intractably.
In rugby this tactic is called collapsing the scrum.
Recently Bill Illis, in the threads on Spencer and Braswell, showed convincingly that if you compare cloud cover with outgoing global electromagnetic radiation, that cloud cover accounts for more of less 100% of variation in outgoing radiation, with R2 as high as 0.77.

October 30, 2011 4:53 am

SOLUTION TO CLIMATE CHANGE AND POWER CRISIS
(Reward NRs. 100,000/= One Lakh to First who can prove wrong) Dr. Dev Bahadur Dongol
(In The Rising Nepal: Overturning Global Warming; 25 June 2009 and Don’t Blame Gases For Green House Effect; 24 September 2009 and By Mark W. Hendrickson; Don’t Treat Co2 As A Pollutant, 25 June 2009)
What we know
a. Related to climate change – CLIMATE CHANGE DUE TO GASES IS IMPOSSIBLE: SOLUTION TO Climate Change
1. Green house is made using transparent solid materials – plastics or glasses. We cannot build a structure using fluids. So gases can’t form a green house, thus no GHE due to gases.
2. The higher the altitude our climatic atmosphere, troposphere, is colder.
3. At 30,000 feet Ozonosphere is minus 58 degree centigrade.
4. Heat transmission – always higher to lower temp. Heat reached upper region of the troposphere cannot come back to hotter places below.
5. Fluids (liquids and gases) by convection method of heat transmission deliver heat from hotter to colder zone. Thus air helps the earth to cool down. This process goes on all the time nonstop but the process is not good enough to cool down the sun heated earth as the gases carry least amount of heat.
6. Troposphere is a homogenous mixture of gases, not layered. As the air of the atmosphere is always moving up and down, to and fro, the freely moving molecules can’t be layered. Had it been layered co2 would be at the bottom of the atmosphere i.e. just above the earth’s surface. Then we are dead. We need o2 to be alive.
7. Air is a perfect transparent medium after space. It does not reflect light so we don’t see air. Opaque materials reflect light so we see them. If the air is opaque? We wouldn’t need eyes. So there is no way for gases in the higher altitude to send heat back.
8. Closed room gets heated uniformly but upper part is warmer as hot air goes up. So if GHE due to gases were possible our atmosphere would be hotter at higher altitude.
9. a. It becomes cold immediately when it rains. b. Annual frequency of rain is decreasing. Reduced frequency of nature’s effective cooling system, the rain cycle, is causing the ‘global warming’. Or, it could not be cooler as it would with more rain.
10. Rain cycle is related to heat and evaporation only and no other factors. Rain can occur without plants; though it lets water to go in the atmosphere by transpiration and hold water on earth by not allowing soil to dry quickly as surface without plants. Evaporation for regular rain cycle can’t be from sea, lakes or rivers (4 billion yrs on not warm enough) but from land surface. Why not more rain cycle nowadays? Warmer, sea surface area and temp increasing (favorable for evaporation)? Half portion of the earth is always exposed to the sun and they do not vary temp seasonally as land surface does daily. Human settlement is reducing evaporation from land areas by covering it with houses, roads, pavements etc; deserts, and deforestation etc. Evaporation of water can deliver maximum quantity of heat and reduce the temperature. So rain cycle needs new explanation.
11. Land surface changes temperature even on daily basis – hot during day time and cold during night (or seasonally as well) unlike sea or lakes or river water (they are almost consistent even in 4 billion years).
Thus global warming or climate change due to gases is impossible. No one has explained the reason nor can be explained scientifically. Instead of warming, gases are cooling the earth by convection method of heat transmission naturally and man has no control over the process.
Causes and solution: by keeping land surface areas always wet as used to be in old days, the evaporation of water will be consistent and thus rain cycle will be regular. It is an easy job for mankind now and it is possible only till we have snow on mountains. At the end of holy festival we always had rain (in the evening). Covering of land surface areas by human is reducing the evaporation. We are doing this mistake because we studied that rain cycle occurs from the evaporation of water from sea or lakes or rivers. Regular rain means colder weather, snow on mountains, rich vegetation/ balanced ecosystem, recharging ground water and eventually reducing sea water level. Climate change problems are all related to water or rain cycle. Without regular rain cycle problems related to water can’t be solved.
Conclusion: Thus it can be concluded that we have climate change because we are studying the process of rain cycle wrong way scientifically.
b. SOLUTION TO POWER CRISIS (we cannot blame water)
(New Ways to Harness Hydropower; The rising Nepal, 2009 March 14 and धेरै सस्तोमा जलविद्द्युत; गोरखापत्र, २३ जेष्ठ २०६६)
We can harness many times more hydropower from already installed hydropower installations by adding more turbines in series. The application of standing still water column to running water condition has been a blunder in hydropower engineering. At present we are harnessing minimum hydropower. In a standing still water column pressure effect of the water column varies according to the height. But in a running water column the pressure effect is uniform throughout the water column (Bernoulli Theory). Therefore by installing multiple turbines in series we can run all of them uniformly. (See demonstrations).
Demonstration: water meter is a miniature form of turbine. We can install many of them in series and run all of them uniformly. We use force of gravitation to run water in hydropower. So it is more appropriate to say g-power than say hydropower. We cannot reduce nor block nor shift force of gravitation; it is always there at a given point. The series connection of turbines is also applicable with thermal power-plants (fossil fuels or nuclear) as they use steam, a fluid to drive turbines.
Dr. Dev Bahadur Dongol email: dev.dangol@yahoo.co.uk Mobile-9841 647 393
Resi: 4 25 30 45 Shahid Shukra Galli, House no.24 Teku , Kathmandu – 12
Blog: devbahadurdongol.blogspot.com

October 30, 2011 6:02 pm

Challenge to IPCC / UNFCCC, SHAME ON YOU
Solution to CC and Power crisis
Dear Dr. Pachauri and Mr. Algore,
Please give me either one scientific reason/ theory that justifies CC is due to gases OR STOP ACCUSING GASES for CC. Just accusation is not science. CC by gases is impossible. Please visit devbahadurdongol.blogspot.com for solutions to CC and ‘power crisis’. Summary is attached for your convenience. I have also explained the mistake being done in the hydropower engineering and, its correction can give us unlimited hydropower.
Challenger,
Dr. Dev