On 14/12/2019 10:46, Ahem A Rivet's Shot wrote:
> That seems to be a rather more complex question than "how much
> difference does a reflective contrail make" which boils down to "how much
> energy does it reflect into space". People have talked about deploying
> reflectors of some kind to control climate and they've always seemed to
> need to be unreasonably large, it's surprising to me if the combined
> contrails makes a large enough reflector to have such an effect. Many true
> things are surprising though, so it may well be the case.

Are you perhaps a photographer who used to set exposures manually?

One stop is HALF the radiation.  A typical cloud cuts radiation by a
factor of four. Two stops.  Serious overcast is 8-10 times less - 3-3½
stops...


Clouds are the elephant in the climate change room.


Clouds are not a percent or two change in incident radiation. They are a
massive order of ten change. Even wispy contrails make a significant
difference.

Clouds are not modelled in climate change models. They are
'parametrized'. Average values are assumed.

Clouds transfer heat from the surface to high in the stratosphere above
most of the CO2, where they can radiate away to space without being  'in
the greenhouse'.

Conversely high level cloud is an excellent greenhouse itself, reducing
ground level radiation by reflecting it back, by far more than CO2.

The only significant climate change gas is water vapour.

Svensmark et al propose that cloud incidence is modulated by the impact
of particular sorts of cosmic rays whose density is modulated by the
position in the galactic plane and the suns radiation. A theory of
climate change that has been vilified for not being 'on message'.

Water vapour is however supposed to be the mechanism for the invisible
and never detected 'positive feedback' that it is necessary to introduce
to the basic science of CO2 re-radiation in order to get steep enough
rises to match the 1950-1998 rises.

Unfortunately those steep rises stopped in 1998, although CO2 rises did
not, and the other effects of alleged water vapour feedback - tropical
hotspots in the stratosphere - were never detected.

Without the water vapour positive feedback CO2 induced climate change is
negligible.

The fact that steep rises were detected in the late 20th century that
have more or less halted in the 21st is an embarrassment to climate
change purists. CO2 increase has not moderated at all. But climate
change has. Ergo something other than CO2 must be doing a large part of
it. But the scary predictions require that CO2 did ALL of the late 20th
century warming. Without that proviso CO2 induced climate change is a
boring inconsequential footnote.

1/. Just because it is warming, doesnt mean that CO2 is to blame.

2/. The fact that the rate or warming is not coupled to CO2 levels
indicates that something else is going on. Big enough to cause all the
warming, or to stop it dead in its tracks. Whatever.

3/. The supposed  unprecendented rapid rate of warming is illogical: the
proxies that are used to measure temeparures in the deep past do not
have decadal resolutions. In short we dont know how rapidly climate
changed in te past, althought mammoths frozen to death with undigested
grass in their stomachs suggests that catastrophic rapid cooling has
occurred.




>
>  The thought that occurs to me is that if normal US domestic air
> traffic really does reduce the temperature over the US by two degrees (by
> reflecting sunlight of contrails or any other mechanism) then we have the
> solution to global warming without even considering the causes. All we have
> to do is arrange sufficient contrails to dial in the temperature we want
> with fast (three days made it show clearly) response.
>

Yes, but that doesn't allow you to make massive profits selling useless
technology to solve a problem that doesn't exist, nor does it justify
centralised control of the lifeblood of postmodern civilisation - energy.

Remember ClimateChange™ is not about climate change. Its is about poower
contr9l and transferring money from the pockets of citizens to the
oligarchy. In short it is part of the post modern neo feudalism.

If the science was sound they wouldn't need Greta Thunberg.


>  Of course reasoning from a single data point and an untested theory
> is a good way to go very wrong, but I would find it hilarious if it were
> proven and the next move was to encourage widespread air travel in order to
> improve the climate.


Contrails certainly reduce overnight frosts.



--
“it should be clear by now to everyone that activist environmentalism
(or environmental activism) is becoming a general ideology about humans,
about their freedom, about the relationship between the individual and
the state, and about the manipulation of people under the guise of a
'noble' idea. It is not an honest pursuit of 'sustainable development,'
a matter of elementary environmental protection, or a search for
rational mechanisms designed to achieve a healthy environment. Yet
things do occur that make you shake your head and remind yourself that
you live neither in Joseph Stalin’s Communist era, nor in the Orwellian
utopia of 1984.”

Vaclav Klaus

--- SoupGate-Win32 v1.05