I think the phrase "greenhouse effect" was very poorly chosen. Many
people in temperate climates have never experienced a greenhouse.
Gardeners use confusing terms like "cold frame" and "hot house" which
may do the same thing (although some greenhouses are heated). On the
other hand, in many tropical countries the word "greenhouse" refers to a
leaf shelter used to protect young plants from direct sunlight. When I
taught college in the Solomon Islands, the students found this very
confusing.
Perhaps "parked car on a summer day effect" would be more connected to
people's experience.
John
On Fri, 2010-12-17 at 12:05 +0000, Brian Orr wrote:
> Yunus,
>
>
> I think a slightly more accurate description of what actually goes on
> with global warming could be needed if anybody asks what is the
> 'greenhouse effect' - essentially radiation from the sun has very
> little of it's energy trapped by the atmosphere and so either it heats
> the earth having penetrated the atmosphere or it's reflected back.
> That which heats the earth is in part re-radiated into the atmosphere,
> but because it is radiated at a different wave-length compared with
> most of the incoming radiation from the sun, much of it is trapped by
> "greenhouse gases", the most important being CO2.
>
>
> The 'trapping' of the energy here is manifest in that the CO2
> molecules are made to vibrate more, i.e. exhibit a higher temperature
> in degrees Kelvin, Celsius, Fahrenheit, it doesn't matter - it still
> feels warmer - and it still is the driving force behind global
> warming.
>
>
> But most people are very aware of what actual green houses do, even if
> they don't know why. Most people have been in a greenhouse and nearly
> everybody knows what to expect if they enter a house porch on a sunny
> day. Quite simple really as a point of fact: green houses trap the
> sun's 'heat'.
>
>
> There is really no need to get that techie here unless you're talking
> to scientists or to a lay-person who has clearly shown they want to
> understand more clearly.
>
>
> Most people will accept that greenhouse gases warm the earth if
> scientists are agreed on that, which basic experiment and theory
> demonstrate is so. A few contrarians dispute this, but they can
> generally be left to stew. But a large proportion of people will baulk
> at stage 2 of the argument, which is that man's contribution to
> greenhouse gases has emerged as an immense problem. The basic reaction
> seems to be either "the first contention must be wrong, 'cos I can't
> accept the (logical) conclusion." or "I'm not going to get my mind
> around this because I've got other things to do and I can't be
> bothered to see if there could be a connection between stage 1 of the
> argument and stage 2."
>
>
> And so we now move up into 'stupid people', democracy, politicians,
> Kyoto, Copenhagen, Cancun and the "end of civilisation as we know it".
>
>
> But the whole collapsing edifice does not stand or fall on the average
> layman's understanding of what is meant by the greenhouse effect.
>
>
> Brian Orr
>
> On 17 Dec 2010, at 11:17, Mohamed Yunus Yasin wrote:
>
> >
> > thanks for the answers....i agree, but the reason why i asked the
> > question was - if we take the kelvin-ian approach, ie temperature as
> > the molecules ability to vibrate, then if the molecules inside the
> > greenhouse is vibrating slowly, whilst outside the greenhouse, the
> > molecules are vibrating faster, the the faster molecules outside
> > will have a slower effect on the slower moving molecules inside the
> > greenhouse...........so the next question, is the CO2 density same
> > across the planet? personally i prefer to use the phrase Climate
> > Change, rather than Global Warming.
> >
> > in anycase, if one wants to develop the kelvinian approach to this
> > problem, one has to develop it in detail for the public, otherwise,
> > we may have a new set of problems from the deniers!
> >
> > peace
> > yunus
> >
> >
> >
> > ____________________________________________________________________
> > Date: Thu, 16 Dec 2010 11:35:38 +0000
> > From: [log in to unmask]
> > Subject: Re: Global cooling or roasting? A Kelvin-eye-view of NASA's
> > Nov 2010 temperature maps
> > To: [log in to unmask]
> >
> > Yunus,
> >
> > A Greenhouse can maintain higher temperatures than the ambient
> > temperature by storing/retaining reflected radiation within its
> > structure. When UV rays from the Sun are absorbed by the ground or
> > other surfaces, with the exception of reflective 'albedo' surfaces,
> > the energy is re-radiated as Infra-Red radiation which in the case
> > of a greenhouse is partially retained by the glass (which allowed
> > some of the UV to pass through). Ditto in the atmosphere with
> > greenhouse gases having good Infra-Red capture rates.
> >
> > In theory then, excluding the complicated dynamics of the atmosphere
> > and climate, we should be having warmer summers and winters on
> > average globally.
> >
> > Regards,
> >
> > Jonathan
> >
> > On 16 December 2010 11:30, Mohamed Yunus
> > Yasin <[log in to unmask]> wrote:
> >
> > Alastair,
> >
> > i just had a thought (does not happen that often i am
> > afriad). We know CO2 is a greenhouse gas. My
> > understainding of a greenhouse structure is that: A
> > greenhouse amplifies the ambient temperature outside the
> > greenhouse......if so, does that mean that if the earth is
> > becoming a greenhouse, we will have hotter summers and
> > colder winters?
> >
> > peace
> > yunus
> >
> >
> > ____________________________________________________________
> > Date: Thu, 16 Dec 2010 10:40:57 +0000
> > From: [log in to unmask]
> >
> > Subject: Global cooling or roasting? A Kelvin-eye-view of
> > NASA's Nov 2010 temperature maps
> >
> > To: [log in to unmask]
> >
> >
> >
> > Folks … some of us at a meeting of local community groups
> > interested in grassroots education held in the new Centre
> > for Human Ecology office in Govan, Glasgow, yesterday were
> > discussing the psychology of perceptions of global warming
> > against a backdrop of the freezing November we’ve had. (This
> > is bcc’d to those people and others for interest.)
> >
> > Below is the latest NASA data mapping for Nov 2010. As you
> > will see, it shows a coldness anomaly for Scotland of 2
> > degrees C. That may not seem much, but if you take as a
> > baseline the freezing point of water (which is what matters
> > for glacial melt, as distinct from absolute zero on the
> > more-fitting-to-Glasgow Kelvin Scale) then the average
> > temperature over day/night and summer/winter for Scotland is
> > only 7 C (14 C for the world as a whole). As such, a 2 C
> > negative anomaly is quite a bit – some 30% on Scotland’s
> > baseline relative to water-freezing.
> >
> > (Kelvin’s temperature scale, starting from absolute zero
> > where there is no molecular movement at -273 C (sorry
> > Vérène, that’s where the dancing stops), should be used for
> > any calculations of absolute percentage heat distance … it
> > was named after the geologist, physicist and theologian,
> > Lord Kelvin, a.k.a. William Thomson, who took his name from
> > the River Kelvin which enters the Clyde immediately opposite
> > our new premises, just 300 yards away. On Kelvin’s scale of
> > absolute heat content, the global warming anomaly for Nov in
> > the Arctic is a third of 1%).
> >
> > What is really shocking on this NASA map is the way that,
> > like the one I previously circulated for last January but
> > much more pronounced, it shows that northern Europe is a
> > small regional anomaly of coldness amidst a world that is
> > otherwise mostly cooking – especially in central Asia and
> > the Arctic regions, which are most sensitive in terms of
> > glacial melt and therefore rising sea levels. The average
> > global temperature anomaly was 0.73 C. Some of you at our
> > meeting yesterday were wondering how come our local weather
> > pattern this month has been one of bitterly cold weather
> > suddenly oscillating with sudden warmth. I’m not a weather
> > man, but when the UK is sitting with all that hot air around
> > us there’s no shortage of heat if the wind comes from the
> > right way, and I would guess it likely that, like last
> > winter, jet stream anomalies (which one recent paper
> > suggests are due to Arctic warming) have pushed the Arctic’s
> > cold air south of where it should be.
> >
> > These maps can be found, or generated to your own parametric
> > specifications,
> > at: http://data.giss.nasa.gov/gistemp/ and, specifically
> > for the first map below and making others like
> > it, http://data.giss.nasa.gov/gistemp/maps/ .
> > Note that the lower set of maps (below) are already claiming
> > 2010 to be the warmest year of 131 years (i.e. within the
> > reliable instrumental record, I presume) . This may be
> > disputed according to which data set is used once the
> > December results come in. There are several different
> > sources of data – terrestrial, oceanic, various levels of
> > atmospheric – measured in different ways. The NASA website
> > to a degree allows you to change these parameters. Even
> > climate change contrarian Roy Spencer of UAH, who interprets
> > data in a manner that most plays down
> > anomalies http://www.drroyspencer.com/ ,acknowledges in his
> > latest post that “2010 is now in a dead heat with 1998 for
> > warmest year.”
> > Bottom line? Britain’s current icy winter does not go
> > against the evidence that the Earth is radically warming.
> > Double bottom line? Lord Kelvin walked with a limp because
> > he slipped on ice in the winter of 1860-6, so watch out!
> > Alastair.
> >
> > Fig 1: Global map
> >
> >
> >
> >
> > http://data.giss.nasa.gov/gistemp/graphs/2010vs2005+1998.gif
> >
> >
> >
> > ********************************************************
> > * Website: www.AlastairMcIntosh.com
> > *
> > * Email: [log in to unmask]
> > *
> > * Alastair McIntosh
> > * 26 Luss Road
> > * Drumoyne
> > * Glasgow G51 3YD
> > * Scotland
> > * Tel: +44 (0)141 445 8750
> > *
> > * Quick web links: My Books Articles Work
> > *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >
> >
> >
> >
>
>
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