A brief survey of potential global warming solutions. What is more interesting to me than the engineering is the politics and ethics of all this. Asteroid diversion falls in the same category. But at least some of these things could drive a need for low-cost space access in an unprecedented manner.
But this is one that doesn’t really seem to be in this category, unless it were mandated. It’s more of a “think globally, act locally” approach:
On the opposite end of the spectrum is the ultra-low-tech approach of painting rooftops white to reflect sunlight.
We’ve been thinking about doing that anyway, just to reduce our air conditioning bill. With a gray cement tile roof, that soaks up a lot of sun, it’s hotter than Hades’s kitchen in the attic this time of year, and that could really cool things down.
I remember the issue (more broadly described as “albedo control”) from World Future Society workshops in the mid-seventies on the dreaded and immanent global cooling crisis. Shiny tin-plated roofs are even better for reflecting more sunlight. Also on the agenda was creating a preference for concrete or asphalt paving, depending on which effect was desired.
Why does everyone miss the obvious solution?
HATS!
If we would all just wear tin foil hats, not only would we not be losing the war on terror in Washington (those pesky brain-scanners!), but the reflected sunlight would end all fears of global warming forever. If enough people sign up, we might even be able to restore the Earth to its glorious, original 4 K or so!
HATS! HATS FOR ALL!
I favor genetically engineered, lighter-colored Johnson grass.
Before people rush off to try things on complex, poorly understood systems, I offer a cautionary word: Kudzu.
The road to hell is pave with good intentions.
I view geoengineering as one of the ‘kill apps’ that could truly justify larger space efforts in the mid to late 21st century. In theory, it does not require much mass at all near the Earth-Sun L1 point to deflect sufficient solar radiation to significantly counter projected global warming (although there are other effects, as noted in the article.) The reason is that the deflector need only perturb the affected solar radiation a degree or so, so it misses the Earth, not absorb it or reflect it completely. This greatly reduces the theoretical mass requirements over, say, mirrors of equal blocking capacity.
“kill apps” is right.
Could kill lots of people as we really don’t have much of a clue as to what drives Earth’s climate system. I’ll support this when we do, likely say sometime in the 25th century.
It always amazes me that people can both believe global warming is a terrible potential risk, yet dismiss the notion of geoengineering out of hand. These two positions are not compatible. If the world is indeed in danger of terrible worst case outcomes, then ruling out work on potential partial fixes would be the height of irresponsibility.
What sort of ‘deflector’ are you thinking of? A cloud of dust? It doesn’t seem that it would stick around long enough to be cost-effective.
Why not a flock of solar sails, programmed to station themselves just sunward from the L1 Point? They could even fly themselves from Earth orbit, reducing the cost of deployment.
Going back to the roof thing. We did that to our house in Cairns (northern Australia) and it made a real difference.
It also made a big difference to the glare that the neighbours further up the hill had to cop. But we didn’t think about that until we visited them after it was done.