Executive Summary

     The proposal is to build a very large orbiting shield which will intercept sunlight before it reaches the Earth and reflect it back into space.  The shield will consist of a very thin metal foil covering a sparse matrix of ribs.  In order to minimize the cost, the materials needed for this shield will come from the Moon.  The shield will be built robotically both to save cost and because humans are not suited to working in space.  How large a shield will be necessary?  Our initial estimate is 6 percent of the cross-sectional area of the Earth.  Since the cross-sectional area of Earth is about 50 million square miles, the shield will need to be about 3 million square miles (roughly the size or area of Australia).  Since the shield will orbit the Earth, it will only intercept sunlight when it is on the sunny side of the Earth.  Thus the effect of the shield will be to reduce incident radiation from the Sun by about 3%.   How long will it take to build this shield?  Suppose that we could build one square mile in the first year of assembly.  By doubling the effort each year thereafter (through the expansion of our Lunar manufacturing facilities), we could complete the shield in about 22 years.  Including three years of startup, the entire project could be completed in 25 years.  One additional year would double the size of the shield to 6 million square miles and give a reduction of 6% in the incident sunlight (if this were deemed necessary).

      The cost of this project would be surprisingly low.   Since the very very vast majority of material would come from the Moon, that part will be FREE.  All we need to pay for is the startup facilities.  The startup facilities would consist of a large electromagnetic projectile launcher (EMPL) built on Earth and configured to throw its payloads to the Moon - as in Jules Vern's Moon gun (cost about $5 billion).  We would require just one robotic mission to the Moon to put in place the initial manufacturing capability (cost about $1 billion).  Other costs include sending additional materials to the Moon via the EMPL. These would include robots, computers, and other parts which could not be built easily on the Moon from materials found there (cost about $2 billion).  We will also require one mission to the orbital site of the shield which would put the initial assembly equipment in place (cost about $1 billion). Finally, there would be the cost of supervising the construction of the shield over 22 years (cost about $1 billion).  Thus the total cost of the Sun shield which would solve the global warming problem would be about $10 billion.   

      Of course there are several major hurdles to overcome before this shield could be built. The first question would be what latitudes would the shield cover.  Assume that we choose to build a shield which is 3000 miles wide and 1000 miles high.  We could orient this either North to South or East to West.  If it were oriented with its long side going around the Earth, it would cover about 50 degrees from East to West and about 17 degrees from North to South.  This could be from 8.5 degrees South to 8.5 degrees North on either side of the equator.  If the shield orbits Earth twice per day, then its shadow would take about 1.5 hours to pass overhead on each orbit.  If the shield were turned 90 degrees, it would cover 17 degrees from East to West and 50 degrees from North to South.  In this case it would cover from 25 degrees South latitude to 25 degrees North latitude and would pass overhead in only a half hour.  The second problem would be to put the proposal before the United Nations in an attempt to secure global approval for the shield.  We feel sure there will be plenty of people who will oppose this plan - either because they don't believe it can be accomplished or because they have some objection - such as worrying about the shield falling or because it will get in the way of astronomical telescopes.  There are even a few people who do not believe that global warming is actually happening.  However, the seriousness of global warming grows greater with each passing year and we need to do something before it is too late.

Problem solved 

      A possible problem with this shield proposal was that it would block satellite signals from satellites which orbit above it.   However, it appears that simply by punching a bunch of holes in the foil, we can eliminate this problem.  Thus the foil would look like a swiss cheese or a checkerboard.  This would allow the satellite signals to pass through with little attenuation.  Obviously this will require a somewhat larger shield area to make up for the holes - but this is not a problem either.

What is the evidence of global warming?

Carbon dioxide (a greenhouse gas) concentration increasing

• The CO2 concentration in the atmosphere has been increasing steadily for 50 years.
• First look at the CO2 concentration over 400,000 years from the Vostok ice cores
• 
• Compare this to Mauna Loa CO2 measurements over the last 50 years
•   

Methane (another greenhouse gas) buildup

• Methane trapped in frozen tundra may be a ticking time bomb. (* new 3/22/06*)  Aparently as much as 400 billion tons of methane may be trapped in the frozen tundra in the arctics.  This is about 3000 times the current methane content of the atmosphere.  Methane is more than 20 times as strong a greenhouse gas as carbon dioxide.  The warming and thawing of the tundra may start a chain reaction which could release billions of tons of methane into the atmosphere which would greatly exacerbate the global warming problem.

Surface temperature increasing

• Global average temperatures are slowly increasing
• Temperatures have risen about 0.7 deg Celsius over the last century.
•      
• Many of the hottest years on record are recent ones. The ten hottest years were:
•  2005, 1998, 2002, 2003, 2004, 2001,  1997, 1995, 1990,  1999
• Graphically you can see the trend starkly.
•     
• Temperature hit 100 in London (August 10, 2003) for the first time in recorded history.

Ocean temperatures increasing

• Recent headline:  Caribbean coral suffers record die-off.    (* 3/31/06 *)
• Costal ocean temperatures are so high that sea corals are being killed globally.
• Up to 90% of corals are dead or dying in many areas.
• It is now too late to derail or delay the disaster.
• The increase in the temperature of the oceans is providing fuel for stronger and more frequent hurricances and typhoons - like last year when we saw a record number of hurricanes in the Caribbean.   Japan also set a record for the number of typhoons to hit Japan.
• Sea levels are slowly increasing, threatening cities such as Venice, Italy
• Sea level as measured at San Francisco, California, USA.
•      

Glaciers melting

• In Montana's Glacier National Park only 27 of the 150 glaciers which existed in 1910 remain today and they will be gone in only 20 years.
• Glaciers are in retreat all over the world.
• Here is a spectacular site by Gary Braasch called " World View of Global Warming"
• He shows numerous "before" and "after" pictures of glaciers - such as the following:
•            
•  Upsala Glacier         Rhone Glacier
• Over 90% of the ice shelf north of Ellesmere Island (Canada) is gone.

Animals are dying 

• Animal ranges are changing due to changes in the local climates.
• Walruses are starving in the Bering Sea because they are adrift on ice flows in water too deep to feed.
• In Canada, polar bears are starving because Hudson's Bay is ice-free too long each year so they cannot catch enough seals to survive. Pregnant females are losing so much weight that they fail to produce enough milk for their cubs, which then suffer increased mortality. Once females fail to attain a minimum weight they won’t give birth at all, and scientists can already document a 15 percent drop in birth rates.
• Also in Canada, river temperatures are so high now that salmon are being killed on their way to their spawning grounds - thus killing off the salmon FOREVER. 
• Frogs are dying all over the world - not just a few frogs here and there but WHOLE SPECIES are dying off FAST.
• Vanishing Frogs
• Recent Amphibian Declines in Lower Central America
• Amphibious Assault

Plants effected

• Plants are germinating earlier and earlier and moving farther and farther North.
• Nearly 4 million acres of mature white spruce forest on the Kenai Peninsula (in Alaska) have been killed by a growing population of spruce bark beetles (Dendroctonus rufipennis) since about 1987.
• Louisiana (USA) is losing land at a rate of about 25 square miles per year.
• This effect has now been shown to be primarily due to subsidence of
• the land.  A new NOAA report  says that the northern part of the Gulf
• of Mexico is sinking at a rate of 60 inches per century or about 0.6 inches
• per year (whereas sealevel is only rising by 8 inches per century).  
• Worldwide there are increases in droughts and forest fires.

 The Sun is getting hotter too

• Nasa satellite data shows that Solar radiation reaching the Earth is 0.036 percent warmer than it was in 1986.
• Confirmed by a Swiss/German research team whose data shows that the sun is brighter now than 100 - 150 years ago.

 Arctic changes are the greatest

• Alaska data
• Average temperature has risen 3 degrees C (= 5.4 degrees F) in the last 30 years.
• The sea level around Alaska has risen a foot in the last century.
• The permafrost is melting - which is causing buildings to sink into the mud.
• 98% of glaciers & sea ice are melting.
• Alaska glaciers
•    Denali 1919        2004
•    Holgate 1909      2004
•    Muir 1941           2004
• Over 90% of the ice shelf north of Ellesmere Island (Canada) is gone.
• Scary pictures of the northern polar regions in 1979 & 2000 
• Polar ice has been decreasing by 1% per year since 1979.

                                    1979                                                                          2000

**New** Polar Melting Video

New picture of Polar Ice Extent in September 2007

                                     Minimum 9/16/2007                        Ice extent 9/21/2006

              You can see that the "Northwest Passage" north of Canada was open for the first time in thousands of years.  Rate of Ice Melting Shocks Warming Experts   In September of 2007, the minimum polar ice extent was 4.13 million square kilometers (1.59 million square miles) on September 16, compared to 5.32 million square kilometers (2.05 million square miles) at the minimum in 2005.  This is a drop of 23% in just two years.  At this rate the Artic will be ice-free by 2020 - not 2050 as previously supposed.

Master Plan

• Build a large Earth to Moon electromagnetic projectile launcher.
• Build an Energia HLLV to carry our initial manufacturing facility to the Moon.
• Send the Energia to the Moon with our equipment.
• Set up the first Lunar base and our manufacturing facilities.
• Built a large solar array on the Moon the provide power to run everything.
• Build small EMPLs on the Moon to throw manufactured parts into Earth orbit.
• Assemble Sun shield in orbit using robots.

                                See my book "JOBS for the 21st Century" for details

What is the mass of the shield?

• Assume the mass is 1 ounce per square yard.
• There are 1760 * 1760 = 3097600 square yards per square mile.
• The mass is then 3097600 ounces per square mile = 193600 pounds.
• The mass in Tons is 193600/2000 = 96.8 Tons per square mile. (Round to 100 T)
• Shield mass is 3,000,000 times 100 T = 300 Million Tons.
• The cost to lift it FROM EARTH at $2000 per pound would be $1200 Trillion.
• The cost to lift it from the MOON is NOTHING = NIL = FREE FREE FREE.

Is 300 Million Tons a lot?

• The mass of the shield is equivalent to about 1/16 of a cubic mile of sea water.
• One cubic mile of sea water weighs about 4.718 Billion Tons.
• Equivalently, a cube of sea water 2107 feet on a side weighs about 300 Million Tons.
• There are about 1.37 billion cubic kilometers of water in all the oceans of the world.
• The weight of all that water is about 1.40 billion billion metric tons. (1.4 x 10^21 Kg)
• The total mass of our planet is about 5.976 x 10^24 Kg.
• All Earth's water constitutes 0.0234 % of the mass of our planet.

Comments?   Email me at crwillis@androidworld.com