USING COSMIC NUDGING [Changing the Orbits of Asteroids] TO FIGHT GLOBAL WARMING
by Professor John F Banzhaf III, George Washington University, Washington, D.C.

Below is Professor Banzhaf's original proposal from 2019 to use astronomical engineering - cosmic nudging - to fight global warming; a concept now being widely discussed, including even an article in Scientific American magazine.

The New York Times has reported that, as the effects of climate change become more devastating, and the success of massive cooperative global efforts to sufficiently reduce greenhouse gas emissions becomes less likely, some scientists are proposing - as a completely outside-the-box tactic at least worth studying - a strategy of solar geoengineering in which massive changes in the atmosphere would reflect more of the sun's rays back into space.

But many are calling the concept a dangerous and illusory fix.

As another outside-the-box idea which might also be worth at least some consideration and analysis, a well known scientist has suggested a cosmic alternative to fight global warming - one which does not require any reduction in the emission of carbon dioxide or methane, nor even difficult-to-enforce widespread international cooperation - and which might even cost less than some of the drastic emission restrictions now being considered: very slightly Increasing The Earth's orbit

The basic concept was originally suggested by Matteo Ceriotti, Lecturer in Space Systems Engineering at the University of Glasgow, and involves very substantially increasing the Earth's orbit to reduce the amount of solar energy reaching its surface when the sun, billions of years from now, expands and becomes much hotter.

While Ceriotti's proposal was addressed to a problem still many years in the future when Earth would become unbearably hot, the basic concepts involved in changing a planet's orbit are well known.  Indeed, the science fiction film "The Wandering Earth" dramatizes - although in an unrealistic and cinematic-type fashion - one such attempt.

Ceriotti admits that his proposal, aimed at moving the Earth from its current orbit to one a full 50% further from the sun [from about 93 million miles to 139 million miles, a increase of approximately 46 million miles], similar to Mars', while theoretically possible, is clearly not feasible with today's technology.

However, providing a remedy for the more immediate problems of gradual global warming, on a time scale now being considered by many governments and scientific bodies, would require a much less drastic change in the earth's orbit which might in the near future become feasible, especially considering the huge costs and major modifications in life style that the alternative of reducing carbon emissions appears to entail.

What Will Happen If The Earth Gets Slightly Warmer

The recent and very important UN Intergovernmental Panel on Climate Change report analyzed what will happen when the Earth gets even slightly warmer than pre-industrial levels.

The UN put the cost of a mere 1.5°C [2.7°F] increase in temperature at $54 trillion in today's dollars, a 2.0°C [3.6°F] increase at $69 trillion, and a 3.7°C [6.7°F] increase at a stunning $551 trillion. To put these costs into context, the latter figure represents more than all the wealth now existing in the entire world.

According to NASA, Earth's global temperature in 2013 averaged 14.6°C [57.3°F], or 287.75°K on the Kelvin scale, where 0°K is absolute zero. Thus, an additional 1.5 degrees on the Kelvin scale would mean an increase in absolute average temperature of only about 0.5% [from 287.7K to 289.2K].
 
The amount of sunlight (heating energy) falling on the surface of a planet is roughly inversely proportional not to its distance from the sun, but rather to the square of its distance from the son. Thus, for example, moving a hypothetical planet in an orbit originally 50 million miles from the sun to one twice as far [100 million miles] away would cause the amount of energy falling on its surface to be only one fourth - not one half - as great.

Using these figures, it appears that it would be necessary to increase the average distance of the Earth from the sun by only about 0.3% [290,000 out of about 93,000,000 miles] to reduce the heat energy equivalent, which various surfaces on the planet are now receiving, by 1.5°C or 1.5°K.

Technological Limitations

While this represents only a very rough approximation, it does suggest that changing the orbit by a relatively minute amount might be possible using existing technology, and/or new technology (e.g. energy from nuclear fusion) likely to be perfected in a few years if such efforts can be funded by hundreds of billions of dollars provided by major governments, and involve the same extraordinary innovative planning and research of the type used to permit men to live in space and land on the moon.

Ceriotti and others have noted that there are many well known ways to change the orbits of bodies in space, and some have actually been used to help redirect interplanetary probes, as well as studied just in case it ever becomes necessary to deflect an asteroid from getting so close to the Earth as to cause serious problems.

These alternative methods for changing orbits, some of which appear to be equally applicable (though on a much larger scale) to possibly nudging the Earth into a slightly more distant [by 0.3%] orbit, include:
■ employing an electric thruster, and more specifically an ion drive, which works by firing out a stream of charged particles that propel a body in the opposite direction;
■ using a focused light beam, such as a laser, to change the Earth’s velocity;
■ constructing a huge solar sail floating in space near the Earth; or
■ utilizing a gravitational sling shot; a well-known technique for two bodies to exchange momentum and change their velocities with a close passage; a tactic used several times successfully to propel spacecraft.

Some suggest that nudging large asteroids into new orbits, which could then cause a cumulative sling shot effect on the earth over many years, might be the most feasible alternative - both technologically and economically - in the near future.

Indeed, it might be possible to exploit so-called "Δv leveraging" in which a body such as a large asteroid can be nudged slightly out of its orbit and, as a result, years later, could swing past the Earth, providing a much larger impulse to increase Earth's orbit by a tiny amount.

Nudging Asteroids

In theory, and perhaps maybe even in practice, large asteroids could be nudged out of their current orbits, and into new ones in a position to help sling shot Earth, by techniques such as a nuclear blast on the asteroid’s surface, having an unmanned spacecraft collide with an asteroid at high velocity, using solar sails, or a combination of methods.

Other techniques for nudging asteroids into new orbits include providing a continuous push over a considerable period of time by a space “tugboat” connected to its surface, or by a spacecraft hovering nearby.

While no one is seriously proposing that we abandon plans to limit greenhouse gases in favor of a cosmic nudge strategy, and recognizing that all these orbit-changing possibilities would be enormously expensive, it is suggest that this novel outside-the-box idea be at least considered and seriously evaluated, and compared to the huge economic costs and major lifestyle changes required to stop global warming by slashing the emission of greenhouse gases, or by using massive solar geoengineering.

During a recent subcommittee hearing, Congressman Louie Gohmert, a Texas Republican, seemed to propose that one way to fight climate change would be to alter the Earth's orbit around the sun.  Responding to Gohmert's proposal, Congressman Ted Lieu tweeted, obviously tongue in cheek, that he would introduce a bipartisan resolution asking Captain Marvel to help since "she can alter planetary orbits with her superpowers."

But a more practical and realistic step might be for Gohmert and/or Lieu to formally ask the Congressional Research Service, NASA, or some other appropriate body to report on whether a small (approximately 0.3%) increase in the Earth's orbit would tend to counterbalance current global warming and, if so, how the estimated expense of producing that orbital change compares with the costs (monetary and otherwise) of fighting climate change by substantially reducing the amount of greenhouse gases emitted worldwide.

If science can not only guide a vending-machine-sized spacecraft traveling at 14,000 mph to hit a rapidly moving asteroid only 525 foot wide many millions of miles away, but actually determine to the nearest hundredth of a second the precise time of impact [7:14:23 PM Eastern Time], it should be able to determine whether the concept of altering the Earth's orbit by less than half a percent to fight global warming is worth any further study.

JOHN F. BANZHAF III, B.S.E.E., J.D., Sc.D.
Professor of Public Interest Law Emeritus
George Washington University Law School
"The Man Behind the Ban on Cigarette Commercials"
FAMRI Dr. William Cahan Distinguished Professor
Fellow, World Technology Network
Founder, Action on Smoking and Health (ASH)
Inventor of the "Banzhaf Index"
(202) 994-7229 // (703) 527-8418
http://banzhaf.net/   jbanzhaf3ATgmail.com   @profbanzhaf