Moderated Global Warming Discussion

[BenBurch]

The reason people who want to lie about AGW for political reasons highlight local cold weather and ignore the global picture is that they know they can use that with the more ignorant voters who make up a large part of their "base". (Base being a good term for them.)

 

[Bill Thompson]

• What is it about greenhouse gasses that reflect the sunlight back onto the earth while it does not reflect the sunlight outside the earth back into space? If its property was that it reflected light, wouldn't it not be changing the temperature at all since it would be reflecting the same percentage of light in both directions.
• If these gasses reflected light, wouldn't we be worried about global cooling since more light would not be reaching the land?
• How does an actual greenhouse work? Does a greenhouse actually work by trapping heat inside while not reflecting it away in the first place? Doesn't it actually work because plants produce the heat somewhat and also the oxygen they produce is thinner?
• If greenhouse gasses were reflecting light back onto the surface of the earth, wouldn't the land be warmer now at higher elevations? Instead, it is colder there. Snowfall is always reported first in the mountains.

 

[Stray Cat]

Definitely approaching a more reasonable consideration of the issues.

Approaching?
It's where I've been for quite a while.

Most natural climate change is irrelevent for several reasons, the primary one being that it tends to encroach on time scales of tens of millenia rather than decades-centuries. Impacts can be fairly rapid once tipping points are breached, but for the most part the approach is obvious long before those points become eminent.

The way I understand it is that even if carbon output of humans was zero by tomorrow, it would have little stabalising impact on the climate for centuries because the damage has been done and our carbon output hangs around a long long time. So regardless of what we can do to stop carbon output, we are still going to have to live with climate change. The complexity of the matter is compounded by the climate affecting the planet and the planet in turn affecting the climate.

I agree that the best solution would be to simply place a global ban on the mining/drilling, refinement and open-cycle combustion of all fossil fuels, but it is a solution that is unlikely to be enacted or enforced until there are viable alternatives in place. Without such a ban, the next best option is to price the carbon fuels so that their full detrimental impact is accounted for, or so that alternative energy systems are a lower cost competitive option.

That's the problem for me though.
The way these things are handled by politicians is not "accounting" for anything. It is doing nothing more than gradually increasing their revenues at a level where the 'taxed' can slowly adapt to paying a bit more.

The same tactic has been used for years with petrol duty (increased by a penny or so every year), cigarettes (increased by a penny or so a year) and we're told it's for our own good... No, it's not, because the money raised by these taxes isn't being ring fenced and used to counter what they are claiming they were introduced for.

If all the motoring taxes were used for the improvement of cleaner public transport then they could justify it. If all the tobacco taxes were used for the education of young people to stop them from starting to smoke and investment into the Health Service then they could be justified.

And finally if the 'green taxes' were all ring fenced and used solely for projects that were shown to have a positive counter effect to AGW, then they could be justified. At the moment, we pay more and are left with confusion as to why we are paying more and where this money is disappearing to. The increases are so minimal that people will complain and then after a while, they will get used to paying the slightly higher prices and do nothing to reduce their use of fossil fuels etc.

As for the plastic bag tax that has little to do with climate change issues, and is actually more a land-fill/pollution issue as such bags generally do not break down in the environment for inordinately long periods of time so we end up with a lot of plastic bags throughout our environment. Paper is a renewable resource and breaks down fairly rapidly in the environment,...a much better option, IMO.

Which again is part of the problem of allowing politicians to be the PR machine for environmental issues. I know that plastic is more a land fill issue than it is about climate change... but ask joe public and they don't understand. Because the message is confused and ever environmental issue is automatically being labeled 'climate change' because it's the hot topic.

Is is not only inaccurate it is scare mongering... not by scientists, but by politicians who wish to sneak pointless taxes on people with the least resistance and saying climate change is more urgent (and from their PoV justifiable) than saying land fill, because if they said land fill, I'm sure a lot of people would be asking if plastic is such a problem, then why the these supermarkets who are now charging us 10p for a plastic bag still over wrap every bit of their own produce in pointless plastic.
Better still would be to charge us 10p for a biodegradable bag and ban plastic ones.

Sorry, I didn't mean for this post to be so long and whingy

 

[Trakar]

For all our sakes I hope waxing poetically doesn't contribute to Global Warming.

This is really the most contentious issue with Global Warming. I believe the issue with tipping points was first lamented over when the role of CO2 in the atmosphere was discovered. It's impossible to look at the history of Global Warming and not see the correlation between political interest and correctness of the theory.

I think working out which came first is key. I'm pretty sure "something wicked" arrive to the party with Al Gore.

Like most things you seem pretty sure of, this too is incorrect.

The wickedness to which I speak is the lack of consideration by many self-centered people for the consequences of their actions, and the fact that even when such consequences and detriments are discovered and pointed out, a preference to ignore the long term drawbacks to enjoy short term gains.

 

[Trakar]

I also beleive we are at the bottom of the sun activity cycle at the moment, which could be causing the cooler winters? rather than AGW effects. I guess time will tell. I heard something mentioned on a radio program and looked it up.

the primary issue is that it is winter, there is more moisture in the air (from more energetic environmental systems - AGW), and the normal arctic isolation systems are breaking down and the cold polar air masses are spilling into lower latitudes as warmer flows replace them.

The sun has a very minor role in these issues, it has climbed back from minimum and seems to be headed into a normal, if somewhat tepid more active cycle since this time last year. (should peak -solar max- in May of 2013, next min sometime around Jan 2019 - http://www.swpc.noaa.gov/SolarCycle/index.html )

 

[Trakar]

Hence the paradox of calling it Global Warming, as the OP suggested.

Anthropogenic factors are the forcing stimulus, "Global(ly averaged) Warming" is the effect of those factors, climate change is the product resulting from that effect. How the various local, regional and hemispheric variables interact to reflect these issues, at any given particular instant, is weather.

 

[Trakar]

I also keep my carbon foot print low but I'm not a shiver in the dark proponent - I see no reason not to have a high tech, advanced industrial society with all and more of the perks we have now in a near carbon neutral civilization.
Sweden thinks so too and is well on it's way.

My real concern is the political will to do so....the technology is available to get to carbon neutral tho not to reverse the existing carbon load.

The other concern which is not addressable is there are simply too many people for the planet .....agw is merely a sizeable added stress on that reality.

That is a largely self-correcting problem, not that such corrections are painless or simple, but one way or another they are inevitable. Security, basic human rights provisions, education and an vital economy are the pillars that sustainability are built upon.

 

[Trakar]

...The links you cite refer only to the coldest December on record. The "so far" is an important qualifier, its omission makes your original post a misrepresentation.

The misrepresentation is in thinking that the coldest December at Miami Beach since 1927, or the coldest December in Brittan since 1910, is in any way reflective of the planet's average temperature.

Which according to NOAA:

•The combined global land and ocean average surface temperature for December 2010 was 0.37°C (0.67°F) above the 20th century average of 12.2°C (54.0°F). This tied with 1982 and 1994 as the 17th warmest December on record. It was the coolest December since 2000.


•The global land surface temperature for December 2010 was 0.38°C (0.68°F) above the 20th century average of 3.7°C (38.7°F). This tied with 1994 as the 30th warmest December on record.


•The worldwide ocean surface temperature for December 2010 tied with 1994 and 1998 as the tenth warmest December on record, 0.36°C (0.65°F) above the 20th century average of 15.7°C (60.4°F).


•For the year (January–December), the combined global land and ocean surface temperature tied with 2005 as the warmest such period on record, at 0.62°C (1.12°F) above the 20th century average of 13.9°C (57.0°F). 1998 is the third warmest year-to-date on record, at 0.60°C (1.08°F) above the 20th century average.

http://www.ncdc.noaa.gov/sotc/global/2010/12

 

[Trakar]

Since when are global warming threads allowed outside of the global warming discussion?

Ahhhh! Thankee, I was wondering where all these posts came from at once!!?

Now my eyes have been opened!

 

[lomiller]

• What is it about greenhouse gasses that reflect the sunlight back onto the earth while it does not reflect the sunlight outside the earth back into space? If its property was that it reflected light, wouldn't it not be changing the temperature at all since it would be reflecting the same percentage of light in both directions.

• 
  Greenhouse gasses don’t block visible light but they block long wave IR, which is how the Earth gets rid of the energy it receives from the Sun.
  
  

  [*]If these gasses reflected light, wouldn't we be worried about global cooling since more light would not be reaching the land?]

  
  See above
  
  

  [*]How does an actual greenhouse work? Does a greenhouse actually work by trapping heat inside while not reflecting it away in the first place? Doesn't it actually work because plants produce the heat somewhat and also the oxygen they produce is thinner?

  
  Greenhouse is a loose analogy. Actual greenhouses work primarily by blocking heat from escaping via convection. Obviously heat can convect out of the earth’s atmosphere greenhouse gasses or no.
  
  

  [*]If greenhouse gasses were reflecting light back onto the surface of the earth, wouldn't the land be warmer now at higher elevations

  
  Once again, part of what makes a greenhouse gas is that it’s transparent to visible light so your question doesn’t make sense.

 

[lomiller]

The way I understand it is that even if carbon output of humans was zero by tomorrow, it would have little stabalising impact on the climate for centuries because the damage has been done and our carbon output hangs around a long long time. So regardless of what we can do to stop carbon output, we are still going to have to live with climate change. The complexity of the matter is compounded by the climate affecting the planet and the planet in turn affecting the climate.

If we stopped emitting CO2 temperatures would stabilize within a decade or two. They may not return to normal for a very long time but they would stop going up.

 

[BenBurch]

• What is it about greenhouse gasses that reflect the sunlight back onto the earth while it does not reflect the sunlight outside the earth back into space?
  
  ...

• 
  
  Doesn't work that way.
  
  GHGs are opaque to particular wavelengths of infrared that approximate the temperature of the Earth.
  
  They absorb that heat and re-emit it in a random direction.
  
  As a result, the sky glows in those IR frequencies.
  
  It has this effect on incoming IR in those frequencies too, and if that were all of the energy that heats the earth, the effect would be nil.
  
  However all sorts of other frequencies of sunlight light pass through the atmosphere and these gases are not opaque to them.
  
  This light strikes objects on the ground, and is converted to heat. Heat that in large part is re-emitted in those characteristic frequencies that GHGs are opaque to.
  
  It is this energy that builds up when the GHG blanket becomes more dense.

 

[Trakar]

Good points/questions all! I'd be happy to try and address these issues a bit, at least as well as I'm able.

• What is it about greenhouse gasses that reflect the sunlight back onto the earth while it does not reflect the sunlight outside the earth back into space? If its property was that it reflected light, wouldn't it not be changing the temperature at all since it would be reflecting the same percentage of light in both directions.

• 
  
  First, there are a few misunderstandings to correct. Greenhouse gasses (GHGs) generally don't much interact with most sunlight at all. What they interact with are thermal, or IR, frequencies of light. Roughly half of of the sunlight incident on our planet's outer atmosphere ends up being absorbed by the ground/sea upon which it shines. ~45% of this energy is re-emitted outwardly in the form of IR (thermal) radiations. GHGs are gasses that absorb IR radiations. The absorption results in an excitation of the molecule, which then returns to its more stable state by emitting another IR photon in a generally random direction, with a roughly 50/50 up down split. The longer the free path of IR in the atmosphere (the longer on average that an IR photon can travel without encountering an absorbing gas molecule (GHG) or speck of IR absorbing dust/soot, the less IR (thermal) energy will be reflected back to the Earth (remember the 50/50 issue). The higher the concentration of GHGs the shorter the free path of the IR photons and the more IR that is re-emitted/"reflected" back towards the Earth.
  
  

  [*]If these gasses reflected light, wouldn't we be worried about global cooling since more light would not be reaching the land?

  
  Global cooling occurs from a number of factors, but the most consistent and dominant factor (beyond dramatic decrease of Solar output) seems to be declines in atmospheric GHGs, which we can understand through the above explanation be be the result of an increase in the mean free path of IR (thermal) radiations through our atmosphere.
  
  

  [*]How does an actual greenhouse work?

  
  More importantly, what is the effect of a greenhouse? The gasses were characterized for their effect not because of mechanism of function.
  
  

  Does a greenhouse actually work by trapping heat inside while not reflecting it away in the first place? Doesn't it actually work because plants produce the heat somewhat and also the oxygen they produce is thinner?
  [*]If greenhouse gasses were reflecting light back onto the surface of the earth, wouldn't the land be warmer now at higher elevations? Instead, it is colder there. Snowfall is always reported first in the mountains.

Colder higher, thinner air, less concentration of gasses, longer free path,...see how easy this is!

 

[Trakar]

...Sorry, I didn't mean for this post to be so long and whingy

Not at all, apologies for the gruffies, there are a lot of weasels in rabbit costumes, nothing personal intended!

Couple of standard references just to keep this post topical and educational:

American Institute of Physics - The Discovery of Global Warming - http://www.aip.org/history/climate/index.htm

Global Climate Change Research Explorer - http://www.exploratorium.edu/climate/

Skeptical Science: Examining Global Warming Skepticism - http://www.skepticalscience.com/

 

[DC]

• What is it about greenhouse gasses that reflect the sunlight back onto the earth while it does not reflect the sunlight outside the earth back into space? If its property was that it reflected light, wouldn't it not be changing the temperature at all since it would be reflecting the same percentage of light in both directions.
• If these gasses reflected light, wouldn't we be worried about global cooling since more light would not be reaching the land?
• How does an actual greenhouse work? Does a greenhouse actually work by trapping heat inside while not reflecting it away in the first place? Doesn't it actually work because plants produce the heat somewhat and also the oxygen they produce is thinner?
• If greenhouse gasses were reflecting light back onto the surface of the earth, wouldn't the land be warmer now at higher elevations? Instead, it is colder there. Snowfall is always reported first in the mountains.

greenhouse gases do absorb and radiate. only a small part is radiated back into space.

http://www.ucar.edu/learn/1_3_1.htm

 

[CapelDodger]

I think working out which came first is key. I'm pretty sure "something wicked" arrive to the party with Al Gore.

No, it arrived with Margaret Thatcher. She isn't North American so you may have missed it, but she was on the case long before anybody had heard of Al Gore. It was her intervention that brought AGW onto the world stage.

Unusually for a politician, Maggie has a science degree. One (of many) reasons why she would never have considered Monckton for the role of "science adviser". (The many other reasons are why she never considered him for the role of adviser at all. When she still had her wits she despised silly little men like him.)

 

[CapelDodger]

whoa, ease off a little. If you look at my post Im asking the question not making a statement. It is a fact is it not that we are at a sun activity minimum are we not?

Coming off one, certainly.

Im aware also that despite this global temperature for first half of 2010 was the warmest on record and I understand that it has been discovered that the Suns activity plays a small role in global temperatures compared with AGW.

So small that it's extremely difficult to tease out from the noise. People have been trying to find a signal since the sunspot-cycle was first identified, with no success until very recently.

I was just asking though if the Suns current minimum could affect the weather over the past 2-3 years and be contributing to the colder winters, within the context of a net increase of global temperature.

It's the distribution of heat within the atmosphere which determines weather, and I'd have thought the Sun's impact would be quite evenly spread. The marked change in Arctic sea-ice cover recently seems a far more likely candidate to me. Open water can interact with the atmosphere in and Sun in ways that ice can't.

Fortunately we'll be getting more data in the next few years as solar activity increases and Arctic sea-ice decreases.

I am also aware/heard what has been discussed here that Europe may actually get colder winters due to climate change due to a change in the jet stream. I go to realclimate often, though I find it a complex subject.

The jet streams are influenced (possibly caused, I'm not sure about that) by latitudinal heat and associated pressure contrasts. They're sort of intermediate between those and the weather down here.

Then there are Rayleigh waves to consider, but realclimate gets away from me too there .

 

[CapelDodger]

To the best of my knowledge the little ice age was not invented. It is a period of time where the mean temperature was lower than the period before and after and therefor someone named it the little ice age. This name did not come about until the 20th century, but to say that it was invented gives it the feel of voodoo science, which to the best my knowledge is not the general accepted stance.

I said it was invented as a historiographical fad. Which is to say, as a method of interpreting history. "Fad" does reveal my low opinion of such efforts to find faux-scientific formulae to explain history, and, of course, spawn any number of innovative papers and doctoral theses. I can understand the problem : history has been seriously picked-over already, and finding a genuine new insight takes a lot of work.

Come up with the idea that climate has been a major driver of history and you have an untouched sandbox to play in. It never commanded much respect in the academic world and has only resurfaced because deniers in the early days vaguely remembered stories of Frost Fairs which they'd heard at school. (They also grasped at the Urban Heat Island effect, again vaguely remembered from schooldays, and still cling to that as well.)

An irony is that deniers will point to any historical event as climate-related and proof that "climate is always changing" while arguing that climate change now will have little or no impact. I guess they just don't do irony .

 

[CapelDodger]

I didn't write the OP

You posted what icerat responded to, viz:

Hence the paradox of calling it Global Warming, as the OP suggested.

How do you summon a paradox? Or are you trying to imply that the OP is deficient in some way? It's very hard to tell, and that smiley is no help at all.

Give me something icerat and I can work with, please, some specific argument, not crypticisms.

 

[CapelDodger]

In the UK at least it is well understood that our winters are warmer than they would be expected to be at this latitude because of "warm wet westerly winds in winter", as I was taught to recite at primary school. So the idea that if those winds are disrupted we'll get colder winters is easy for most Brits to grasp. I've explained it to several without difficulty myself.

I bet you got Moscow as the counter-example too .

Perhaps the greater prevalence of AGW denial in the US continental interior is related to their natural experience of wild seasonal change. A silly idea, I know, but there's a few sociology papers in it.

The links you cite refer only to the coldest December on record. The "so far" is an important qualifier, its omission makes your original post a misrepresentation.

Short-term expedients are getting ever shorter in the denier arsenal. Boy-bands have more staying power these days. Not much talk about Antarctic sea-ice last NH summer, I noticed. It's now the season for talking about Arctic sea-ice recovery and not a peep there either.