How to Cool a Planet With Extraterrestrial Dust

Fascinating study... gradual temperature change slow enough for plants and animals to evolve. It’s possible this was when scaled creatures began to evolve feathers. It’s interesting that this study looks exclusively at how meteorite collision dust cooled the planet nearly 500 million years ago but makes no comparison to the much more recent Younger Dryas impact theory from only 10,800 years ago when comet fragments hit glaciers including in Greenland which catastrophically sent massive sheets of ice into the Gulf Stream effectively shutting down the ocean’s warming currents and plunging the planet into a thousand year freeze. But once the dust settled, which also contributed to the short ice age, ocean levels rose more permanently than they had ever been throughout the majority of human history and the earth warmed to a climate that did not bring the majority of the lost glaciers back. I know what some people are thinking... why don’t we use dust to cool our warming planet? If there’s one thing studying ice cores, asteroids and climate teaches us is that there can be many different consequences from the interference of sunlight in our atmosphere and our magnetosphere, cold or hot.

“Fossil” meteorites do not exist. Fossils are always biologically induced remains, and never inorganic. Meteorites are inorganic. This is what we in the discipline call a “Big Yikes”

If humans were capable of evolving from chimpanzees over several tens of thousands years into a species that could put men on the moon why should we assume resolving the Global Climate Change aka Earth Warming could not be resolved by the same species ? Or by the next stage in our evolution into Cyborgs ?

We need to build big fans at the poles and blow the cold air all around the planet. Long story short problem solved.

Isn't it easier, and safer to plant more trees?

Not so fast! Reducing solar radiation by placing dust in the atmosphere, or even in space at the Lagrange points, may reduce atmospheric heating but will not reduce our production of CO2 and the amount of CO2 already in the atmosphere. Increasing CO2 has recently been shown to affect the nutritional value of plants by altering the ratio of Carbon to Nitrogen and Phosphorous. If CO2 continues to rise, we risk our food sources. Even worse, reduced sunlight will stunt plant growth. So we'll have plants with stunted growth and lower levels of nutrition. Even meat animals eat plant based foods, so this will reduce the nutrition available to both vegans and carnivores alike. Reducing solar radiation is another techno-fix that is doomed to failure and will actually make matters worse. Next idea? How about we just stop putting CO2 into the atmosphere by abandoning fossil fuels and try to sequester carbon through such low-tech solutions as planting trees and practicing no-till farming. The answers are out there, but they're on the earth, not in interstellar space.

Will we still be able to breath the air? And will SAD incidents have explosive growth in human and maybe other animal population. Will there be enough sunlight for plants to eat? Will this really lessen the impacts of greenhouse gases or will greenhouse gases react more benignly with less sunlight, or not? I feel like I’m dealing with people who are thinking of a bunch of ways to get healthy without working out and eating less unhealthy food.

One of the most dangerous aspects of Global Warming is the tendency to start talking about global interventions.

Fred Hoyle, the man who first described stellar nucleosynthesis, also wrote a popular science fiction book, The Black Cloud. In his book sunlight was unable to penetrate the cloud and reach the Earth. Turns out his book was just science ahead of its time. If we are talking about mad science like asteroid capture to cool the Earth then my suggestion would be to use a higher albedo lunar regolith. The lunar dust is nearby, transporting the lunar dust takes less energy, it provides an economic incentive to colonize the moon, and if the dust once in place is pushed out of the lagrange point then it is already broken up and would not survive re-entry. Both the sun and the earth receive 1.4kW per square meter. Solar panels are about 20% efficient. The dust on the surface of the moon has a temperature of 400K in the sunlight and 100K in the shade. If the dust were a carnot heat engine it naturally is 75% efficient. Using lightweight mylar solar reflectors might boost that into the 90% efficiency range. Today's mass manufactured high temperature superconductors would work right now on the moon in the shade without additional cooling. In other words using the energy of sunlight on lunar dust could power a superconducting maglev launcher to accelerate a trainload of dust into orbit. Besides if we are planning on building a Dyson sphere out to 1AU then we should get started.

Someone seriously proposes, with a straight face, that “we” (who might “we” be?) “capture” (how?) an asteroid and “bring” (how?) it to a Lagrange “point” (actually, points, since LPT1s, LPT2s and LPT3s constantly move) — presumably within 175,000 miles of Earth. And after “we” accomplish such an amazing feat “we” then abrade it using enormous robot machines of unknown design so vast clouds of dust will shroud Earth? How? Rube Goldberg would have had a field day with this. Endless fun. We can’t so much as fabricate a simple paperclip in near Earth orbit. Not so much as a paperclip. Any someone proposes we do all this? Humans haven’t traveled any farther than the Moon and that was a half-century ago. Although our exploratory probes and orbiting telescopes have accomplished miracles most aren’t much larger than a two-door refrigerator-freezer. The largest space telescope is about the size of a city bus. None has ever possessed any capability to even land on a bolide, much less capture it. Nor does technology that can alter a bolide’s orbit and alter it exist; even a tiny one. All this esoteric gadgetry requires decades of R&D to invent followed by more time to fabricate and deploy. How long? A century? Two? One or two centuries at least. AGW won’t give us a decade to act decisively to save Earth, if that much. Might a more realistic solution be to stop burning carbon? Stop deforestation? Stop destroying planet Earth?

Whether it's sulphur dioxide in the stratosphere or solar shading from space, stories about cooling the planet by blocking sunlight never acknowledge that *less sunlight probably means reduced crop yields.* Since disruptions in the global food network are the biggest concern with climate change, this strategy seems like robbing Peter to pay Paul. And a global megaproject requires all powerful nations to cooperate ... but global warming has been a net POSITIVE for Russia.