A Return to "Snowball Earth"
The natural state of most planets is cold, very cold. Planet Earth owns some prime orbital real estate near its sun, but even so it has experienced periods of Snowball Earth, when virtually the entire planet was covered with snow and ice. If humans are not careful how they approach the chaotic issue of Earth's climate, they could very well push the planet back toward that strange and very cold attractor. Here is one way it could be done:
HIGH-FLYING BLIMPS, based on existing protoypes, could support a hose no thicker than a fire hose (above) to carry sulfur dioxide as a clear liquid up to the stratosphere, where one or more nozzles (below) would atomize it into a fine mist of nanometer-scale aerosol particles.Remember the idea of using "near space" as a waystation to Earth orbit? The type of lighter-than-air craft involved are very similar. One big difference between the two schemes is that the climate repercussions of massive cooling of the planet could lead to the dieoff of billions of humans, due to widespread crop failure.
The cost to construct a Stratospheric Shield with a pumping capacity of 100,000 tons a year of sulfur dioxide would be roughly $24 million, including transportation and assembly. Annual operating costs would run approximately $10 million. The system would use only technologies and materials that already exist—although some improvements may be needed to existing atomizer technology in order to achieve wide sprays of nanometer-scale sulfur dioxide particles and to prevent the particles from coalescing into larger droplets. Even if these cost estimates are off by a factor of 10 (and we think that is unlikely), this work appears to remove cost as an obstacle to cooling an overheated planet by technological means. _NextBigFuture
A similar geoengineering climate scheme involves the use of stratospheric mirror-balloons to reflect any unwanted solar radiation back into space. The mirror-balloons -- unlike the sulfur dioxide aerosols -- would be controlled so as to block sunlight, allow the sunlight through, or to focus sunlight on a particular area of land surface, ocean, or atmosphere. The weapons potential of the mirror-balloon geoengineering scheme should be obvious.
Human scientists barely understand the salient mechanisms of Earth's chaotic climate. Certainly stratospheric water vapour concentration is also likely to be extremely important in the overall scheme of climate.
But once humans begin to actively interfere with the radiative balance of Earth on a grand scale, they risk pushing the scale toward a catastrophic ice age, which would be incalculably worse for the human population of the planet than any realistic temporary warming scenario from anthropogenic greenhouse gases.
People are getting de-sensitised by the constant doom-and-gloom predictions from faux environmentalists and climate pseudo-scientists. Particularly when many of these predictions are decades old, and no closer to coming true than when they were originally published or proclaimed. The IPCC in particular is losing credibility by the day.
But the momentum from all the decades of carbon hysteria and faux environmental doom will take time to dissipate. Many academics, journalists, and other slow thinkers will take years or decades to die off -- or wise up to the obvious fact that their most closely held beliefs are not supported by the evidence or the passage of time.
The SO2 injection scheme pictured at top is a good example of a "file it and forget it" idea. Anyone who wants to push the planet into an ice age so as to trigger a massive human dieoff.orgy may want to pursue the idea further, however.