The Solution to Global Warming
A $10 Billion Sun shield for planet Earth
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.
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
Methane (another greenhouse gas) buildup
Surface temperature increasing
Ocean temperatures increasing
Animals are dying
The Sun is getting hotter too
Arctic changes are the greatest
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 Melt ing 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.
See my book "JOBS for the 21st Century" for details
What is the mass of the shield?
Is 300 Million Tons a lot?
Comments? Email me at firstname.lastname@example.org