General AGW discussion thread

[Trakar]

Can you think of any time in the last 3500M years when there was any shortage of water vapour in the atmosphere? The ability of a gas to 'force' the climate has nothing to do with it's residency period and everything to do with how much of it there is at any one time. Since the hydrological cycle never goes on holiday, you can take it as read that water vapour is doing it's stuff continuously.

This is an inappropriate use of the term "force" with respect to climate issues.

Water vapor is a greenhouse gas and a factor in the Earth atmosphere's greenhouse effect, but it is not a forcing factor in climate change in the current environment. Water vapor is a feedback effect, but it is related to the overall average temperature and cannot act as a forcing factor until that overall average temperature approaches much closer to the boiling point of water. Until much higher average temperatures are reached, any water vapor above the current Vp (which is determined mostly by temperature and pressure) will precipitate out of the atmosphere within a matter of days at the most, and cannot sustain a feedback loop of escalation which would be neccessary for it to act as a climate forcing factor.

[Stroller]

cannot sustain a feedback loop of escalation which would be neccessary for it to act as a climate forcing factor.

I think that in conjunction with a latitudinal shift of the jet streams, it can act as a negative or positive feedback on the climate in response to other changes in the atmosphere and the incoming radiation, solar windspeed, and other external variables.

Because there is always so much more water vapour than co2 in the atmosphere, it will swamp any effects the latter may have.

Are you aware of work done in the area of atmospheric water vapour, the hydrological cycle, and it's long term changes? It seems to me far too little attention has been paid to this major player in the climate system.

[William]

Edmonton, Alberta sets a record cold temperature of -51F today. That is the coldest temperature every recorded in Edmonton for the month of December and within 4F of the coldest temperature every recorded in Edmonton (The month of January is typically colder). Note the coldest temperature every record in Edmonton was set in January, 1972.

The weather which is occurring in both North America and Europe matches what occurred in the 1970s. As I said I am expecting 1880's cold however that may occur winter 2010/11 rather than 2009/10.

As I said high GCR reduces the formation of high altitude clouds and increase the formation of low level clouds. High altitude clouds warm the planet via a greenhouse mechanism particularly at night.

Record cold temperatures require a change in the mechanisms.

The temperatures in the below quote are in Fahrenheit. -40F is the same as -40C.

I see more extreme cold weather forecast for the US and Europe.

http://www.accuweather.com/world-ind...bar&traveler=0

Even by hardy Canadian standards, it is cold. The low temperature in Edmonton dropped to 51 degrees below zero. This is the coldest temperature ever measured during the month of December. The low at Edmonton Sunday morning was only a few degrees shy of the all-time record low temperature of 55 degrees below zero set Jan. 26, 1972. High temperatures were extremely cold Saturday. The afternoon high in Edmonton Saturday was only 22 degrees below zero. High temperatures across northern Alberta and in the northern Territories were 25 to 30 degrees below zero

[Trakar]

I think that in conjunction with a latitudinal shift of the jet streams, it can act as a negative or positive feedback on the climate in response to other changes in the atmosphere and the incoming radiation, solar windspeed, and other external variables.

Because there is always so much more water vapour than co2 in the atmosphere, it will swamp any effects the latter may have.

Are you aware of work done in the area of atmospheric water vapour, the hydrological cycle, and it's long term changes? It seems to me far too little attention has been paid to this major player in the climate system.

Please support any of these broad, sweeping, and generally incorrect to my understandings of the involved sciences, assertions with mainstream scientific citations.

[Trakar]

Edmonton, Alberta sets a record cold temperature of -51F today. That is the coldest temperature every recorded in Edmonton for the month of December and within 4F of the coldest temperature every recorded in Edmonton (The month of January is typically colder). Note the coldest temperature every record in Edmonton was set in January, 1972.

The weather which is occurring in both North America and Europe matches what occurred in the 1970s. As I said I am expecting 1880's cold however that may occur winter 2010/11 rather than 2009/10.

As I said high GCR reduces the formation of high altitude clouds and increase the formation of low level clouds. High altitude clouds warm the planet via a greenhouse mechanism particularly at night.

Record cold temperatures require a change in the mechanisms.

The temperatures in the below quote are in Fahrenheit. -40F is the same as -40C.

I see more extreme cold weather forecast for the US and Europe.

http://www.accuweather.com/world-ind...bar&traveler=0

And yet globally, we are facing a year that has been either the 5th or 2nd warmest on record ever, and all indications are that next year will sweep past 1998/2005 (which was the hottest on record, depending upon whether you adhere to Nasa or Hadley)

[William]

And yet globally, we are facing a year that has been either the 5th or 2nd warmest on record ever, and all indications are that next year will sweep past 1998/2005 (which was the hottest on record, depending upon whether you adhere to Nasa or Hadley)

No problem Trakar. October was the coldest October in the US in 113 years. The planet is cooling. The data over the next months will support that assertion.

This is of course a El Nino year.

There does seem to be some problem with GISS temperature measurement. I am sure they will solve that problem shortly.

[William]

August, 2009 Prediction

http://www.ctv.ca/servlet/ArticleNew...90804/20090804

El Nino, the precocious weather system with the cute name, is back, meteorologists say, which means that after a summer of record low temperatures, much of Canada may experience warmer days just in time for Christmas.
According to a report issued Monday by the Climate Prediction Center, an agency of the U.S. National Oceanic and Atmospheric Administration, El Nino conditions "are present across the equatorial Pacific Ocean."

Sea surface temperatures are currently between 0.5 and 1.5 degrees Celsius warmer than usual across the equatorial Pacific Ocean, which can have a dramatic impact on air currents and affect weather worldwide.

"Current observations and dynamical model forecasts indicate El Nino conditions will continue to intensify and are expected to last through Northern Hemisphere winter 2009-10," the report says.

http://www.accuweather.com/world-ind...bar&traveler=0

Somewhat Colder than Predicted. Green Christmas?

Even by hardy Canadian standards, it is cold. The low temperature in Edmonton dropped to 51 degrees below zero. This is the coldest temperature ever measured during the month of December. The low at Edmonton Sunday morning was only a few degrees shy of the all-time record low temperature of 55 degrees below zero set Jan. 26, 1972. High temperatures were extremely cold Saturday. The afternoon high in Edmonton Saturday was only 22 degrees below zero.

[nauthiz]

No problem Trakar. October was the coldest October in the US in 113 years. The planet is cooling. The data over the next months will support that assertion.

October was indeed cold but it is not representative of the season: Overall the autumn came in at about the 25th percentile - i.e., one of the warmer ones the US has seen. In fact, that cold October was immediately followed by the 3rd warmest November on record.

source

[Torsten]

October was the coldest October in the US in 113 years.

As for the rest of the planet: "The combined global land and ocean surface temperature for October 2009 was the sixth warmest on record."

Hmm, while I'm at it: "This was the second warmest September on record, behind 2005, and the 33rd consecutive September with a global temperature above the 20th Century average. The last below-average September occurred in 1976."

A report for November was not yet available at the time of this post.

Regarding your linked August 4th CTV story, you of course failed to note that the "prediction" was not one made by meteorologists. The bit about Christmas seems to be speculation by the story's author, designed to get the reader's attention. The article quotes two meteorologists:

"According to L'Heureux, it is too early to predict the severity of this El Nino system.

"We do believe that it will continue to be weak-to-moderate strength through the fall," L'Heureux said. "Then at this point our forecast is anything is possible thereafter."

Phillips said he, too, cannot predict El Nino's exact impact on Canada's winter weather.

The system is still developing, and its severity will depend on both how warm the water gets and the surface area that warm water covers, he said.

Why did you leave that out?

This page shows what Environment Canada forecast for autumn temperatures, and what actually happened.

And yes William, about that -46C in Edmonton, it is just weather. Stations north of there (like the ones I recently charted) are warmer than Edmonton. That should make you think about the movements of large air masses.

So how about this for a novel idea William? Before posting these weather stories, check a weather map. Go to the Environment Canada website and snoop around to see what is happening elsewhere in this country, and what the history for those places has been.

The planet is cooling. The data over the next months will support that assertion.

And will your "data" once again consist of weather stories culled from the news services?

[Jetlack]

Funny how when temperatures hit record lows, blizzards, across North America its called "weather", but record highs, heatwaves or floods are "climate change".

[tusenfem]

No problem Trakar. October was the coldest October in the US in 113 years. The planet is cooling. The data over the next months will support that assertion.

This is of course a El Nino year.

There does seem to be some problem with GISS temperature measurement. I am sure they will solve that problem shortly.

Acutally, November was one of the warmest Novembers ever here in Austria, seems like the world is warming up. If you can read German look here. Only 1926 was warmer in November.

Stop confusing weather with climate!

[tusenfem]

Funny how when temperatures hit record lows, blizzards, across North America its called "weather", but record highs, heatwaves or floods are "climate change".

Nope, you are wrong here, climate change (or global warming if you don't like) can cause BOTH hot spells and cold spells in local areas due to changes in circulation etc. etc. Just one hot or cold summer does not mean a thing. However, it is William who continuously keeps on mistaking local weather phenomena for climate.

[Ari Jokimaki]

Because there is always so much more water vapour than co2 in the atmosphere, it will swamp any effects the latter may have.

As you have already been shown (one example here) the research that shows how CO₂ indeed has measurable effects, it is now time that you give us the scientific body of evidence that shows how water vapour swamps CO₂ effects. You have presented this as a fact so you should have no trouble to give us the peer-reviewed references that prove your claim to be true.

Are you aware of work done in the area of atmospheric water vapour, the hydrological cycle, and it's long term changes? It seems to me far too little attention has been paid to this major player in the climate system.

There is a huge amount of research on water vapor. Here is for example Dessler et al. (2008): "The water-vapor feedback implied by these observations is strongly positive, with an average magnitude of [lambda]q = 2.04 W/m²/K, similar to that simulated by climate models." These have been shown to you before, more than once (one example here and here's another).

If you still think that this issue has not been studied enough, here's Google Scholar search results for search words "water", "vapor", and "infrared" for you. As you see, there's more than 450,000 papers for you to study, well perhaps not all of them are exactly on the subject at hand, but there's plenty of relevant research out there. Already the first search result seems interesting, "Infrared continuum absorption by atmospheric water vapor in the 8-12 um window" - Roberts et al. (1976).

[Strange]

This is an inappropriate use of the term "force" with respect to climate issues.

Water vapor is a greenhouse gas and a factor in the Earth atmosphere's greenhouse effect, but it is not a forcing factor in climate change in the current environment. Water vapor is a feedback effect, but it is related to the overall average temperature and cannot act as a forcing factor until that overall average temperature approaches much closer to the boiling point of water. Until much higher average temperatures are reached, any water vapor above the current Vp (which is determined mostly by temperature and pressure) will precipitate out of the atmosphere within a matter of days at the most, and cannot sustain a feedback loop of escalation which would be neccessary for it to act as a climate forcing factor.

I am not completely sure I understood this.

Is the point that, yes water is a greenhouse gas but its concentration is roughly constant (because of its short lifetime in the atmosphere)? In other words, if you pump extra CO2 into the atmosphere ever day, the concentration will gradually increase because it sticks around. But if you pump extra water vapour into the atmosphere every day, it will precipitate out roughly as fast as you pump it in? (all other things being equal)

The conclusion being that they both have an effect on climate (temperature of the planet) but you can only change climate with CO2, not with H2O?

[Trakar]

No problem Trakar. October was the coldest October in the US in 113 years. The planet is cooling. The data over the next months will support that assertion.

This is of course a El Nino year.

There does seem to be some problem with GISS temperature measurement. I am sure they will solve that problem shortly.

First, the US is not the World. Second, exactly how are you qualifying "the US". Third, got reference? There is no problem with the GISS temperature measurement that I am aware of, but please do feel free to present your evidence in support of that assertion.

Looking at this graph from NOAA,



it looks like it was colder in October of 1975, Oct. of 1925, and Oct. of 1915. A one month or even one year cold snap in one relatively small section of the globe in a year where the averages set new record highs, does not indicate global cooling by any reasonable consideration of the issue.

NOAA: 2009 Global Temperatures Well Above Average; Slightly Above-Average for U.S.

Global Temperature and Precipitation Highlights:

Global land and ocean annual surface temperatures through October are the fifth warmest on record, at 1.01 degrees F above the long-term average.

NOAA scientists project 2009 will be one of the 10 warmest years of the global surface temperature record, and likely finish as the fourth, fifth or sixth warmest year on record.

The 2000 – 2009 decade will be the warmest on record, with its average global surface temperature about 0.96 degree F above the 20th century average. This will easily surpass the 1990s value of 0.65 degree F.

Ocean surface temperatures (through October) were the sixth warmest on record, at 0.85 degree F above the 20th century average.

Land surface temperatures through October were the fifth warmest on record, at 1.44 degree F above the 20th century average.

Arctic sea ice extent reached its third smallest annual minimum on record behind 2007 and 2008. The past five years have produced the lowest sea ice extents on record.

[Jetlack]

Nope, you are wrong here, climate change (or global warming if you don't like) can cause BOTH hot spells and cold spells in local areas due to changes in circulation etc. etc. Just one hot or cold summer does not mean a thing. However, it is William who continuously keeps on mistaking local weather phenomena for climate.

Thats interesting because one doesnt hear the media blame global warming or climate change when there are record lows, and blizzards.

My point is that there is a double standard in the reporting of freak weather events. If its cold its just the way it is, but if its more hot than usual then it immediately gets blamed on agw.

[Trakar]

I am not completely sure I understood this.

Is the point that, yes water is a greenhouse gas but its concentration is roughly constant (because of its short lifetime in the atmosphere)? In other words, if you pump extra CO2 into the atmosphere ever day, the concentration will gradually increase because it sticks around. But if you pump extra water vapour into the atmosphere every day, it will precipitate out roughly as fast as you pump it in? (all other things being equal)

The conclusion being that they both have an effect on climate (temperature of the planet) but you can only change climate with CO2, not with H2O?

This is very roughly correct, not to say that there are no conditions where atmospheric water vapor can act as a climate forcing agent, but not under the present general environmental conditions.

[Trakar]

Thats interesting because one doesnt hear the media blame global warming or climate change when there are record lows, and blizzards.

You trying to claim that the media isn't very scientifically accurate, logical or factually correct in its presentation of climate issues?!?!?!

Say it isn't so!!!

[Stroller]

This is very roughly correct, not to say that there are no conditions where atmospheric water vapor can act as a climate forcing agent, but not under the present general environmental conditions.

However, this is not to say that water vapour couldn't act as an amplifying mechanism for other climate forcing agents. AGW proponents believe raised co2 caused by higher temperatures could lead to a positive feedback from increased water vapour. Nir Shaviv has shown that there is a feedback mechanism amplifying solar variation's effect on global temperatures, and that the most likely candidate is another form of water vapour - clouds.

Clouds are notoriously difficult to measure both in terms of extent of cover and strength - even sign - of feedback, but indications are that they can change on multi-decadal scales and have a hand in climate variation. This is why climate model projections have large uncertainties, no-one can yet model clouds down to the resolution needed to account for their effect.

The IPCC cheerfully admits this in the small print of their report, but then goes on to say in the policy makers summary that they are 90% certain co2 has a ~1.7W/m^2 forcing on the climate...

[Ivan Viehoff]

No problem Trakar. October was the coldest October in the US in 113 years. The planet is cooling. The data over the next months will support that assertion.

So you haven't actually got the data to support your assertion, you are just guessing.

New local daily record low temperatures from time to time are a statistical inevitability, even with quite a bit more average warming. What we can see is that local daily record high temperatures are being set at twice the rate of record daily low temperatures in the USA over the last decade.

http://www.ucar.edu/news/releases/2009/maxmin.jsp

Meanwhile, scientists working on the earth's energy budget seem to think there is a 0.9 W/m2 excess of heat in over heat out, but they can't quite work out for sure where the earth is stashing all this heat. If it is going into the deep ocean, where we have little data, then what will be the consequences of that?

http://ams.allenpress.com/perlserv/?...AMS2634.1&ct=1

[Stroller]

Meanwhile, scientists working on the earth's energy budget seem to think there is a 0.9 W/m2 excess of heat in over heat out, but they can't quite work out for sure where the earth is stashing all this heat. If it is going into the deep ocean, where we have little data, then what will be the consequences of that?

http://ams.allenpress.com/perlserv/?...AMS2634.1&ct=1

Interesting. So this extra 'heat in' is coming from the sun presumably?

I did some calculations a while back which showed that to account for the 25mm of sea level rise between 1993-2003 attributable to thermal expansion, the Earth's oceans absorbed an extra 14x10^23J or so, roughly equivalent to a 4W/m^2 forcing. That would have to be due to reduced cloud mostly, since the sun doesn't vary that much and co2 ain't strong enough. This means that a lot of the increase in global temperature during that decade at least was due to natural climate change - not human emitted co2.

From the abstract:

A lack of closure in the energy balance at the surface is accommodated by making modest changes to surface fluxes, with the downward longwave radiation as the main residual to ensure a balance.

According to the Southampton Oceanography team, the 'lack of closure in the energy balance' amounts to around 30W/m^2

No wonder Kevin Trenberth laments the "travesty" of our "inability to account for current cooling".

And it should be noted that his choice of "downward longwave radiation as the main residual to ensure a balance" is entirely arbitrary.

I have another candidate.

[nauthiz]

Funny how when temperatures hit record lows, blizzards, across North America its called "weather", but record highs, heatwaves or floods are "climate change".

Generally only by people who don't really understand the topic. Personally, in real life I have a habit of correcting friends when they assume that unseasonably warm weather is because of global warming.

[SolusLupus]

Funny how when temperatures hit record lows, blizzards, across North America its called "weather", but record highs, heatwaves or floods are "climate change".

Strawmen: So much easier to fight.

Understanding is so much harder.

[Trakar]

However, this is not to say that water vapour couldn't act as an amplifying mechanism for other climate forcing agents.

Rather, quite the opposite, atmospheric water vapor, as a primary greenhouse gas, whose concentration (and persistence) in the terrestrial atmosphere is almost entirely dependent upon temperature and pressure (Jr. High Chemistry Combined Gas Law anyone?), is always an amplifier of any forcing agent that drives up atmospheric temperature.

AGW proponents believe raised co2 caused by higher temperatures could lead to a positive feedback from increased water vapour.

Cite or Reference?
Doesn't sound like anything I've ever heard any peer-reviewed topically relevent, mainstream science paper or knowledgable proponent say.

Nir Shaviv has shown that there is a feedback mechanism amplifying solar variation's effect on global temperatures, and that the most likely candidate is another form of water vapour - clouds.

Nir Shaviv has asserted, and yet failed to adequately support his against the mainstream scientific perspective in regards to climate and climate change.

Rahmstorf, S., D. Archer, D.S. Ebel, O. Eugster, J. Jouzel, D. Maraun, G.A. Schmidt, J. Severinghaus, A.J. Weaver, and J. Zachos, 2004: Cosmic rays, carbon dioxide, and climate. Eos Trans. Amer. Geophys. Union, 85, 38, 41.
http://pubs.giss.nasa.gov/docs/2004/...storf_etal.pdf


Please stick to mainstream scientific perspectives and support your assertions with references to such works,...or propose your against the mainstream perspectives in the appropriate forum.

[JESMKS]

I was told many years ago that the temperature of groundwater in watertable aquifers generally approximates the mean annual air temperature of the overlying area. If this is true, wouldn't the annual or biannual monitoring of groundwater temperature provide a useful tool in monitoring changes in the earth's temperature?

[lomiller1]

Can you think of any time in the last 3500M years when there was any shortage of water vapour in the atmosphere? The ability of a gas to 'force' the climate has nothing to do with it's residency period and everything to do with how much of it there is at any one time. Since the hydrological cycle never goes on holiday, you can take it as read that water vapour is doing it's stuff continuously.

Forcing has a very specific meaning and you are not using it correctly. A forcing is an outside effect that forces a parameter within the system to some other value. The will, in turn, change the system’s attractor and therefore it’s behavior.

If you try and change the amount of water vapor in the atmosphere it will revert back to it’s original state in very short order. When the water vapor is gone any effect it had one the system is gone as well, therefore emitting water vapor cannot change the system output.

[lomiller1]

Somewhat Colder than Predicted. Green Christmas?

It was very close. The Canadian Prairies didn’t have any winter weather until December. I was still cycling to work in shorts in late November because temperatures were 5-10 deg above normal for most of the month. This current cold snap is the first sign of winter weather and it’s the latest freeze up on record.

[nauthiz]

Can you think of any time in the last 3500M years when there was any shortage of water vapour in the atmosphere? The ability of a gas to 'force' the climate has nothing to do with it's residency period and everything to do with how much of it there is at any one time. Since the hydrological cycle never goes on holiday, you can take it as read that water vapour is doing it's stuff continuously.

You're making the same mistake in terminology that I did and was recently corrected on in detail. lolmiller1 is right; water vapor does have the ability to act as a forcing, but under current conditions it's not much of one and primarily acts as a feedback mechanism.

[lomiller1]

You're making the same mistake in terminology that I did and was recently corrected on in detail. lolmiller1 is right; water vapor does have the ability to act as a forcing, but under current conditions it's not much of one and primarily acts as a feedback mechanism.

Any forcing effect would be indistinguishable from zero. Assuming a similar sensitivity as CO2, to get ~3 deg or warming you would need to create enough water vapor to permanently double the amount of H2O in the atmosphere across the whole globe. IOW the amount of water you had to evaporate would exceed the entire current rainfall on the entire planet. The heat used to evaporate the water in the first place would probably outweigh the greenhouse warming.

[Torsten]

It was very close. The Canadian Prairies didn’t have any winter weather until December. I was still cycling to work in shorts in late November because temperatures were 5-10 deg above normal for most of the month. This current cold snap is the first sign of winter weather and it’s the latest freeze up on record.

Yes, and I forgot to mention in my last reply to William that in his selective reporting of regional cold weather events he seems to have missed the fact that less than a month ago Edmonton broke two high temperature records going back to 1959, on November 16th and 17th.

The whole notion of averaging over the globe goes out the window when it comes to him promoting his idea. And if anyone dares mention that they are presently suffering under a heat wave, William calls that "selective reporting of extreme weather".

'Nuff said.