FAQ

A. No my design is self cleaning. A combination of the angle of the reflectors and wind ensures
that the dust does not settle.

However the design is such that it will not be affected by sandstorms. The panels are raised off the ground with a
small hole at the centre of each panel. Hence any airborne sand that settles on top would not stay for long.

A. This system is providing a mechanism to directly cool the Earth, the light energy is not trapped in the atmosphere, or reflected back down by the greenhouse gas layer in our atmosphere. An important note:- Infra red energy is what you would feel on your skin if you stood in front of a fire, it is Infra red energy that is reflected by the greenhouse gas layer back to the Earth. Or another way of looking at this is if visible light travels into through our atmosphere to Earth it can also go back into space again. There is some light energy is absorbed by dust particles in our atmosphere which in turns heats the atmosphere, however the reflectors provide a greater net cooling to the earth compared with soil, gravel, roads and crops for a given land area.

Q. If we did lower the temperature of the earth’s atmosphere with reflectors would that be seen as ‘job done’ by politicians?

A. I’m with Stern and his report. Something has to be done sooner rather than later.

Somehow I doubt fuel cell cars will be the dominant mode of transport for a while yet, nor do I believe that massive investment in renewables, such as OTEC to supply a modest 40% of the worlds electrical power, will happen.
I also agree that by using reflectors, they may be seen as an answer, It should not be and certainly not by policy makers. My stance is that reflectors in the desert are a relatively cheap fix to buy us time.
We are talking about survival of society as we know it, I have a young son, and it is his generation onwards that is at greatest risk. It is so very possible we will have wars because of uninhabitable land, vast areas of flooding, massive forest fires, many many cities submerged by sea water, massive global slowdown in the economy, famine disease and inevitably many millions of people will die.

A. No, though it is known that this principle will work as areas of snow or ice reflect the suns rays back into space.
Prototyping will perfect the ideal design that can withstand storms and offer the greatest reflectivity.
I must add I'd be happy to project manage the above.

A. At this time it not clear how many solar reflectors would be required to effect a 1 degree cooling of the earth.
Though it is clear that Global warming is likely to cost untold billions of dollars and lives.
Solar reflectors should be far cheaper than other ideas proposed, such as launching a giant sun
shade into orbit, and is more practical than filling areas of the ocean with reflective floating balls.

The estimate first year cost including installation for panels covering 1% of the Sahara desert is just
$56 Million US dollars. Annual running costs including ground rent is estimated to be $17 million USD.
See also costs page link.

A. I understand that in the last 50 years the Sahara has spread south to cover an extra 65 million hectares of
land, thus they should welcome this solution. Also the shade produced would be a habitat for plant growth.
As a result the local population have a double spin off benefit from siting these reflectors in the deserts.

Q. Would the reflectors create adverse local weather effects?

A. Reflectors would be placed ‘in patches’ as directed by climatologists to minimise local effects. The
Hadley cell mechanism has been raised as a matter of concern and further research is advised.

A. Yes the Mojave, Kalahari, Arabian and the Australian Great Western Deserts should be used too.
The more spread out the better, as it would minimise any local effects.

Q. Why not use solar cells to collect energy instead of bouncing it back into space?

A. I believe the solar tower solution. (www.enviromission.com.au) is the better deal if large infrastucture can be placed in the deserts. However these solutions would cost many billions of dollars.

Hence the solar reflectors is a quick and cheap (relatively) way of counteracting the effect on global warming.

A. The effect would be very similar to flying over snow or even lots of cloud. Pilots may require sunglasses.

A. No, solar reflectors are designed to directly cool the earth in a fast response to the
Global warming that we see today. Greenhouse gases still need to be dealt with over the next 100 years.

A. In practice this would be difficult to implement on private properties, also the dense population
centres are often at the higher latitudes and often under cloud thus the
cost effectiveness and practicality is less.

Q. A method of creating more and longer lasting clouds has been proposed as an alternative idea of
reflecting the sun which could be cheaper. Why are desert based reflectors better?

A. Extra clouds would have opposition from many in the public, including sun bathers, farmers and tourists.

Q. How much land is required to make a 1 degree cooling of the climate?

A. This will be up to the climatologists. I have calculated that if 10% of just the Sahara desert were covered in reflectors then a colossal 288,809 TWh per year can be radiated back into space. This will cool the earth but by how much is not clear at this time.

A. Once in place they will need minimal maintenance. The reflective part is designed to last at least 20 years. The supporting structure is designed to last at least 100 years.

A. When it is seen that the cost of implementing the solar reflectors concept is many times cheaper than dealing with rising sea levels, crop failure or famine, governments and insurance companies of the world will need to lead the way in financing the project.

Q. What is happening to the solar energy that is striking the desert sand at the moment?

Some of the suns energy hitting the sand is converted into heat, directly heating the atmosphere and consequently melts ice caps etc. Some of the energy is radiated back into space as infrared energy (much the same as if you put your hand near a radiator you would feel the infrared heat.)

The remaining energy is bounced back into space. As per one of my slides, infrared energy is increasingly bounced back to the earth by blanket effect created by the extra CO2 in the atmosphere. See the slide CO2 attached.

Q. Have you any idea what is the ratio of the amount of solar reflection of the reflector when compared to desert sand e.g. “These bounce 10 X the energy back into space than compared to raw desert!”

Yes, the standard measurement tool for this is called Albedo, which is the measure of reflectivity.

Black    0
Forest 0.05–0.2
Grassland and cropland             0.1–0.25
Dark-coloured soil surfaces        0.1–0.2
Dry sandy soil             0.25–0.45
Dry clay soil     0.15–0.35
Sand 0.2–0.4
Mean albedo of the earth          0.36
Glacial ice       0.3–0.4
Light-coloured soil surfaces        0.4–0.5
Fresh, deep snow       0.9
Water 0.1–1
Absolute white surface 1

This shows that snow reflects most of the light energy falling on it and that most surfaces absorb it.