Tabling ideas - From Rainmaking to Sunshields
Sam Carana
Have you heard about the various techniques used to create more rain?
Small airplanes are increasingly used to disperse salt into clouds to
capture moisture. If done at the right moment, this can result in rain
in areas that experience droughts. Rain is much valued for better
harvests and for hopusehold use. More rain could also prevent deserts
from spreading, make existing deserts fertile, improve soil quality,
save rain forests, etc. So, making rain at will is a very interesting
concept.
Interestingly, manipulating clouds could also have further beneficial
impacts. Clouds become more reflective as the number of droplets in
them increases. Rainclouds could thus act as a natural heat shields,
bouncing more incoming sunlight back into space. Also, by filling the
clouds with smaller droplets, they tend to last longer, thus reflecting
more sunlight back into space over longer periods, before the clouds
disperse.
The trick is to increase humidity in low-level clouds, or
stratocumulus, to make them bounce more sunlight back into space, off
their bright, shiny tops.
The idea to selectively increase the reflectivity of the Earth's clouds
dates back to John Latham, an atmospheric physicist based at the
National Center for Atmospheric Research in Colorado, who suggested it
in Nature about 15 years ago.
You may remember Stephen Salter, who designed a floating canister 30
years ago that captured wave power by driving a generator from the
motion of bobbing up and down on the waves. Capturing wave power in
such a manner seems indeed a tantalising way to generate a constant
stream of clean energy.
Well, some time ago, the same Stephen proposed to make rain with
floating wind turbines that make very choppy waves, known as Faraday
waves. A high-frequency ultrasonic generator would spin seawater around
inside a grooved drum, producing tiny waves that are thinner than a
human hair, throwing tiny droplets of water from their crests up into
the air. As this fine mist of sea-spray evaporates, tiny particles of
sea-salt remain in the air and get sucked up into the air, especially
when the sunshine causes rising currents of air. These little salt
particles act as centres attracting extra droplets to form darker
clouds further up in marine stratocumulus clouds.
Stephen envisages a multitude of ships to criss-cross the oceans,
remotely controlled with their position tracked through GPS and their
destination determined by wheather patterns.
This idea of making rain in this way could also be combined with
another idea discussed earlier in this group, i.e. of exploiting
temperature differences in the sea.
http://groups.google.com/group/greenhouseeffect/msg/4a21d06ae5b08c04
The deeper you go down into the ocean, the colder it gets. At the
lowest points, the temperature is near freezing point. Ships could drag
a pipe along, reaching down a few hundred metres into the ocean.
Thrhough this pipe, cold water could be pumped up by a solar-powered
pump to be released back into the sea from a little tower of, say, two
metres high. As the cold water falls down into the sea, the evaporation
will act as an air-conditioner. Furthermore, condensation around the
top of the pipe will drip down and can be captured in containers, to be
sold as fresh water.
So, apart from harvesting clean, potable water in the above way, such a
ship could also be anchored at a location where it could throw part of
the seawater up into the air in the way Stephen Salter proposed, as a
fine mist, in order to produce more rain in the proximity of a dry area
on land.
But will it all work? Some of the water could also rise higher up into
the atmosphere and increase humidity of cirrus clouds at high
altitudes, thus trapping the heat underneath and heating up Earth even
further through the greenhouse effect.
Also, it could cause too much rain to fall in one region, and too
little elsewhere, disrupting globally-balanced weather patterns. Since
we can expect more forceful cyclones and tropical rains as a result of
global warming, we need to be very careful not to artificially increase
risk of flooding and other disasters. As discussed earlier in this
group, the Atlantic warm stream may well change its course due to an
increase of cold water from glaciers in Greenland, caused by global
warming. Some therefore predict ice-age conditions in north-west Europe
in future.
http://groups.google.com/group/greenhouseeffect/browse_thread/thread/50b7bbd75b11f3a0
So, we need to assess the risks of manipulating climate and weather in
various ways, not only to ensure that action will work as intended, but
also to avoid that an anticipated beneficial outcome in one area will
come at the cost of disasters elsewhere. We need more research,
comparing the various alternatives by means of computer modelling to
asses the various scenarios. We need to put all such projects on the
table, including combinations of the various approaches next to the
alternative of taking no action at all. We need to include ideas
ranging from rainmaking to sunshields, and assess which combinations of
projects will work best.
Earlier in this group, the initiative of positioning shield in the sky
above Earth was discussed. Large shields could be positioned in orbit
in the sky to make areas such as deserts receive less sunlight and thus
become more fertile. Such shields could deflect sunlight selectively,
their positions remotely controlled from Earth, so that one area could
be shielded from the sun at one period, and another area at a later
period. Also, the shields could be moved into a parallel position for
minimal shielding.
The shields could be covered with solar panels, for generating power,
or could be used to grow food that could be transported down to Earth.
Also discussed in that post was possible use of such shields as
mirrors, deflecting sunlight towards Mars, with the aim of eventually
terraforming Mars.
http://groups.google.com/group/greenhouseeffect/browse_thread/thread/cb2d03e4bfec4fa4
Sam Carana
Sam Carana
Such evaporation will have some (temporary) cooling effect, but the real impact on global warming will come from albedo change. When there's much wind at night, offshore wind turbines could produce more energy than is needed on the grid. Such surplus power could be stored and - at times when there's little wind - be used to pump up sea water and have this sprayed by the turbines as a fine mist over the water. This spray will contain tiny particles of sea-salt that get sucked up into the air, especially when there's little wind and sunshine causes rising currents of air. These little salt particles will attract further droplets of water from the surrounding air, forming clouds that are lighter in color from space than sea water.
I wonder to what extent such increased cloud coverage could mitigate global warming. On the one hand, the extra clouds will reflect more sunlight back into space, but on the other hand water vapor is itself a greenhouse gas. While the albedo difference between clouds and sea water is obvious, some of the evaporated water could rise higher up into the atmosphere and increase humidity of cirrus clouds at high altitudes, thus trapping the heat underneath and heating up Earth even further through the greenhouse effect. Also, such evaporation could cause unwanted salty rain to fall over land.
Has anyone done any modeling on this?
Cheers!
Sam Carana
Through this pipe, cold water could be pumped up by a solar-powered
Sam Carana
with the aim of reflecting more sunlight back into space.
As discussed, one of my worries is that if water gets up too high in
the atmosphere, it will trap some of the light underneath, thus
strengthening the greenhouse effect. What worries me even more is the
possibility that Earth will start loosing hydrogen and oxygen to
space, if we artificially increased humidity. I wrote about this
danger in this thread:
http://groups.google.com/group/greenhouseeffect/browse_thread/thread/8166677519b1aa33
Does anyone know of any studies into the possibility of hydrogen and
oxygen ions escaping from Earth into space?
Cheers!
Sam Carana
the undersigned
Just replying to some of your concerns about water vapor.
I remember studies about ozone depletion dating years back, to 2001 to
be precise. One of the concerns was that more water vapor reaching
higher altitudes would lead to ozone depletion.
One such study was "Climate and ozone response to increased
stratospheric water vapor", by Drew T. Shindell, of the NASA Goddard
Institute for Space Studies and Columbia University, New York, NY.
The URLs I have on this are:
http://www.giss.nasa.gov/research/news/20010417/
http://pubs.giss.nasa.gov/abstracts/2001/Shindell.html
http://pubs.giss.nasa.gov/docs/2001/2001_Shindell.pdf
This would suggest that ozone depletion should be added to the
concerns.
I understand that you suggest to store surplus energy from wind
turbines and then to use this energy to run the wind turbines (in
reverse, I suppose), while spraying seawater in front of the wind
turbines, seeking to induce cloud formation.
Instead, why not simply send such surplus energy directly into space?
That way, you wouldn't have to store it first. Just keep the turbines
going and - once the grid doesn't need any further electricity -
convert the energy directly into microwaves and send them off into
space.
This may be just what we need in terms of global warming. Sending some
of that surplus energy off into space may be sufficient to shield of
from catastrophic global warming. Of course, we should accompany this
with dramatically reducing greenhouse gases.
Cheers!
T.U.
On Dec 19, 11:23 pm, Sam Carana <sam.car...@gmail.com> wrote:
> Over the years, I've discussed ideas to could increase cloud coverage,
> with the aim of reflecting more sunlight back into space.
>
> As discussed, one of my worries is that if water gets up too high in
> the atmosphere, it will trap some of the light underneath, thus
> strengthening the greenhouse effect. What worries me even more is the
> possibility that Earth will start loosing hydrogen and oxygen to
> space, if we artificially increased humidity. I wrote about this
Sam Carana
into the water.
I suggest that we do some calculations, in order to better evaluate
such methods.
How about using Google Documents for a collaborative document on
this?
Cheers
Sam Carana
On Dec 29 2008, 9:40 pm, the undersigned <theundersig...@gmail.com>
wrote:
>
> ... why not simply send such surplus energy directly into space?
The Undersigned
Sending Surplus Energy Into Space
I've invited a few people to join in.
Is there anyone who could help doing the calculations?
Here's another idea. I've read about how meteorites have struck Earth in history, apparently caused severe depression of temperatures (including ice ages), as dust clouds covered Earth for many years. I've started a collaborative study into this, called
Covering Earth in Dust
Care to join in with that one as well?
T.U.
Sam Carana
I'm also doing a study on carbon capture by vehicles, called:
Let Vehicles Take CO2 from the Sky
I've invited you to collaborate.
Cheers!
Sam Carana
Sam Carana
stream of 1 PW (one petaWatt) into space, to compensate for the heat
that is trapped by the greenhouse effect. In other words, sending
surplus energy from wind turbines into space would indeed be a mere
drop in the ocean. I have added the calculations to the collaborative
page.
Cheers!
Sam Carana
On Tue, Jan 6, 2009 at 5:11 PM, The Undersigned
<theunde...@gmail.com> wrote:
> I've started a collaborative document called:
> Sending Surplus Energy Into Space
>
> I've invited a few people to join in.
> Is there anyone who could help doing the calculations?
>
> T.U.