Space Ring Could Shade Earth and Stop Global Warming
By Robert Roy Britt
Senior Writer
posted: 27 June 2005
02:14 pm ET


A wild idea to combat global warming suggests creating an artificial
ring of small particles or spacecrafts around Earth to shade the
tropics and moderate climate extremes.

Space Ring Could Shade Earth and Stop Global Warming
By Robert Roy Britt
Senior Writer
posted: 27 June 2005
02:14 pm ET


A wild idea to combat global warming suggests creating an artificial
ring of small particles or spacecrafts around Earth to shade the
tropics and moderate climate extremes.

There would be side effects, proponents admit. An effective
sunlight-scattering particle ring would illuminate our night sky as
much as the full Moon, for example.

And the price tag would knock the socks off even a big-budget agency
like NASA: $6 trillion to $200 trillion for the particle approach.
Deploying tiny spacecraft would come at a relative bargain: a mere
$500 billion tops.

But the idea, detailed today in the online version of the journal Acta
Astronautica, illustrates that climate change can be battled with new
technologies, according to one scientist not involved in the new work.

Mimic a volcano

All scientists agree that Earth gets warmer and colder across the
eons. A delicate and ever-changing balance between solar radiation,
cloud cover, and heat-trapping greenhouse gases controls long-term
swings from ice ages to warmer conditions like today.

Earth's Atmosphere

An illustration of the ring of particles or spacecraft casting a
shadow on equatorial Earth. To keep the particles in place,
gravitationally significant shepherding spacecraft might be employed.
They would herd the particle much like small moons keep Saturns rings
in place.


Those who are often called experts admit to glaring gaps in their
knowledge of how all this works. A study last month revealed that
scientists can't pin down one of the most critical keys: how much
sunlight our planet absorbs versus how much is reflected back into
space.

Nonetheless, most scientists think our climate has warmed
significantly over the past century and will grow warmer over the next
hundred years. Various studies claim the planet is destined to warm by
anywhere from 1 to 20 degrees Fahrenheit over the next few centuries.
Seas will rise dramatically, the scenario goes, inundating coastal
cities. But another group of scientists argue that the temperature
data supporting a warming planet is not firm and that projections,
based on computer modeling, might be wildly off the mark.

Either way, perhaps our fate is more in our hands than we might have
imagined.

"Reducing solar insolation by 1.6 percent should overcome a 1.75 K [3
degrees Fahrenheit] temperature rise," contends a group led by Jerome
Pearson, president of Star Technology and Research, Inc. "This might
be accomplished by a variety of terrestrial or space systems."

The power of scattering sunlight has been illustrated naturally, the
scientists note. Volcanic eruptions, such as that of Mt. Pinatubo in
1991, pumped aerosols into the atmosphere and cooled the global
climate by about a degree. Other researchers have suggested such
schemes as adding metallic dust to smoke stacks, to flood the
atmosphere and reflect more sunlight back into space.

In the newly outlined approach, reflective particles might come from
the mining of Earth, the Moon or asteroids. They'd be put into orbit
around the equator. Alternately, tiny micro-spacecraft could be
deployed with reflective umbrellas.

A ring created by a batch of either "shades the tropics primarily,
providing maximum effectiveness in cooling the warmest parts of our
planet," the scientists write. An early version of their idea was
presented but not widely noticed in 2002.

Eccentric but reassuring

Those researchers who don't buy the argument that global warming is
occurring at any significant rate nor that humans are largely to blame
may warm up quickly to the new idea.

Benny Peiser, a social anthropologist at Liverpool John Moores
University in the UK, tracks climate research and the resulting media
coverage. He's among the small but vocal group that goes against
mainstream thought on the topic of global warming.

"I don't think that the modest warming trend we are currently
experiencing poses any significant or long-term threat," Peiser told
LiveScience. "Nevertheless, what the paper does show quite
impressively is that our hyper-complex civilization is theoretically
and technologically capable of dealing with any significant climate
change we may potentially face in the future."

Peiser also notes that the Kyoto Protocol, a global agreement to
reduce greenhouse gas emissions, is estimated to cost the world
economy some $150 billion a year. He also sees a broader rationale for
supporting the seemingly bizarre manner of managing Earth's
temperature budget.

"I believe that this mindset, despite its apparent eccentricity, is
actually rather reassuring," Peiser said. "It provides concerned
people with ample evidence of the extraordinary human ingenuity that,
as so often in the past, has helped to overcome many predicaments that
were regarded as impenetrable in previous times."

He also sees an ultimate big-picture reasoning to look favorably on
the notion of controlling Earth's climate.

"Whatever the cost and regardless of whether there is any major risk
due to global warming," Peiser said, "it would appear to me that such
a space-based infrastructure will evolve sooner or later, thus forming
additional stepping stones of our emerging migration towards outer
space."